Appendix A: The Skinner Report at Swanage (1940)

Transcribed from the original in RSRE TRE 4/4/457

Preliminary Reports on Tests on Ships using 10cm Waves - November, December 1940 by H. W. B. Skinner

The following tests were performed at Swanage by Members of TRE, and subsequently by Members of the Signal School, Portsmouth, who were temporarily attached here. The apparatus used was the GEC E.1198 Magnetron (9.1cm) as transmitter, and a crystal mixer with 4Smc IF. The transmitter power was nominally SkW, but the exact amount radiated is not exactly known. Transmitting and receiving aerials were placed at the foci of paraboloidal mirrors, 3ft in diameter, giving a gain of about 500. These were mounted so that their axes could be pointed towards the ship, manually or otherwise. In a few experiments, flat cylindrical-parabolic mirrors with an aperture of 6ft x 9in were used. The gain of these mirrors is about 250. We thought that the flat beam (narrow in a horizontal plane but about ±15° in a vertical plane) might be suitable for use on a ship, rolling in a rough sea. The alternative would be a complex system of gyro• stabilization. Three sets of radio-apparatus were used - A and B, of which B was an almost exact copy of A. Apparatus C was also very similar, the main difference being that it was better engineered. The performances of the three sets of apparatus were not quite identical. This is unfortunately inevitable in the present early state of development of 10cm apparatus.

TEST 1. 7th November, 1940. Apparatus A - Site Leeson House (250ft) Sea fairly calm. The Tit/ark, a boat of 92 tons and steel construction was foIlowed end-on to 7 nautical miles (signal approximately 3 times noise). The boat began to return towards the apparatus. Signals very clear, though fluctuating, the whole time.

TEST 2. 11th November, 1940. Apparatus B - Site Leesoll House (250ft) Sea fairly calm. Submarine (U-class, the Usk) was seen up to about 7\12 nautical miles. Strong signals up to 6 nautical miles. These figures apply to the stern-on view. The broadside-on view seemed to give signals about twice as strong. Horizontal polarization of the source seemed slightly preferable to vertical polarization. Between 4 and 41;2 miles, the submarine dived and the signal disappeared. On coming to the surface, the signal re-appeared at a time when at most the periscope and conning-tower were visible. Signals at extreme range are always rather fluctuating, and at extreme range were liable to disappear for rather long intervals.

274 The Skinner Report at Swanage (1940) 275

TEST 3. 8th December, 1940. Apparatus C - Site Leeson House (250ft) Sea fairly smooth. Titlark followed end-on to 12 nautical miles (signal equal to noise). It seems probable that in the interval between Tests 1 and 3, some slight improvement in the apparatus had been effected.

TEST 4. 15th December, 1940. Apparatus B - Site Leeson House (250ft) Sea fairly calm. Titlark followed end-on to 9 miles, but seen as strong echo at 10 miles when turning. From this it seems that Apparatus B was somewhat less sensitive than Apparatus C, but probably about the same as Apparatus A.

TEST 5. 16th December, 1940. Apparatus B - Site Peveril Point (60ft) Sea calm. Titlark followed end-on to 5 nautical miles; seen turning at 6.3 miles. Signals otherwise similar to those in the previous tests. TEST 6. 17th December, 1940. Apparatus B - Site near Swanage Pier (20ft). Sea fairly calm. Titlark followed end-on 3.5 nautical miles.

TEST 7. 18th December, 1940. Apparatus B - Site near Swanage Pier (20ft). Sea fairly calm. The flat paraboloids were substituted for the circular mirrors. The Titlark was followed end-on to about 3 nautical miles. The decrease in range is due to the lower gain of the flat parabolic mirrors. * * * It is characteristic of ship-detection that the signal strength decreases very rapidly with range near the extreme range. This is much more marked than for an aeroplane signal, as would be expected theoretically. For a ship we may have a very clear echo at a certain range, but at a range of Ih or 1 mile greater, the ship may be practically invisible. This applies especially to observations from low altitudes. This fact makes it doubtful if a considerable increase of range can be obtained by increased transmitter power. On the other hand somewhat increased ranges would probably be obtained by the use of wavelengths even shorter than 9cm. It would appear probable that the Usk gives somewhat weaker signals than the Titlark, though not very much weaker. The range obtained for the Titlark from different heights could very likely be reproduced for the Usk, with a maximum range difference of not more than about Ih mile. H. W. B. SKINNER

TRE 4/4/457 20th December, 1940 HWBS/MT

This is the report referred to in History jj, para.3S2, note (2). (See Chap.1, ref.4.) Appendix B: Radar in Convoy Protection (1942)

The paper which follows dated 4 October 1942 gives a good idea of the situation prevailing at that date - just eighteen months after type 271 first went to sea for the Orchis trials - as well as quoting reports of some of the actions in which radar played a significant role. It was addressed to all 171 seagoing ships then in the Western Approaches Command - 57 destroyers, 23 sloops, 9 frigates, 9 coastguard cutters, 67 corvettes and 6 others, as well as many shore authorities. Drafted initially by Lieutenant A. ,. B. Naish, RNVR, Command RDF Officer, it was signed by the Commander-in-Chief, Admiral Sir Percy Noble. There is a copy in ADM 220/78. Annotations in square brackets by the present author.

From ... THE COMMANDER-IN-CHIEF, WESTERN APPROACHES Date ... 4th October, 1942 No.W.A.689/506

RDF IN CONVOY PROTECfION

POLICY

When the capabilities of Asdics became known to the enemy, U-boats adopted the policy of surface attack by night. This policy was immediately successful, and it soon became apparent that a means of detecting U-boats on the surface at night was a vital necessity. 2. RDF was introduced into the Western Approaches solely for this purpose. 3. In view of the varied uses to which RDF is now put, it is perhaps useful to stress that the detection of U-boats at night is the factor on which RDF policy in this Command must be based. 4. While experiments were in progress to adapt the then existing sets for A/S use, Signal School, with remarkable speed, produced type 271. It was immediately recognised that this was the answer to the surface U-boat, and the RDF policy of obtaining the maximum information of U-boats at night became identified with the policy of fitting the maximum number of RDF sets type 271. 5. The structural limitations of fitting type 271, involving compensation for top weight and in certain cases the removal of the director, are well known, but it is significant that these losses are accepted most willingly by those who have had most experience with type 271 in action against U-boats. 6. When type 271 was first used at sea, large numbers of breakdowns occurred, and even those sets which were in working order were frequently operating below the maximum efficiency. The electrical and structural weaknesses responsible for many of the early breakdowns have now been corrected, but the most important factor in the increased reliability of type 271 has been the appointment of experienced RDF officers to escort groups. It is now clear that type 271 can be made to work at sea, but it is also clear that occasional breakdown will continue to occur. The presence in the escort group of an experienced RDF

276 Radar in Convoy Protection (1942) 277 officer, equipped with an adequate supply of spare components, is an essential part of the present RDF policy. 7. It has seemed necessary to stress the technical side of the group RDF officer's work, as there are so far very few ratings capable of dealing with RDF defects, and this places the maintenance of RDF equipment in a rather different category from the maintenance of the rest of the ship's armament. 8. While a glance at the classified shipping losses is sufficient to show that RDF policy must be based on the U-boat, air warning cannot be neglected. The problem here is rather different. While it is most desirable that every escort should be fitted with type 271 to produce the most effective A/S screen, it is not essential for every ship to be fitted for air warning, and the remarkable success of H/F D /F has led, in certain ships, to the replacement of the air warning set by H/F D/F. While unable to compete with type 271 in the matter of U-boat detection, the air warning sets (types 286, 290 and 291) are designed to combine air and surface warning and in ships not fitted with type 271 they give valuable information of surface vessels and U-boats at close range. Until type 242 interrogators are fitted to type 271 the air warning sets provide the only means of identifying friendly ships and aircraft by IFF, and of making use of the shore RDF beacons. [Radar beacons were set up ashore for navigational use principally for aircraft but responded to ships' 1.5m radar. Harvester with type 286M got a response from St John's, Newfoundland, out to the limit of the range scale, 60 miles, with a bearing accuracy of ±5°. (CAFO 2396/41,11 Dec 1941.)] 9. The conflicting claims of RDF, H/F D/F, directors, searchlights, and secondary armament are constantly under review. Limitation in supply of materials and labour, the state of progress of research, the claims of new construction, future policy and the probable future policy of the enemy are some of the factors which have to be considered. It need hardly be said that the fullest consideration is given to reports from sea of the changing requirements of escort vessels.

USESOFRDF

10. The varied uses to which RDF is now put are perhaps best illustrated by the following extracts from reports: A - Detection of U-boats

[Convoy] OG 82 - 'At 2145/14th April [1942] Vetch detected by RDF (type 271) a U• boat on the port bow of the convoy. This was chased by Vetch and Stork and destroyed at 2309 ... [Vetch's] RDF obtained contact at 7,500 yards and held the target throughout a gunnery action until the U-boat submerged.'

SL 115 - HMS Lulworth had just engaged and rammed an Italian submarine. '2107N [9.07pm in a time zone one hour behind Greenwich time] - They now surrendered, and as the U-boat had scraped across my forefoot, removing his starboard screw I imagine, I came alongside some fifty yards from his port side, that being the easier side to board owing to his port list, and sent my boarding party away. We ordered them not to destroy their papers which I am afraid they had already done, and layoff threatening them with our guns while the boarding party got aboard. 278 Appendix B

'2125N - I received an RDF report of the approach of the second U-boat, but was very reluctant to abandon my boarding party until I was satisfied they were in complete control of the Italian of whose condition I was not sure. As the new enemy was beyond the hull of the first which I was keeping illuminated by my forward and after searchlight, I felt I was safe from his torpedoes and justified in 'playing possum' with a view to giving him the impresSion he was undetected, and luring him into a perfect position for a counter attack. He obliged and when he was just clear of the Italian conning tower I raised the beam of the forward searchlight and opened fire at a thousand yards with my O.5in machine guns. Going full speed ahead at the same time and cutting across the Italian's bows straight for him. I hoped to blind him with my searchlight and could see my tracer hitting his conning tower.'

OS 34 - 'RDF type 271 has once again proved its ability to co-operate with the Asdic set in preventing attack on convoy. It is interesting to note that the only attack which was able to be carried out on the convoy was pressed home when Gorleston was astern of station (2355N 118). As Orissa was not fitted with RDF, this left the starboard bow of the convoy uncovered. 'Gorleston obtained an RDF contact at 2350/19 but owing to an error in voice pipe communication the information did not reach the Commanding Officer. However, at 0002N/19 RDF contact was obtained at 3,200 yards [1.6 miles] which led to the chase of a U-boat. Contact was held during the chase and finally at 0035N/19, due probably to a defective engine, the U-boat dived at a range of 2,400 yards [1.2 miles]. The diving was correctly recorded on the RDF screen. Subsequently at 0113NI19 Folkestone obtained an RDF contact at 5,000 yards [2.5 miles] and on illuminating observed a U-boat diving. Asdic contact and hydrophone effect were obtained immediately.'

Operation 'Pedestal' - the Wolverine (Cdr P. W. Gretton) sinks Italian U-boat Dagabur by ramming in western Mediterranean. 'At 0054B/12, dark night, no moon, bright stars, in position "0" for Orange in Screening Diagram No.5 on HMS Furious (Senior Officer of Screen HMS Keppel) Mean Line of Advance 262°, speed 21 knots. On port leg of zig zag No.12 (steering 232°), RDF type 271 contact was obtained, bearing 265°, range 5,000 yards [2.5 miles]. 'At a range of 4,800 yards the Officer of the Watch altered course towards, I arrived on the bridge at range 4,500 yards. At a range of 3,500 yards, ordered the signal "JOHNNY 284" to be made by Broadcast Method to HMS Keppel on R/T. When range was about 1,000 yards [half a mile] I passed the same signal by V IS to HMS Malcolm who was in position "P" for Pudding. 'Depth charge pattern "A" for Apples was set and ''B'' gun was put on the bearing. Fire was not opened in order to make sure of ramming. 'At about 600 yards I identified contact as a submarine, increased to full speed, three boilers fortunately being connected, and altered course to ram. I also sounded "Crash Stations" on the alarm rattlers in order to clear the mess decks. 'The submarine was rammed amidships abreast the after end of the conning tower at an inclination of 90° to the right; my speed was 20 knots. 'The submarine rolled over and sank immediately in position 37°18' North 1°55' East. This was another triumph for RDF type 271, contact having been held down to a range of 600 yards. The set was in full working order after the ram, the shock of which was considerable.' Radar in Convoy Protection (1942) 279

B - Escort joining convoy AT 19 - 'Newark made contact with AT 19 (SS Queen Mary) at 0706/7 by RDF type 271 at 18,200 yards [9.1 miles]. Three distinct echoes were obtained from this huge ship, which was not Sighted until the range had closed at 4,000 yards [2 miles].'

C - Use in fog SC 86 - 'The meet at WESTOMP. [The Western Ocean Meeting Point in about 49° West where the mid-ocean groups took over convoy escort from the Canadian groups based in Newfoundland who were responsible for escort from the Halifax Ocean Meeting Point (HOMP).] 'This was accomplished in a visibility of about 50 yards. Twelve months ago, before the days of H/F D/F and type 271 it would have been deemed miraculous. As it was, without any difficulty and in perfect safety, the Group was led in from astern at 12 knots and dispersed to their places on the screen as Hesperus continued through the convoy, greeted the Commodore by loud hailer in passing and arrived alongside Walker's port quarter for the convoy documents by Coston gun line ... '. Watson effect was used while moving among the convoy. [The first two to three hundred yards of the A-scan of type 271 were taken up by the 'ground wave' so that echoes within that range could not be observed in the normal way. However, a target as large as a merchant ship produced a chracteristic distortion of the ground wave itself, known as 'Watson effect', Although this effect did not give precise range and bearing, it enabled an experienced radar operator to prOvide the bridge with enough information to manoeuvre within the convoy without danger of collision, given fifty yards of visibility.]

ONeS) 106 - 'Dense fog was encountered at about 1630 on the 3rd July and did not lift until 1430 on the 4th. 'During this period, the position of all the five ships relative to Ripley was constantly before me by means of bearings and ranges reported by the type 271. During the hours of darkness, the Hampton Lodge was plotted drawing out from the convoy and she appeared to shape course direct for her destination, Wabana. By the time it got light enough to risk going within talking distance she had faded from the screen:

D - Use of type 252 [ship IFF responding to type 286/290 and aircraft ASV.J for homing HMS Hesperus (fitted 286P and 271) 'Type 252 has proved most helpful during continuously foggy weather. It was possible to plot the course and speed of Vanessa, who is fitted with this set, and to home her to the Group from a distance of twelve miles. The frequency of the "pip" is such that it is difficult to obtain an accurate bearing.'

E - Use of RDF in navigation HMS Rockingham approached the Newfoundland coast on 20 April in heavy mist. By making use of soundings, a D/F bearing from St Johns WIT station and RDF ranges and bearings from land, Cape Race was rounded and when the fog cleared the DR position was only a quarter of a mile in error. A speed of 16Vz knots was maintained throughout and visibility was usually 1,000 yards. HMS Newark reported ' ... Thick weather was experienced all the way and very low cloud. RDF type 286P was used in conjunction with soundings to round Barra Head which was not seen, landfall being eventually made on Tiree and Rum Islands.' 280 Appendix B

F - Use of type 271 against aircraft Results of a trial by HMS Landguard (fitted type 271 only) 'The capabilities of type 271 against aircraft have been worked out in some detail using a sextant to measure angles of sight and hence obtaining the height of the aircraft. 'They indicate that echoes can be obtained from aircraft at heights up to at least 1,500ft, even at 3,000 yards when the angle of sight is over 9°. In good visibility aircraft can be followed with glasses out to about 15,000 yards, but on several occasions with Hudsons and Sunderlands the RDF has obtained echoes out to 30,000 yards [15 miles]. 'The general conclusion is that though aircraft are usually reported by lookouts before being picked up by type 271, once the bearing of the target has been indicated the set can be of considerable value in giving ranges and in following the movements of the aircraft, especially after it has passed out of sight, e.g. by giving warning when it turns round. Hence, although type 271 is not normally used when visibility is good, it is considered well worth operating the set in daytime when an enemy aircraft is sighted or known to be in the vicinity.'

G - Use of type 271 in spotting [gunnery] Extract from a report by the Commanding Officer HMS Dahlia 'On the 18th May 1942 off Lough Foyle buoy, a practice shoot was carried out with the ship's 4in gun. Weather fine, visibility very good. Ten salvos were fired within the space of two minutes. Type of target, Battle Practice Pattern VI. 'Throughout the practice, RDF type 271 was in operation and the flight of the projectile, from soon after leaving the gun to the moment of its fall, was, on the whole, clearly followed. 'Although the echoes, both of the target and the projectile, were distinct, the base of the target echo occupied some 200-250 yards on the scale, and, occasionally, the smaller and swiftly moving projectile echo became incorporated with the former making it difficult to establish exactly the RDF distance of the fall of shot, particularly in the case of near misses.'

LIMITATIONS OF RDF 11. Briefly the present limitations of RDF are: - Sets must be reasonably compact, very robust, constructed as far as possible out of components and materials already in production, sufficiently simple for maintenance at sea to be possible, and capable of being produced quickly in large quantities. - Rough weather reduces the efficiency of type 271 by deflecting the narrow radiated beam away from the target [because of ship movement in bad weather]. The use of a wider beam has been tried but it causes too great a loss of range and too many side echoes to be acceptable. Even if the additional topweight involved in stabilizing the aerials could be accepted, the rough weather problem would not be solved entirely as small targets are frequently obscured by waves, and large waves give rise to unwanted echoes. - There is as yet no evidence that U-boats are able to DfF RDF transmissions, but if U-boats are eventually fitted for this purpose the greatest security will almost certainly be achieved by ships using type 271 in preference to other sets. Radar in Convoy Protection (1942) 281

FUTURE DEVELOPMENTS IN RDF

12. Future developments in RDF will probably consist in providing:- - Plan Position Indicators to ships fitted with type 271. This gives a plan picture of the convoy and surroundings. The present straight scan will be retained in addition. - Type 242 interrogators [which] will enable type 271 to obtain IFF response from aircraft, ships fitted with type 252, and shore beacons. - Improved bearing indicators for type 271. - Mark IV 271 equipment, giving increased range and increased discrimina- tion between targets at nearly the same range. - Improved gunnery facilities for type 271. - Increased ranges for air warning sets. - A simplified IFF situation giving greater security and reliability. Appendix C: Height Determination by Radar Basil Lythall

Originally intended for air warning in battleships and cruisers, the first naval radars achieved ranges large enough for fighter interception, always provided some information could be obtained about the height of the attackers. A rough indication of height was needed in time to despatch the fighters, with better estimates as they neared the interception zone. This appendix describes the pursuit of that goal.

During much of the war the term 'heightfinding' was applied indiscriminately to any method of deducing the height of an aircraft detected by a surface radar. It was later replaced by 'height determination' - while 'heightfinding' was reserved for special-purpose radars able to pinpoint targets in elevation and find height directly from the angle of sight and slant range. In fact no British radar wholly dedicated to heightfinding appeared before the end of the war and the Navy had to rely almost entirely on indirect methods, using types 79 and 281 for 'height estimation' - a much less precise process in which the height had to be deduced from the variation of echo strength with range. To achieve and maintain a reasonable standard required constant training and practice, and depended heavily on the experience and skill of the operators. Ambiguities could arise, particularly with 281, and the method was also sensitive to the performance of the radar. In the absence of a reliable performance meter during much of the war, performance could only be checked by frequent flight trials with friendly aircraft - often difficult if not impoSSible in wartime for ships other than aircraft carriers. Yet from rudimentary beginnings this rather crude process reached a surprising degree of refinement. With some initial help from the scientists, the techniques were largely developed through the initiative, enthusiasm and ingenuity of individual radar officers and ratings, especially in aircraft carriers, working closely with fighter direction officers and accumulating experience the hard way, often through enemy action against convoys and task groups in which the Navy suffered grievous losses. By 1945, the British Pacific Fleet was able to make a unique contribution to joint operations with the US Navy by providing long-range height estimation as a complement to the superior American capability in low cover and in numbers of true heightfinders.

PRINCIPLES OF HEIGHT ESTIMA nON

Metric radars (Figure c.l) were designed with a broad vertical beam to provide simultaneous detection at all heights, but in practice unavoidable gaps in vertical cover were caused by reflection of radar energy at the sea surface, producing a

282 Height Determination by Rndar 283

HEIGHT (FEET)

26,000

12,000

RANGE (MILES)

HORIZON 1,600 r:::~==~:::::!~~---~~------:~40

SEA LEVEL

Figure Cl The vertical coverage pattern of a metric-radar. There are many lobes between horizon and zenith, but our interest is confined to the lowest two or three, which are drawn with an expanded vertical scale. Ambiguities can occur if an aircraft is not detected in the first lobe, either because it passes over the top of it or because the set has been employed on sector sweeping and has not swept the target bearing for some period. A first detection at 40 miles could imply a height of 1,500, 12,000 or even 25,000 feet. pattern of 'lobes' separated by successive 'minima'. Performance is poor at angles of sight near the horizon; that is, against low-flying aircraft, and again at certain higher angles. An aircraft approaching at constant height must fly through this pattern. As it enters the first lobe the echo strength will increase steadily, but will then decrease and fall below the threshold again as the aircraft reaches the first minimum; the cycle is then repeated through successive lobes, producing a characteristic variation of echo strength which will be different for each height. Of particular interest is the range at first detection. Very small for low flyers, the range will increase with the height of the aircraft and so can provide an estimate of the height from the known coverage pattern. Above a certain height, however, it will decrease rapidly because the aircraft is flying above the top of the radar's first lobe and will not be detected until it reaches the second. Unless the top of this lobe is higher than the aircraft can fly there will be uncertainty about which lobe the aircraft is in when first detected, leading to two or more widely different estimates of height which may require considerable time to resolve. For type 79 the top of the first lobe was typically 35-40,000 feet; for the shorter wavelength type 281 it could be at least 10,000 feet lower. 284 Appendix C

Should the radar performance fall below standard - for example because of a drop in transmitter power or receiver sensitivity - the threshold contour will shrink, the estimate of height will be in error and the top of the first lobe will be lower. Similar uncertainties can be caused by differences in number, size or aspect of the attacking aircraft. The 1Y.z metre air-warning sets on smaller ships (286 and 291) were virtually useless for height estimation because their aerials were much too high for their wavelength, producing a large number of lobes, with many ambiguities and very intermittent tracking. US warning sets also used this wavelength and had similar problems, although the more powerful SK, fitted in larger ships including a number of British escort carriers, had ranges similar to 79 and 281, allOwing more time to eliminate the many ambiguities. A few British LSTs specially fitted as fighter direction ships had RAF GCI radars; these had a more useful lobe pattern, comparable in accuracy to 79 and 281, because the centre of the aerial was only about 30 ft high - the optimum for this wavelength. GCI radars at RAF land sites used a more accurate method of determining height. The vertical aerial array was split into two equal parts at different heights, and signals from the two were compared. This was not practicable with 79 and 281 as the height difference between the two aerials would have had to be some tens of feet and in a ship there was no space available. An equivalent capability only became possible when carriers were fitted with both 79 and 281 and results from the two sets could be compared.

DEVELOPMENT OF TIlE TECHNIQUE

Almost from the start it was realized that a rough estimate of height should be possible from the range of first detection. In September 1939, Curlew, newly fitted with 79Z, was at Plymouth en route to working-up at Scapa. Lieutenant John Hodge, RNVR, the ship's radar officer, and Lieutenant Commander Hartley, an application officer from Signal School, organized trials with RAF aircraft, from which they constructed what was probably the first experimental graph of variation of detection range with height. Enemy air raids on Scapa soon had Curlew refining the data in real earnest, and she went on to develop the technique successfully during the Norwegian campaign, until she was regrettably sunk off Norway a few months later.1 fllustrious, the first aircraft carrier to be equipped with radar, reported in July 1940 after flight trials off Bermuda, stressing the 'supreme importance' of height information for directing interceptions, but also the weakness of having it only at first detection. Even this would be inaccurate if detection occurred at less than maximum range, for example because the radar had previously been operating in another sector before being trained all round? Meanwhile, at Signal School, A. W. Ross had derived formulae for variation of echo strength with range, but pointed out that estimates of height would be sensitive to the state of the radar, so that each ship would need to calibrate its own set using controlled aircraft, and then ensure that it remained as nearly as possible in the same condition. Failing a full calibration a simple formula would give a rough estimate of height from the range of first detection, and to supplement this Ross suggested a second method - recording the ranges at which the echo passed through successive minima. This method should not be sensitive to set performance, but might be too late for effective interception.3 The first method had already been demonstrated by Curlew; the second was found experimentally to be accurate provided the target could be continuously Height Determination by Radar 285 tracked. Ross also found that results from Rodney and Valiant indicated that both methods should be feasible, and in July 1940 all ships concerned were issued with a Signal School pamphlet describing both methods and advocating a judicious combination of the two. An addition to the type 79 handbook followed; by then the first method seems to have become limited to range of first detection rather than following the growth of the signal as Ross originally advocated. The formulae were in terms of heights above the radar than above the sea, and the ship's radar officer had to perform an additional calculation to allow for the curvature of the earth's surface.4 F. Hoyle joined Ross in December in 1940 and was asked to extend the study and to include type 281, which had recently had successful trials in Dido. To avoid computation by ship's officers, Hoyle devised a graphical presentation in which curves of constant height above the sea surface were superposed on the vertical polar diagram, so that true height could quickly be read off by eye. His first report did not allow for variations between individual radars and was not well received in the Fleet; it was followed in October 1941 by a more comprehensive paper illustrating the nominal performances of both 79 and 281 for a variety of installations in capital ships and carriers. This used an even simpler presentation, soon to be become universal, in which true heights were drawn as a series of horizontal lines.s Polar diagrams appear more distorted and the lobes appear thinner and turn upwards, as does the radar horizon. All these calculations embodied a correction to allow for the effect of water vapour in the atmosphere. This can be shown to be equivalent to increasing the earth's radius to 4/3 times its actual value. This compendium gave a quick insight into the comparative performance of the two radars and different ship installations. The true height of the top of the lobes could be read off directly, showing that with 281 there was a much greater region of height ambiguity than with 79, but that the method of minima should be useful down to smaller heights. In carriers the transmitting and receiving aerials were usually at different heights; this reduced the maximum range but raised· the ambiguity ceiling, so that the bottom lobe of 79 was rarely, if ever, overflown. The structure of the minima became confused, particularly in 281, and therefore less effective for height estimation. Each ship was recommended to construct its own individual diagram, either taken from the worked examples in the report or worked out theoretically, and then to calibrate it experimentally during flying trials. Hoyle followed this up by attending several such trials to confirm that the method really worked.s

THE CONTOUR METHOD

Practical techniques were soon taken a significant step further in Victorious, where it had occurred to the ship's radar officer, Lieutenant John Maynard, RCNVR, that a whole family of signal amplitude contours could provide a more continuous method of estimating height than relying on first detection alone (see Figure C.2). Using Hoyle's report as a basis, Maynard calculated a series of curves, each for a different level of signal amplitude in relation to noise.6 The scheme was tried out in flying exercises over two weeks in June 1942; signal amplitude was recorded at various ranges and the height estimated by noting where the observed range intersected the appropriate contour of signal amplitude. It was found that height estimates by this method were often correct to 1,000 feet, and that the radar operator could maintain plots on several aircraft at one time. There were limitations - for example ambiguities could occur if first 286 Appendix C

TRUE HEIGHT IN THOUSANDS _____+- ____-7~~ __~~~~~----~------60 OF FEET

40+------+----~~~~----_7~r_--_r~------

30+------~--r-~~----r?~~~~----~~~~------

1It Detection Lobe

10+-~~~~~~~--~~------_7~------~------

20 40 60 80 100 120 DISTANCE IN SEA MILES

Figure C.2 A typical coverage pattern for type 281, plotted with true height as the y-coordinate. The lobes appear distorted and the horizon curves upwards. Examples of echo growth curves are plotted in the lowest lobe and contours in the lobe above it. detection was at less than maximum range - nevertheless Victorious found the use of contours to be the most satisfactory method yet employed, although many more calibration tests were needed in order to assess the effects of number, size and aspect of aircraft, sea state and certain characteristics of the radar. Here perhaps was an answer to nlustrious's earlier plea?

ECHO GROWTH CURVES

Victorious's report of 22 June 1942 arrived at Signal School (by then ASE) just when the draft of an Admiralty Manual on 'Height Finding by RDF' was almost complete. CB 4224(42) had concentrated on the methods of First Detection and Minima and how to combine the two, but there had evidently been just enough time before publication in October to digest and include information from Victorious. An additional page at the end of the main text contained a brief resume of the contour method, referred to experience gained to Victorious and recommended that the technique should be tried after familiarity with the more elementary methods had been acquired. Height Determination by Radar 287

Also squeezed on to this last page was a short note on 'A practical method of combining the three heightfinding systems'. A series of height-lines is ruled on the vertical polar diagram at intervals of, say, 5000 ft. On these lines are then drawn reference curves of echo-amplitude versus range obtained during calibration. Ranges and echo-amplitudes reported by the operator are plotted on a suitably engraved sheet of perspex and superimposed on the height-line estimated from first detection. For each aircraft detected, the plot is then compared in shape with the reference curve and the estimated height revised if necessary to obtain a better fit. By comparing the shapes of curves, even though their amplitudes might differ, this method exploited known relativities within the polar diagram without being sensitive to absolute quantities such as radar performance or size of raid, but the procedures required were considerably more difficult, with many graphs to be plotted and then compared with other graphs. And the method works best only when aircraft maintain a constant height; if they do not do so, recourse to the contour method may be necessary.s First called 'Variation of Echo Amplitude' and then 'Echo Growth Curve', this elegant but rather laborious method became known throughout the Fleet as the 'Geddes method', after its originator Lieutenant-Commander Murray Geddes, RNZNVR. It remained the recommended practice throughout the war, but was not by any means universally adopted; indeed, there seems to have been a continuing controversy about the comparative merits and problems of contours and echo growth curves, until it eventually came to be accepted that the methods were complementary.

THE WAR IN THE MEDITERRANEAN

Before the 1942 manual could be distributed, ships were having to practice their existing height estimating skills in dire earnest. In August 1942, after exercising with other carriers en route for Gibraltar, Victorious became flagship of Operation 'Pedestal' - the first Malta convoy to include a carrier force equipped with metric radars and numerous fighters. Chapter 7 tells of the heavy shipping losses sustained, but there had also been conspicuous successes by fighters, and the surviving carriers, Victorious and Indomitable, had established close coordination in warning, height estimation and fighter direction. In a continuous series of joint conferences on the journey home the lessons were absorbed and ground rules established for improved layout of operational spaces, displays, communications and so on, which were quickly introduced into new carrier construction. It was decided that, from mid-1943, the policy should be to fit all carriers and fighter direction ships with both 79 and 281, thereby considerably improving their potential for height estimation (see Figure C.3). Because the lobes and minima of the two sets did not coincide, many ambiguities which would have occurred with a single set were removed, or if not could quickly be resolved. Careful examination of the way the echo strength varied on each radar could give a much more confident estimate of height, and in principle at least it was possible to deduce when an aircraft was not flying level, or even flying down a minimum of particular radar in an attempt to escape detection. The value of the combined installation was demonstrated during troop landing operations during 1943 which also led to two other innovations. 281 was given a sector selection display so that echo amplitudes on a chosen bearing could be measured without stopping aerial rotation and prejudicing the new sIdatron plan position display. And because the new centimetric radars, particularly 2730, had 288 Appendix C

HEIGHT --, (FEET) ,,-.. , I 40000 ,...... 79 I I ~-----.Q...... ~ 30000

20000

10000

RANGE; SEA MilES

Figure C.3 Type 79 and type 281 in a single ship. The overlapping lobes remove many ambiguities and give some clue if the aircraft changes height.

shown their value in detecting low flyers as well as surface targets, type 277 was fitted with PPl's and a height position indicator, thereby being given a true heightfinding mode against low fliers, though only at much shorter ranges than high flyers could be detected by the metric sets. All this led to the need for a Height Filtering Position (HFP), where height information from all sources could be assessed and combined before presentation to the FOO. Layouts and locations varied from ship to ship, but all contained the necessary plan, sector and height displays, together with the height plot - a large• scale representation of the vertical polar diagram, with contours and/or echo growth curves to taste, covered by a perspex sheet on which target data could be plotted. Height plots varied in design and layout according to the ideas of individual ships, and many different procedures were invented for using them.9 Even so there were marked differences in performance achieved, especially between aircraft carriers and other ships. Good height estimation was critically important to carriers for the direction of their own fighters. They were able to use routine flights for frequent radar calibrations and for regular training of operators, and particularly in Fleet carriers this led to the development of strongly motivated teams capable of consistent performance. The contour method seems to have been the most popular and Victorious continued to develop it in depth, gradually calibrating the system to take account of factors such as the number of aircraft in a Height Determination by Radar 289 group, whether they were approaching or receding, and the precise response law of the radar receiver. Most other ships found it much more difficult to obtain flying trials for their own needs - indeed some radars were never calibrated at all! Height estimation was often unreliable and there were many complaints not only from Fleet commanders but from the ships themselves. The inability to monitor radar performance in a quick and simple way remained a serious weakness, and although a radar performance meter was developed by 1943, the war in Europe was over before it became widely fitted in the Fleet.

PREPARATION FOR OPERATIONS IN THE FAR EAST

By 1944, with the end of the war against Germany in sight, there was a much needed breathing space and it seems to have been time for stocktaking. A much more comprehensive edition of CB 4224 was issued in June, and an introductory paragraph set the scene as seen from ASE and Headquarters:

There are numerous 'methods' of height-finding with W A sets in the Fleet, some peculiar to individual ships. Despite this, however, the standard of accuracy has been poor. Individual radar officers have been given considerable freedom to choose (or invent) whatever method they preferred, mainly because the subject was a new and unexplored one. Conditions have now changed. Sufficient experience is available to make it possible to choose one method and adopt it as standard practice. The adoption of such a standard method is made more necessary by the institution in larger ships of a Height Filtering Position or a Radar Display Room. To man and operate this, WA operators must be trained in height-finding, and it is impossible to do this with a variety of methods.lo

Echo growth still remained the recommended standard. The contour method was not regarded as an alternative standard, although it was acknowledged that it might need to be used in certain cases. The use of echo growth curves with specimen results for a variety of situations was covered at length for types 79, 281, and for the two sets combined. Advice on calculating polar diagrams allowed a choice for the individual inclinations and abilities of radar officers, giving a choice between an approximate method and a more accurate one, and there were detailed instructions for carrying out calibration runs and applying the results. For the first time there was mention of the human factors involved. For example, it was stressed that all height plots should be drawn with standard scale ratios to make it easier for operators transferring from one ship to another. The personnel needed at the Height Filtering Position were listed, with their functions, followed by a syllabus for their on-board training. The author evidently spoke from bitter experience in a previous seagoing appointment: 'Height-finding demands intelligence, and any training scheme is almost bound to fail if ratings are selected for the job merely because they are no good as WA operators.' And the first item in the training syllabus hints at practical problems, perhaps especially with the echo amplitude method: 'Simple graphs and how to read them. Experience has shown that the average rating finds graphs rather difficult as they involve unfamiliar thought processes.'lt 290 Appendix C

WAR IN THE PACIFIC

CB 4224 (44) was intended as the heightfinder's 'bible' for British ships being prepared for Pacific operations, although in the event a number of them did not arrive before the war was over. Chapter 10 brings out the critical importance of height information in these operations; this still had to be obtained from lobe reading with the metric sets, apart from the one American SM-1 heightfinder in Indomitable. For the first time since radar had been fitted, the majority of ships had carried out enough calibrations and radar/aircraft-direction exercises to ensure reason• able efficiency in height estimation, at least at first detection, and the many radars in the force could all contribute to the solution. By combining information from all ships, a significantly more reliable estimate could be obtained, and the Squadron FDO was generally able to produce an estimate within 1-2,000 feet using only the theoretical polar diagrams of the sets involved. In joint operations with the US Navy this long-range height information provided a valuable exchange for the improved low cover of the American Ph metre and lOcm sets and their plentiful supply of heightfinders. Height estimation after first detection was much less consistently successful. It worked well for targets at constant height, but could be rendered almost useless by intelligent tactics by the enemy, whereas these could usually be sorted out by the SM-1 heightfinder. It was also very slow, and once SM-1 had picked up a raid within 50 miles the results were so consistently accurate that it was no longer worthwhile to continue with height estimation. And in the presence of many friendly aircraft - frequently more than 1,500 - tracking of enemies could be so difficult with the broad-beamed metric sets that height estimation was again impracticable.12

POSTWAR

Lobe reading remained an essential technique for many years after the war. It was the only method of height determination between the outer limit of the warning radar, extended to 200 miles with 960, and the maximum range for heightfinding, increasing to 80 miles with the introduction of 983. Experience in the Pacific had shown that, if aircraft deliberately changed height or aspect, the use of echo growth curves could be difficult and at time dangerously misleading; the use of contours was therefore given full weight as a complementary method. A standardized height plot was recommended, containing both a full set of contours and echo growth curves at 5,000 feet intervals - making a truly formidable looking array of lines and curves even when drawn in several colours. For a single ship using an intelligent combination of all methods it was reckoned to be possible to achieve an estimate within 2-3,000 feet on all aircraft above 5,000 feet by the time they had reached a range of 50-60 miles, with a rough estimate soon after first detection. For aircraft below 5,000 feet an estimate within 1,000 feet ought to be possible soon after detection. As regards initial detection, estimates from individual ships would be less accurate but, as had been found in the Pacific, combining all the information available would giver results within 1-2,000 feetP Height Determination by Radar 291

ANNEX: PRINCIPLES OF HEIGHTFINDING

A simple heightfinding radar employs a narrow vertical beam scanning up and down to pinpoint a target in elevation. Angle of sight and slant range, which together determine the height, can be presented on a height position indicator (HPI) in much the same way as bearing and range are shown on a PPI, and the absolute height read off directly from calibration lines. Moreover the difference in height between attacker and fighter, which is what matters during interception, will be independent of errors in absolute height. With the advent of high-power centimetre-wave techniques in 1942, a shipbome radar of this type could be seen as feasible. At this wavelength the vertical aperture of the aerial need be no more than, say, 10-15 ft, but the need for triaxial stabilization will mean a heavy mounting suitable only for large ships. With its narrow vertical beam the radar can work down to much lower angles of sight, but to obtain full range performance it must stop rotating in azimuth while the height of a particular target is determined. To acquire each target the heightfinder beam must be put into the required bearing by the use of an ,Azicator Display' which presents the all-round picture from the warning radar together with a cursor indicating the azimuth of the heightfinder beam. A radar capable of reliable heightfinding out to 80 miles did eventually emerge as type 981/983 (see Table Cl on following page) but not until after the war. It was delayed in part by pressure for more ambitious schemes to provide height information on all targets in the fighter direction zone without interrupting the plan display picture. This would have involved rotating the heightfinder aerial at the same rate as the warning aerial and replacing its mechanical up-and-down nodding with movement with an electrical method; the idea was abandoned in 1944 in favour of developing 981 on a separate mounting. Chapter 9 relates what followed. Type 277, soon to be fitted in increasing numbers, was provided with a heightfinding mode using the elevation stabilization mechanism to rock the aerial. Although it could detect low fliers well before the metric sets, its maximum reliable range of 25-30 miles for heightfinding was of little use for fighter direction, except in the crudest sense - 'if detected by 277 it must be low; if by a metric set it must be high'. And azimuth rotation had to be stopped to measure height, so that two sets were needed on the same ship unless the principle role of surface surveillance was to be prejudiced. To fill the gap before 981 arrived, some ships were fitted with the USN SM-1, whose heightfinding range of 50 miles in normal conditions was a very notable improvement. One set, in Indomitable, saw action in the Pacific; this was the only case where a true heightfinding radar made a significant contribution to height determination in the RN during the war. Soon afterwards, 277 was provided with a larger aerial, to become 2770, with a heightfinding performance similar to SM-1, although without conical scanning to assist in maintaining the target in view. ~ IV

Table Cl Official performance figures for heightfinding sets in 194914

Aerial outfit Range of set for heightfinding Minimum Height Radar Beam width angle of finding set Polarization Stabilization elevation accuracy Letter for Height- Maximum Maximum Vertical Horizontal finding reliable

277P AUK H 4S 4S Azimuth and 4S 25 miles ~o to 3/.° elevation ±1,200 to ±2,OOOft. at 25 miles 277Q ANU V 2.5 0 4.0° Azimuth and 2S "40 miles 60 miles ~o to 3/.° .... elevation ±3,ooo ft at 60 miles 981/983 Am V 2.25° 6.0° Triaxial to 1.25° 80 miles 120 miles ±1,ooo ft 6 arc-minutes at 70 miles

.. With a well-trained team. .... These represent maximum errors. The average over several 'cuts' gives ±1,500 ft at 60 miles in calm sea conditions. Appendix D: Radar in Submarines

EARLY DAYS The first British submarine to have radar was the large prewar Proteus, fitted experimentally with type 286P in the summer of 1941.1 The aerial array was the same as that fitted in destroyers and sloops, on a telescopic mast just abaft the after periscope standard. The mast was raised so that the aerial was above the periscope standards for use on the surface and lowered to bring it below the jumping wire when submerged. Submarine fitting posed many problems not met with in surface vessels, not the least of which was finding space below for the equipment needed, so that earlier fittings in existing boats tended to be in the larger ones. The Naval Staff History describes Proteus's first attack by radar in the Aegean in November 1941:

Proteus then moved across to St. Georgio Island and on the evening of the 9th picked up a convoy by radar, one of the earliest reports of this form of 'sighting'. Lieutenant-Commander Francis decided to shadow the convoy (on the surface at night) and attack submerged after the moon was well up. Shadowing was carried out from 20SO/9th until 0320/1Oth when the German (ex-Greek) steamer Ithaka (1,773 tons) was torpedoed and sunk.2

In December 1941, the Commander-in-Chief reported that in the Mediterra• nean, Proteus had achieved ranges of 6.5 miles on a battleship, 2.5 miles on a destroyer, 1 mile on a motor launch, 5 miles on an aircraft at 500ft, but 30 miles on one at 2,OOOft.3 Pointing out that these ranges were better than those achieved on trials, Admiral (Submarines) told the Admiralty that it was now clear that radar was very desirable in submarines. The primary object should be maximum warning of surface craft plus accurate bearing and range for weapon control, 'but that warning of approaching aircraft is rapidly assuming greater importance, especially at night, and may well eventually exceed the importance of surface craft warning. It follows that if aircraft are able to bomb submarines on the surface at night - and this form of anti-submarine warfare is rapidly developing - submarine operations are very severely handicapped.,4 It was proposed that type 291 or 286P should be fitted in all the larger existing submarines, and in all new construction. By August 1943, over sixty operational submarines had been fitted with type 291W.5 (Radar type numbers for submarines all had the suffix 'W'.) In these early days, however, the 1.5m radar was far from popular with submarine commanding officers because it was feared it would give the submarine's position away. One CO recalls a report which circulated, telling how a submarine on passage in the Indian Ocean had switched on her type 291 W and ten minutes later was attacked by Japanese bombers. This was taken, by an

293 ~

57. Submarine Scorcher,1945, with type 291W aerial in the raised position.

(IWM) Radar in Submarines 295 unreasoned but almost impossible logic, to have been cause and effect. But the word went round and, as with some justice it was felt that practically everyone's hand was against the submarine, most COS preferred not to invite what might be more trouble by using their radar.6 There was also the reactionary emotion - a submarine CO to an ASE scientist: 'The Mark I eyeball is more effective than your radio stuff, and it takes up less room.,7 However, radar was used, if somewhat reluctantly, as shown by the following report from Torbay with type 291W in April 1943, returning to Algiers after a patrol in the Tyrrhenian Sea:

At 2250, radar detected an echo to the south, range 1,500 yards. A dark shape was soon seen. Closed to attack, but even when range was down to 900 yards, target was only vaguely visible when on top of the heavy swell and its silhouette could not be made out or its course seen. Diesel HE [hydrophone effect] was heard on the asdic. Radar ranges then showed that it was going away, so gave chase. Torbay was just able to catch up again and in the meantime the enemy hauled gradually round to starboard to a course of 350°, the original course having been about 210°. It is thought that she had seen Torbay the first time the range was closed and had taken her for a patrol craft and decided to withdraw northward. When the range by radar had been closed to 750 yards, the U-boat dived in position 38°19'N 4°22'E.1t was maddening to have had her in range for so long without being able to see her. The whole chase was carried out by radar ... 0020 - Broke off the hunt. Passed enemy reports and steered for Algiers.s

The general feeling among British submarine officers at that time about radar - at 1.5m at any rate - is summed up in Torbay's comment on that incident:

While the radar is of enormous value on occasion, I have formed the opinion that it is easy to OF and it is only a question of time before the enemy get to know the frequencies used by HM Submarines, when it will be most dangerous, or at least compromising, to operate it in enemy waters. It should give warning of the approach of enemy forces, of course, but this is not positive as for ten minutes in every hour the set has to be switched off for cooling.9 However, seagoing opinion was not universally anti-radar. By operating type 291 W continuously when on the surface during her patrol close inshore north of Corsica in May 1943, Shakespeare decided to make a test case for using radar near the enemy coast. No enemy anti-submarine measures ensued and there were considerable benefits, particularly with navigation.1O (This patrol included entry into the port of Calvi and a bombardment of the aerodrome at a range of 800 yards.) Trenchant in the Far East always used radar on the surface by day for aircraft warning, and was never once surprised. t t Until 1943, Admiral (Submarines), the operational authority to whom the Admiralty turned for advice on submarine matters, was lukewarm on radar generally, and failed to press for a centimetric set (which could not easily be OFed) for surface warning and torpedo control, because, for space reasons, air warning would have had to be sacrificed. Then came a change of heart, largely brought about by news of the great successes of US submarines which since 1942 had been fitted with 10em surface search radar, SI, as well as SA, a fairly basic 1.5m air search radar (which gave warning and range of aircraft but no bearing). Their offensive achievements in night attacks - using radar to seek out the enemy 296 Appendix D and then using it for weapon control - as opposed to the defensive attitude, merely using it to warn when the enemy was near, fired Admiral (Submarines) with enthusiasm. 'The achievements of the US submarines,' he wrote in a letter to the whole British submarine service, 'show what can be done with the right equipment in the hands of determined men.,12 Enclosed with that letter were extracts from reports by US and British submarines where radar had been successfully used (including that of Shakespeare mentioned above). Radar equipment, he said, was not 'just another gadget' but was an essential part of a submarine's ability to operate offensively, as well as being able to 'prepare herself against impending air attack and the enemy's A/S measures,.13 At ASE, considerable thought had already been given to the development of a suitable set for submarines but, as ASE told DSD, no firm action could be taken until the Admiral (Submarines) produced a Staff Requirement which spelt out priorities between surface and air capabilities.14 This was eventually done on 19 June 1943, first priority being the detection of surface vessels; the second, provision of accurate data for torpedo and gunnery control; and last, warning against aircraft. IS ASE proposed to develop a hybrid set to be known as type 267W, with a PP! that could be switched to display either a 3cm 'seaguard' picture or the 1.5m 'airguard', the former not only giving a high-discrimination PPI picture, but also supplying accurate ranges and bearings of the target for plotting and fire control. The first version would not entirely meet the Staff Requirements and would suffer the disadvantage (overcome in postwar versions) that it could only be used when surfaced because the aerials would be on a fixed mast which protruded only a small amount above the periscope standards. However, compared with the old 291W without a PPI or accurate ranging, it would greatly enhance the submarine's capabilities. A contract had been placed with Metropolitan Vickers at Manchester and production was hoped to begin in March 1944 - but this was only a target. Not soon enough, said Admiral (Submarines),t6 though he fully realized that the delay in the start of the development at ASE was entirely due to the fact that he had not backed the surface warning set for submarines until 1943.17 Indeed, it was to be March 1945 before type 267W was first used operationally, much of the later delay being due to the difficulty in obtaining 3cm magnetrons because, in the autumn of 1943, the RAF had the highest priority for supply for use in Bomber Command's Mark m H2S.18

TYPE 291W IN AN ATTACK OFF NORWAY

In September 1944, HM submarine Sceptre (Lieutenant Ian McIntosh) on her tenth war patrol, was given a small patrol area off the SW coast of Norway near Egersund, containing a stretch of open coast protected in some degree by reported minefields. The weather was mostly fairly calm with some periods of fog and low visibility, improving from time to time. Within the area there was considerable activity by German anti-submarine trawlers, fishing vessels and some small coasters below the size that were allowed to be attacked, but no larger ships were sighted by day, probably because of a sustained period of day attacks on convoys by RAF Coastal Command. Sceptre was fitted with type 291W airguard radar operating with an A-scan display and no PP!. In common with the then usual practice in submarines, it was seldom used as it was feared that it would give the submarine's position away. Against aircraft, reliance was placed on visual sightings and if on the surface the standard practice was to dive without trying to identify until safely under, Radar in Submarines 297 experience having taught that 'friendly' aircraft were as liable to attack as enemy ones, often more damagingly. In view of weather conditions and the lack of daytime targets, it was decided that continuous radar watch should be kept when surfaced each night, usually between 8.3Opm and 5.15am, with the object of detecting any convoy movements on the inshore route, or any possible U-boat movements on the routes they were believed to take further to seaward. No ill effects resulted from this policy and it had its reward on 20 September, the day before Sceptre had been ordered to leave patrol. Just before 9pm on the 20th, a possible target was detected by radar at a range of 5.5 miles, some 20 miles WSW of Egersund. Sceptre went to diving stations, altered course to close on the surface and, at 9.09, a plot was started. Range accuracy on that set was good but bearings were very unreliable. However, quite a good plot was generated using range only and by 9.25 the enemy was reckoned to be steering about 150° at 12 knots. Sceptre altered course to run parallel 2 miles off the enemy track, and speed was increased to a maximum of 14~ knots to give chase and reach a good attacking position. By lOpm, bearing had been gained and course was altered 5° to port to reduce the distance-off-track. By 10.13, a suitable attacking position having been reached and the enemy course and speed from the plot confirmed, Sceptre altered to port to an attacking track, reducing speed to avoid closing too much. During this run-in, the target was sighted and, at just over half a mile, identified as an A/S trawler. By now, three new echoes had been seen close together about 2 miles on Sceptre's port bow and these were assumed to be a convoy, the final target. Course was altered to starboard to present a smaller visual target to the trawler escort and to pass under her stern to get inside the screen. Turning a full circle before steadying on a course of 090°, Sceptre closed the convoy on a 118° track, the enemy course being 152°, speed 12 knots. Three ships in line ahead were sighted - an A/S trawler followed by two merchant ships - silhouetted against Egero light which had just been switched on for the convoy's benefit. At 10.31, six torpedoes were fired, aimed at the two merchant ships. Two hits were seen on each target and both were thought to have sunk because, after five minutes, the fires in each suddenly disappeared and the radar echoes were lost. Sceptre withdrew on the surface at top speed and was able to listen to the explosions of some 35 depth charges with equanimity.t9 We have mentioned the apprehension felt by many submariners about giving away their position by using radar. Sceptre's experiences in her next patrol in the same area off Norway is relevant here, when she tried, not unnaturally, to use her radar at night. Early in the morning of 18 October 1944, after five minutes of radar transmission, interference produced so much 'mush' on the A-scan as to obscure any possible echo information, the 'mush' extending SOo either side of the bearing 015°. On the evening of the 19th, just after surfacing, the same thing occurred after about five minutes. This was obviously deliberate jamming and, equally obviously, the enemy must know Sceptre was there. On the 21st, Trafalgar Day, she used radar in short bursts and was not jammed but got no useful information. Later that night, she carried out a surface attack on a convoy using, faute de mieux, the 'Mark 1 Eyeball' with results very similar to the attack on the previous patrol. On surfacing the next night, she again had only four or five minutes transmitting before jamming obliged her to switch off and stand down the radar watch. Probably lack of resources prevented the Germans from taking any offensive action against Sceptre. But although they seemed to know of her presence, their 298 Appendix D protection of the convoy on Trafalgar Day left much to be desired - which suited Sceptre very well.2o

THE US TYPE SJ IN BruTISH SUBMARINES IN THE FAR EAST

In September 1943, Admiral (Submarines) asked the Admiralty to acquire a number of American IDem type 5J sets to fill the gap until type 267W was ready.21 The first two of these were fitted in Tiptoe and Trump, building at Barrow, completing in the summer of 1944. The aerial - or antenna in American terminology - was on a non-elevating mast abaft the periscope standards. After working-up patrols in the North Sea, the submarines sailed for the Far East early in 1945, to be based in Fremantle. In their first war patrols, 51's performance was very indifferent, but the situation was transformed in April 1945 when the maintenance staff in the British depot ship Adamant sought the help of the US Navy, which also had a submarine base at Fremantle. Tuning and a few modifications (to convert to 5Ja) soon improved matters. Both boats had complained of the lack of air cover, so Adamant fitted them with a modified 291W additional to the 5J, as well as a l.5m search receiver 5N4, using the same aerial. In her next patrol, Tiptoe reported that 5J worked well, detecting 10 to 20 ton junks at 3 miles, a US submarine at 6 miles and land at 50 miles or more. During the first week of the patrol, at least twelve 5J contacts were investigated at night; in the event, they all turned out to be junks and the like, but would otherwise have passed without being detected. As a navigational aid, 5J was splendid, though rather less so in the Java and Flores Seas, not because of the radar but because of the inaccuracies of the charts. The 1ash-up' 291 was not satisfactory, however. Trump had much the same experience until her SJ broke down completely halfway through the patrol. In their last war patrols off the south coast of Java from 16 July to 21 August 1945, Trump and Tiptoe worked together as a 'wolf pack'. In a highly successful patrol, 5J radar was used extensively not only for its prime purpose but also for communication between the two when surfaced at ranges of up to 8 miles, something which British radar equipment was not then capable of doing. The aerial was trained on the consort and the IDem beam used with a morse key for wireless telegraphy in half-hourly routines. As this system was highly secure, no codes were needed, making possible very close understanding between commanding officers. 'This fluent freedom of thought,' wrote Lieutenant Anthony Catlow of the Trump, 'was only made possible by the SI radar.' Lieutenant Richard Jay of Tiptoe reported that aircraft could be detected at about 7 miles with the new type of antenna reflector fitted by the US Navy in Fremantle. But sadly, he said, the 291 was useless ... 'It is requested that it may be removed from the wardroom pantry at an early date.,22

TYPE 267W OPERATIONAL

The trials of the development model of the dual-wavelength type 267W were carried out in the submarine Tuna but the first two operational sets were fitted in Turpin (Lieutenant J.5. 5tevens), building at Chatham, and Tapir (Lieutenant J. C. Y. Roxburgh), building at Barrow, at the end of 1944. In an account of Tapir's first patrol, Admiral Roxburgh tells how wonderful it was to see the 3crn picture on the PPI showing the coast of Scotland as if it were a map. He goes on: Radar in Submarines 299

58. Submarine Turpin, 1944, with 3cm 'seaguard' aerial of type 267W forward (to the left) of the periscope standards, l.5m 'airguard' aerial in the lowered position to the right. (IWM)

Steve and I sailed in March/April 1945 for our first patrols [off the coast of Norway] in our brand new 'T' class submarines after work-up in the Clyde/ Derry areas. We were allocated adjacent billets off a couple of lighthouses near Bergen. He was some five days ahead of me. On the first evening in my billet we detected on our passive sonar what we took to be a dived submarine. We proceeded to track it and when we heard the contact blowing tanks we knew we had a submarine contact. I immediately came shallow to break surface and expose my type 267 aerial. This gave us an unmistakable surface contact which we plotted as going away. I promptly surfaced and gave chase, very soon obtaining splendid fire control information from the radar plot. It seemed the contact was taking me out of my area into Steve's, so I ordered a rushed enemy report to be prepared, informing Turpin an enemy submarine was approaching her area. At the same time, I continued to converge on the contact and had all my torpedoes ready for firing. Imagine my surprise when, just before I broke W /T silence to make my enemy report, 300 Appendix D

an Aldis lamp flashed the challenge at me, immediately followed by, 'Don't shoot - Steve here!!' Turpin had in fact spent their first five days on patrol in my area, having arrived in dense fog with some understandably shaky navigation. They had got an evening fix in clear weather the night that I arrived and discovered to their horror they were in my area, which they knew I was just entering. Steve had surfaced to get to hell out of it as quickly as possible, knowing I would not hesitate to attack if I came across him. (I actually sank a Gennan U-boat there a week later!) Steve with his 267W radar had got an equally good plot of me after I had surfaced and was giving chase and could see our tracks converging. He also got interference on his 3cm set from another source on the same frequency. This convinced him it was me - hence his anxious signal. If we had any such interference we did not notice it - we were just convinced we were onto a good thing and were going for it.23

Type 267W had a fixed-height 'seaguard' aerial, usable only on the surface. Type 267PW - with the 3cm aerial array on a periscopic mast usable at periscope depth - did not come into service until after the war, the first trials being in Amphion, the first production model in Alderney in 1946.

TAILPIECES

• By Rowland T. Harris, sometime AB (Radar) in the submarines Thrasher and Trenchant, with type 291W, 1943-6.

. . . On our exercises out of Dunoon, I vividly recollect being asked - not ordered - to try to give the steering orders in order to negotiate a passage between two islands somewhere in the Minches. Needless to say, Skipper [Lieutenant A. R. Hezlet] and lookouts were on the bridge, but they were not needed. 291 was accurate within yards!24 [In fact, the navigating officer was standing alongside him in the Control Room with the captain checking for safety on the bridge.25]

• By Arthur Dilley, sometime AB (Radar) in Thrasher and Trenchant, 1943-6.

The most interesting bits came when, working as fall-of-shot spotter in gun action, occasionally some spirited Japanese characters would shoot back and the sight of echoes approaching the ground wave instead of the opposite concentrated the mind on giving accurate range changes ... The compensations for radar operators included diving stations in the Wireless Office where, once the shallow depth gauge had been shut off, we had no means of knowing how deep we were and were isolated from occasional slight panics caused by deep dives to escape the enemy's attention. Interspersed with operating came the nonnal seaman's duties, i.e. lookout, helmsman, hydroplane operator, buoy jumper, harbour stations on the after crest, and cleaning the seamen's heads, this latter being part of the Admiralty's plan to keep Jack occupied when not at sea.26 Appendix E: Radar in Coastal Forces

THE FIRST COASTAL FORCES RADAR

After A. w. Ross and his Signal School team had designed the 'bedstead' aerial for destroyers in the summer of 1940 so that the RAF's ASV Mark IT could be fitted in small ships as type 286M (p. 58), they turned their attention to designing a lightweight aerial suitable for Coastal Forces craft such as motor torpedo boats (MTBs), motor gun boats (MGBs), steam gunboats (SGBs) and motor launches (MLs). This aerial had three sets of fixed dipoles at the top of the craft's mast so that a transmitting array pointed right ahead and two receiving arrays pointed one on either bow, the relative strength of the echo signal between the two giving a measure of the bearing relative to the ship's head. It was similar to the arrays used in aircraft and was a lightweight version of the destroyer aerial. It had been tried out in an MTB by January 1941,1 and by September, two MTBs, one MGB, and seventeen MLs had been fitted with type 286MU.2 (For Coastal Forces radar, the suffix 'U' was added to the basic radar type number.) By November, general fitting had begun in all MTBs (except 60ft boats), MGBs, SGBs and MLs (except 72ft Harbour Defence MLs).3 The boats in the 7th and 8th MTB Flotillas all had radar when they sailed for the Mediterranean in April 1942. Meanwhile, a lightweight rotating aerial had been designed and was fitted in MTB 35 for trial towards the end of 1941.4 General fitting began in mid-1942, all Coastal Forces fixed aerials eventually being replaced, so that the sets became type 286PU. The next development was the fitting of the more powerful all-naval type 291U with the same rotating aerial, the first development model being installed in MGB 320 in June 1942,5 general fitting in new-construction boats starting in early 1943, though it was to be some time before all type 286s were replaced in existing craft. Type 291 U was to remain the main radar in Coastal Forces until the end of the war in Europe, used for aircraft warning and navigation in daytime and for surface warning and occasionally torpedo weapon control at night. But it had its limitations: being a 1.5m set, it was easy for the enemy to detect and had a wide beamwidth, so bearing accuracy, based on relative not compass bearings, was poor; the only display was an A-scan, the aerial was hand-rotated, and the plotting arrangements in the boats were rudimentary. British officers who saw the American IDcm type SO with PPI display and power-rotation - which came into service in the US PT Boats (Patrol Torpedo boats) early in 1943 - were green with envy. So much so that, in the Mediterranean in 1943, British MTB flotillas doing night attacks on Axis convoys would try to have a PT Boat in company so that they could make use of its superior radar and plotting arrangements.

301 302 Appendix E

59. An MTB, showing (1) WC type 291 U; (2) fixed directional interrogator type 242. (Radar Mallual, 1945)

OPERATIONS OFF ELBA

A prime example of this cooperation occurred in two of the most successful operations by light forces in the Mediterranean in 1944, which were planned and executed by Commander Robert Allan, RNVR, who led a heterogeneous force of British LCGs (Landing Craft Gun), MTBs and MGBs and American PT boats based on Bastia in Corsica in attacks on German military supply convoys off the west coast of Italy. Allan had trained and exercised his sixteen vessels to work as a miniature battle fleet, in which the LCGs, armed with 4.7in guns, acted as capital ships; and he controlled them all by radar and radio from an American PT boat in which he sailed as 'admiral'. In operation 'Gun' on the night of 27/28 March, Allan's force attacked a southbound convoy of armed barges escorted by two Italian destroyers off Capraia Island. All six barges were sunk and the two escorting destroyers were driven off by the PT boats. In a similar and even more successful operation, 'Newt' on 24/25 April, Allan in PT 218 had under him three LCGs, three MGBs, three MTBs, and seven PT boats. The first action took place just after midnight against a southbound convoy of three barges and a tug from Leghom. All were Radar in Coastal Forces 303 destroyed, as were two armed barges patrolling nearby which came to their assistance, a third being driven ashore. Later in the night, the J7I' boats engaged three German torpedo boats minelaying west of Capraia, one of which struck a mine and was sunk by her own forces. There were no Allied casualties. All of this was made possible, first by shore radar in Corsica tracking shipping in the channels between Corsica, Elba and the Italian mainland, and secondly by the PPIs of 10cm SO surface search radar fitted in the J7I' boats. (The British boats had the I.Sm type 291U air/surface warning radar - but no PPIs.) Allan conducted the battle from the Combat Information Center of J7I' 218, where he had a clear picture of the situation and was able to vector craft as necessary, talking direct by voice radio. When necessary, he was able to detach an MTB unit under a Deputy Controller in another J7I' boat to deal with stragglers.6,7 As we saw in Chapter 9, vectoring of coastal forces from a ship was to be done again a few months later, during and after the assault on Normandy, this time from frigates. But once again, the British controllers had to use US radar.

US RADAR IN BRITISH BOATS Such was the impact of the American IOcm type SO radar with its PPI display and power rotation, after the success of Operations 'Gun' and 'Newt', that the Senior Officers of the Fairmile 'D' flotillas in the Mediterranean entered negotiations for some unofficial Lend-Lease arrangement to secure it for their own boats.

60. MGB 658 in the Adriatic, October 1944, showing the radome of the American SO surface search radar. (L.e. Reynolds) 304 Appendix E

Fortunately, with joint operations so finnly established over many months, relations with 'RON IS' (the USN's 15th PT Squadron) were so excellent that these negotiations were successful, and MGB 657 was the first Fairmile 'D' to be fitted with SO radar, in June 1944. It is said that the deal involved an unspecified quantity of Scotch whisky: but the detail is shrouded in mutual confidentiality. By December 1944, at least six more 'D's were fitted with the set, enabling operations in the Adriatic to have the enormous search and plotting advantage it gave, especially as mixed units with PT boats were not normally possible. Eight US-built Vosper MTBs equipped with the SO sets arrived in the Mediterranean in November 1944 and were formed into the 28th MTB Flotilla. They worked up diligently, specifically concentrating on deriving maximum operational value from a combination of an excellent search, detection and plotting radar with the availability of Mark VIII torpedoes with magnetic pistols. They achieved spectacular success in the first four months of 1945, operating in the northern Adriatic. Once the enemy target had been picked up at extreme range and its course and speed plotted, the boats would set intercepting courses for an optimum firing position, and were able to move in at slow speed on silenced engines. This enabled surprise to be achieved with its benefits of uninterrupted approach and accuracy of torpedo firing angle. In ten interceptions of enemy convoys by this flotilla, forty-three torpedoes were fired, twenty-four hits claimed, and nineteen ships sunk. None of this would have been possible without the superior PPI radar equipment.8

CENTIMETRIC RADAR FOR COASTAL FORCES

Let us now return to 1942. Our Coastal Forces badly needed centimetric radar, but how was it to be provided? British naval radar design and production facilities were stretched to the limit, and the 10cm type 271/2/3 radar then being fitted in corvettes and above could not be made compact enough or light enough for fitting in Coastal Forces craft. As mentioned on p. 234 above, the solution adopted was to ask the National Research Council of Canada to develop a high-resolution radar on the 3cm band, with power-rotation and PPI displays. The first design work on this new radar - to be called type 268 - proceeded fast and a preliminary model was tested near Halifax in October 1942, with gratifying results. In April 1943, a set was sent bl. air to England, accompanied by three Canadian engineers led by K. C. Mann. This was fitted in MGB 680. And centimetric radar might do something else for Coastal Forces. The MGB was the equivalent afloat of the night fighter in the air, so, in the spring of 1942, Commander R. T. Young of the experimental department of the Navy's gunnery school, HMS Excellent, proposed that the lock-follow Air Interception radar (AIF or AlSF) being developed at TRE for night fighters might be fitted to MGBs to make blind fire by their 2-pounder guns practicable against enemy vessels at night. That summer, trials were carried out tracking small vessels and low aircraft on the slipway at Lee-on-Solent, on the 'rolling platform' at Eastney, and at sea in MGB 614, where the AlSF scanner was mounted on a wooden structure in the position of the forward gun. In the sea trial, in both calm and rough weather, the average lock errors in both azimuth and elevation were something less than lho.lO In December 1942, however, TRE's AlSF programme received a considerable setback from the loss in an aircraft crash of the prototype AlSF. Luckily for the RAF this coincided with the arrival of the first American centimetric AI, the 3cm SCR 720 with a helical scanner rotating at 360 rpm, classified by the RAF (and the Radar in Coastal Forces 305

Royal Navy) as AI Mark X. This was to remain the standard AI equipment in the RAF until 1957.11 In March 1943, AI Mark X - for naval purposes designated type 269 - was fitted to the 2-pounder gun mounting of MGB 680. Two months later, the Canadian tactical warning type 268 already mentioned was also fitted, with the scanner at the top of her mast. On 5 July, she gave a successful demonstration of these two 3cm radar sets in the Solent to senior naval officers and civilian scientists. For type 268, the trial was most successful, resulting in an immediate Admiralty order for 1,000 sets to be produced in Canada, later increased to 1,500.12 However, type 269 was not so successful. Mr Robin Board, then commanding MTB 680, says that his memories of it are anecdotal:

• The dustbin-sized nacelle fixed to the pom-pom which so restricted the view from the bridge when coming alongside. • The tendency to leave the target without warning and lock on to the Ryde ferry. • The amazement of the ship's company watching sausages being cooked in the waveguide. • The ship's company's certainty that the operator would become impotent, and their fascinated interest in him after each leave period.13

Type 269 never came into service and in October ASE reported that work on it had stopped.14 Production of type 268 in Canada was plagued by difficulties - caused at least in part by suggested modifications from Britain to cope with the 'Sehnorkel' threat - and the first batch of production sets (only eleven) did not reach England until January 1945,15 too late to have any influence in the war in Europe - which was sad for Coastal Forces because it was to prove a most valuable piece of equipment. With hindsight, one wonders whether efforts could have been made to acquire the American SO search radar for British-built boats once the delays to type 268 became evident.

SURFACE FORCE DIRECTION

As mentioned on p. 109, a naval 10cm type 271 (army manned) was installed on the South Foreland north of Dover in July 1941, reporting to the combined services plot in Dover Castle. On the evening of 8 September, a German convoy was detected leaving Boulogne at a range of 24 miles. Dover plotted it tracking to the north and east and at 11.5Opm directed three MTBs onto the attack off Calais. The target was held by radar until 1.45am as far as Gravelines (nearly 30 miles) and MTBs made a further attack at 2.01.16 Many such actions with Coastal Forces craft under WIT shore control, making use of shore radar, took place during the next year or so off Dover and elsewhere. True coastal force direction afloat, analogous to fighter direction, where the craft were actually given courses to steer - 'vectored' - by Coastal Forces control ships using RIT came into full operation in 1944 in Operation 'Neptune' as an anti-E• boat measure as described on p. 220 above. The idea was first suggested by Lieutenant M.G. Raleigh, RNVR,t7 Assistant Staff Officer (Operations) at Portsmouth and was enthusiastically welcomed by Captain Coastal Forces (Channel), who, with his staff (Lieutenant-Commander Peter Seott, RNVR, and Lieutenant Christopher Dreyer), followed it through and made it happen. As we saw above, something like it had already been used to some extent in Operations 306 Appendix E

'Gun' and 'Newt' against enemy convoys in the Mediterranean, but details of the tactics did not reach ID< until July 1944.18 Coastal Forces control ships were destroyers or frigates with good radar and plotting facilities, particularly the US-built 'Captain' class frigates with SL search radar and automatic plotting tables. With specially trained control officers (ex• MTB COS) to supervise the plot and vector the attached craft, they were virtually secondary shore plots stationed so as to provide radar cover of the convoys routes wherever it could not be provided by shore radar. The normal practice was to detail a frigate and two units of two or three MTBs as one force and to sail in company where practicable. Each control ship patrolled a six-mile line at 12 knots, coordinating its movements with adjacent patrolling frigates so that large gaps in the overall patrol line were avoided. The MTBs remained stopped at some convenient position (usually at each end of the frigate patrol line) so arranged that they were at all times visible on the radar scan of the directing ship. Once a detection had been plotted by the control ship, the attached craft were vectored by the control officer to intercept, subject to his orders until themselves in contact with the enemy, either by radar or visually. On occasions the control ship also provided illumination of the target. In the later stages of the evacuation of Le Havre, it became the practice to add one or two 'Hunt' class destroyers to the force. These acted as support for the MTB units, since some of the convoys were heavily escorted and were sailing close inshore, so that there was also trouble from shore batteries. The destroyers usually patrolled in companl with the controlling frigate, keeping station on the frigate in line ahead.1 During the course of Operation 'Neptune', there were many examples of the value of the control ship technique, both in defensive actions to protect the cross• Channel convoy route against E-boat attack, and in offensive actions against German convoys evacuating Cherbourg and, later, Le Havre. It was most noticeable that contact with the enemy was almost always obtained. Operating from Cherbourg with the US Navy in the later stages of the Channel War in August 1944, Peter Scott conducted one classic little operation - a splendid example of Allied cooperation. Embarked in a USN frigate, he controlled a mixed force of two British '0' class destroyers, and three MTB units - one of US PT boats, one Canadian and one Free French. They had a brief and inconclusive action off Guernsey but sank one trawler and one 'M' class minesweeper. After the Channel had been cleared by the end of August 1944, the MTB flotillas and control ships moved to the Nore Command and operated for the remainder of the war in Europe, mainly protecting the Thames-5cheldt convoy route against E-boat torpedo and minelaying attacks. Appendix F: Naval Airborne Radar

David Brown, FRHistS

Two years, almost to the day, before the outbreak of the war, all the major future uses of airborne radar were demonstrated in a single bad-weather sortie by an Avro Anson aircraft attached to the Air Ministry's Radio Research Station. The experimental set then known as 'RDF 2', had been flown for the first time as recently as 17 August 1937, but, as mentioned on p. 18 above, on 4 September, in the hands of Dr E. G. Bowen, the leader of the airborne radar development team, it located HMS Courageous and her destroyer screen in low visibility, homed the aircraft to make a visual identification, detected Courageous's fighters as they were scrambled. Finally, the radar permitted Bowen to navigate to an accurate landfall, in cloud that extended from 12,000 feet to near sea level. All that was lacking in the Anson was WIT, to report its sighting. Despite this very early success, no operational aircraft was fitted with air to surface vessel radar (ASV) on 3 September 1939. Technical difficulties and rival demands on Dr Bowen's small team - particularly the priority given to the development of Air Interception (AI) radar - were largely responsible, but it was perhaps unfortunate that the Admiralty, which clearly had a major interest in ASV, was not given an official demonstration of its capabilities until May 1938. Six radar sets were requested for immediate delivery, but the niceties had to be observed and a joint Air Ministry-Admiralty conference had to be held to lay down guidelines for operational requirements, tactical development and trials. The conference took place in early August 1938, but the demonstration of the rival forward- and sideways-looking systems scheduled for September had to be cancelled owing to the Munich crisis. On 21 September, however, the AOC-in-C of Coastal Command, Air Marshal Sir Frederick Bowhill, recommended to the Air Ministry that ASV should be adopted immediately as standard equipment in maritime reconnaissance aircraft. This recommendation, and persistent Admiralty demands, failed to produce any orders for pre-production ASV sets until July 1939, when 24 were ordered, of which six were to be fitted to Royal Navy aircraft. The design of the ASV Mark I had still not been finalized and the alternators could not be delivered for three months: not until November 1939 was the 1.Sm ASV I flown in a Coastal Command Lockheed Hudson and the first sets were delivered to the Royal Navy in the following month, for trials installation in Supermarine Walrus and Fairey Swordfish aircraft. At this stage, the Royal Navy's interest in ASV was for Fleet use, at night and in bad weather; the early trials were entirely devoted to the development of the appropriate 'night shadowing equipment' tactics to be used to gain and hold contact with enemy surface ships, as preliminaries to a carrier air strike or a capital ship duel. It was therefore left to Coastal Command to pioneer the anti• submarine development and use of ASV, in trials and on actual convoy escort missions.

307 308 Appendix F

The ASV I proved in service to be very fragile and its unreliability was not helped by a lack of instructional handbooks and maintenance manuals at squadon level. It also had a number of undesirable characteristics, not the least of which was interference with the parent aircraft's W /T reception. By February 1940, however, a full production model had been designed and engineered and two firms were asked to produce 4,000 ASV Mark II sets, for delivery from 1 August 1940. Unfortunately, the Air Ministry bureaucracy failed to recognise the importance of the programme and the formal order was not placed until April. A month later, AI production was given precedence over that of ASV, even to the extent of 80 ASV I transmitters being diverted. By the end of 1940, Coastal Command had only 49 aircraft equipped with ASV, while the Royal Navy had only its trials aircraft. The Admiralty itself contributed to the delay in availability of the ASV 11, for it provided the basis of the type 286 radar, fitted in small surface ships from the late autumn of 1940. Production increased rapidly early in 1941 and during the first three months of that year components for 1,000 complete sets of ASV 11 were delivered to the Services. ASV II remedied most of the pre-production Mark I's shortcomings and, with minimal development, the Royal Navy's variant, ASV IIN, remained in front-line service throughout the war. Operating in the ultra-high-frequency band, on 214MHz (the RAF's ASV 11 was tuned to 176MHz), with an initial peak power output of 7kW, it could give a range of up to 15 miles against a medium-sized ship and, under good conditions, up to 4 miles against a surfaced submarine. Fitted to the inter-wing struts of the Walrus and Swordfish aircraft, the distinctive splayed dipole antennae had little effect on the performance of biplanes which rejoiced in the Service nicknames of 'Shagbat' and 'Stringbag'. The first naval front-line unit to be fitted with ASV UN was the spotter• reconnaisance catapult flight embarked in HMS King George V, which received two radar-equipped Walrus amphibians in mid-March 1941. Other Home Fleet Walrus flights quickly followed and as individual Swordfish were fitted with radar they were delivered piecemeal to squadrons. In April 1941, 825 became the first Swordfish squadron to be entirely re-armed with ASV Swordfish and it was the nine aircraft of this unit which, flying from HMS Victorious to the south-west of Iceland, first used ASV UN in anger, to locate and attack the Bismarck, just after midnight on 25 May 1941. On the afternoon of 26 May, the Ark Royal launched her first torpedo striking force against the German battleship. Only the leader's aircraft was radar• equipped but the ASV picked up a target close to the briefed position and the Swordfish dived through thick cloud to deliver a surprise attack in low visibility. Eleven torpedoes were released and it was only a combination of a known defect in the firing pistol and HMS Sheffield's swift reactions which prevented the first radar-assisted 'own goal'. The subsequent attack was, of course, highly successful and led to the destruction by gunfire of the Bismarck. King George V's Walrus flight played no part in the action, but remained in the battleship's hangars, their fuel drained down to reduce the fire hazard. When the Ark Royal was torpedoed on 14 November 1941, most of her radar• equipped Swordfish were lost with her. 812 Squadron re-armed with aircraft from the pool held at Gibraltar, but there were only four ASV sets available when this unit was called upon to begin a little-known but highly successful short anti• submarine campaign. The German Navy was known, from 'Enigma' decrypts, to be passing batches of U-boats into the Mediterranean through the Straits of Gibraltar and 812 Squadron was ordered to reinforce the night surface patrols, the ASV 11 fitted to the RAF Catallnas based at Gibraltar being at this time so unreliable as to be useless. The patrols began on the night of 27/28 November Naval Airborne Radar 309

61. The tangled wreckage of two Swordfish, seen after an altercation aboard Eagle in the spring of 1942. The port reflecting-dipole receiving aerial of the victim is at centre bottom of the photograph, while the assailant's simple 'towel rail' transmitter extends along the leading edge of the upper wing centre-section, on three insulated supports. The shorter horizontal bar, mounted below the wing ahead of the pilot, is part of the torpedo sight. (D. T. R. Martin) and continued for two months. Of 22 submarines which attempted the passage, 1 was completely deterred by the Straits defences, five were damaged and forced to return by the Swordfish, whose efforts were crowned in the early hours of 21 December by the destruction of UAS1, the first U-boat to be sunk at night by aircraft, or as a direct result of radar, or by any land-based aircraft, naval or RAF. The intended replacement for the Swordfish, the Fairey Albacore, had been in service since the summer of 1940 but had won its laurels in the eastern Mediterranean without the benefit of ASV. Indeed, it was not until the end of 1941 that the problem of serious interference between the aircraft compass and the radar alternator was solved. Thereafter, the aircraft were equipped as quickly as possible and in March 1942 Victorious's two squadrons used their radar to good effect in a torpedo attack on the Tirpitz which narrowly failed to score hits. Priority for Albacore re-equipment went to the Home Fleet squadrons and thus, when Fonnidable sailed for the Indian Ocean in February 1942, her squadron, like all but a handful of the Albacores aboard the Indomitable, which was already on station, lacked ASV and she had to 'borrow' a pair of ASV-fitted Swordfish. As Admiral Somerville's plan for dealing with the Japanese carrier fleet relied primarily on night search and strike, this was hardly a satisfactory state of equipment. In the event, one of the Indomitable's radar-equipped Albacores did 310 Appendix F

62. The Barracuda's ASV ITN antennae had to be mounted above the wings, owing to the peculiar geometry of the aircraft's wing-folding mechanism. They differed from previous fittings of this radar in that each antenna incorporated both the transmitter and receiver elements. This example is taking off from Furious, whose type 291 radar and type 72DM homing beacon are also well illustrated. (IWM) make the only contact between Somerville's carriers and ship of the Japanese fleet, as the latter was withdrawing beyond air torpedo striking range. By mid-1942, sufficient ASV UN sets were available to equip all embarked aircraft which could be fitted and work was well advanced on its replacement. The Admiralty had from the outset stated a requirement for all-round coverage but this was not practical until the development of centimetric radar, with its smaller transmitter-receiver scanner. In December 1941, a successful bid was made for a new centimetric radar specifically for its new torpedo-bomber, the Fairey Barracuda and design work began on ASV XI. In the meantime, the Barracuda appeared to be approaching acceptance for service and had to make do with ASV UN: it could hardly be said that the overwing combined transmitter• receiver antennae marred the already 'over-loaded Christmas-tree' looks of the Navy's newest monoplane. At the same time (late 1941), the Admiralty decided that embarked night• fighters were urgently required. The existing Fairey Fulmar two-seat fighter was chosen for trials with the RAF's AI Mark VI metric set, as an interim measure, but the intention was to fit its successor, the Firefly, with a dual-purpose centimetric radar, for air-surface and air-air use. In the event, this was not achieved and the centimetric AI XI which was installed in a small number of Fireflies proved to be unusable in any role. Naval Airborne Radar 311

63. Belt and Braces: the Swordfish Ills operated by 860 Squadron (Royal Netherlands Navy) from the Dutch-flagged merchant aircraft carrier Gadila retained the ASV IIN fitted to the inter-plane struts even after the fitting of ASV XI. The positioning of the latter's 'bathtub' scanner dome below the engine meant that no weapons could be carried under the fuselage, while the weight of equipment was such that the crew had to be reduced to two and rocket assistance was necessary for take-off from the short decks of the MAC ships. (The tube of the port rocket can be seen projecting obliquely behind the radar dome.) (RNethN)

ASV XI, on the other hand, was a success, with a range of up to 10 miles against a surfaced U-boat and 40 miles against a carrier; the same cannot be said of the aircraft for which it was intended. As the Barracuda was experiencing serious problems, priority was given to the fitting of the centimetric radar to the Swordfish, specifically for anti-submarine work. The first trials aircraft flew in February 1943, as the Battle of the Atlantic reached its climax, and the first squadron re-equipped with the ASV XI-fitted Swordfish III in November 1943. Afloat, these aircraft served only aboard the escort carriers, operating in the Atlantic and in the Arctic, where the squadrons scored some notable 'kills'. One successful Swordfish III squadron, 819, was given a quite different task in the summer of 1944, providing night anti-E-boat patrols before and during the Normandy invasion; so successful was it in this new role that it moved to Belgium in October 1944 and continued its coastal patrols until March 1945. The ASV XI-fitted Barracuda III arrived in service as 819 Squadron began to demonstrate the usefulness of the centimetric radar in coastal waters. The equipment was limited by aircraft centre-of-gravity difficulties and it had been decided that only one new aircraft in four would be built as a Mark III and that these would not serve in Fleet carriers. In the event, only one Barracuda squadron 312 Appendix F armed with this Mark, the Canadian-crewed 821, went to sea at all, aboard the Canadian-manned Puncher, and it undertook only one offensive operation - a minelaying mission off the Norwegian coast. Several other squadrons formed, but all were employed on anti-E-boat and anti-midget submarine patrols in the southern North Sea. It was obvious from the summer of 1944 that the ASV IIN Barracuda's days as the principal carrier strike aircraft were numbered. While it could cope with operations off the ill-defended coast of Norway, its performance in subtropical conditions was completely inadequate. Fortunately, the US Navy's Grumman Avenger was now being delivered in sufficient numbers to re-arm all the Fleet carrier squadrons. This aircraft was equipped with the standard American metric 'ASB' (air-to-surface, Type 'B') radar, a direct copy of ASV IIN, but towards the end of 1944 new aircraft began to arrive equipped with 'ASH' (officially designated AN / APS-4) radar. This remarkable piece of kit had first been seen in Britain early in 1944 and large-scale orders had promptly been placed. A 3crn set, it had been specifically designed and miniaturised for external carriage on single-engined aircraft and the scanner, transmitter, receiver and alternator were all packed into a streamlined 3501b 'bomb'. It lacked the all-round scan of the ASV XI, but ASH's performance was as good and its light weight and lack of demand upon the parent aircraft's internal volume made it the obvious replacement, not just for ASV IIN but also for ASV XI. Even more telling was its air-to-air capability - ASH was the dual• purpose radar which the Admiralty had been seeking since late 1941. The failure of the Firefly night-fighter programme had resulted in the Fulmar being retained, primarily as a training aircraft. Many of the crews which graduated from the RN Night Fighter School at Drem subsequently served with RAF squadrons, but in early 1944, with Luftwaffe guided missile squadrons beginning a night offensive against Gibraltar convoys, three-aircraft flights of night-fighter Fulmars, equipped with metric AI IV radar, embarked in escort carriers on that route. Of course, no convoy accompanied by one of these carriers was approached by enemy night bombers and it was not until a year later, in March 1945, on the Arctic convoy route, that the only 'scramble' of a Fulmar night-fighter was attempted: the fighter was too slow to catch the intruder and crashed on landing. A single ASH-equipped Firefly night-fighter squadron (1790) arrived in the Pacific shortly before VJ day but too late to embark in HMS Implacable. Two more Firefly squadrons were then working up in the United Kingdom, as were two Grumman Hellcat squadrons, equipped with 'AlA' (AN / APS-6) radar, which resembled ASH but was designed specifically as a pilot-interpreted night-fighter radar, which had been used very successfully by the US Navy since the autumn of 1944. At the end of the war, the metric ASV IIN (and the similar ASB) was still in use, having given excellent service for four and a half years. ASV XI had proved to be a useful radar during the last eighteen months of the war in Europe, but in the front line it did not survive the disbanding of the Swordfish and Barracuda squadrons. For the immediate future, ASH, with its virtues of light weight and acceptable performance, would fulfil all the Royal Navy's airborne needs; it had arrived too late for widespread service, but by the end of 1945 it had displaced every other radar in the aircraft of the British Pacific Fleet and it was to survive as the principal naval ASV radar for another twelve years. The avenue opened by AlA was not explored by the Royal Navy after the return to the US Navy of the last Hellcat night-fighters in the spring of 1946. Night-fighting, it was reasoned - by the Observers' 'guild', which guarded Naval Airborne Radar 313 jealously the black art of radar operation - was too complex for one-man operation and for the next thirty years, until the introduction of the Sea Harrier, this remained the province of the two-seat aircraft. In fifty years, however, no AI• assisted 'kill' has been scored by a naval fighter, in contrast with the conspicuous success of radar-equipped strike and anti-submarine aircraft. Glossary of Technical Terms and Abbreviations

Abbreviations used in references are listed on p. 321.

AA Anti-aircraft A-arcs The arcs on which all guns of a ship's main armament will bear, thus allowing them all to fire simultaneously at the enemy. AB Able Seaman ACNS Assistant Chief of Naval Staff Acorn valve A small high-frequency valve about 1 inch in diameter shaped like an acorn, with the leads arranged radially around the middle of the envelope. ADEE Air Defence Experimental Establishment (Army). ADR Aircraft direction room ADRDE Air Defence Research and Development Establishment (Army) Admiralty organization Divisions of the Naval Staff responsible for operational matters, such as the Operations, Plans, Training and Staff Duties, and Naval Intelligence Divisions, reported to the First Sea Lord through the Deputy and Assistant Chiefs of Naval Staff. Admiralty Departments generally responsible for maUriel matters, such as the Naval Ordnance, Naval Construction, Scientific Research, and Signals Depart• ments, reported to the Controller. From the outbreak of war, operational sections of the Signal Department and the Naval Ordnance Department were in London, maUriel sections in Bath. AEW Airborne early warning AFCC Admiralty Fire Control Clock AFCT Admiralty Fire Control Table AFO Admiralty Fleet Order AI Air interception (airborne radar) AIO Action Information Organization AMRE Air Ministry Research Establishment ANCXF Allied Naval Commander Expeditionary Force ARL Admiralty Research Laboratory A/S Anti-submarine 'A'-scan See Display

314 Technical Tenns and Abbreviations 315

Asdic Underwater detection equipment using acoustic waves. An acronym based on Allied Submarine Detection Investi• gational Committee (c.1920). US - Sonar (qv). ASE Admiralty Signal Establishment ASV Air to surface vessel (airborne radar) Azimuth Horizontal angle measured about a nominally vertical axis Back echoes The main beam of a directional aerial is accompanied by some radiation in other, unwanted, directions, known as side lobes or back lobes. Such lobes can give rise to echoes from large targets at short ranges in those directions, which can be wrongly attributed to the direction of the main beam. Such unwanted responses are known as side echoes or back echoes. Beam riding A method of controlling a missile in flight whereby a radar beam held on the target is used by the missile to derive its own guidance signals. Beam-switching A method of obtaining accurate bearing and/ or elevation of a target by rapid switching of the radar beam between two directions, thus producing two echoes. When the echoes are equally matched, the bearing is correct. Blind fire Using radar bearing, range, and if necessary elevation to fire at an unseen target. BPF British Pacific Fleet BPR Bridge plotting room BR Book of Reference - an Admiralty publication with a security classification of Restricted or lower BTH The British Thomson-Houston Co Ltd CA Coast Artillery (army radar) CAFO Confidential Admiralty Fleet Order CAM Catapult Aircraft Merchantman CAP Combat air patrol CB Confidential Book - an Admiralty publication with a security classification above Restricted CD Coast Defence (army radar) CDS Comprehensive display system CH Chain Home (RAF radar) CHL Chain Home Low (RAF radar) C-in-C Commander-in-Chief CO Commanding Officer, or Chain Overseas (RAF radar). Common aerial working The use of a single aerial array for both transmitting and receiving. CPO Chief Petty Officer CRBFD Close range blind fire director CRT Cathode ray tube CVD Ultra short wave Communications Valve Development (committee) CVE Escort aircraft carrier (US) CW Continuous wave DCT Director control tower, on which gunnery radar aerials were mounted, placed high in the ship to get the best possible view of the target, visually and by radar. Its laying and training on the target was followed (via the TS (qv» by 316 Glossary

individual turrets and guns when in 'director firing', the normal method. Often abbreviated to Director. See also HA Director. DE Destroyer escort (US) DF Direction finding J:X;D Director of the Gunnery and AA Warfare Division Dipole Aerial or element of an aerial consisting of two equal collinear rods, of total length equal to about one half the wavelength Director Common term for DCT (director control tower) (qv) Discrimination In radar, the ability to distinguish between (and if necessary range on) two targets close together. Range discrimination is achieved by very short pulse length, bearing discrimination by narrow beamwidth. Also used to define the ability of radio receivers to distinguish between signals of different frequency. Display The method of presenting radar echoes to the observer. The most common naval types were: 'A' Display (formerly A-scan, the term generally used in this book), which shows the target's range (but no bearing) when the radar beam is trained on it. PP] (plan position indicator), which shows simultaneously both range and bearing of targets as bright spots on a CRT with a long afterglow. It thus gives a complete picture of the surroundings as detected by radar. PPI display requires the aerial to be kept spinning or sweeping. Skiatron, a display involving the optical projection of a form of PPI onto a ground glass screen, to facilitate plotting. Echoes appear as dark paints, as opposed to PPI where they are normally bright echoes on a dark background. Sector display, which shows on a type of 'A' Display all echoes within one or more selected small sectors of bearing. Used in height estimation and interrogation positions. Meters: are sometimes used to match echoes produced by beam-switching. HP] (height position indicator) which, for a given bearing, shows elevation, range and height on a display like that of a PP!. DN! Director of Naval Intelligence DNO Director of Naval Ordnance DR Dead reckoning DRE Director of Radio Equipment DSC Distinguished Service Cross DSD Director of the Signal Department/Division DSM Distinguished Service Medal DSR Director of Scientific Research and Experiment DTM Director of Torpedoes and Mining ECM Electronic countermeasures - anti-radio/radar techniques and tactics, particularly the jamming of transmissions. Formerly RCM (qv). Elint Electronic intelligence - the gathering of data by ECM (qv) techniques. Formerly known as Y equipment (qv). Technical Terms and Abbreviations 317

EMI Electric &: Musical Industries Ltd. ESM Electronic support measures - passive measures of gather• ing electronic intelligence FAA Fleet Air Arm FD Fighter direction FIX) Fighter direction officer FDT Fighter direction tender, a specially equipped vessel based on the hull of a landing ship tank (LST) FKC Fuze-keeping clock GA Gunnery Fire Control, Aircraft (RN radar from 1943) Gain Factor by which power is increased GB Gunnery Fire Control, Barrage (RN radar) GC Gunnery Fire Control, Close-range (RN radar) GCI Ground Control of Interception (RAF radar) GDR Gun direction room GEC The General Electric Company Limited (of England) GL Gun Laying (Army anti-aircraft radar) GS Gunnery Fire Control, Surface (RN radar) HA High angle (gunnery) HACP High Angle Control Position. Analogous to the TS (qv). HACS High angle control system HA Director A DCT (qv) when applied to long-range AA systems HE Hydrophone effect (asdic). See p. 146. HF/DF High frequency direction finding HFP Height Filtering Position, where all available radar height• finding information is received, filtered, and passed to where it is required HMSS His Majesty's Signal School, until 1941 housed in the Royal Naval Barracks, Portsmouth. HMSS's Experimental Depart• ment, responsible for radar development, became ASE in 1941. HPI Height position indicator. See Display. IF Intermediate frequency IFF Identification Friend or Foe - an ultra-high-frequency radio interrogator (qv) and transponder (qv) system used in association with warning radars to differentiate between friendly and hostile or unidentified contacts Interrogator A secondary radar which could activate an IFF transponder (qv). See IFF. K-band Electromagnetic wavelengths of about I.Scm (20,000 MHz) Klystron Radio valve for amplifying or generating centimetric microwaves by forming electrons into bunches as they cross a gap. LA Low angle (gunnery) LCG Landing craft, gun LCH Landing craft, headquarters LSF Landing ship, fighter direction. Boxer (ex-LST) was the only one completed. LST Landing Ship, Tank MADP Main air display plot Magnetron Microwave generator employing an external magnetic field MBE Member of the Order of the British Empire MGB Motor gunboat 318 Glossary

Mile Where 'mile' is used in this book as a unit for distance at sea, the nautical or sea mile should be assumed - one minute of latitude, equivalent to 6,080 feet (usually rounded off to 2,000 yards in naval practice, including wartime British naval radar) and 1.8532 kilometres. The English land mile is 1,760 yards. ML Motor launch MPI Mean point of impact (gunnery) MTB Motor torpedo boat NA Naval attache n.m. Nautical mile - See Mile NOD Naval Ordnance Department NRC National Research Council of Canada PO Petty Officer PPI Plan position indicator. See Display. PT boat Patrol torpedo boat (US) Radar An acronym from RAdio Detection And Ranging Radar beacon A type of IFF transponder of which aircraft can obtain the range and bearing for homing purposes. Radar beacons are also used for distress purposes and ashore to assist ships and aircraft. Sometimes called a Racon. Radome Radar dome, protecting the aerial array from wind, weather and spray RAE Royal Aircraft Establishment (RAF) Rate-aiding A mechanical or sometimes electrical means of establishing the rate of change of a target's range, bearing or elevation by following its position as smoothly as possible. The fire• control director or radar aerial was then driven at these rates by remote power control (RPC)/servo-mechanism (qv) which helped the operators follow the target more smoothly, which in turn resulted in more accurate determination of the target rates. RCM Radio countermeasures (which include radar) - earlier name for ECM (qv) RCNVR Royal Canadian Naval Volunteer Reserve RDF Radar. See p. xix RDR Radar Display Room. The compartment of the Action Information Centre where displays from all warning sets, and the Height Filtering Position, were situated. RF Radio frequency rms Root-mean-square - square root of the arithmetic mean of the squares of a set of numbers (statistics) RN Royal Navy RNR Royal Naval Reserve RNVR Royal Naval Volunteer Reserve RNZNVR Royal New Zealand Naval Volunteer Reserve RPC Remote power control. See Servo-mechanism. RRDE Radar Research and Development Establishment (Army) R/T Radio telephony SA Ship-to-Air (RN radar up to 1943). 5-band Electromagnetic wavelengths of about lOcm (3,000 MHz). Technical Terms and Abbreviations 319

Scanning The technical process whereby some radar sets automati• cally search in azimuth or in elevation, or in both simultaneously. Servo-mechanism A closed-cycle control system in which a small input power controls a large output power in a strictly proportionate manner. In this book, it is usually synonymous with remote power control. SGB Steam Gunboat Side echoes See Back echoes. Skiatron See Display. Sonar Underwater detection equipment. Acronym for SOund Navigation And Ranging. The US version of British asdic (qv). Sp. The Special Branch of the RNVR, to which many wartime radar officers belonged, e.g. Lieutenant (Sp.) A.B. lones, RNVR Special Intelligence Intelligence from a particularly sensitive and absolutely reliable source, available as a result of the solution of high• grade codes and cyphers, distributed to specially selected and severely restricted numbers of recipients by means of one-time pad cyphers. Code name: Ultra (qv). SS Ship-to-Ship (RN radar up to 1943) STAAG Stabilized tachymetric anti-aircraft gun Staff Requirements When the development of a new naval system or equipment was proposed, the operational requirements - in terms of range (maximum and minimum), accuracy, tactical deploy• ment, and, for radar, operating frequency - would be prepared by the Naval Staff with help and discussions with Admiralty Departments. These would be formalized as 'Staff Requirements' and sanctioned or rejected by the Admiralty Board. STC Standard Telephones & Cables Ltd Thyratron A gas-filled valve with heated cathode, able to carry very high currents, which operated as a switch TI Target indication TIR Target indication room TIU Target indication unit Transponder A radio or radar device which, on recelvmg a signal, transmits a signal of its own, as with IFF (qv) TRE Telecommunications Research Establishment (RAF) 1'5 Transmitting Station - A compartment between decks which housed the fire-control predictors. They were fed with target information (range, bearing, elevation) from optical instru• ments (sights and rangefinders) and/or radar equipment trained on the target; they calculated the future position of the target; and they transmitted to the gun mountings the predicted ranges, bearings and elevations for the guns to hit the target. In larger ships, the 1'5 was concerned with LA (surface) fire control only, the HA equivalent being the HACP (qv). 320 Glossary

TSR Torpedo spotter reconnaissance (aircraft) VDU Universal display unit UHF illtra high frequency, 300 to 3,000 MHz illtra Code name and message prefix for Special Intelligence (qv), and for messages containing Special Intelligence USN United States Navy VHF Very high frequency, 30 to 300 MHz VIS Visual signalling VT fuze Variable time fuze - a proximity fuze which uses radar principles to initiate the detonation of a shell or bomb at a supposedly lethal distance from an air target or at a set height above a surface target. WA Warning of Aircraft (RN radar from 1943) WC Warning, Combined aircraft and surface (RN radar) Window Metal-foil strips dropped in quantity from aircraft which gave echoes on the enemy radar simulating our own forces. Working up A period spent in exercises working up the efficiency of the ship's company of ships newly commissioned after building or refit WRNS Women's Royal Naval Service WS Warning of Surface craft (RN radar) WIT Wireless telegraphy WW1 World War 1, 1914-18 WW2 World War 2,1939-45 X-band Electromagnetic wavelengths of about 3cm (10,000 MHz). Yequipment Receiving and DF equipment employed for obtaining and analysing radio intelligence. Later known as Elint (qv). Y service The interception of enemy signals, including DF References

For published works, full titles and sources are given only when they are not listed in the Bibliography. References prefixed ADM, AIR, A VIA, PREM, etc., refer to documents at the Public Record Office, unless otherwise indicated. The following abbreviations will be used:

ADR Air Defence Research (Committee) AFO Admiralty Fleet Order AL Admiralty letter ARE Admiralty Research Establishment ASE Admiralty Signal Establishment CAFO Confidential Admiralty Fleet Order CAC Churchill Archive Centre, Churchill College, Cambridge, where the documents generated by the Naval Radar Trust project will be deposited C-in-C Commander-in-Chief CSS Captain, HM Signal School CSSAD Committee for the Scientific Study of Air Defence DSD Director, Signal Division, Admiralty FO Foreign Office HF Home Fleet HMSO HM Stationery Office IWM Imperial War Museum, London Med Mediterranean [Fleet] NHB Naval Historical Branch NMM National Maritime Museum, Greenwich NRT Naval Radar Trust PRO Public Record Office, London RSRE Royal Signals and Radar Establishment, Great Malvern

1 Setting the Scene (pages 1-10)

1. Printed in ASE Christmas card, 1943. 2. ADM 220/70. DSD to CSS, 13 Aug 1935. 3. For early radar in Britain, USA, Germany, France, Netherlands, USSR, Japan, and Italy, see Burns, Radar Development, and Swords, Technical History. 4. CAB 102/640, 641 & 642 are Parts I, 11 and m of typescript History of the Development and Production of Radio and Radar, hereafter cited as History. This particular source is in History, I, paras. 149-50. Two abridged versions of this - one official version with annotations (CAB 102/10), one on sale to the public without annotations - were published by HMSO in 1964 in the History of the Second World War series as Postan, Hay and ScoU, Design and Development of Weapons.

321 322 References

5. CAC, NRT. Wright to Rawlinson, 20 July 1975. On the Alder proposals, see Burns and Coales & Rawlinson in Burns, Radar Development, 18-20 and 55. 6. On the Butement and Pollard proposals, see Burns in Burns, Radar Development, 20-2. 7. Rowe, One Story,S. 8. CAC NRT. Freeman papers, Air Ministry minute 12 Nov 1934. 9. Ibid .. 15 November 1934. 10. AIR 20/80. Reprinted in Swords, Technical History, 278-81. 11. Ibid., 281-5. 12. Montgomery Hyde, British Air Policy, 330. 13. History I, para. 24, n(2). For the early history of radio in the Royal Navy, see Hezlet, The electron and sea pawer. 14. Montgomery Hyde, British Air Policy, 322-3. 15. CAB 16/132, f.14: ADR minutes, 27 May 1935. Roskill, Hankey, il, 144ff. 16. ADM 220/70. Shearing's notes on 'Meeting at the Air Ministry, Whitehall S.W.1, 18 March, 1935.' The official minutes are in AIR 20/181. 17. Ibid., Shearing's minute of 21 March 1935. 18. The minutes of the Tizard Committee are preserved in AIR 20/181, with the supporting papers in AIR 20/80 and 20/81. The minutes of the Swinton Committee are in CAB 16/132, with supporting papers in CAB 16/133 and 16/134. A more detailed and reasonably unbiased account of the Tizard and Swinton Committees will be found inter alia in Montgomery Hyde, British Air Policy, 322-33, which draws on published personal accounts by Churchill, Rowe and Watson-Watt, and on Clark's Tizard. 19. History 11, para.134, n(3). 20. ADM 220/70. Signal School meeting, 1 act 1936, Enclosure C. 21. Watson-Watt, Three Steps, 123. 22. History 11, para.170, n(3). For more detail on valve production and research, see Callick, Metres to Micrawaves. 23. CAC, Wilkins papers. AWLK 1,27. 24. CAC, NRT ND 64. J.F. Coales, 'Naval RDF (radar), the formative years'. 25. ADM 220/70. Wimperis to Wright, 10 July 1935. 26. Ibid., DSD to CSS, 12 July 1935. 27. Ibid., CSS to DSD, 27 July 1935. 28. Ibid., DSD to CSS, 13 Aug 1935. 29. Ibid., Signal School meeting 1 Oct 1936, Encl. B & c. 2 1935-9: The Beginnings of the Navy's Radar (pages 11-29)

1. History 11, paras.165, n.6. Yeo's notes can no longer be found. 2. CAC, Wilkins papers, A WLK 1,27. 3. ADM 220/70. Signal Dept meeting, 11 Oct 1935. 4. Ibid., Signal School meeting, 1 Oct 1936, Enclosure C. 5. Ibid., CSS to DSD, 28 Nov 1935. 6. CAB 16/132, f.31. ADR minutes, 9 Dec 1935. 7. Ratsey, 141. About 1972, O.L.Ratsey (one of the earliest Signal School scientists to be concerned with radar) compiled a history of the Signal School's Experimental Department and ASE, entitled As We Were. Never published, a copy at ARE Portsdown has been consulted and is hereafter cited as 'Ratsey'. 8. ADM 220/70. Signal School meeting 11 Oct 1935, Encl.B. 9. CAC NRT ND 64. Coales, 'Naval RDF ... '.2215 10. ADM 220/70. Signal School meeting, 1 Oct 1936, with enclosures. References 323

11. Ibid. 12. Ibid., CSS to DSD, 24 Dec 1936. 13. Ibid., 16 Feb 1937. 14. For the Normandie radar, see R. B. Molyneux-Berry in Burns, Radar Development, 46-8. 15. ADM 220/70. CSS to DSD, 16 Feb 1937. 16. ADM 220/70. Cecil minute, 27 July 1937, and Ratsey 141. 17. CAB 16/132, f.63. ADR minutes,S July 1937. 18. Bowen, Radar Days, 42-5, gives an eye-witness description of events. AIR 7/ 101 contains photographs of the radar scan during these trials. 19. ADM 220/70. CSS to DSD, 24 Aug 1937. 20. Ibid., Makeig-Jones to Wylie, 31 Aug 1937. 21. Ibid., CSS to DSD, 16 Sept 1937. 22. Ibid., DSD and DSR, No.5RE.1476/37 of 28 Oct 1937. 23. Coales, 'Naval RDF ... '. 24. Ibid. 25. Ibid. 26. CAB 16/132, f.80, 15 May 1938. 27. ADM 220/70. Brundrett to WiIIett, 23 Oct 1937. 28. CAC NRT ND85. Coales, 'Preparing for War'. 29. Callick, Metres to Microwaves, 2-7. 30. ADM 220/70. Horton minute, May 1938. 31. Ibid., 'Detection of Aircraft and Ships by Radio Methods', enclosure to CSS to DSD, 22 Feb 1938. 32. Ibid., 2pp undated draft minutes of meeting, giving names of those attending; and DSD minute dated 31 May 1938 from docket SD.0345/38. 33. Ibid., DSD minute 'RDF development', 31 May 1938. 34. Ibid., CSS to Cdr Bowen of DSD, 25 Apr 1938. 35. Quoted in Rawlinson, J.D.S, lEE Proceedings, 132, A (Oct 1985),442. No copy of this important document (AL M/PD.06766/38 of 17 May 1938) has yet been found, but copies were almost certainly sent to other Commanders-in-Chief. 36. ADM 220/70, DSD paper 'RDF development', 31 May 1938, p.3. 37. CAB 16/132. ADR minutes, f.93, 14 Nov 1938. 38. ADM 220/70: AL SD.0345/38 of 16 Aug 1938 to C-in-C Portsmouth. 39. ADM 220/70, Head of CEI minute, 9 June 1938. 40. Rawlinson Proc.lEE, 132. 41. ADM 1/15193, CSS, 'RDF in HM Ships: a brief outline of progress', 26 July 1941. 42. ADM 116/3873. Combined Fleet Exercises 1939, serials II and XI. 43. ADM 220/70. CSS paper, 'Memorandum on expanded effort on RDF', 26 July 1939. 44. Ibid., Naval RDF Panel minutes, 27 July 1939. 45. Ibid., AL SD.0684/39 of 10 Aug 1939 to C-in-C Portsmouth. 46. CAC, NRT. Stainer to Howse, 9 March 1987. 3 1939-40: The Phoney War - But Not at Sea (pages 30-51)

1. CAC, NRT. Capt W. H. Watts to Howse, 23 Aug 1988. 2. ADM 220/71. Rodney to C-in-C HF, 2 Nov 1939. 3. For fleet bases, see Roskill, War at sea, i, 76-82. 4. ADM 277/1. Admiralty typescript, Miscellaneous Weapon Development Departmellt, Admiralty, 1940-45 (nd), p.5. 5. Watson-Watt, Three Steps, 304. 324 References

6. For an account of AMRE and TRE, see History, Il, paras.95-121; for RRDE and ADRDE, see paras.176-205. 7. AIR 2/2942, minute 62a, note by Watson-Watt, 13 Sep 1939. 8. Ibid. minute 62b, note by Brundrett, 13 Sep 1939. 9. The Air Ministry side of the story is given in detail in AM File S.45641 in AIR 2/2942, and summarized in History, Il, paras.92-4. The corresponding Admiralty files in ADM 1/10662 are very much thinner. 10. Roskill, Hankey, Hi, 481ff. 11. CAC, SMVL 1/30. Somerville's pocket diary for 1939. 12. ADM 205/2. Churchill to Pound et al., 22 Sep 1939. 13. AIR 2/2942, min.69b. Kingsley Wood to Churchill, 21 Sep 1939. 14. AIR 2/2942. Churchill to Kingsley Wood, 23 Sep 1939. 15. Cockcroft, J. D., 'Memories of radar research', Proceedings lEE, 132, A (Oct 1985),327. 16. Somerville, 16 Sep 1939. 17. CAC, NRT, ND 86, J. F. Coales, 'The outbreak of war'. 18. CAC, NRT. Wright to Howse, 12 Feb 1989. 19. Ibid. 20. AVIA 46/36, No.l1a. Note of Mr Jay's interview with Mr A.S.C.Phillips at ASE, 30 Oct 1946, f.4. 21. ADM 1/15193. 'RDF in HM Ships', 8. 22. ADM 220/71. Bawdsey's 24 May 1939 gives the full list of RDF code letters. 23. ADM 205/2. Somerville to Controller, 'Progress of RDF installation in HM Ships', 25 Sep 1939. 24. ADM 1/15193. CSS 'RDF in HM Ships', 5-6. 25. ADM 220/72. Minutes of RDF Policy Meeting, 15 Feb 1940. 26. ADM 220/74. Somerville to DNO and DNC, 'RDF Type SS (Type 281) - trials and first fitting' (SD.0143/40), 15 Feb 1940. 27. CAC, NRT. Rawlinson lecture text, 'The history of naval radar, 1935-1944', 12. 28. ADM 1/15193. CSS, 'RDF in HM Ships, 8. 29. CAC, NRT. Cdr F.C.Morgan, 1/87, vi-vii. 30. Roskill, letter to Editor, 'Radar for detecting surface ships', Naval Review, 67 (1979), 149. 31. Except where otherwise cited, most of the information in this section came from ADM 1/15193. CSS, 6-8, or from Coales op.cit ref.17. 32. Trenkle, Die deutschetl Fu Ilkmeflverfah reil, 116-7. I am grateful to Professor R. V. Jones for drawing my attention to this reference and to Herr Trenkle for his subsequent help. 33. Millington Drake, The Drama of the Graf Spec, 183. 34. ADM 1/9759. Naval Attache, Buenos Aires, War Despatch No.4, 21 December 1939, Report by British prisoners from Grat Spee. 35. ADM 223/69. Decypher from Millington-Drake, 14 January 1940. 36. ADM 116/4472 provides most of the information in this account. We know that Bainbridge-Bell wrote at least five reports at the time (ADM 116/4472, NA Buenos Aires War Despatch No. 9, 15 Mar 1940 & DNI minute 13 Apr 1940), but a diligent search has failed to find any of them, presumably for security reasons. However a copy of his 'Report on visit to Montevideo to inspect the radio installation on the Control Tower in the "Admiral Graf Spee". January 1940', written two years after the event on 25 Jan 1942, giving the main technical details but none of the cloak-and-dagger aspects, is preserved in CAC NRT. IWM Misc.490 is a secondary account by Commander V. F. Smyth, an acquaintance of Bainbridge Bell's entitled 'Mr References 325

Labouchere Bainbridge-Bell's Trip to Inspect the Graf Spee', dated 29 Apr 1988. 37. CAC, NRT. (50(1) Montevideo to Admiralty for DN! 2235/7/2/40. 38. Ibid., P. C Redgment to Howse, 4 Mar 1989. 39. ADM 116/472. Millington-Drake to FO No.84, 14 March 1940. 40. ADM 116/5475. Treasury to Admiralty, 9 October 1941. 41. Ibid., DSD minute, 14 December 1941. 42. Trenkle, Funkmeflverfahren 43. For the organization of British scientific intelligence, see Hinsley, British Intelligence, and Jones, Most Secret War, 618. 44. CAC, NRT. Searie, MS Recollections, 12 Aug 1987. 45. Ibid., Sir John Hodge, MS recollections, Feb 1989.

4 1940: Norway and the Fall of France (pages 52-71)

1. CAC, NRT. F. E. Butcher to Howse, 23 July 1987. 2. Sir John Hodge, personal communication. 3. Cdr F. C Morgan, personal communication. 4. ADM 116/3873. Combined Fleet Exercises, Serial 11, 1 Mar 1939. 5. Hezlet, Electron, 193. 6. CAC, NRT. Macdonald journal extracts, transcribed 16 Mar 1988. 7. HMS Dryad MSS, Coke to Schofield, 17 Aug 1973; private communications, Coke to Woolrych, 1987-9. 8. Ibid. 9. Bowen, Radar Days, 90. 10. CAC, NRT. Falloon, Fenwick, Ross, Shayler. 11. ADM 1/15193. CSS, 'RDF in HM ships - a brief outline of progress', 26 July 1941, 10. 12. Capt D. B. N. Mellis, personal communication. 13. ADM 220/86. CSS, trial results, 12 June 1940. 14. ADM 220/86. DSD to CSS, 18 July 1940. 15. ADM 220/77. DTSD memo 21 Sep 1940. 16. CAC, NRT. Admiral Sir Rae McKaig's recollections, 30 July 1987. 17. Ibid., Cdr F.C Morgan No.1/87, xix-xx. 18. Hezlet, Elcctron, 194-5. 19. ADM 220/76. Illustrious to CSS, 27 July 1940. 20. Private communications, Coke, Pollock, Goodwin, Going, Sutton, Vincent- Jones to Woolrych, 1988-9. 21. Admiralty. BR 1736 (53) (1), Naval Aviation, I, 126 (ADM 234/383). 22. Ibid., 132. 23. As note 20. 24. D. L. Plollockl, 'Aircraft Direction during the War', ND Bulletin 4 (June 1948), 10. 25. ADM 220/74. CSS to 050, 'Trials of type 281 in HMS DrOO', 5 Nov 1940. 26. AOM 226/76. ASE to ONO, 24 Mar 1943. 27. Coales, Calpine & Watson, 'Naval Fire-control Radar', Journal of the Institution of Elcctrical Enginccrs, 93 Part IIIA, No.2 (March-May 1946), 354. 28. Ibid. 29. Bowen, Radar Days, 143. 30. Coales's notebooks show that he visited Swanage between the end of August and the end of October, and J. R. Atkinson remembers that his visit was the first from Signal School. 31. CAC, NRT. Lovell to Hawse, 9 Nov 1988. 326 References

32. Lovell, Echoes of War, 51. 33. RSRE MSS TRE 4/4/457. H. W. B. Skinner, 'Preliminary report on tests on ships using 10cm waves - November, December 1940', 20 Dec 1940. This paper is reproduced in full in Appendix A. 34. Much of this section has been drafted by C. A. Cochrane, a member of the Signal School team that went to Swanage in 1940. I am grateful also for the help of Sir Bernard Lovell and Sir Alan Hodgkin. 35. ADM 1/15193. CSS, RDF in HM ships', p. 13. 36. On the Tizard Mission, see Clark, Tizard, Chapter XI; Bowen, Radar Days, 150- 95; Roskill, Hankey, ii, 475; and Roskill, Churchill and the Admirals, 109. 5 1941(1): Matapan and the Sinking of the Bismarck (pages 72-98)

1. Admiralty, BR 1736(48)(2), Home Waters and Atlantic, 276--8. 2. ADM 220/76. Valiant to RA 1st BS, 'Low angle trials of RDF short-range gunnery attachment', 10 Feb 1941. 3. Admiralty, Home Waters, 278-9. 4. ADM 220/86. May 1941. 5. Admiralty BR 1736(11), Selected Mediterranean Convoys, 1941-42, 11. 6. Pack, Matapan, 120. 7. ADM 1/11377, Battle of Cape Matapan, awards and decorations. 8. Ibid. 9. Quoted in Pack, Matapan, 77. 10. ADM 220/76. DSD to ASE, 6 Aug 1941. 11. Ibid. 12. Hezlet, Electron, 209. 13. Roskill, War at Sea, i, Map 36; and iii-2, Appendix T. 14. Churchill, Second World War, v, 6. 15. Ibid., ill. 106. 16. Roskill, War at Sea, i, 609. 17. ARE Archive Y. Admiralty CB 04110(41)/5, Monthly report of progress in HM Signal School, May 1941. 18. ADM 220/79. AL SOO.2053/41, 1 Oct 1941. 19. ADM 1/11065. Walker & Vanoc's reports of proceedings under Captain (D) Liverpool's 22 March 1941. 20. Roskill, War at Sea, i, 476-7; Poolman, Allied Escort Carriers, 12; Brown, Carrier Operations, 42. 21. CAC, NRT. NRF1, 'XG2 Section of Admiralty Signals Establishment, November 1940 to November 1944', compiled by N. E. Davis. 22. History, para.353, written in 1946, cited the minutes of this important meeting as being in ASE File F1.271 (I). In 1972-3, Ratsey reported them missing. Today, that file (now PRO ADM 220/78) starts in the middle of a paper of March 1941 and it is obvious that earlier papers have at some stage been removed. 23 ADM 220/78. DSD minute, 4 Jan 1941. 24. CAC NRT. Landale to Guy Hartcup, 23 March 1966. I am extremely grateful to Mr Hartcup for showing me this letter, written in connection with his book The Challenge of War. 25. ADM 220/78. CSS to DSD (personal), 29 March 1941. 26. CAC NRT. Orton to Hawse, 7 Nov 1988. 27. Ibid., Raynsford to Hawse, 9 March 1989. 28. ADM 1/11063. Landale & Hogben trial report, 5 May 1941. 29. ADM 220/78. Orchis to Captain (D) Greenock, 3 June 1941. References 327

30. CAC NRT. Rawlinson text for lecture, 'The history of naval radar, 1935-1944'. 31. ADM 220/78. CinC Nore to Admiralty, 3 June & 21 Sept 1941. 32. Coales, 'The Outbreak of War.' 33. ADM 220/86. Drury to CSS, 17 May 1941. 34. Paddon, S. E., 'HMS Prince of Wales - radar officer', Salty Dips, i (NOAC, Ottawa, 1983). 35. ADM 220/76. H. J. W. Reeves manuscript report, 30 Apr 1941. 36. ADM 220/74. Horton, staff minute, 13 Feb 1941. 37. Ibid., Lockwood to Alexander, 5 April 1941. 38. Ibid., DSD to Controller, 8 Apr 1941. 39. CAC, ELLS 4/2. Suffolk to RA 1st CS, 11 June 1941, End.1. 40. CAC ELLS 3. R. M. Ellis unpublished autobiography, When the rain's before the wind, pp. 19.8 to 19.9. 41. Von Miillenheim-Rechberg, Battleship Bismarck, 1982 edition, 99-101. 42. Ellis, CAC ELLS 4/2. 43. Von Miillenheim-Rechberg, Battleship Bismarck, 101-2. 44. Ellis, CAC, ELLS 4/2. 45. Sieche, Erwin, 'German Naval Radar to 1945, Part 2', Warship 22 (1978), 146-8. 46. Von Miillenheim-Rechberg, Battleship Bismarck, 149. 47. Roskill, War at Sea, i, 404. 48. Paddon, HMS Prince of Wales,' 66. 49. NMM MS 88/100. R. Adm. A. D. Torlesse, 'History of a naval observer', Section 6(1), 4-5. 50. Von Miillenheim-Rechberg Battleship Bismark, 148. 51. Roskill, War at Sea, 409-18. 52. ADM 220/86. Wake-Walker to Warner personal, 12 June 1941. 53. ADM 1/11260. C-in-C HF's report, p. 17. 54. Ellis CAC ELLS 4/2 p. 15.7. 55. HMS Dryad MSS, Capt. D. G. Goodwin, 11 Apr 1983.

6 1941(2): The Battle of the Atlantic and Pearl Harbor (pages 99-127)

1. Admiralty, CAFO 186/41,23 Jan 1941. 2. Admiralty, CAFO 1180/41, June 1941. 3. ADM 1/15193. CSS, 'RDF in HM Ships - a brief outline of progress', 26 July 1941, 14. 4. ADM 220/77. Minutes of meeting 22 May 1941. 5. ADM 220/81. Minutes of meeting 19 June 1941. 6. ADM 220/79. Gunnery/RDF staff requirements, 23 April 1943. 7. ADM 220/70. Minutes of Admiralty meeting, 11 Oct 1935. 8. Admiralty CB 04110/42(2), ASE Monthly Report, February 1942. 9. Lovell & Hurst, 'William Bennett Lewis', Biographical Memoirs of Fellows of the Royal Society, 34 (1988), 470-1. 10. ADM 220/76. Minute by H.M. Cecil ('83'), 27 Mar 1941. 11. D. L. P[ollock], 'Aircraft direction during the war', ND Bulletin, 4 (June 1948), 13. 12. CAC, NRT. J. W. Sutherland reminiscences, 10 Aug 1987. 13. Admiralty, CB 04110/42(8), ASE monthly report, August 1942. 14. ADM 220/79. AL SOO.2053/41 of 1 act 1941. 15. Admiralty, CB 3090, Instructions for installation . .. (1943). 16. ADM 220/78. Chief Supt. ADRDE, report on Type 271 X, no date but forwarded by CSS to DSD 15 Aug. 1941. 17. Ibid., Yates minute, 17 Oct 1941. 328 References

18. ADM 220/80. C-in-C HF to Admiralty, 23 Sept 1941. 19. Admiralty, Selected Mediterranean Convoys, 19. 20. Paddon, 'HMS Prince of Wales', 68. 21. ADM 220/80. C-in-C HF to Admiralty, 2 Nov 1941. 22. AFO 3368/40 of 5 Sept 1940. 23. Burton (ed.), Canadian Naval Radar Officers, 48. 24. ADM 220/78. Creasey to Willett, personal, 11 Sept 1941. 25. Beesly, Very special intelligence, 156. A good account of how Ultra affected naval operations is given in Winton, Wtra at Sea. See also Hinsley, British Intelligence in the Second World War. 26. ADM 220/78 Creasey to Willet. 27. Ibid. 28. Admiralty, CB 04050 series, Monthly Anti-submarine Reports. 29. CAC, NRT. Knight to Howse, 18 April 1989. 30. Dickens, Capt P., Warship profile 20,6,183-6. 31. ADM 1/12305. HMS Marigold - sinking of U.433. 32. Admiralty Monthly Anti-Submarine Reports. 33. Trenkle, Funkmepverfahren, 130. 34. ADM 220/74. Various Naval Staff minutes in Docket NAD.998/41, Sept to Nov 1941. 35. For the wartime evolution of the Fighter Direction Branch, see Schofield, HMS Dryad, 93-108. 36. Roskill, War at Sea, i, 478-9; Poolman, Allied escort Carriers, 14-18. 37. Roskill, War at Sea, i, 479. 38. Paddon, 'HMS Prince of Wales', 72. 39. Ibid., 73. 40. ADM 1/12181. Prince of Wales and Repulse - reports from survivors, December 1941. 41. CAC, NRT. Armstrong to Howse, 3 Jan 1988. 42. Ibid., Fanning to Howse, 18 Jan 1988. 43. Ibid., Macdonald to Howse, 7 Feb 1988 & 6 Apr 1990. 44. Ibid., Butler to Howse, 9 July 1987. 7 1942: Malta Convoys and the Invasion of North Africa (pages 128-61)

1. Admiralty, BR 1736(7)(48), Passage of the Scharnhorst, Gneisenau and Prinz Eugen. 2. War Office (Sayer), Army Radar, 130, 147. 3. CAC, NRT. Fanning to Howse, 11 June 1989. 4. CAC, Willett papers. Memo, 22 April 1943, p. 2. 5. CAFO 861/43 of 29 April 1943. 6. Admiralty, CB 4497, Simple Guide, 23-25. 7. CAC, NRT. Morgan to Howse, 7 Sept 1989. 8. ADM 220/204. RDF Bulletin No.1, report 11. 9. CAC, NRT. Laws to Howse, 27 July 1989. 10. ADM 220/204. RDF Bulletin No. 1, report II. 11. Ibid. 12. Admiralty, CAFO 328/42, 19 Feb 1942, all ships except submarines, operational MTBs at home priority. 13. Bowen, Radar Days, 181. 14. Hezlet, Electron, 232. 15. Lovell, Echoes of War, 162. References 329

16. I am grateful to Rear-Admiral P. W. Burnett for this description of HF/DF tactics. 17. Admiralty, ASE Monthly Report, January 1942. 18. Hezlet, Electron, 230. 19. For wartime HP/DF generally, see P.G. Redgment, 'HP/DF in the Royal Navy', Journal of Naval Science, 8 (1982),32-43, 93-103. 20. ADM 220/204. RDF Bulletin No.1, report 3. 21. CAC, Willett papers. Creasey to Willett, 8 July 1942. 22. CAC, NRT. Yates memoirs for 1943. 23. Ibid., 1942. 24. C. A. Cochrane, private communication. 25. Ibid. 26. Pollock, 'Aircraft direction'. 27. Quoted in Pack, Sirte, 81-3. 28. Ibid., 134. 29. Admiralty BR 1736(11), Selected Mediterranean Convoys, 76. 30. AVIA 46/37, no.6. Interview with Young, 4 July 1945. 31. ADM 220/78. Marigold sea trials report, 22 May 1942. 32. ADM 220/80. ASE trials report, Landale and Yates, 18 July 1942. 33. Ibid., C-in-C HP to Admiralty, 5 Aug 1942. 34. Ibid., minute ASE to DSD, 16 July 1942. 35. CAC, Willett papers. Memo, 22 Apr 1943. 36. CAFO 67/43,14 Jan 1943. 37. ADM 220/204. RDF Bulletin No.2, report No.2. 38. Paddon, 'HMS Prince of Wales', 75-6. 39. CAC, NRT. Hordern to Howse, 29 June 1989. Hamlet, Ill, iv. 40. NOAC, Ottawa, Salty Dips, i, 77. 8 Sicily, Salerno and the Sinking of the Scharnhorst (pages 162-90)

1. CAFO 2925/43,1 July 1943. 2. CAFO 477/43, 11 March 1943. 3. ADM 220/79. Minutes of Admiralty meeting 'RDF priorities', 17 November 1942. 4. Ibid., ASE meeting 17 Dec 1942. 5. ADM 220/74. Minutes of Admiralty meeting, 8 Sept 1943. 6. Pollock, 'Aircraft Direction', 13. 7. ADM 220/204. Radar Bulletin No.5, Report No.3, August 1943. 8. Admiralty, BR 2435, Technical Staff Monograph 1939-45: Radar, 21. 9. ADM 220/204. Radar Bulletin No.5, Report No.2. 10. Pollock, 'Aircraft Direction', 14. 11. ADM 220/204 op.cit. Report No.1, July-Sept, 1943. 12. Ibid. Report No.3, August 1943. 13. Roskill, The War at Sea, iii(1), 30. 14. ADM 220/78. DSD minute SD.05577 /42 of 14 Det 1942, as amended 3 Nov. 15. Ibid. 16. ADM 220/204. Radar Bulletin No.2, Report No.9, Mar 1943. 17. CAFO 1590/43,29 July 1943. 18. ADM 220/80 ASE Trials report, 18 July 1942. 19. ADM 220/81. Minutes of Haslemere meeting 'Requirements for future main armament RDF', 19 June 1941. 20. Ibid. Minutes of RDF/Gunnery staff requirements meeting VI, 16 October 1941. 330 References

21. Ibid. 22. ADM 220/228. Aust. & NZ Scientific Research Liaison, London, Report No.474, Sept 1943. 23. The document laying down the Staff Requirements has not been found. The figures quoted here for zone limits are from Admiralty, Radar Manual, and height accuracy from CAC NRT, Yates, Sydney Lecture No.1, para.41., 1945. 24. ADM 220/250. ASE paper 'Microwave fighter direction equipment', 13 March 1944. 25. Admiralty, ASE Monthly Reports, June to Dec 1943. 26. Winton, Death of the Scharnhorst, 80; Sieche, Erwin, 'German Naval Radar to 1945, Part I', Warship 22 (1978), 8-10. There is, however, some doubt as to what radar was fitted at the time of Scharnhorst's last sortie. 27. CAC NRT. Typescript, Radar for the non-technical officer, 115-6. 28. Ibid., 109. 29. In this account, I have used many sources including Admiralty, Sinking of the Scharnhorst, Roskill, War at Sea, ill(1), and Winton, Death of the Scharnhorst. But above all, I wish to thank Captain H. R. K. Bates, DSC, RN, for his help in criticizing and revising the draft. 30. CAC NRT. Bates to Howse, 17 June 1990. 31. ADM 1/16676. Sinking of the Scharnhorst - honours and awards. 32. Ibid. 33. Winton, Death of the Scharnhorst. 34. Quoted in Admiralty, Sinking of the Scharnhorst. 35. ADM 220/204. Radar Bulletin No.6, Report No.1, December 1943. 36. Ibid., Bulletin No.5, Report No.2, July 1943. 37. Ibid., Report No.l, July/September 1943. 9 1944: Normandy, Before and After (pages 191-231)

1. Roskill, War at sea, ill part I, 308. 2. ADM 220/85. SO EG37 report, 26 Apr 1944. 3. Ibid., FO Levant & E. Med. to Admiralty, 31 Mar 1944. 4. Ibid., CRT to DTSD & DRE, 11 Sept 1944. 5. Ibid., Port Radar Officer Belfast to ASE, 14 Feb 1944. 6. Ibid., Cdre (D) HF to ASE, 23 Nov 1944. 7. HMS Dryad MSS. DRE to ASE, 13 July 1945, 'Reports by Commander Pollock', 18. B. AFO 320B/45, 14 June 1945. 9. ADM 220/250. ASE paper 'Microwave fighter direction equipment', 13 March 1944. 10. Admiralty, AFO 1174/44, 9 Mar 1944. 11. Admiralty, BR 2435 - Technical Staff History Monograph, Radar, 39, 42. 12. Quoted in Roskill, War at Sea, ill, part 2, 13. 13. Ibid. 14. Roskill, War at Sea, chapters XIV and XV, 1-73. 15. CAC NRT. A. W. Ross - Reminiscences, Jan-Aug 1944 (March 1988). 16. Jones, Most Secret War, 405ff; Twinn, 'The use of Window (ChafO to simulate the approach of a convoy of ships towards a coastline', in Burns, Radar Development, 416ff. 17. Jones, Most Secret War,400ff. lB. Except where otherwise cited, the radar details in this section are based on Admiralty CB 004385 A, B & C (ADM 239/367, 368, 369), Report by ANCXF on operation 'Neptune' - from the signal and radar sections of the reports by References 331

ANCXF (Ramsay), Commander Eastern Task Force (Vian), or the Naval Commanders of the British Forces'S', 'G', and']' (Talbot, Douglas-Pennant, and Oliver). 19. Admiralty CB 004385A (ADM 239/367), Report by ANCXF, Appendix 10, para.104-120, pp. 115-7, gives further detail of RCM achievement. 20. CAC NRT. P. G. Redgment to Howse, 16 Feb 1990. 21. H. St. A. Malleson, 'The Decca Navigator system on D-day, 6 June 1944. An acid test', Journal of Naval Science, 7, 4, (1981), 240-6. C. Powell, 'Early history of the Decca Navigator system', Journal of the Institute of Electrical and Radio Engineers, 55, 6 (June 1985),203-9. 22. E. M. B. Hoare, personal communication. 23. R. F. Hansford, 'The development of shipborne navigational radar', Journal of the Institute of Navigation, 1, 2 (April 1948), 121. On PPI prediction, see ADM 1/16013, ASE monographs M.666 and M.675. 24. ADM 1/16095. Minute by Staff FDO, Eastern Task Force, 14 June 1944. 25. Admiralty, CB 004385B (ADM 239/368), p.42, Enclosure No.9 to Report of Naval Commander Force ,]" para.14(b). 26. ADM 220/250. Aircraft Direction Bulletin No.3, Nov 1944, 10-12. 27. Hansford, 'Shipborne navigational radar', 123-4. 28. On the VT fuze, see Baldwin, The Deadly Fuze. 29. Knowles Middleton, Radar development in Canada, 63-5. 30. Admiralty BR 1736(42)(1), 'Neptune', 8. 31. Roskill War at Sea, iii part 2, 114. 32. ADM 220/250 Aircraft Direction Bulletin No. 3 (November 1944),5-6. 33. ADM 199/1094. Bel/alia to RA 1st CS, 17 November 1944. ADM 199/1094 contains the operation orders and reports of proceedings of operation 'Counterblast' . 34. Ibid. 35. CAC NRT. Lewin to Howse, 21 June 1989. 36. IWM MSS 86/11 /1.

10 1945: The End of the War (pages 232-52)

1. ADM 199/337. Minute by DGAAWD, 9 March 1945. 2. Ibid. RA 1st CS to C-in-C HF, 26 Jan 1945. 3. Ibid. Capt (D) 17th DF to RA 1st CS, 17 Jan 1945. 4. Ibid. Norfolk's gunnery report. 5. Ibid. Apollo to RA 1st CS, 12 Jan 1945. 6. Knowles Middleton, Radar development in Canada, 54. 7. ADM 220/216. 'Radar type 972'. 8. Hansford, 'Shipborne navigational radar', 124-6. 9. Daily Sketch, 15 Aug 1945, 5. 10. Yates, personal communication. 11. CAC, NRT. Yates, transcript of radar lecture no.l given at Sydney on 11 July 1945, paras.9-12. 12. Ibid., para.33. 13. ADM 1/13247 - FD ships - draft staff requirements. 14. ADM 1/16373 - FD ships in assault operations. 15. ASE Monograph M.761 - Project Knobbly - Report of fitting out, operation, and sea trials in HMS Boxer (Jan 1946). 16. ASE Bulletin, Sept 1945 (RH.600(7», 25. 17. Winton, Forgotten Fleet, 219-31, and Winton, Haguro. 18. ADM 199/116. Ca pt D.26 to VA 3rd BS, 18 May 1945. 332 References

19. ADM 116/5173. 20. HMS Dryad MSS. 'Reports by Commander Pollock', para.6(a). 21. Vian, Action This Day, 191. 11 Wartime Projects Postwar (pages 253-64)

1. For a good description of the development of British naval radar in the immediate postwar years, see Mitchell, Alastair, 'The Development of Radar in the Royal Navy 1945-60', Warship, 17 (January 1981), 45-58. See also Friedman, Naval Radar. 2. Hansford, 'Shipborne navigational radar', 125-33. 3. ADM 220/21, 'ASE turn-over statement gunnery radar Cdr. A.F.P. Lewis to Lt.Cdr. F. C. Morgan, June 1946'. This file, together with ADM 220/222, 'Turn-over statement Cdr. F.c. Morgan to Cdr. T. W. Best, January 1949', gives an excellent summary of the development of gunnery radar between 1945 and 1949. 4. Part V Staff Requirements for LRS 1; detailed requirements for radar, dated 22 Feb 1945. This was issued by DGD under a cover note which expressed concern that the requirements might lead to excessive weight and complex• ity, but saying that this should be resisted. 5. AL GOO 2248/45 of 27 Aug 1945. 6. Mitchell 'Radar in the Royal Navy 1945-60', 47. 7. Admiralty, CB 4497, Simple Guide to Naval Radar, 8. 8. Ibid., 10; and ASE Monograph M.758 - C. A. Cochrane, A description of types 960P, 980, and 981 and the radar display in the Action Information Centre, January 1946 (not in PRO). 9. For general descriptions, see Mitchell, 'Radar in the Royal Navy 1945-60', 51, and Friedman, Naval Radar, 200. For more detailed information, see R. Benjamin, 'The post-war generation of tactical control systems', Journal of Naval Science, 15,4 (1978),263-76.

Appendix C Height Determination by Radar (pages 282-92)

1. CAC NRT. Hodge MS recollections, Feb 1989. 2. ADM 220/76. fllustrious, 'Interim Report on Directing Systems for Fleet Fighters', 24 July 1940. 3. Ibid. lA. W. Ross], 'Determination of the Height of an Aeroplane by R.D.F.', 30 July 1940. 4. Ibid., C-in-C HF to CSS, 29 June 1940; Ross minutes, 9 & 17 July 1940; CSS to C-in-C HF, 3 Aug 1940. 5. ASE Monograph M.382 (Oct 1941), [?F.Hoyle], 'Notes on the Vertical Polar Diagrams ... '; also CAC NRT, Hoyle MS Recollections. 6. CAC NRT. Maynard to Howse, 12 Dec 1990 & 8 Feb 1991. 7. Ibid., Victorious to C-in-C HF, 22 July 1942, enclosed with Maynard, 12 Dec 1990. 8. Admiralty, CB 4224(42), Heightfinding by RDF (1942). 9. Admiralty, CB 4224(44), Height-finding by Radar (1944) refers to several examples. Ajax conceived a logarithmic plot, which once constructed allowed heights to be read from a series of standard curves. 15th Cruiser Squadron adopted the practice of adjusting the receiver gain control to maintain a constant echo level and drawing the corresponding contours on the height plot. Pozarica and Malaya each devised ingenious devices for determining References 333

height at close range by exploiting fades through successive minima. Several other schemes had been proposed, for example by Illustrious (measuring rate of change of echo voltage) and Palomares (ratios of echo amplitudes from 79 and 281). 10. Ibid. 11. Ibid. 12. Dryad archive. O. Pollock, 'Aircraft Direction in the British Pacific Fleet', 13 June 1945; Formidable report on the operation of type 277, 2 Jan 1946; E.O.G. Lewin, 'Heightfinding by Radar', 15 Mar 1946. 13. Admiralty, CB 3180, Heightfinding by Radar (1949). 14. Ibid.

Appendix 0 Radar in Submarines (pages 293-300)

1. AOM 220/79. AL SDO 2053/41 of 1 October 1941, lists of ships fitted and to be fitted, p. 5. 2. Admiralty BR 1736(52), 2-Mediterranean, 60. 3. AOM 220/83. C-in-C Med signal to Admiralty, 2011B/21/12 1941. 4. Ibid. Admiral (Submarines) to Admiralty, 6 Jan 1942. 5. Admiralty, CB 3090, Fitting of RD.F. Equipment (1943), 59. 6. CAC NRT. McIntosh to Howse, 1 Feb 1988. 7. CAC NRT. L.J. FitzGerald reminiscences, 12 Jan 1988. 8. AOM 220/204. Quoted in OSO, Radar Bulletin No. 4, 14 July 1943, p. 10. 9. Ibid., 11. 10. AOM 1/13476. Admiral (Submarines) to Captains (S), etc, The employment of radar in submarines', 3 July 1943. 11. CAC NRT. Hezlet to Howse, 24 Feb 1992. 12. Ibid. 13. Ibid. 14. AOM 220/83. ASE to OSO, 'Production dates for radar type 267W', 16 Aug 1943. 15. RN Submarine Museum A.1944/55. Admiral (Submarines) to Admiralty, 'Staff Requirements for Submarines', 19 June 1943. 16. AOM 220/83. Admiral (Submarines) to OSO, 7 July 1943. 17. Ibid. Admiral (Submarines) minute, 4 Sept 1943. 18. FitzGerald reminiscences, 12 Jan 1988. 19. CAC, NRT. McIntosh to Howse, 1 Feb 1988. See also AOM 199/1841. 20. Ibid., 22 Feb 1992. 21. AOM 1/13478. Admiral (Submarines) to Admiralty, 8 Sept 1943. 22. AOM 199/1867-8. Tiptoe and Trump patrol reports. 23. CAC NRT. Roxburgh to Howse, 12 Oec 1988. See also AOM 199/1845. 24. Ibid. Harris to Howse, Oct 1989. 25. Ibid. Hezlet to Howse, 24 Feb 1992. 26. Ibid. OilIey to Howse, 17 Oct 1989.

Appendix E Radar in Coastal Forces (pages 301-6)

1. Admiralty CB 04110(41)(1), MOllthly Report of Progress ill HM Signal School, Portsmouth, Jan 1941. 2. AOM 220/79. AL SOO.2053/41 of 1 Oct 1941. 3. Admiralty, CAFO 2295(F), 27 Nov 1941. 4. ADM 220/79, AL SOO. 2053/41 of 1 Oct 1941. 334 References

5. Admiralty, Monthly Report, June 1942. 6. ADM 199/268. Reports on Operations 'Gun' and 'Newt'. 7. ]. Lennox Kerr & W.Granville, The RNVR (London, 1957), 199-202. 8. CAC NRT. L. C. Reynolds to Hawse, 3 March 1992. 9. Knowles Middleton, Radar Development in Canada, 55. 10. Lovell, Echoes of War, 82-3. 11. Ibid. 12. Public Archives of Canada, NRC File 45.52.59, s.d. 27 August 1943, cited in Knowles Middleton, Radar Development in Canada, 55. 13. R. W. V. Board, private communication. 14. Admiralty, CB 04110(43)(10), Admiralty Signal Establishment - Monthly Report of Progress in the Experimental Department, Oct 1943. 15. Ibid., Jan 1945. 16. ADM 220/78. VA Dover's 0805A/9/9/41. 17. Admiralty BR 1736(42)(1), 'Neptune', 44. 18. CAC NRT. C. W. S. Dreyer to Howse, 3 March 1992. 19. Ibid. An appendix to Admiralty CB 03143, Instructions for Coastal Forces Warfare, describes the control ship technique in some detail. Select Bibliography

General

By far the most important single primary source of information for this work has been the ADM 220 class of documents at the PRO, Kew, containing the surviving records of HM Signal School's Experimental Department and of ASE from 1934 to 1950. These, together with other Admiralty documents at the PRO, have been used to provide the frame of reference for the whole book. To put flesh on this skeleton, the principal sources have been the communications from surviving Admiralty scientists and naval personnel - from Fellows of the Royal Society to laboratory assistants, from Admirals of the Fleet to Ordinary Seamen - those who actually designed, procured, used and maintained the wartime naval radar equipment. In 1986, the Naval Radar Trust began to collect monographs, reminiscences and recollections as well as primary material such as notebooks and diaries, and this was augmented after letters by the author to various journals and magazines in 1987. This archive is preserved in the Churchill Archive Centre, Churchill College, Cambridge, as Class 'NRT'. Other repositories having Significant quantities of primary material include the MoD's Naval Historical Branch in London, the Admiralty Research Establishment at Portsdown, and HMS Collingwood at Fareham. Readers requiring more detailed contemporary information on user matters are recommended to consult the Admiralty's Radar Manual (Use of Radar) of 1945 (CB 4182/45, ADM 239/307). On technical matters, HMS Collingwood has a large collection of handbooks for wartime radar. Secondary sources specific to British wartime naval radar are very sparse. Other than the Proceedings of the lEE's Radiolocation Convention of 1946 and a few monographs published in the Restricted MoD publication Journal of Naval Science, only the Admiralty's Technical Staff Monograph Radar 1939-45 (1954, BR 2435, ADM 234/539), Hezlet's The Electron and Sea Power (1975), Friedman's Naval Radar (1981) and Callick's Metres to Microwaves (1990) go into any detail. However, the Naval Radar Trust intends to publish a volume containing a series of monographs on the more technical aspects to complement the present volume which is primarily addressed to the general reader. Secondary sources for general naval history, many of which are listed below, are plentiful. Special mention must be made of Roskill's magisterial War at Sea (1954-61) and the excellent series of Naval Staff Histories and Battle Summaries in the Admiralty's BR 1736 series (in classes ADM 186 and ADM 234). However, as these were published before the lifting of security restrictions on the highly important wartime Special Intelligence ('Ultra'), works such as Beesly's Very Special Intelligence (1977), Winton's Ultra at Sea (1988) and Barnett's Engage the Enemy more Closely (1991) should be consulted.

335 336 Select Bibliography

Printed sources

ADMIRALTY, BR 1736 - Naval Staff histories (Select list) (6) Mediterranean, Selected Operations 1940 (1943) - ADM 234/325. (7) The Passage of the Scharnhorst, Gneisenau and Prinz Eugen Through the English Channel (1948) - ADM 186/803. (11) Selected Convoys (Mediterranean), 1941-1942 (1957) - ADM 234/336. (17) Sinking of the Scharnhorst (1950) - ADM 234/343. (42) Operation 'Neptune' 2 vols (1947) - ADM 234/366-7. (43) Naval Operations in the Assault and Capture of Okinawa, March-June 1945 (Operatioll 'Iceberg') (1950) - ADM 234/368. (44) Arctic Convoys, 1941-1945 (1954) - ADM 234/369. (48/2) Home Waters alld Atlantic, April 1940 - December 1941 (1961) - ADM 234/372. (50) War with Japan - Vo!. VI, The Advallce on Japall (1959) - ADM 234/379. (51) Defeat of the Enemy Attack 011 Shippillg, 1939-1945 2 vols. (1957) - ADM 234/578. (52) Submarines Vol. 1, Home & Atlantic; vo!. 2, Mediterralleall; vol. 3, Far East (1953, 1955, 1956) - ADM 234/380-2. (53) The developmellt of British Naval Aviatioll, 1919-1945. 2 vols. (1954, 1956) - ADM 234/383-4. -, Admiralty Fleet Orders (AFOs) and Confidential Admiralty Fleet Orders (CAFOs) - ADM 182 series. -, CB 04050 series, Monthly Allti-submarine Reports - ADM 199/2057-ti2. -, CB 04110 series, HMSS/ASE MOllthly Reports, 1941-ti - copies ARE. -, CB 04272 series, Coastal Forces Periodic Review - copies NHB. -, CB 4224 (42), Heightfindillg by RD.F. (1942) - copy HMS Collingwood. -, CB 04092/42, Instructiolls for the Use of IFF Sets and RDF Beacons (1942) - ADM 239/293. -, CB 04092A/42, Summary of RDF Identification (IFF, RDF Beacons and Interrogators) (1942),- ADM239/294. -, CB 04262, Notes on the Direction of Fighters by HM Ships (1942 & 1944-5) - ADM 239/352. -, CB 3090, Instructions for Installation and Fitting of R.D.F. Equipment and Associated Communications (1943) - copy NHB & photocopy CAC; not found in PRO. -, CB 04092/44, Instructions for the Use of IFF Transpollders and Radar Beacons by Allied Forces (1944) - ADM 239/295. -, CB 4224(44), Height-finding by Radar (1944) - copy HMS Collingwood. -, CB 004385 A, B, C, Report by the Allied Naval Commander-in-Chief Expeditionary Force on Operation 'Neptune'. (The Assault Phase of the Invasion of NW Europe, Operation 'Overlord',), 3 vols. (Oct. 1944) - ADM 239/367. -, CB 03143, Instructions for Coastal Force Warfare (1944), with appendix on Control Ship technique (1945) - ADM 239/220. -, CB 4182/45, Radar Manual (Use of Radar) (1945) - ADM 239/307 & photocopy CAC. -, CB 3180, Height Determination by Radar (1949) - copy HMS Collingwood. -, CB 4497, Simple Guide to Naval Radar (1949) - copy NHB & photocopy CAC; not found in PRO. -, BR 2435, ex-CB 3213, Technical Staff Monograph: Radar 1939-45 (1954) - ADM 234/539 & photocopy CAC. AIR MINISTRY (Air Historical Branch), Second World War, RAF Signals - Vo!. IV (CD 1063), Radar ill Raid Reportillg (1950) - AIR 10/5519; Vo!. VI(SD736), Radio in Maritime Warfare (1954) - AIR 10/5555. Select Bibliography 337

ALLISON, D. K., New Eye for the Navy: the Origin of Radar in the Naval Research Laboratory (Washington DC, NRL report 8466, 1981). BALDWIN, Ralph B., The Deadly Fuze. Secret Weapon of World War 2 (London, 1980). BARNETI, Correlli, Engage the Enemy More Closely: The Royal Navy in the Second World War (London, 1991). BASSETI, Ronald, H.M.S. Sheffield: the Life and Times of 'Old Shiny' (London, New York and Sydney, 1988). BEESL Y, Patrick, Very Special Intelligence: the Story of the Admiralty's Operational Intelligence Centre (London, 1977). BLACIFalklands War (London, 1987). BURNS, Russell (ed.), Radar Development to 1945 (London, 1988). BURRELL, Sir Henry, Mermaids do Exist: the Autobiography of Vice-Admiral Sir Henry Burrell, Royal Australian Navy (Retired) (Melbourne, 1986). BURTON, E. F.(ed.), Canadian Naval Radar Officers: the story of university graduates for whom preliminary training was given in the Department of Physics, University of Toronto (Toronto, 1946). CALLICK, E. B., Metres to Microwaves: British development of active components of radar systems 1937 to 1944 (London, 1990). CHURCHILL, Winston 5., The Second World War, 6 vols (1948-54). -, see also GILBERT. CLARK, Ronald W., The Rise of the Boffins (London, 1962). -, Tizard (London, 1965). CLAYTON, Robert & ALGAR, Joan, The GEC Research Laboratories, 1919-1984 (London, 1989). CONNELL, G. G., Valiant Quartet: His Majesty's Anti-aircraft Cruisers Curlew, Cairo, Calcutta and Coventry (London, 1979). CONWAY, Conway's All the World's Fighting Ships, Part I, the Western Powers (London, 1983). COSTELLO, John & HUGHES, Terry, The Battle of the Atlantic (London, 1977). CROWTHER, J.G. & WHIDDINGTON, R., Science at War (London, 1945). CUNNINGHAM, Admiral of the Fleet Lord, A Sailor's Odyssey (London, 1951). CUNNINGHAME GRAHAM, Angus, Random Naval Recollections 1905-1951, Admiral Sir Angus Cunninghame Graham, KBE, CB, JP, of Gartmore (Privately printed [1979], copy at CAC). ELLIOTI, Peter, Allied Escort Ships of World War Il: a Complete Survey (London, 1977). FRIEDMAN, Norman, Naval Radar (Greenwich, 1981). -, The Postwar Naval Revolution (London, 1986). -, British Carrier Aviation (London, 1989). GILBERT, Martin, Winston S. Churchill, Vol. V -1922-1939 (London, 1976), Vol. VI- Finest Hour, 1939-1941 (London, 1983), Vol. VII - Road to Victory, 1941-1945 (London, 1986). GUERLAC, Henry E., Radar in World War Il, 2 vols (New York, 1987). HARTCUP, Guy, The Challenge of War: Scientific and Engineering Contributions to World War Two (Newton Abbot, 1970). - & ALLIBONE, T. E., Cockcroft and the Atom (Bristol, 1981). HEZLET, Sir Arthur, The Submarine and Sea Power (London, 1%7). 338 Select Bibliography

-, The Electron and Sea Pawer (London, 1975). lllNSLEY, F. H. et al., British Intelligencein the Second World War, 3 vols (1979, 1981, 1984). HOLM, John, No Place to Linger: Saga of a Wartime Atlantic Kiwi (Wellington, NZ, 1985). JONES, R. V., Most Secret War (London, 1978; citations from 1979 paperback edition). KNOWLES MIDDLETON, W. E., Radar Development in Canada: the Radio Branch of the National Research Council of Canada, 1939-1946 (Wilfred Laurier University, Ontario, 1981). LOVELL, Bernard, P.M.S. Blackett: a Biographical Memoir (London, 1976). -, Echoes of War: The story of H2S Radar (Bristol, 1991). -, see also SAWARD. MACINTYRE, Donald, U-boat Killer (London, 1956). -, The Battle of the Atlantic (London, 1961a). -, Fighting admiral: the Life of Admiral of the Fleet Sir James Someroille, GCB, GBE, DSO (London, 1961b). MILLINGTON DRAKE, Sir Eugene, The Drama of the Graf Spee and the Battle of the Plate (London, 1964). MONTGOMERY HYDE, H., British Air Policy Between the Wars, 1918-1939 (London, 1976). OTTAWA, Naval Officers Association of Canada, Salty Dips Vo!. 1 (Ottawa, 1983). PACK, S. W. c., Night Action Off Matapan (London, 1972). -, The Battle of Sirte (London, 1975). PAGE, Robert Morris, The Origin of Radar (New York, 1962). POOLMAN, Kenneth, Escort Carriers, 1941-1945 (London, 1972). -, Allied Escort Carriers in World War Two in Action (London, 1988). POPHAM, Hugh, Into Wind (London, 1969). POSTAN, M. M., HAY, D. & SCOTT, J. D., History of the Second World War - Design and Development of Weapons (Chapter XV - The Development of Radar) (London, 1964). POTTER, John Deane, Fiasco: the Break-out of the German Battleships (London, 1970). PRICE, AHred, Instruments of Darkness: the History of Electronic Warfare, 2nd edn. (London, 1977). PRITCHARD, David, The Radar War: Germany's Pioneering Achievements, 1905-1945 (Wellingborough,1989). RAVEN, A. & ROBERTS, J., British Battleships in World War 11 (London, 1976). -, British Cruisers in World War 11 (London, 1980). ROBERTSON, Terence, Walker, R.N. (London, 1958). ROHWER, Jiirgen, The Critical Convoy Battles of March 1943: the Battle for HX.229/ SC.122 (London, 1977). ROSKILL, S. W., The War at Sea 1939-1945,3 vols (London, 1954, 1956, 1960, 1961). -, Han1cey, 3 vols (London, 1970-4). -, Churchill and the Admirals (London, 1977). ROWE, A. P., One Story of Radar (Cambridge, 1948). SAWARD, Dudley, Bernard Lovell: a Biography (London, 1984). SCHOFIELD, Vice Admiral B. B., The Loss of the Bismarck (London, 1972). -, Navigation and Direction: the story of HMS Dryad (Havant, 1977). SCOTT, Peter, The Battle of the Narrow Seas: a History of the Light Coastal Forces in the Channel and North Sea, 1939-1945 (London, 1945). SMITH, Peter c., Task Force 57: the British Pacific Fleet 1944-1945 (London, 1969). SOMERVILLE, Sir James, see MACINTYRE. SWORDS, S. S., Technical History of the Beginnings of Radar (London, 1986). Select Bibliography 339

TAYLOR, Denis & WESTCOTT, CH., Principles of Rndar (Cambridge, 1948). TIZARD, Sir Henry, see CLARK. TRENKLE, Fritz, Die deutschen Funkmef1verfahren bis 1945 (Heidelberg, 1986). VIAN, ~ir Philip, Action This Day: a War Memoir (London, 1960). von MULLENHEIM-RECHBERG, Baron Burkard (SWEETMAN, J, tr.), Battleship Bismarck: a Survivor's Story (London, 1980: citations from Triad Grafton edition, 1982). WAR OFFICE (Brig. AP. Sayer), Second World War, Anny Rndar (1950). WATSON-WATf, Sir Robert, Three Steps to Victory (London, 1957). WHITLEY, M.J., Destroyers of World War 1I: an International Encyclopedia (London, Sydney, 1988). WINTON, John, The Forgotten Fleet (London, 1969). -, Sink the Haguro (London, 1978). -, Find, Fix and Strike (London, 1980). -, The Death of the Scharnhorst (Chichester & New York, 1983). -, Ultra at Sea (London, 1988). WOODWARD, Admiral Sandy, with ROBINSON, Patrick, One Hundred Days: The Memoirs of the Falklands Battle Group Commander (London, 1992). Table of Type Numbers of Naval Radar Sets: Operational or Designed, 1935-45

AI - Air interception INT - Interrogator ASV - Air to surface vessel LA - Low angle BCN - Beacon Rg. - In the ranging mode CCA - Carrier Controlled Approach (types 279 and 281) FD - Fighter direction Rx - Receiver GA - Gunnery fire control, aircraft, Sw. -Sweeps high angle (or combined low TI - Target indication angle and high angle) Tx - Transmitter GB - Gunnery fire control, barrage WA - Warning of aircraft GC - Gunnery fire control, close WC - Warning (combined aircraft range, high angle and surface) GS - Gunnery fire control, surface W g. - In the warning mode (i.e. low angle) (types 279 and 281) HA - High angle WS - Warning of surface craft. Ht-fndr. - Height-finder ~ - Variable around this IFF - Identification Friend or Foe frequency.

In the numbering of naval radar sets, the first, second and third major modifications to the basic set were indicated by the suffixes M, P and Q respectively, ego type 286P. The suffix B indicated adaption to single-mast working.

Information not available is generally marked with a dash.

340 Type Classification Wavelength Freq. Power Tosetl number nominal MHz kW (abandoned) Description

79 WA 7.5m 39-42 70 1938 Long range air warning for large ships. See 279. 79B WA 7.5m 39-42 70 1941 Single-masted version of 79 (originally 79M). 91 Jammer SOcm-3m 90-600 10-25W1 1941 Jamming of German metric and decimetric radar. Initially sine-wave modulation, ultimately noise. 241 INT 1.5m 214 1941 For use with 281 and IFF Mk.2N. 242 INT 1.5m 182 or 179 1 1943 For use with WS and WC sets and IFF Mk.3. 242M INT 1.5m 182 or 179 2-10 1943 Ditto 243 INT 1.5m 179 or 171 1 1943 For use with 281 and IFF Mk.3. 244 INT 1.5m 1943 For use with US type SL and IFF Mk.3. 245 INT 1.5m 1944 For FD ships. 251/M/P BCN 1.5m 176/177 7 1942 Modified RAF transponder coded to give ships' identity. 252 IFF 1.5m 38-52 & 1942 IFF Mk.2 in ships. 195-220 253/P IFF 1.5m Sw.157-18710 1943 IFF in ships (Mk.3). Sweeps frequency. 2535 IFF 1.5m Sw.157-187 10 1943 253 when fitted ashore. 255 BCN 1.5m 214 1944 Marker buoy for use only with 291. 256 BCN 1.5m 214 1944 Shore radar beacon for use only with 291. 257 CCA 3cm 1945? Carrier controlled approach (BABS). 258 BCN l.5m 179/182 1943 Shore radar beacon responding to 242. 259 BCN 1.5m 1944 Beacon for carriers responding to AI Mk.l0. 261 WS 50cm (1941) Based on 282. 261W WS 3cm (l942) Early 3cm development, leading to 267W. 262 GC 3cm ~9,650 20 1945 STAAG, CRBFD. 263 GB 3cm (l945) Auto barrage for main or secondary armament, replacing 283. 267W/MW/PW WS/WC 3cm& ~9,670 15-25 1945 Submarines. Hybrid WS/WC with common 1.5m &214 &100 display. 268 WS 3cm 9,400 1945 For coastal forces, replacing 291U.

1 Depending upon frequency. ~ ..... cont. uverletlf Type ClassificatiDn Wavelength Freq. Power To sea ~ number naminal MHz kW (abandoned) Description N

269 GS 3cm 10,000 (1943) Modified 3cm AI set for coastal forces gunnery. 271/M/P WS IDem :::::3,000 5-10 1941 Small ships. 271Q WS IDem :::::3,000 70 1943 Small ships 272/M/P WS IDem :::::3,000 5-10 1941 Small cruisers, carriers, sloops, etc. 273/M/P WS IDem :::::3,000 5-10 1941 Large ships. 273Q WS IDem :::::3,000 70 1943 Large ships 274 GS IDem :::::3,300 400 1944 Main armament directors, replacing 284. 275 GA IDem 3,530 400 1945 HA directors (HA/LA directors in destroyers), replacing 285. 276 WS IDem 3,000 500 1944 Small ships, replacing 271 /2. 277/P/Q WS IDem 3,000 500 1944 Replaced 271/2/3. Could measure approximate elevation. 2775 WS/low air IDem 3,000 500 1943 277 permanent shore installation for surface and low air. 2m WS/low air IDem 3,000 500 1943 Trailer-mounted 277. 'Monrads'. 279 WA 7.5m 39-42 Wg.70 1940 Long range air warning for large ships. Type 79 Rg.6O with gunnery ranging. 280 WA/GA 3.6m 82 25 1940 Based on Army GL1. In Carlisle and 'Bank' class ships only. 281 WA 3.5m ~94 Wg.6OO 1940 Long range air warning for large ships. Rg.l,OOO 281B WA 3.5m ~94 600 1943 Single-masted version of 281. 281BM/BP /BQ WA 3.5m ~94 350 1945 Continuous rotation. 282 GC 50cm :::::600 15 1941 Pom-pom directors, etc. 282Ml/M2/M3 GC 50cm :::::600 60 or 80 1942 Increased power. 282M4 GC 50cm :::::600 60 or 80 1942 Beam switching. 282Q GC 5Dem :::::600 150 Beam switching and increased power. 283/M GB 50cm :::::600 150 1943 Auto-barrage for main or secondary armaments. 284/M/P GS 5Dem :::::600 As 282 1940 Main armament directors. 285/M/P/Q GA 5Dem :::::600 As 282 1940 HA directors (HA/LA directors in destroyers). Type Classification Wavelength Freq. Power To sea number nominal MRz kW (abandoned) Description

286M/P WC 1.5m 214 7 1940 Small ships. 286M fixed aerial, 286P revolving aerial 286PQ WC 1.5m 214 lOO 1943 Small ships. Higher power. 286U WC 1.5m 214 7 1941 Coastal forces. 286W WC 1.5m 214 7 1941 Submarines. 287 Minewatch 50cm ~600 15 1941 284 adapted for minewatching ashore. 288(1) GC 50cm ~600 15 (1941) 284 adapted for Armed Merchant Cruisers. 288(2) GC 50cm ~600 15 284 adapted for training ashore. 289 GA 70em ~430 1940 Dutch. Fitted in lsaac Sweers and Heemskerck only. 290 WC 1.5m 214 lOO 1941 Small ships, replacing 286 but abandoned in favour of 291. 291/M WC 1.5m 214 lOO 1941 Small ships, replacing 286/290. 291U WC l.5m 214 lOO 1943 Coastal forces. 291W WC 1.5m 214 lOO 1943 Submarines. 293/M WC/TI IDem 3,000 500 1944 Destroyers and above. Replaced 271/2/3. 294 WC/ID IDem 3,000 (1944) Combined plan-display and heightfinding, replacing 277. 295 WC/ID IDem 3,000 (1944) Higher-powered 294. 650 Jammer ~6m ~50 10-2Ow 1944 Jamming of air-launched Fx.l400 and Hs.293 anti-ship guided weapons. Sine-wave modulation. 651 Jammer ~6m ~50 2-1kw 1944 As type 650 but capable of handling multi-missile attack. CW modulation. 930 GS/splash IDem 3,000 7 1945 Splash-spotting; naval version of Army CA No.1, Mk.5 ('William') 931 GS/splash 1.25cm ~24,OOO 1945 Splash-spotting, Canadian 940/1 INT 1.5m 209 1 1944 G-band interrogator with 28IBP /BQ. 951 BCN Marker beacon for use with 10em WS and WC sets. 952 BCN Rx3cm Rx~9,400- 1945 Portable combined ops. navigational. Triggered by Tx l.5m Tx 182 X-band, response on type 242. 960 WA 3Am ~88 450 1946 Long-range air warning for large ships, replacing 281/79/279. w cont. ooerleaf ~ Type Classification Wll'Oe1ength Freq. Power To sea number nominal MHz kW (abandoned) Description ~

961 CCA 3an ~9,320 Carrier controlled approach. Modified A5V ll. 970 WS IOcm ~3,300 1943 Combined operations. Modified RAF H2S ll. 971/M WS 3an ~9,320 1945 As 970 but based on H2S ill. 972 WS 3an ~9,375 1946 Surveying. 980 WC/ID IOcm 3,000 500 (1949) Fighter direction plan display, replacing 294/5. 981 Ht-fndr IOcm 3,000 500 (1949) Fighter direction heightfinder, replacing 294/5. 990 WC IOcm 3,000 (1944) Low cover, to go with 960, 294/5. 992 11 IOcm 3,000 1959 Target indication, replacing 293. American sets fitted in British ships SA WA 1.5m 1943 'Captain' and 'Colony' class frigates. SG WS IOcm ~3,195 1943 Indomitable, Victorious, escort carriers. SI WS IOcm 1945 Submarines Tiptoe and Trump. SK WA 1.5m 1943 Escort carriers. SL WS IOcm 1943 'Captain' and 'Colony' class frigates. SM-l ID 1O.7cm ~2,800 1944 Carriers Indomitable, Ocean; ID ships Boxer, Palomares. SO WS IOcm 1944 Coastal forces. SQ WS 12cm 1945 Big ships' portable 'after-action' set. Naval Airborne Rizdar ASVMk.ll ASV 1.5m 176 1940 Standard RAF version ASVMk.ITN ASV 1.5m 214 7-22 1941 Naval version of A5V ll. Swordfish, Walrus, Albacore, Barracuda ASVMkJCI A5V 3an 35-50 1943 Swordfish ill, Barracuda ill ASB ASV l.5m 214 1944 US copy of ASV ITN. Avenger

ASH ASV/AI 3an ~9,375 35 1944 US AN/ APS-4. Avenger, Firefly. Barracuda V AI Mk.IV AI l.5m 10 1944 Fulmar AIA AI 3cm 1945 US AN / APS-6. Hellcat

Principal source: Admiralty, CB 4497, Simple Guide to Naval Radar (1949). General Index

Notes: Primary references to radio and radar equipments are gathered together in the 'Type Designation Index' on pages 378-83. Civilian staff of HM Signal School and Admiralty Signal Establishment are indicated by the terms HMSS, HMSSI ASE or ASE according to whether their period of service was before, through or after the change from HMSS to ASE (August 1941). Figure and diagram references are given by page numbers in bold type.

AA Range, Eastney, 44, 58 Admiralty accuracy I precision of radar general, Admiralty organization, 314; bearing accuracy, factors affecting, 106; HMSSI ASE staffing, 26,156; values, 26, 40, 43, 65, 106, 137, 169, priorities, 17, 18, 163; contracts with 184,277; Brundrett's assessment, 22; civilian bodies, 20, 67; radar high priority, 106; benefits from successes on record, 157; fitting beam switching, 41, 103, 106, 1~, policy for types 79 and 281, 171; 137, 169, 184; of blind fire, 103, 137; plans for S.E. Asia, 237; request to of detection of other radars, 26; of Canada, 234; new systems, 253; shell splash spotting, 65; rough Horton to Admiralty, 208; and values from fixed aerials, 58, 79; Somerville, 159-60 'user' reports, 91, 232, 297 Departments, see Naval Ordnance; height estimation precision, staff Operational Research; Radio requirements, 186; values attained, Equipment; Scientific Research and 285,290 Experiment; Signal (up to 1944); range accuracy, need, 56; values, 40, 105, Torpedoes and Mines 184; better than optical equipment, Naval Staff Divisions, see Air Warfare 22,43,55,105,136,269;fromrangel and Training; Anti-submarine amplitude data, 203, ranging panel Warfare; Gunnery and AA Warfare; for type 279, 40, 41; 50cm radar Naval Air; Naval Intelligence; inadequate in long-range sets, 102; Navigation; Signal (from 1944); various methods, 103; 'user' reports, Tactical; Training and Staff Duties 232, 297 Staff Requirements, see Naval Staff tracking accuracy, type 901, 257 Requirements Achates, HMS (destroyer), 158 Admiralty Gunnery Establishment acoustic detection, see asdic (AGE),226 acoustic homing torpedoes, ('Gnar), 233-4 Admiralty Research Laboratory, 7, 10, 17, Action Information Centre, precursor, 182; 132 general, 203-6; administration, 208; in Admiralty Fire Control Table, 76 sinking of Haguro, 247; ship fittings, Admiralty Signal Establishment, ASE 233, 238-9; see also, Bridge Plotting becomes a separate Command, 99, 102; Room, Operations Room, Radar move to Surrey, 132; visit by King Display Room George, 135; 'production' year, 135; Activity, HMS (escort carrier), 166 Gunnery Section, 135; HPI OF, 143, 146, Adamant, HMS (submarine depot ship), 298 147; production and fitting of type 271, Aden, air defence plan, 62 149,151-2, 156; prefabrication, 149; 'A' Display (A-Scan), see displays plan-packing, 149; magnetron power, Adkins, Bruce. M. (HMSSI ASE), 117 156;waveguides, 156; naval Admiral Graf Spee (German pocket compliments to, 147, 149, 157; priorities, battleship), 45, 46, 47, 49 163,166,222-4,237,241; staffing, see Admiral Hipper (German cruiser), 128, 156 staffing of HMSSI ASE; senior staff, Admiral (Submarines), 293, 29~, 298 165, 266; Captain WilIett and

345 346 General Index

Admiralty Signal Establishment (cont.) outside contractors, 186 Commander C.V. Robinson, 88; parabolic cylindrical ('pig trough'), see administration, 206; outside types 284, 982 contractors, 166, 186, 187, 258, 267; polar diagrams, vertical, 283, 285, 286, second generation lOcm radar, 177; 288; vertical lobes,282-3, variation children saved, 178-9; 'Neptune', 209, within lobes, 287, wavelength effect, 211, 213; projectiles and missiles, 192, 169; side lobes inherent, 151; side 225-6,257; specification for types 992 lobes, 43; use of combined vertical and TIU3, 227; 'Bubbly', 237-8; diagrams, 174, UK v US sets, 251; 'Knobbly', 237, 241-2; postwar 'user' reports, 43, 175 merchant navy radar, 234, 235; new polarization, 260 system development, 253; last entire radar 'lens', see types 901, 90S, 984 'in-house' development, 257; radar for rotation, powered, 173, 174, 178, 181,195, submarines, 2%; for earlier references, 203; speed, 182,227,235 see HM Signal School scanning, conical, 185, 199, 201; helical, Adonis, HMS (trawler), 88 304 Aegean, see Proteus, Wster Queen stabilization, 110, 189, 291 , Aegean Islands, German evacuation of, 228 yagi ('fishbone'), against dive bombers, Aerials 43; see also types 262, 282, 284, 285 aperture, 183 see also aerial entries in Type Designation array efficiency, 105 Index 'bedstead', first model, 58; see also type Aeronautical &: General Instruments Ltd 286M (AGD,26 'cheese', 70; see also types 271, 272, 276, 'after action' radar sets, 240, 344 277,293 'ahead-throwing' weapons, 142, 157 circular paraboloidal, Swanage trials, 69, AI, see Type Designation Index 70,274; see also types 262, 271/3/7 Aircraft Direction, see Fighter Direction classification by code, ANB, 261, 262; air defence of Fleet, 117, 169-73, 186-7, 217, ANU, 260; AUJ, 177; AUK, 177, 260; 247-8 AQR, 1%, AQS, 262; AQT, 262; Air Defence Position, (ADP), 122, 125-6, ATE, 262; AUR, 195 250 common aerial/single mast Air Defence Experimental Establishment working, 89-90, 315; see also (Army) (later RRDE and then types 79, 277, 279, 281, 282, 28S ADRDE), 12, 33, 106 directional, 8, 22 Air Defence Officer, 122 'dustbin', 170, 264 Air Defence Research and Development feeders, design, 45; coaxial, 156, 157; Establishment (Army), 33, 109 short, 125; slotted waveguide, 259, Air Defence Research Sub-Committee of the 264; waveguide, 83, 156-7, 180, 195, Committee for Imperial Defence, see 259,305 Swinton Committee lanterns, original, 83; location, 109; large air direction frigates, 259 ship version, 110; enterprise, 131; air interception lock-on radar, 304 moulded perspex to minimise side Air Ministry, pessimism, 4; Daventry trial, echoes, 151; unfinished lantern, 150; 6; HMSS aid in valve supply, 8; called see also radome and types 271/272/ for greater investment, 23; pressed for 273 single radar R&:D centre, 12, 33-4; for submarines, 294, 299; type S] non• appoints scientist to Air Intelligence, elevating mast, 298 49; and Horton, 37 gain, values, 274; factors affecting, 28, 59, Air Ministry Research Establishment, 33, 70, 66, 70, lOS, 157, 201 see also Telecommunications Research 'mattress', on German radar,45,46,47,48, Establishment 188; see also types 960P, Gel and SK Air Plot, 226, 240 mirror, removes back echoes, 151; see also Air Warfare and Training Division types 276, 277 (Admiralty), 196, 206 naval constraints in design, 11, IS, 41 aircraft carriers, see carriers or specific type 'nodding', 199,201, 202 of carrier on gun directors, pom-pom, 43; Staff Aircraft Direction Centre, Kete, 263 Requirements, 44; German usage, Aircraft Direction Room, lOS, 240 44; trials, 59; integration, 223 'airguard' submarine radar, 296, 299 General Index 347

Ajax, HMS (cruiser), Mediterranean Fleet, Anti-Submarine Warfare Division, 64, 73, 75; Battle of Cape Matapan, 75; Admiralty, 68, 83, 113,147 logarithmic plot for height estimation, Antigua, HMS (frigate), 202 332; radar sets fitted, 64, 73, 75 Antwerp, reached by Allied convoys, 191, Albacore aircraft, 309 221-2 Albion, HMS (light fleet carrier), 263 Anzio, operation 'Shingle', 191-2 Albion class light fleet carriers, 259 Apollo, HMS (minelayer), 232, 233, 234 Alder, L.S.B. (HMSS), provisional patent, 3 Application Officers (HMSS and ASE), 16, Alderney, HMS (submarine), 300 19,108,206,284 Alexandria, base of Mediterranean Fleet, 61, Arbiter, HMS (escort carrier), 237 73--4; ASE Officer trouble-shooting, Arbutus, HMNZS (radar/radio maintenance 195 ship),247 Algerine class minesweepers, 234 Archer, HMS (escort carrier), 167 Algonquin, HMCS (destroyer), 229 Archer class escort carriers, 169, 201 Allan, Commander Robert, RNVR, 302-3 Argonaut, HMS (cruiser), 219, 251 Allied Naval Commander Expeditionary Argus, HMS (fleet carrier), 153, 154 Force, 209, 210 Ariguani, HMS (fighter catapult ship), 80-1, Allen West, Brighton, 39, 87, 149, 156 100 Altenfjord, Norway, base for Scharnhorst Ark Royal, HMS (fleet carrier), near miss by and Tirpitz, 188, 191 bomb at Scapa, 30, 32; Norwegian Alynbank, HMS (auxiliary AA ship), 100 campaign, 56; Force H, 61-2; sunk, 99, Ambuscade, HMS (destroyer), 59, 107, 147 117,308; and FD,56, 63, %, 119 American radar, see types SA, SCR 720, Ark Royal, HMS (postwar carrier), 259, 263 SI/Ca), SK, SL, SM-l, SO, SP, SQ, YE Annada, HMS (destroyer), 242 Amphion, HMS (submarine), 300 Armed Merchant Cruisers (AMC), 100 Anderson, W.P. (HMSS/ ASE), 15, 20 Armstrong, G.K., Sub-lieutenant, Angus, Scotland, proposed site for radar RNVR;125 R & D centre, 33 Armyrada~ 109, 129, 135, 158, 163, 255 anomalous propagation: in type 284 trials, A-scan, see displays 59; in 'Avalanche', 174, 175; in sinking asdic, definition, 315; U-boats change of Haguro, 248; in Pacific, 196,251 tactics, 77, 276; cooperation between Anson, HMS (battleship), 238, 240, 242, 255 radar, HF/DF and HE, 115, 146,278; in Anson aircraft, 18, 307 Battle of Atlantic, 80; off Norway, 233; antenna, see aerial in submarines, 295; 'passive' sonar, anti-aircraft 299; see also hydrophone effect general, prewar priorities, 24; Ashanti, HMS (destroyer), 230 rangefinder, 40 Ashford School, air raid warning, 178-9 gunnery, 222; radar on directors, 44, 89; Assault Escort Carriers, 241 auto-barrage computer, 106, 137; ASV, see Type Designation Index use of surface armament, 138; fire Athabaskan, HMCS (destroyer), 176 control, see gunnery radar - barrage; Atlantic, Battle of, general, 77-81, 113-6, postwar, 255, 257; missile systems, 142-7; proclamation, 77; losses, 142; 2S8; see also Bofors, STAAG critical, 72; urgent need of radar, 68, anti-aircraft cruisers, priority radar fittings, 113--4; impact of centimetric radar, 27, 63; in Norwegian Campaign, 52; in 265,311; HF/DF, 146; in Allied favour, Mediterranean, 61; Cairo in 'Harpoon' 162 and 'Pedestal', 153, 154, 156; sets fitted, Atlantic Charter, 99, 110 100,101 Attacker, HMS (escort carrier), 174 anti-aircraft - other ships, destroyer pickets, Audacity, HMS (escort carrier), 90, 100, 250; frigates, 259; sloops, 195 119-20,166 anti-E-boat measures, 305, 311, 312 AUJ (aerial), 177 anti-jamming, 166 AUK (aerial), 177, 260 anti-midget submarines, 312 Aurora, HMS (cruiser), 107 anti-submarine measures, type 271, 86; type auto-aiming signals, 185 277Q 260; A/S ships, 144, 23S; ASV, Auto Barrage Unit (ABU), 137 307,308, 311; 'Enigma', 113; radar auto-following, 166 fitted helicopters, 270; convoy automatic search, lock-on and control for protection reports, 277; see also Battle of gunfire, 256 Atlantic, HF/DF, U-boats auto-ranging system, 185 348 General Index

Auxiliary AA ships (for convoys), 169 visit by Somerville with submarine, 35, 'Avalanche', Operation (Salerno 37-8; early work on Army's GL radar, landings), 162, 174, 17~ 43; Bowen and airborne radar, 67; Ava/on, HMS (trawler), 87 research staff evacuated to Dundee, 33 Avenger aircraft, 244, 312 'Bay town', Operation, (invasion of awards mainland Italy), 162 DCM award, 97 BBC, 6, 20 DSC award, 115, 189 Beachy Head radar and Decca stations, 129, DSM award, 75, 11~, 189, 247 213 DSO award, 115 beacons, see radar beacons MBE award, 51, 120 Beale, Commander George, 63, 64, 75 Mention in Despatches, 189 beam-riding, 234, 257, 315 Victoria Cross, 158 beam sharpening, 163 'Azicator', see displays beam shapes, fan beam, 261; pencil beam, 110 beam splitting/switching, description, 315, B1 (Norwegian submarine), 86 106-7; bearing accuracy improvement Badkin, AB (Radar) J., 189 v. range reduction, 110, 169, 232; use Bainbridge-Bell, L.H. (HMSS/ ASE), initial optional, 169; devised by Butement, visit to HMSS, 8; Graf Spee radar 106; German version, 45; remote investigation, 48, 49 displays near fire control, 136 Baird Television, 39 beam width, for ASV, 67; for merchant navy Baldwin, Stanley (Prime Minister, radar, 235; narrow beam for better T1, 1935-7),4,6 228; for pencil beam, 110; PPI wide Balkans base for German aircraft, 72, 77 beam problems, 91, 108-9, 154; rough banana boats, 80 sea problems, 280; of specific aerials, 'Bank' class (auxiliary AA ships), 342 59, 260; of Swanage trial set, 274 Barents Sea, Battle of, 128, 158-9, 188 Beaufighter aircraft, 155, 175, 228 Barfleur, HMS (destroyer), 223; trials of type beginnings of naval radar, early references, 275, 184, 224; other sets fitted, 9/70, 1, 2; abortive ideas, 3; navy told of 242; first TIR, 183,224, 227; Pacific, 242 radar 'secrets'; 8-10; preliminary Barham, HMS (battleship), 76, 77 requirements, 11; concern that radar is Barracuda aircraft, 310, 311, 312 a security risk, 11; navy presses for barrage balloons, 210 own research unit, 12; initial echoes at barrage fire control radar, see gunnery Eastney, 15; first sea trials, 16; first sets Barrow, submarine construction, 298 to sea, 25; accelerated prewar research, Bates, Lieutenant H.R.K., RNVR, (later 28; two radar-fitted ships ready for Captain RN), 189 WW2, 30; 'radar rangefinder' Bath, Admiralty technical departments, 35, welcomed, 55; development of 10cm 314 radar starts, 83 'Battle' class (destroyers), 183, 224, 227, 242, Begum, HMS (escort carrier), 167 255 Belfast, HMS (cruiser), sinking of battle cruisers, 157, 188 ScharnllOrst, 187-8; BPF, 238, 242; Battle Cruiser Squadron, 91, 93-4 'Bubbly' modifications, 238; into Battle of Atlantic Committee of War reserve, 255; radar sets fitted, 158, 188, Cabinet, 77 242, 255, 260; and type 273Q, 188 Battler, HMS (escort carrier), 174 Bel/ona, HMS (cruiser), night actions off battleships, radar range v. gunnery range, Norway, 229, 230, 232, 233, 234; 135, 183; shore bombardment, 247-8; jamming enemy coastal radar, 233; in BPF, 237, 10/8, 247-8, in 'Bubbly', radar sets fitted, 229, 233; and type 238,240; in 'Husky', 174; in 'Pedestal', 272P, 229; and type 277, 233; and type 153--4; postwar radar, 253; all 'in 284, 229, 232 reserve', 260 Benjamin, R. (ASE), 34 Bawdsey Manor, RAF radar research 'Berserk', Exercise, 1942 (carrier station, proposed for all British radar cooperation/FD), 154 research, 12, 33; Army scientists, 12, 33; BelWick, HMS (cruiser), 64, 73 HMSS liaison, 13, 15, 17; Biggin Hill, Air Defence Experimental demonstration of type 79X postponed, Establishment, 12 17; progress with CH, 18; priorities, 19; Biggs, Sub-Lieutenant Colin, RNVR, 234 General Index 349

'Bigot' (security code word), 209, 215 Fleet Train, 247; US type SQ issued, Bigsworth board, 56, 98 240; British contribution to long range Birmingham, HMS (cruiser), 73, 89, 258, 259 height determination, 282; type 931 not Birmingham University, 67, 156, 187 ready by end of war, 255; great Bismarck (German battleship), 94, 95; radar technical advances in four years, 251; set FuM023, 93, 94, 95; sunk, 72, 90-7, in 'Bubbly', 237, 240; in 'Iceberg', 232, 308; 248; in neutralization of North Biter, HMS (escort carrier), 169 Formosan airfields, 248 Black Prince, HMS (cruiser), 207, 258 British Thomson-Houston Co., Ltd., 45, 186 Black Swan, HMS (sloop), 195 Broadsword, HMS (frigate), 272 Blackett, Professor P.M.S. , 5, 6 Broke, HMS (destroyer), SO, 107, 144 B/ake, HMS (cruiser), 256 Brooking, Captain Patrick W.B. (Captain blast from own guns, safe sites scarce in big Superintendent, ASE, December 1943), ships, 110; in Kenya, 112; in Battle of 208 Barents Sea, 159; type 286 survives Browning, Captain Hugh, 232 blast in Repulse, 126; German ships Bruce, Commander the Hon J.B., 15 affected, 93, 96 Bruges Decca station, 221 blind pilotage, 195, 221, 235; see also Bruiser, HMS (tank landing ship), 241 navigation Brundrett, F.W. (HMSS), Secretary, HMSS, Bluebell, HMS (corvette), 116 15; Admiralty, 19; direct control of 'Blue Fox' radar, 271 guns, 22; recruitment of scientific staff, Board of Admiralty, 24, 28, 124 34,35,39 Board, Lieutenant R.W.V., RNVR, 305 'Bubbly', Project (upgrading of warning Bofors gun, 163, 185 radar in BPF), 237--a, 240 Bohm, O.M. (HMSS/ASE), height Bulolo, HMS (headquarters ship), 219 finding, 163 Bulwark, HMS (light fleet carrier), 263 bombardment, 175, 209, 230, 248 Burcham, W.E. (TRE), 68 Bomber Command (RAF), 296 Burdock, HMS (corvette), 217 Bonaventure, HMS (cruiser), 41, 64, 74 Burghard, Captain G.F., 165, 206 Bondi, H, (later Sir Hermann), (ASE), 34 Bumett Vice-Admiral R.L., 158, 188, 190 Borthwick, Lieutenant-Commander W.J., Butcher, F.E. (telegraphist/radar operator), RNVR, Operation 'Neptune', 209 in Curlew, 52 Boot, H.A.H. kamikaze Canadian Navy, 176; cruisers, 255; MTBs, attacks, 248-50; pickets against air 306 attack, 250-1; long periods at sea; 248; Canadian Radar Officers, 62, 113 350 General Index

Cap d'Antifer peninsula, 220 Christchurch, Dorset, Air Defence Cap de la Hague, 220 Experimental Establishment, (Army), Cap Griz Nez, 81 33,35 Cape Bon, 63 Churchill, Sir Wins ton, Prime Minister, Capel, near Dover, shore station, 179 1940-45, urged increase in RAF, 4; capital ships, 132, 154, 159, 255 Swinton Committee, 6-7; First Lord of Capraia Island,Operation 'Gun', 302-3 Admira1ty, 33; visit to HMSS, 35; 'Captain' class frigates, 195, 201, 202, 220, resists Horton transfer, 37; proclaims 306,344 Battle of Atlantic, 77; travels to Captain (Coastal Forces), 305 USA,110 Captain, Radar Training, 195, 206 Civil Establishments Branch of Captain, H.M. Signal School, early radar Admiralty,25 contacts, 10, 11; priorities, 16; Murray civilians at sea, 91, 125 succeeds Dorling, 18; HMSS 'caught Close Range Blind Fire Director, 186, 243, with trousers down', 19-20; naval 256,341 thanks after Bismarck action, 97; ceased Coales, J.F., (later Professor), (HMSS/ ASE), specific work for radar, 206 34, 267; first contact with radar, 8; Captain Superintendent (of ASE), 102, 208 wavelengths below Im, 20, 40,44,68, Carley float, 125 89, 103; gunnery rader, 22, 44, 58; Carlisle, HMS (AA cruiser), 42; fitted with guided missiles, 226 type 280, 43; sea-trials of type 280 coast artillery, 129-31 aerials, 43; Norwegian campaign, 43, coast defence, 3 52, 54, 137; Mediterranean Fleet, 61, Coast Defence radar (Army), 129, 131 62-3, 73; radar sets fitted, 42, 43, 73, coastal craft &: Coastal Forces, first Coastal 100, 342; and barrage fire, 136; and FD, Forces radar, 301; cm radar, 304-5; 62-3; and type 280, 42, 43, 62; and control ship technique, 306; vectoring types 79/279/280, 43 by radar, 305-6; E-boat interception, Carrier Controlled Approach radar, 344 220; in 'Neptune', 220, 303; type 268, carriers (non-specific), 27, 117, 171, 227; in 234, 254, 304, 341; type 286, 100, 108, BPF, 248; in 1ceberg', 248; in 343; type 290, 107; type 291, 107; see also 'Meridian', 232, 248; in bombardment, MGBs, MLs, MTBs 248; Japanese carriers, 244; type 275, 'Coastwatcher' radar (German), 233 255; type 277Q, 260; type 984, 264; see 'Coat', Operation (passing forces through also escort, fleet, and light fleet carriers Mediterranean),64 'Castle' class corvettes, 196, 235, 260 coaxial cable, see aerial feeder Catalina aircraft, 96, 308 Cochrane, C.A. (Alec), (HMSS/ASE), 69 catapult aircraft merchantmen, 81, 100 Cockcroft, Professor John D. (Army catapult aircraft, 308 scientist), 38; Tizard Mission, 71 cathode-ray tube, element of radar, 2; Coke, Commander Charles P, (FAA), fighter Messrs A.C. Cosser, 45; PPI, 108-9; direction, in Ark Royal, 56-7, 63; in remote displays, 136; Skiatron, 171-2, 'Pedestal', 154; at Salerno, 174; Fighter 172, see also displays Direction School, 119, 120 Catlow, Lieutenant Anthony, 298 Collingwood, HMS (radar and electrical Ceci1, Commander the Hon. Henry M.A., school) (Fareham, Hampshire), 195, first radar Application Officer, 16; 206, 208, 224 priorities, 19, 245--6; stimulation of collision avoidance, 2, 65, 235, 253 progress, 29; PPI, 108 'Colony' class cruisers, see Fiji class Centaur, HMS (light fleet carrier), 263 'Colony' cIass frigates, 201, 344 centimetric radar, see wavelength Colossus, HMS (light fleet carrier), 238 Central Interrogation Position, 205 Combat air patrol, 250, 270 Ceylon, HMS (cruiser), 258 Combat Information Centre, 303 Ceylon, base for Eastern, British Pacific and Combined Operations radar, 343 East Indes Fleets, 162, 191, 237, 244 combined services plotting room, Chamberlain, Sir Ooseph) Austen, (Foreign Dover, 110 Secretary 1924-29); 6 command and control system, 268 Charts for radar, 214, 215, 215 Committee for the Scientific Survey of Air Chatham Dockyard, 30, 35, 87, 131, 298 Defence (CSSAD), see Tizard Cherbourg, and coastal forces activity, 306 Committee Chichester, Decca station, 213 Communications Branch of Royal Navy, 62 General Index 351

Comprehensive Display System, 258, 262, Corsica, submarine inshore action, 295; 264 shore radar to control coastal Communications Valve Development forces, 303 (CVD) Committee, 22, 23, 25, 67 corvettes, 146, 149, 157, 217, see a/so 'Castle' Concord, HMS (destroyer), 270 class, 'Flower' class conical scanning, see aerial design, general Cossack, HMS (destroyer), 110 'Consol', see Type Designation Index Cossor, A.c. Ltd. , 45 contractors, see outside contractors Coston gun line, 279 Controller (and Third Sea Lord), directs Cotentin peninsula German radar start on naval radar, 1, 10; Swinton stations, 211 Committee. 6-7, 21; chasing progress, 'Counterblast', Operation, (sweep off 15, 21; Applications Officer appointed, Norway), 232-3 16; resource reorganisation, 19-20; countermeasures, see radar appointed Somerville coordinator, 32; countermeasures loan of type 281 to USN, 90; rule for 'County' class cruisers, 92, 135 'Bubbly', 237; see a/so Fraser, 'County' class guided missile destroyers, Henderson 256, 257, 259, 260 convoy Courageous, HMS (fleet carrier), 18, 307 escorts, Audacity, 90, 119-20, 166; Courseulles, British Assault Area HQ in auxiliary AA ships, 169; catapult 'Neptune', 220 aircraft merchantmen, 81, 99; Coventry, HMS (AA cruiser), 52, 56, 63, 73 changing requirements, 277; escort Coventry, HMS (post-WW2 destroyer), 304 carriers introduced, 142; escort Craig, Ordinary Seaman A.B., 75 aircraft 144, 250; FAA and RAF Creasey, Captain G.E. (Director of A/S aboard ship, 81, 311; Escort Warfare), Swanage, 68; radar for Battle Commander, 144; Escort Groups, 79; of Atlantic, 113--14, 147 5th Escort Group, 79; 36th Escort Crete, Allied evacuation, 72, 77; German Group, 120; 39th Escort Group, 95; evacuation, 228 Canadian Escort Groups, 279; USN Croney, Joseph (HMSS/ ASE), 69 escorts, 99; U-boat sightings, 146 cruisers, radar matches gun range, 135; attacked by guided missiles, 312 gunnery range requirements, 183; in radar for escorts, in convoy protection, 'Bubbly', 238; in BPF, 237, 247--8; in 66, 276-81; accelerated production German evacuation of Crete, 228; in of type 79, 22; fixed aerials, 79; 'Harpoon', 153; in 'Husky', 174; in lightweight rotating aerials, 79, 115; night action off Norway, 180; in prefabrication for easy fitting, 149; 'Pedestal', 154; in shore bombardment, 10cm stops back echoes, 151; side 248; in 'Vigorous', 153; sets fitted, 132, echoes in convoy work, 195; US 152, 159, 174, 195, 196,224,253, 254, radars, 201; type 286M, 79; type 279, 255-6, 258-9,260; 15th Cruiser 90 Squadron, 332; Canadian cruisers, 255, classified geographically, Arctic, 147, Italian cruisers, 152; Japanese cruisers, 158-9, 162, 312; Atlantic, 79, 147, 244,247 174; cross-Channel, 306; East Coast, crystal mixer valve, 67, 69, 83, 109, 274 30,87; Freetown, 116; Gibraltar, 115, Cu/ver, HMS (cutter, ex-USN), 146 120,312; Madagascar, 146, 147; Cumber/and, HMS (cruiser), 157, 255 Malta, see below; North Africa, 147; Cunliffe-Lister, Sir Philip, see Swinton, Lord Russia, 138, 158, 187-8, 189, 207; Cunningham, Admiral Sir Andrew, Thames/ Scheldt, 306 Mediterranean Fleet, 61, 63, 73, 74, 76, Malta, 'Excess', 74; 'Halberd', 112; 2nd 117 Battle of Sirte, 152; 'Harpoon', 128, Curacoa, HMS (AA cruiser), 30, 41, 52, 53, 57 153; 'Pedestal' (before, 155; the Curlew, HMS (AA cruiser), fitted with type operation, 128, 153-6, 208, 278, 287; 79Z, 21, 26, 27, 30; visit by Somerville, lessons learned, 173, 174, 182, 186); 35; builds up naval confidence in 'Substance', 110; 'Vigorous', 128, 153 radar, 50; sunk off Norway, 52; other, Allied convoys, 191; German survivors operate type 79 ashore, 47; convoys, 228-9, 233, 234, 305 and FD, 56; and height estimation, 284; Cope/and, Merchant Vessel, 147 and type 79, 50 Coral Sea, Battle of, 128 Curteis, Vice-Admiral A.T.B., 112, 153 corner reflectors, 210 cutters, 276 352 General Index

CVD, see Communications Valve development contracts, 186 Development developments and improvements general, overall, 268-9; Orfordness Dagabur Gtalian submarine), 279 demonstration, 8; early assessments, Dahlia, HMS (corvette), 280 23; at 4m, 13-16; two ships fitted by dan buoy, 217 outbreak of WW2, 21, 25; valve Daring class destroyers, 256 supply urgency, 24-5; priority Daventry Experiment, 6, 7 reminder, 27; IOcm prospects, 70-1; Davies, Lieutenant; 271 of navallOcm radar, 83-4, 180-1; Davis, N.E. (seconded to Signal School from high priority, 99; in gunnery radar, Marconi Company, 1940-44), 102-7, 138, 222-4; in surface cover, beginnings of RCM, 81, 82; jamming 156-8; sea warfare revolutionised, transmitter, 116; jammers at sea, 142 157; high technical content, 277; 'death-ray', 6, 41 1942 requirements, 281; philosophy de Chair, Commander H.G.D., 244, 246 of improvement policy, 181; radar as Decca 12, see Type Designation Index part of a weapons system, 225-6; Decca Company, 213, 221 speed of development, 83, 90, 195, Decca Navigator, see Type Designation 201,234,253; German developments Index in anti-ship guided missiles, 176-7; Deception Operations, 'Fortitude', 210 see also specific topics decimetric waveband, Seetakt detected on priorities, surface rather than air 83cm,81 detection, 11; government priority Dee, P.I. (TRE), 68, 69 to RAF radar, 17; air priority over de Ferranti, V.Z., 166 surface, 24, 26; limited priority to Defiance, HMS (Torpedo School), 2 RDF, 27; highest priority to RDF, 28; Delhi HMS (AA cruiser), 173, 175 Categories A and B defined, 163-6; DEM (French radar), xix schnorkel, 235; for submarine radar, Deneys, Commander J.G.W., 79 296; for production of AI radar, 308; Denmark Strait and sinking of Bismarck, 91, type 285, 61; type 980/981, 261 96 Devonshire HMS (guided missile Denny, Commodore M.M. (Chief of Staff, destroyer),257 Home Fleet, 1943), 1 DF Section, HMSS, 17, 19,20 depot ships, 171 Dido, HMS (cruiser), type 281 prototype,41, Deptford, HMS (sloop), 115 type 281 sea trials, 52, 65, 90, 285; type destroyers, fleet destroyers, 132; 8th Flotilla, 279 fitted, 64; severely damaged, 77; in 63; 16th Flotilla, 126, 130, 131; 21st 'Spellbinder', 232-3; 'Bubbly', 238; no Flotilla, 130, 130; 26th Flotilla, 232, 244, TI radar by 1946, 258; and collision 247; 'C' class, 255; '0'-class destroyers, avoidance, 65; and height 306; Type 42 destroyers, 271; radar determination, 285; and type 281, 90 matches gunnery range, 135; gunnery Dido class cruisers, 39, 41, 66 control requirements, 225, varied Dieppe raid, 128, 212 tasks, 147; prefabricated huts, 149; in diffraction of radar beam, 175 BPF, 248, 250-1; in Battle of Barents digital Fire Control System, see Fire Control Sea, 158-9; in second Battle of Sirte, Dilley, AB (Radar) Arthur, 300 152; in German evacuation of Crete, diode switch, 90 228; in 'Harpoon', 153; off Norway, direction finding, of other transmissions, 54, 228-9, 232, 233, 234; in 'Pedestal', 154; 233,280,295; of landmarks, 279; see also in sinking of Haguro, 246; in sinking of HF/DF Scharnhorst, 188; in 'Vigorous', 153; sets Director Control Towers, 43; early days, fitted, 132, 147, 153, 185, 195, 196,223, 227; main armament, 183; part of 255--6,260; German destroyers, 139-40, weapon system, 225; accuracy of 158, 188; Italian destroyers, 152, 302; whole system, 185, 225; displays in Japanese destroyers, 244, 246; Russian director, 222; type 282 on pom-pom destroyers, 139 director, 58; see also HA director detection of radar transmissions, 11, 26, 66, director trainer, 43, 136 271,280 discharge lines, 131 DeTe-Gerat (German radar), xix discrimination, 316 Deutschland (German pocket-battleship), bearing discrimination, 70, 91, 107, 184, 131,158 258 General Index 353

range discrimination, 105; 184 Dover, Capel shore radar station, 179 displays Dover Castle, 82, 110, 305 general, 316; 'clutter', 210; from scratch, Dover Straits, German coastal batteries, 81; 22; A.c. Cossor, 45; remote, 136, 203; Scharnhorst and Gneisenau Channel trace expansion, 105-6, 136, 184; dash,129 height position indicator, 192; range Dover Z Stations (jamming), 116, 117, 212 v. amplitude, 203, see also A-scan; Dow, Commander USN, technical liaison triple choice with type SQ, 240; in officer, 90 'Bubbly', 238; RDR, 203, 205, 239, Dowding, Air MarshalI Hugh, 5, 6 261, 262, 289; UDU, 261-2 'Dragoon', Operation, (invasion of Southern A-scan, 118; data 'told' to display, 64, 95, France); 191,227 132,171; uses of range-amplitude Drem, RN night fighter School, 312 displays, 203; land echo saturation, Dreyer, Lieutenant Christopher, 305 175; and type 291W, 296, 297; and Drury, W.F. (HMSS/ ASE), 89 type 291 U, 301 Dryad, HMS (Navigation School), 16, 17,208 Plan Position Indicator (PPI), 108-9, 205, DuBridge, Lee (MI'I), 165 240; envisaged, 181; planned, 186; Duke of York, HMS (battleship), 239; fitted lack of PPI a disadvantage, 87, 108, with IDem radar, 112; new lantern 110, 132, 233, 281; first PPI to sea, design, 152; type 271M replaced by 109; needs continuously powered type 2730, 158; other radar sets fitted, aerial rotation, 171, 173, 203; 188, 242; sinking of Scharnhorst, 181, priority, 108; beam width effect, 188, 189; shell damage to radar, 189; 108-9, 171, 173; pulse length effect, Pacific Fleet, 238, 239, 242; 'Bubbly' 259; EM!, 109, 179; JE model, 179, programme, 238; and type 273, 181, 188; RAF PPIs, 171; TRE PPIs, 108-9; 188,189 US PPIs, 169, 201, 220, 240, 301; Dummer, G.W.A. (TRE), 108 remote PPIs, 171, 173, 182, 195, 203; Dundee, Air Ministry Research for PD, 117, 171, 199,260,261; Establishment, 33, 35; PPI planned for 2nd generation IDem development, 108 warning sets, 177, 178, 195; in new Dunkirk, need of radar against seaborne, 11 radar, 182; in type 291M, 260; PPI invasion, 57 predictions, 215, 216, 221; Dunedin, HMNZS (cruiser), 21 reflectoscope, 215, 221; screen Dutch radar, 343 overloaded with targets, 250, 251; in 28th Mm Flotilla, 304; in control of Eagle, HMS (fleet carrier), 155; attack on coastal forces, 220, 304; in ItalIan battlefleet, 64; no radar, (1941), 'Avalanche', 174, 175; off the Elbe, 74; in 'Harpoon', 153; in 'Pedestal', 154, 303; in 'Husky', 174; in navigation, 155; in 'Berserk', 154; sunk, 154; type 215, 221; in the Scheldt, 221; in 285, 153; and PD, 98 sinking of Haguro, 244, 246, 247; in Eagle, HMS (postwar fleet carrier), 259, 261, submarines, 296, 298; ships fitted, 262-4 general, 169; ships fitted, specific, early warning, see warning radar 109, 110, 152, 173, 244; retrospect, East Coast E-boat menace, 58 269 East Coast convoys, 30, 87 sector displays, the problem, 174; the Eastern (British) Task Force Area in solution, 203, 288; in UDU, 261, 262 'Neptune', 217, 220 Skiatron, 171, 172, 172, 173, 205; easy to Eastern (East Indies) Fleet, Admiral interpret, 201; priority, 163, 166; Somervil1e C-in-C, 128; in 'Vigorous', dilemma, 174; shorter pulse gives 153; Somervil1e on RDF, 159-60; back better picture, 259; in to Ceylon, 162; strengthened, 162, 237; Colossus, 238-9 attack on Sabang, 191 dive bombers, 43, 74, 77, 250 Eastney, 14; accommodation for HMSS Domb, Cyril (ASE),34 extension, 12, 13, 101-2; early radar, 15, Dorling, Captain ].W.S. (Captain of HMSS), 17; more staff and equipment, 19; silica valve work, 10; radar 'secret', 10, extension, 33; Symonds, 20; visit by 15; 1937 situation report, 16; Henderson, 24; visit by Somervil1e, 35; succeeded, 18 work on type 79,17,21,26,40; type 79 Dornier aircraft (German), 32 operational at Eastney during raids on Dover and the radio war, 81, 116, 212 Portsmouth, 57; post-Dunkirk 354 General Index

Eastney (cont.) elevation, measurement of, 184, 185, 259, pressure, 57; team for Swanage trials, 260 69; RAF trailer, 71; duplicating TRE Elkins, Captain RF., 226 equipment, 83; first Eastney-built 10cm Elliott Brothers, 4 set, 83; enthusiasm, 87; bulk order for Elliott Research Laboratories, 258 type 271, 87; new magnetron available, Ellis, Captain RM., introduction to radar, 156; prototypes, 156, 157; and type 271, 97-8; Suffolk and the sinking of 87; and type 279, 57; and type 281, 41, Bismarck, 91-3, 96; gunnery radar used 57; and type 290, 107; Gunnery School for surface detection, 97 AA range, 44, 224, 242; rolling Emperor, HMS (escort carrier), 169, 244 platform for trials, 242, 304 Empress of Britain, s.s., 80 E-boats, 87, 99, 112, 126, 220, 306, 312; Emuss, Lieutenant-Commander F.J. RNYR, countermeasures, 305, 306 209 echoes English Channel, E-boat menace, 58 general, 2, 15; absence of, 156, 189; Enigma, 114,308 amplitude, see below; 79, 86, 126, 151, environment in radar office, 262 219; echo-growth curve, 289; effect Equipment Division, HMSS, 208 of sea state, 280; fluctuating, 107; Erebus, HMS (monitor), 142 fuzzy (rain), 244; ground echoes, 67, Erin, HMS (fighter catapult ship), 81 increased by reflectors, 217; land Erne, HMS (frigate), 145, 195 echoes, see below; permanent echoes, errors, aiming, 225, 257; in line (fall of shot), 219; rogue echoes, 79; saturation, 184, 255; location (factors affecting), 175~; ship echoes, 229, 244, 246, 182; lock-on errors, 304; range (faU of 247; side echoes, see below; spurious shot),255 echoes, 151, 174; target and escort carriers, general, 166; VS (CYE), 201 projectile echoes, 280 escort vessels, see convoys amplitude, variation across beam, 106; in Euryalus, HMS (cruiser), 110, 174 height determination, 174, 250; uses Evershed, e.R. (HMSS), 19 of range v. amplitude data, 203; Excellent, HMS (Gunnery School), 35, 44, comparison of types 273P and Q, 224,304 157; type 284M(3) against 'Excess', Operation (passing forces through Scharnhorsl, 188; V-boat off Norway, Mediterranean), 74 234 Exeter, HMS (cruiser), 45 land echoes, 43, 65, 175, 219; device for Exocet missile, 270, 272 their reduction, 227 expanded trace, 105, 136, 184 side echoes, inherent, 151; reduced by Experimental Captain, HMSS, 81, 101, 208 replacing type 271 lantern, 151; Experimental Commander, HMSS, new wider beam gives more, 280; title, 3; reports on radar, 7, 11, 15; tiresome in convoy work, 79, 151, Willett succeeds Wylie, 18, 19 195 Experimental Department, HMSS, formed, Eclipse, HMS (destroyer), 138, 140 1917, 3; Chief Scientist at Tizard Edden, Commander W.K., 44 Committee, 7; reorganized, 19, 20; Edinburgh, HMS (cruiser), 64 influx of new staff, 38; became ASE, Egersund (Norway), radar assisted attacks 1941, 102, 132 off coast, 229, 233, 296, 297 Eglinton, HMS (destroyer), 126 Egret, HMS (sloop), 176 Fair Isle passage, radar cover, 38 Egypt, base for Beaufighters, 228 Fairlight, near Hastings, coast defence with Elba, and costal forces operations, 303 naval radar, 129 Electra, HMS (destroyer), 125 Fairmile 'D' Flotillas, 303, 304 electric razors, 190, 192 Falklands War, 54-5, 270 Electrical and Musical Industries Ltd (EMI), fall of shot, see shell splash spotting contract for PP!, 109; sea trials, 179; Fanning, Lieutenant-Commander Antony type 262x, 186; type 992, 227, 258; The E., 126, 132 Gramophone Co., 166 Far East, 238, 243, 258, 298 electronic countermeasures (ECM), 211, 259, feeders, see aerial feeders 271,317 Ferranti, Ltd, 166 electronic intelligence missions (Elint), 177, Ferranti, Y.Z. de , 166 316 Field, Lieutenant (Sp.) J.e.G. RNYR, 192, 219 General Index 355

Fife, HMS (destroyer), 270 fighter interception, RAF techniques, 28; Fife, Scotland, suggested site for central interception zone, 120, 177-8, 186,250; radar R ok D centre, 33-4 in ll/ustrious in 'Avalanche', 175; visual fighter catapult ships, 80-1 direction, 250; types 294/5, 199; type fighter direction, initial idea, 55; birth, 56-7; GCI,242; type SM-l, 242 early methods, 56-7, 62; fighter Fiji, HMS (cruiser), 64, 77 defence of Fleet, 77, 80, 117, 153-4, Fiji class cruisers, 39, 66, 112, 255 154-6; PPI suggested, 108-9; technique fire control, centre, 136; control system, 4, diffusion, 63, 75, 152, 177; problems, 225; radar, see gunnery radar 65,117,153-4,156; in 'Avalanche', 174; fire control box, 4 in Carlisle, 62-3; in fllustrious, 64-5; in fire control table, 136 'Berserk', 154; in 'Husky', 174; in Firefly aircraft, 310, 312 'Pedestal', 173, 174; in 'Neptune', 209; Firth of Forth, ships attacked by Ju88s, 32, in 'Knobbly', 237; use of pickets in Far 261 East, 250; occasional use of TI radars, Fisher, Lieutenant (Sp.) Ceri, RNVR, 164 182; FD Branch, 56, 57, 64, 11S-19; FD Fisher, Commander R.L., 7~, 152-3 Landing Ships, 241-2; FOOs, see below; Fiume, (Italian cruiser), 76 FD radar, see below; FD School, 119, Fleet Air Arm, see naval aircraft/squadrons 120, 154; FD Ships, see below; FD fleet carriers, only two operational,117; fit Tenders, see below; fighter type 281/B, 117, 118; Force H in interception, see below; night fighter 'Husky' and 'Avalanche', 174; in Far control, 172, 191, 241; RN Aircraft East, 237, 238, 248; type 960, 259 Direction Centre, 263, 263; visual Fleet Train, 238, 247-8 control, 250 Fleetwood, HMS (sloop), 254 fighter direction officers, visual control, 250; F1iegerkorps X (German), 74, 77 'Pedestal' used as example in FIX) 'Flower' class corvettes, 83, 86, 109 training, 154; PPls near intercept Flying Fox 7 Division, RNVR, 127 position, 171; transfer of techniques, Focke-WuIf aircraft, (German), Battle of 75; FOOs meet in Virginia, 117; Beale Atlantic, 77, 80; Empress of Britain in ll/ustrious, 64; Coke in Ark Ruyal and attacked, 80; FW shot down 400 miles Victorious, 56, 92; Parry in Audacity, from land, 81; CAM successes, 81; 120; Pol1ock in ll/ustrious, 171; some Audacity shoots down FWs, 120; FOOs trained by RAF, 228; RAF detected by type 271Q when flying Controller as well as FIX) in Boxer, 242; low, 157; FWl90s destroy Ashford in Falkland War, 270-1 School, 17S-9 fighter direction radar, FD radar, 260-4; Folkestone, HMS (sloop), lIS, 278 need of radar, 177; plans, 186-7; Force H, Admiral Somerville, 38; and the development, 199-201; priority, 163; Mediterranean Fleet, 61-2, 63; Staff requirements, 181, 186; dedicated Sheffield with radar, 74; Ark Ruyal FD sets, 260, 261; TI set used for FD, torpedoed, 117; in 'Excess', 74; in 182; very complex, 187; plans revised, 'Husky' and 'Avalanche', 174; in 261; project modification, 262; postwar 'Substance', 110 type 984, 262; type SM-l, 201, 251; see Formidable, HMS (fleet carrier), 249; radar also types 294, 295, 980 fitted, 75, 180, 220, 249; second carrier Fighter Direction Ships, lacking in with radar, 63; Mediterranean, 74-5; 'Pedestal', 156; auxiliary AA ships, Battle of Cape Matapan, 75, 76; 169; AA and air direction frigates, 259, severely damaged, 77; repair in USA, 264; in 'Dragoon', 227; in 'Knobbly', 117; unsatisfactory aerial 241; in 'Shingle', 191; in Salemo arrangements, 89-90; type 279 landings, 174; radar set policy, 171, replaced by type 281, 117-18; working 287; in Boxer, 241; in Palomares, 191, up in Indian Ocean, 152; in 'Torch', 242; in lRster Queen, 174, 191, 227-8, 156; prototype ADR, 156; Sicily and 242; types 281B and 79B, 171,287; Sardinia landings, 174; operational types 294 and 295, 186; type GCI, 284; after hit by Japanese planes, 248; type SM-l, 201 Vian's flagship, 251; and FD, 152; fighter direction tenders, air defence of FAA aircraft, 309; and type 276, lOO, beaches in 'Neptune', 217; in FDT 13, 196 217, 218, 227, 242; in FDT 216, 217; in Formosa, Japanese airfields attacked, 247, FDT 217,217 248 356 General Index

Fort Wallington, Portsdown Hill, naval and effective, 222; see also types with GB RAF radar site, 57 classification in pp 340-3 'Fortitude', Operation, (deception operation GC radar, classification, 340; general, 185-6; in 'Neptune'), 210 new type 282 for 'ideal' system, 103; Fortune, HMS (destroyer), 126 equipment more effective, 222; new Foyle Bank, HMS (auxiliary AA ship), 100 equipment integrated with weapons Franklin, HMS (survey ship), 222 systems, 223; type 262 trials, 242-3; sets Fraser Battery, Eastney, 224 fitted, general, 101; see also types with Fraser, Admiral Sir Bruce, Controller of GC classification on pp 340-3 Navy, (1939),32; C-in-C Home Fleet GCI, see Designation Type Index (1943), 162; sinking of Scllarnilorst, 188, Geddes, Lieutenant-Commander Murray, 190; BPF, 191, 237 RNZNVR, his method of Free French MTB, 306 heightfinding, 287 Fremantle, base for British submarines, 298 'Gee', see Type Designation Index Freetown convoy, OS 12, 116 'geneva cross' device, 106-7 French coast, German radar stations on General Electric Company (UK), told of Channel, 116; Allied landings in radar, 22-3; Megaw, 20, 23, 67, 68, 84; Southern France, 191, 227 visit by Somerville, 35; magnetron French North Africa, 128 development, 20, 67, 68, 70, 71, 84, 156, 'Freya', see Type Designation Index 274; tributes, 67, 70, 84; type 282 frigates, control of MTBs, 220; retained type transmitter, 44-5; RCM transmitter, 82 285, 255; air direction, 259, 264; type German air force, 162, 182, 188, 217, 226 277, 196; type 960, 259; type 993, 259 German anti-submarine trawlers, 296, 297 Fuhrer, Rear-Admiral, USN, 165 German coastal batteries, 81, 210 'Fuller' (codeword), 128, 129 German convoys, 305 Fulmar aircraft, in 'Hats', 63; attack on German destroyers, 139, 140, 158, 188 Taranto, 64; in Illustrious in the German jamming, 116-17 Mediterranean, 64; Malta based planes German minelaying aircraft, 210 in 'Excess', 74; in fighter catapult ships, German M-class minesweepers, 306 80; against Bismarck, 96; embarked German Minister in Montevideo, 48 night-fighters, 310, 312 German Navy, general, 220, 230 Furious, HMS (fleet carrier), 152, 154, 278, German radar, in Gra! Spee, 45; in 310 Schamilorst, 55, 188; Bismarck action, 92; Fury, HMS (destroyer), 138 comparison with British radar, 190; fuzes, 137, 138; VT fuze, 320 RAF attacks Channel Coast radar sites, fuze-keeping clock, 4 210-11; for 'Coastwatcher', 'Freya', FX.1400, (radio-guided bomb), 176, 192 Giant and Small Wiirzburgs, Hohentwiel and 'Seetakt', see Type G.10 (German torpedo boat), 49 Designation Index Gadilo (Dutch Merchant Aircraft Carrier), German radio navigational aid:Sonne', 311 known to Allies as 'Consol', 234 Galatea, HMS (cruiser), 64 Ghent, Decca station, 221 Gallant, HMS (destroyer), 74 Giant Wiirzburg, see Type Designation GA radar, classification, 340; dive bomber Index threat, 43; aerials on gun director, 44; Gibraltar, radar transmissions detected at development of 50cm sets, 44; sea long range, 26; convoy access trials, 65-6; ships fitted, general, 101; vulnerability, 80; convoys, 115, 120, plans for second generation, 177-8; 312; convoys attacked by german plans for third generation, 256-7; see missiles, 176, 190,312; Force H base, also types with GA classification on 61; 'Hats', 63; 'Substance', 110 pp. 340--4 Gibraltar, Straits of, U-boats 115; U.451 sunk Gardenia, HMS (corvette), 84 by 812 squadron, 308-9 Garnons-Williams, Commander N.G., 7 Girdle Ness, HMS (trials ship), 257 G-band interrogator, 343 Gladiator aircraft, 62-3 GB radar, classification, 340; general, 137-8; GlasgolV, HMS (cruiser), 64, 73, 238, 242 dive bomber threat, 43; type 283, 66; glider bomb, Hs.293, (German), 175, 176, Staff requirements (1941), 103; auto• 190,192,219 barrage computer, 106; precision Gloriolls, HMS (fleet carrier), 55 ranging panel, 137; much more Glory, HMS (light fleet carrier), 238 General Index 357

Gloucester, HMS (cruiser), 74, 77 Gun Direction System, GDS 3, 258, 259 Glover, Captain Philip F., 18 'Gun', Operation Channel dash with Scharnhorst, 128, Gunnery and AA Warfare Division, 129, 131; hit by shore fire, 129-31 Admiralty, 44, 103, 183, 206, 256, 258 Gold, T. (ASE), 34 Gunnery Equipment Division, 222 Gollin, E.M. (HMSS), 13, 49 gunnery radar Goodwin, Lieutenant D.G., 98 general, the AA problem, 4; prewar steps, Gorleston, HMS (cutter, ex-USN), 278 20, 21, 23, 24, 28, 40; Staff Graf Spee, (German pocket battleship), see requirements, 43, 44, 103, 105, 178, Admiral Graf Spee 225,226; administration, 206; as part Gramophone Co. Ltd, The (part of of a weapon system, 136, 225, 226; EM!),166 barrage contro\, 43, 106, 107, 137-8; 'Gratis', Operation (FAA minelaying off blind fire, 135, 136, 138, 184, 185, Norway), 233 230; close range gunnery, 185-6; Great Orme (N. Wales), trials of type 277T, shell splash (fall of shot) spotting, 178 136, 184; TI, 181-3; AIO in gun Greece, evacuation of, 72, 77 direction, 205-6; need to be put on Green, Leading Telegraphist Jimmy, 52-4 target by warning radar, 209; Gretton, Commander P.W., 278 variable time fuze, 222; gunnery Group West (German), 96 radar at end of War, 254, 255; Grubb Parsons, see Howard Grubb Parsons guided missile control, 256-8; GS radar, classification, 340; sea trials type search-and-Iock-on radar, 259; third 284, 65-6; type 284 in sinking of generation gunnery radar, 256-7; Bismarck, 96; sets fitted, general, 101; fully stabilized digital fire control type 274 priority, 163; lOcm radar, 183, system, 258; see also specific sets 184; type 284M(3) in sinking of classified in 340-4 Scharnhorst, 188; sets integrated with 50-70cm wavelength, 50cm development, weapons systems, 222-4; type 274 in 20, 21, 24; 50cm radar to sea, 58, 66; Norfolk, 232; priority fitting 10cm sets industrial liaison, 61; gunnery for BPF, 242; some 50cm sets in use at ranging equipment added, 73; end of war, 254; LRS 1 for the future, gunnery radar for surface warning, 256-7; see also types with GS 97; dedicated gunnery sets to be classification in pages 341-4 fitted, 117-8; in sinking of Guada1canal, Battle of, 128 Scharnhorst, 188; in night action off Guernsey, action with coastal forces, 306 Norway, 230; rate of ship fitting, guided missiles, genera\' 225-6, 253, 257; 135; ships fitted, genera\' 73, 101; guided missile destroyers, 256, 259; improvements, 102-3; performance, Guided Missile System Mk.1, 257; 103, 105, 135; fire control cover, 122; Gibraltar convoys affected by German see also types 282, 283, 284, 285, 288, missiles, 176, 190, 312 289 Gulf of Siam, sinking of Prince of Wales and 10cm wavelength and below, Repulse, 122 development of centimetric gunnery gun direction radar, 138, 178, 182, 183, 184, 222-4; general, 120-2, 181-3; pre-radar, 121; priorities in fitting, 222-3, 242; X• weapons systems, 122, 256-8; radar band, 234, 242-3; performance, as part of weapon system, 203, 182-3, 188; BPF, 247-8; in Norfolk off 225-6; Air Defence Position, 122, Norway, 232; see also types 262, 263, 126; changes, 270 269, 274, 930, 931 target indication, 226-7, 258-9; TI blind fire, definition, 315; concept, 136; requirements, 181-3; target handling bearing accuracy insufficient, 103; capacity, 227; Target Indication aerial limitations, 136; loss of all• Officer, 226, 227; TIR, 183, 205, 224, round warning facility, 137; 227,239; TI radar specification, satisfactory for surface actions, 138; 120-1; TI radar, scc gunnery radar; TI priorities, 163; Staff requirements, zone, 120; see also AIO 193; progress, 222; review, 268; 358 General Index gunnery radar (cont.) 290; conical scanning, 199; contour blind fire (cont.) against aircraft, 184-5; in method, 285, 286; development of 'Avalanche', 176; with coastal technique, 284-5; Height Display, 288; forces, 304; in night actions off Height Filtering Position, 203, 317; Norway, 229, 232; in sinking of Height Position Indicator, see displays; Scharnhorst, 188; near St Malo, 230; by elevation measurement, 178, 196, in surface actions, 224; and TI, 226; 'Height Finding by RDF, Admiralty in 'Vigorous', 153; type 262 on Manual CB 4224, 286, 289, 290; long ST AAG, 185; beam switching on range, 282; plans specify accuracy type 274, 184 required, 186; post-war, 259, 260, 261- Gunnery School, see Excellent 2, 264, 290; practical method of Gunnery Section, ASE, 125, 222-J combining three systems, 287; gunnery systems, GDS 3, 258-9; LRS I, 226, preparation for Far East, 289; search 256-7, 288; MRS 1, 256; MRS 3, 226, for method not requiring aerials to be 255, 258; MRS 4, 226, 258,; MRS 5, 226, stopped, 199, 260, 261; Sector Display, 258;SRS,256 203, 287; selection of operators, 289; Gurkha, HMS (destroyer), 144 type 281 aerial characteristics useful, gyro, repeaters, 95; sights, 166, 185, 222; 65; type SM-l problem with stabilization, 189 anomalous propagation, 251; use of combined vertical polar diagrams, 174; H.34, HM submarine, 38 use of echo amplitude data, 203, 286, HA Director, 43, 59, 184, 224 287; Vertical Coverage Diagrams, 283, HA Fire Control radar, see GA radar 286, 288; War in Mediterranean, 287-9; Haguro (Japanese cruiser), 232, 244, 246 War in Pacific, 250, 251, 282, 290; see 'Halberd', Operation (Malta convoy), 112 also types 277, 277Q 981, SM-l Halifax Ocean Meeting Point CHOMP), 279 Height Position Indicator (HPI), see displays Hallifax, Captain G.w., 10 Heinkel 111 aircraft (German), 30 Hamer, Lieutenant John, 127 helical scanning, 304 Hamilton, J. (Naval Operational Research Hellcat aircraft, 312 Department), 215 Henderson, Admiral Sir Reginald Hampton Lodge, merchant vessel, 279 G.H.,Third Sea Lord and Controller of Hankey, Sir Maurice, 34; 'Hankey Boys' Navy (1935), I, 32; Swinton scheme, 34-5, 113 Committee, 6-7; tells Navy of radar Hannover (German liner), see Audacity (1935),24 Hansford, RF. (HMSS/ ASE), 215 Hermes, HMS (fleet carrier), 125, 264 Harbour Defence Motor Launches, 217, 301 Hermione, HMS (cruiser), 153 'Harpoon', see convoys, Malta Hero, HMS (destroyer), 152 Harrls, AB (Radar) Rowland T., 300 Hertz, Heinrich, German physicist, 2 Hartley, Commander J. (HMSS Application Hesperus, HMS (destroyer), lIS, 151, 279 Officer), SO, 284 Hezlet, Lieutenant A.R. Oater Vice-Admiral Hartley, Sub-Lieutenant M. (formerly Sir Arthur), navigating by radar, 300; Rosenthal), RCNVR, 90 author cited, 63, 77 Harvester, HMS (destroyer), 277 HF/DF (high frequency direction-finding), Haslemere, HQ of ASE, 101, 132, 135 142~, 147, 268; fitting policy, 179,277; 'Hats', Operation (passing forces through in Battle of Atlantic, 162; in FD ships, Mediterranean), 52, 63, 64 169; aerials, 144, 145,168,170,193,223, Hecla class depot ships, 39 236; Outfit FH3, 144; Outfit FH4, 144, Hedgehog A/S mortar, 157 146 Heemskerck (Dutch cruiser), 343 High Angle Control Position, 137, 185, 223 height determination/estimation/ finding/ High Angle Control System, 4, 43, 55 measurement, terminology, 282; high cover, 117, 171, 199 principles, 282-5, 291-2; early HilJlry, HMS (headquarters ship), 219 experience in Carlisle, 43; problems, 65, Hill, Professor A.V., Tizard Committee,S, 6 174,175; need for improvements, 156, Hipper (German cruiser), see Admiral 172,177; conflict with other needs, 169, Hipper 174, 196, 199; effect of radar set HM Signal School (HMSS), 317; pre-1935, I, performance, 282, 284; Azicator, 205, 3, 7; prewar progress, 16, 28, 32-3; 291; calibration llights, 43, 62,282, 284, Tizard Committee, 7; Orfordness, 8, 10, 285, 288, 289, 290; 'CB 4224', 286, 289, 15; silica valve R&D, 8, 10; authorized General Index 359

to work on radar, 1, 3, 10, 12, 13; Holland, Vice-Admiral L.E., 91, 93 resisted call for radar research to be Home Fleet, detected by RAF radar in fog, centralized, 12, 33; Admiralty 18, 307; two ships with RDF at requirements, 11,41,43,44,28, 103; outbreakof WW2, 21, 30; C-in-C told secrecy, 2, 8, 10, 15, 16, 20, 22; 'Caught about radar, 24; combined Exercise with trousers down', 20; staffing, detects radar transmissions at long recruitment and premises, 12, 13, 17, range, 26; first radar-assisted skirmish, 19,25,27-8,34-5,38-9,44; staff leave, 30; temporary move from Scapa Flow, 88; early aerial design, 17, 43; 1937 32, 49; Tovey becomes C-in-C, 52; reorganisation, 19, 20; D/F Section, 17, radar reinforcement, 64; containment 20; RCM Section, 81, 82; getting sets to of heavy German units, 72; C-in-C's sea, 21, 22, 57; memo on naval uses of views on radar, 90, 110, 157, 158; radar, 23-4; Valve Section, 8, 24, 25,26, Bismarck action, 91, 92; in 'Halberd', 37, 67; Churchill's visit, 35; attempts to 112; Fraser becomes C-in-C, 162; in 'poach' Horton, 37; dispersal of HMSS, sinking of Scharnhorst, 187-8, 190; in 35,37, 101-2, 132, 153; Bristol, 37, 70; 'Substance', 110; Commodore Nutbourne and aerials, 20, 79, 89-90, (Destroyers)' report, 195--6 101; On slow Road and gunnery, 44, 89, homing, 279; see also types 72 and YE 101, 102, 103; Eastney Fort East, 14; Hood, HMS (battlecruiser), damaged at Tantallon, 102; relocation, 25, 101-2, Scapa, 32, sea trials of single mast type 132,135; production methods, 21-2, 26; 279, 90; radar sets fitted, 93, 100; workshops, 21, 22, 26, 39, 83, 84, 87, Bismarck action, 91, 93, 94; radar in 158; genesis of type 281, 40--1; genesis working order prior to that action, 94; of types 282, 284 and 285, 43, 44; sunk, 72, 90 warning radar for small ships, 57; Hordern, Lieutenant-Commander M., components for 50cm radars, 61; RNVR (now Sir MichaeD, 160 Swanage trials, 68-9, 70--1; Admiralty Horton. CE. (HMSS/ ASE), 165, 266; DF Trailer, 69; early lOcm sets, 83, 84, 86; Section (1935), 8; Radar Division, 19, production of type 271, 87, 163; 20, 23, 24, 29, 34, 40, 44, 90, 166, 268; prototype of types 271Q and 273Q, Churchill intervenes, 39; at Swanage 156; PPI and FD, 108; use of outside trials, 68, 69; to Admiralty, 208; tribute contractors, 20, 39, 44-5, 67, 68, 156, to, 265 267; Applications Officers, 16, 108, 237, Howard Grubb Parsons, 187 284; ASE created a separate Command, I-Iowe, HMS (battleship), 158, 196, 224 102; Captain Superintendent ceases Howse, Lieutenant H.D., 79, 80 direct involvement with naval radar, Hoyle, F. (HMSS/ ASE), 34, 285 206; Captain B. Willett and Hs.293, German glider bomb, 175, 176, 190, Commander CV. Robinson, 88; for 192,219 later references see Admiralty Signal Hudson aircraft, 65, 280, 307 Establishment; see also Eastney, 'huff-duff', see HF/DF Nutbourne, Onslow Road Hughes, H.G. (HMSS/ ASE), 8 Experimental Commander, 3; Tizard Hiilsmeyer, Christian, 2 Committee view, 7; Orfordness 'Hunt' class destroyers, 59, 126, 234, 254, 306 report. 15; privy to radar 'secret', 15; HUllter, HMS (escort carrier), 174 reorganisation, 19 Hurricane aircraft, 80, 81 Experimental Department, formation, 3; 'Husky', Operation (invasion of Sicily), 162, Shearing at Tizard Committee, 7; 174,190 reorganisation, 19; recruitment; 38- hydraulics, 185 9; separate Command (ASE) from Hydrophone Effect, 146, 278, 299, see also August 1941, 102; RDF Division asdic move to WitIey, 132, 135 Hoare, Captain E.M.B., 230 'Iceberg', Operation (assault on Okinawa), Hodge, Lieutenant John.R. RNVR, 50--1, 284 232,248 Hodgkin, A.L. (later Sir Alan), (TRE), 68 iceberg detection, 17 Hogben, H.E. (HMSS/ ASE), 86, 165, 266 Identification Friend or Foe, OFF), radar, Hague, HMS (destroyer), 242 317; IFF and radar recognition. 141-2; Hohentwiel ASV, see Type Designation needed, 87; confusing variety in use, Index 173, 176; simplified system called for, Holland, Rear-Admiral CS., 165 281; priorities, 163; policy, 277; Sector 360 General Index

Identification Friend or Foe, (IFF) (cont.) Interrogation (radar), 159, 203, 277, 281, see Display, 174,203; affects rate of search, also specific sets given on pp 340-4 219; compatibility with 11 radar, 259; interrogators, 159, 173, 203, 277, 281 in Battle of Barents Sea, 159; as a Inter-Service, abbreviations, 163; beacon for navigation, 141; Mark 1,141, agreements, 68; committees, 33; 173, 176; Mark 11, 141, 142, 173, 175, communications, 130-1; conferences, 176; Mark IIG, 173, 176; Mark IIN, 141, 84; radar research, 33-4; Radio Board, 173, 176; Mark ill, 173, 175, 176 166; valve developments, 23, 25, 67 nIustrious class fleet carriers, 27, 39, 56 Invincible, HMS (carrier), 270, 271, 272 nIustrious, HMS (fleet carrier), first carrier ionospheric research, 2, 6, 8 with radar, 63, 251, 284; first Iron Duke, HMS (battleship), 32 operational type 277Q 260; later radar 1ronclad', Operation (British landings on fittings, 89, 108, 117, 171,251,260; in Madagascar), 232, 248 Mediterranean Fleet, 63, 73; in 'Hats', Irving, Commander E.G., 222 63; air strike at Taranto, 64; severely Isaac Sweers (Dutch destroyer), 343 damaged in 'Excess', 74; replaced by Isle of Man radar training school, see Formidable, 74; repaired in USA, 117; in Valkyrie Eastern Fleet, 152, 160; in 'Avalanche', Isle of Sheppey Decca station, 213 174; and PO,63, 64, 75, 117, 171, 172; Italia (Italian battleship, ex-Littoria), 176 and height estimation, 333; and type Italian aircraft, 74, 153, 175 279,252; and type 281, 108, 171 Italian Fleet, 73; attacked by Germans, 176; Imperial Defence Committee Report on AA submarines, 154, 277; surface forces, Defence, 4 152,153,156,302 Implacable, HMS (fleet carrier), 196, 238, 312 Italy, armistice, 175; capitulation, 176 Indefatigable, HMS (fleet carrier), 196, 238, Itlu/Tea (German, ex-Greek, steamer), 293 248 Indomitable, HMS (fleet carrier), 155; British radar sets fitted, 117, 170, 172-3, 174, Jackson, Commander H.B., 2 198, 250, 258, 259, 260; American radar Jamaica, HMS (cruiser), 159, 188, 189, 238 sets fitted, 196,201,290, 291,344; first jamming type 293Q fitted, 258; ran aground own, policy, 83; early transmitters, 158; during work up, 117; after repair, 198; radio war at Dover, 116; jammers at work up in Indian Ocean, 152; in sea, 142; in 'Neptune', 210, 211, 231; 'Pedestal', 154; in 'Berserk', 154; in action off Norway, 233; type 651, severely damaged, 154; Skiatron trials, 192; use of 'noise' modulation, 82; 163, 166, 172, 172-3; invasion of Sicily, postwar, 272 174, 190; torpedoed by aircraft, 174; enemy, 23, 129, 159, 213, 272, 297 temperature in radar office, 190; radar• Janus, HMS (destroyer), 179, 180, 182, 183, fitted aircraft, 309; hit by kamikaze 227 attack, 248; attacked Formosan Japan, Pearl Harbor and Gulf of Siam, 99, airfeilds, 248; under Japanese air 122; Allies attack mainland, 248, 251; attack, 250; damage repairs, 251; and Allies attack Formosa, 248; surrender, PO, 152, 154, 172-3; and Skiatron, 174; 253 and height finding, 201, 250, 287, 290, Japanese aircraft, bombers attack British 291; and type 277, 250 submarine, 293; expected to learn from industry, see outside contractors German successes, 182, 226; kamikaze infra-red detection, 7 attacks, 191, 248, 250; sinking of Prince interception of radar by enemy, fear of, 11, of Wales and Repulse, 124-5, 126 26,271,280,293-5 Japanese landings, 124 interference, conflict with WIT Japanese warships, Haguro sunk, 244, 246; communications, 12, 23, 308; redesign carrier fleet, 309-10 to minimise, 26; multiple suite of Jay, Lieutenant Richard, 298 radar, 89, 103; PO ship problems, 242; 'JE', see PPI from land echoes, 43; from jamming, Jellicoe, Admiral of the Fleet, Earl, 268 297; from similar set, 300; with aircraft Jennings, Sub-lieutenant, RNVR, 116 electrics, 309; in 'Neptune', 210 jet-propelled aircraft, 253, 257 intermediate frequency (IF), 274 Jones, RV. (Assistant Director of International Meeting on Radio Aids to Intelligence (Science) at Air Marine Navigation (1946), 254 Ministry), 49 General Index 361

Joubert de la Ferte, Air Marshal Sir Philip, Landing Ship, Tank, 174, 217, 241-2, 284 84 Langley, Captain G.M.B., 137, 183 'Judgment', Operation (attack on Taranto), Largs, HMS (headquarters ship), 219 52 Lark, HMS (AA sloop), 194 Junkers aircraft (German), Ju.52, 228; Ju.88, Laws, Lieutenant (Sp.) R. Alan, 32,139 RNVR, 139-40 junks, 298 Lawson, Commander H.F., Naval Ordnance Jutland, Battle of (1916), 268, 269 Department, 35, 44 Leach, Captain J.c., 93, 94, 125 Knmikaze (Japanese destroyer), 246 Leads, see Norwegian Leads kamikaze suicide bomber, 248, 250 Leamington, HMS (sloop), 146 K-band, see wavelength, 1.25 cm Lee-on-Solent RN Air Station, 58, 304 KeaU, O.E. (seconded to Signal School from Leeson House, 68, 69, 274, 275 Marconi Company, 1940-45), 82 Legion, HMS (destroyer), 79 Kent, HMS (cruiser), 134, 159, 229 Le Havre, deception in 'Neptune', 210; Kenya, HMS (cruiser), 64, 111, 112, 153 German evacuation harassed, 306 Keppe1, HMS (destroyer), 278 Leigh light, 142 Kete, South Wales (RN Aircraft Direction Lend-lease Bill, 72, 90 Centre), 263, 263 Lend-lease ships, general, 167, 195, 201; Keynes, R.D. (HMSS/ ASE), 34 destroyers, 61; unofficial, 303 Kilroy, Lieutenant G.P., 49 le Rossignol, R. (GEC Laboratories), 22 Kinahan, Captain H.R.G., 50 Lewin, Admiral of the Fleet, Lord, 230 King Edward's School, Witley, 101, 135 Lewin, Commander E.D.G., 248, 250, 251 King George V, HMS (battleship), trials of Lewis, Wilfred Bennett (TRE), 108 type 284 prototype, 52, 59, 61, 66, 89, Leydene, Petersfield, HMS Mercury, 101 105, 112; trials of second prototype Leyte Gulf, Battle of, 191 type 273Q, 157; other radar sets fitted, Liberator aircraft, 250 64, 109; PPI fitted, 109; Bismarck action Light Fleet Carriers, 201, 238, 243, 248, 256, 91; first ASV IIN in navy, 308; and type 263 279,160-1 limitations of naval radar, dimensions, 280; King George V class battleships, 39, 160 fear of detection, 11, 26, 54; low air King George VI visits ASE, 135 cover problems, 250, 251; maintenance klystron valve, 67, 317 staff shortage, 276-7; sea conditions, Knight, Lieutenant Duncan, 115 280 'Knobbly', Project (fitting out of long range Lindemann, Professor F.A. (later Lord LSFs for Pacific), 237, 241 Cherwell), 4, 6-7 Knox, Colonel, US Secretary of the Littorio (Italian battleship), 152 Navy, 90 Lively, HMS (destroyer), 110, 144 Kiinigsberg, (German cruiser), 49 Liverpool, HQ of Western Approaches Kola Inlet (Murmansk) Russian base, 140, Command,79 189 Lloyd, David (ASE), 172 'Kondor', see Focke-Wulf local oscillator, 69 Korean War, 242, 243, 253, 258 'Loch' class frigates, 196, 235, 260 Kretschmer, Captain Otto (German Loch Killisport, HMS (frigate), 236 Navy),80 Lofoten Islands, action off, 55 Londonderry, Lord, Air Minister (1931-35),5 Lance, HMS (destroyer), 144 Lovell, A.C.B. (later Sir Bernard), (TRE), Landguard, HMS (cutter, ex-USN), 279 centimetric radar (Swanage), 68, 69, 70; Landale, S.E.A. (HMSS/ ASE), 165, 266; type tribute to aerial development, 84 281 trials, 65; development of 10cm low cover, need for effective radar against radar, 69, 83, 84, 86, 110, 181; low-flying aircraft, 117, 156, 172, 174; prefabrication, 149; Head of Radar and type 281,117,169,171; and type Department (1944), 208 990,186,199; and type SM-l, 196 landing craft, 212, 221 low-flying aircraft, 117, 156, 157, 177, 179 Landing Craft, Gun, 302 Luftwaffe, 64, 72, 74,176 Landing Craft, Headquarters, 213, 213, 221 Lulwortlr, HMS (cutter, ex-USN), 277 Landing Craft (Rocket) 334, 200 Li.itjens, Vice-Admiral, (German Navy), 72, Landing Ship, Fighter Direction, 241-2 73,96 362 General Index

LUtww, (German pocket battleship, Marne, HMS (destroyer), 157 formerly Deutschland), 128, 158 Martlet aircraft, 120, 175 Lyster, Admiral A.L.St G., 63, 64, 154 Massachusetts Institute of Technology, Lythe Hill, Haslemere, HQ of ASE, 101 Mission to ASE, 165 Matane, HMCS (frigate), 219 'M' class German minesweepers, 306 Matapan, Battle of Cape, 65, 72, 75, 91, 97 MacArthur, General Douglas, USA, 248 Mauritius, HMS (cruiser), 123, 238 McAulay, Lieutenant T.B. RNVR, 252 Maynard, Lieutenant (Sp.) John C. RCNVR, McCormick, Sub-Lieutenant (Sp.) R. 155,285 RCNVR, 160---1 mean point of impact (MP!), 184 MacDonald, (James) Ramsay (Prime Mediterranean Minister, 1931--35), 4, 6 general, 63--4, 73--5; Anzio landing, 191; Macdonald, Midshipman R. (later Vice• 'Coat', 64; German use of Admiral Sir Roderick), 55--6, 126 coordinated concentrated air McGrigor, Rear-Admiral RR, ACNS(W), attacks, 182, 226; Germany denied 150, 163; in cruiser sweeps off Norway, air supremacy, 162; 'Hats', 52; 229, 230, 232 landings in S. France, 227--8; loss of Macintyre, Commander Donald, 79 French naval power, 61; under McIntosh, Lieutenant Ian (later Vice• siege, 72, 152; operations off Elba, Admiral Sir Ian), 296 302--3; unusual atmospheric McKaig, Midshipman R (later Admiral Sir conditions, 175; see also convoys, Rae),61--2 Malta McKay, AB (Radar) E., 189 Fleet, combined exercises create fear of Mackendrick, Commander D.W., 120 enemy homing in on radar Madagascar, Operation 'Ironclad' (British transmissions, 26; based on landings); 128; convoys, 146, 147 Alexandria, 73; added ships with Madge, H.W., first civilian wireless expert radar, 64; air attacks on Italian in Vernon (1905), 2--3 battlefleet, 64; air superiority 64; loss magnetic mines, 75 of air control, 74; concern over magnetic torpedo pistol, 304 Hs.293, 192; 'Excess', 74; radar magnetron, 317; see also valves security limits transmission maintenance of radar at sea, responsibility, times, 64 27, 62, 113, 251; priority to maintain medium cover, 171 performance and reliability, 163; some Medium Range System (gunnery) (MRS), maintenance not easy, 109, 195; radar/ 226,255--8 radio maintenance ship in BPF, 247; Megaw, Eric C.S. (General Electric type 276 teething troubles, 195; type Company), valves for centimetric 271 'on the blink' in action, 1312; type radar, 20, 23; magnetron redesign,4 67, 281 gearbox frozen, 139; repair of 68; tribute by Or Landale, 84 damage in Scharnhorst episode, 189; Merchant Aircraft Carriers, 143 Somerville in Warspite, 160 Merchant Navy radar, specification, 235, Makeig-Jones, Captain W.T., 18 237; implementation, 254 Malacca Straits sighting, 244 merchant ships,in Malta convoys, 153, 154; Malaya, HMS (battleship), 90, 153, 332 post-war merchant navy radar, 234, Ma/Colm, HMS (destroyer), 58, 277 254 Malta, under siege, 72, 152, 153; countering Mercury 1, HMS (Signal School, Leydene), German jamming, 116-7; fighter 101 aircraft base, 154, 155~; Italian Fleet Mercury I1, HMS (ASE), 102 surrender, 176; see also convoys 'Meridian', Operation (air attacks on oil Mann, K.c. (Canadian engineer), 304 refineries in Sumatra), 232, 248 Malvern, RRDE, 33 Messerschmidt ME.110 aircraft, 131 Manchester, HMS (cruiser), 73, 156, 160 methods of detecting aircraft, 7 Maplin, HMS (fighter catapult ship), 81 'Metox', German U-boat search Marconi Ltd, staff secondment, 39, 81, 82; receiver, 142 type 282 receiver, 45; types 271/3 Metropolitan-Vickers Electrical Co., 87, 149, prototypes, 156; development 166, 187,296 contracts for types 960 and 972, 186, 'micropup' valve, 23 235,259 midget submarines in North Sea, 312 Marigold, HMS (corvette), 99, 115--6, 157 Midway, Battle of, 128 General Index 363

Millington-Drake, E. (British Minister in Nab Tower as reference echo, 16,59, 156 Montevideo, 1939),48 Nabob, HMS (escort carrier), 169 minefields, 212, 229 Naiad, HMS (cruiser), 41, 64, 73, 77 minelaying off Norway, 233, 234, 312; by Nairana, HMS (escort carrier), 166 German aircraft, 217 Naish, Lieutenant A.J.B. RNVR (later minesweepers, aid to navigational Captain, RN), 276 precision, 109, 212, 213; type 268, 234, Naples, RCM workshop 192 254; type 271, 132, 149; type 286, 132; Nathrow, Lieutenant (Sp.) J. RNVR, 151 first prefabricated type 271, 149; in National Physical Laboratory (NPL), Radio Battle of Barents Sea, 158; in Department, Slough, 6 'Harpoon', 153; in 'Neptune', 210, 212, National Research Council of Canada, 213; German minesweepers, 230, 306 Admiralty seeks physicists, 113; mine warfare, 158,217 K-band set for shell-splash spotting, Ministry of Aircraft Production, 58 224-5; X-band type 268, 234, 304 Ministry of Transport, 235 Naval Air Division, Admiralty, 24, 108, 117 Minotaur HMS (cruiser) (later HMCS Naval Aircraft, airborne radar needed, 28; Ontario), 242 FD specialist, 56; Walrus in ASV Minquier Rocks, engagement off, 230 demonstration, 58; attack on Bismarck, 'Mitre', Operation (minelaying off 96,308; attack on Tirpitz, 191,309; in Norway), 233 Battle of Atlantic, 311; off Norwegian Mobile Naval Radar Stations, MONRADS, coast, 312; phasing-out of fixed wing 220, 342; MONWHYS, 220 carriers, 264; sce also Albacore, Anson, modernization kits, 238 Avenger, Barracuda, Firefly, Fulmar, modulators, 107, 147, 156, 157, 180, 187 Hellcat, Swordfish, Walrus Monitors (ships), 101 Naval Air Squadrons, 812 Squadron, 308; monitor receivers, 81, 82 819 Squadron, 311; 821 Squadron, 312; monitor stations, 116, 117, 212, 219, 220 825 Squadron, 129,308; 1790 Montevideo and the Gra! Spec, 45, 48, 49 Squadron, 312 Morey, P. (HMSS/ ASE), 86, 88 Naval Intelligence Division, Admiralty, 49 Morgan, Leading Seaman J., 116 Naval Ordnance Department, Admiralty, Morgan, Lieutenant Frank (later AA responsibility, 4, 178; Tizard Commander), 63 Committee, 7; dive bombers, 43; type Mortimer, Flight-Lieutenant, 271 279, 76; type 282, 44; type 285, 58, 61 Motor Gun Boats Naval Radar Panel, 27 general, plan to use type 271 for Naval Radar Trust, xv, xviii, 335 vectoring, 87; type 286 fitted, 108; Naval Staff, policy-making, 206; view that blind fire system abandoned, 163; detecting ships more important than lightweight aerial for type 286MU, detecting aircraft, 17; first meeting on 301; development of lock- follow Air radar calls for expansion of HMSS Interception radar, 304; in Valve Section, 24-5; priority on radar operations off Elba, 302-3 limited, 27; scant prewar attention to specific, MGB 320, 301; MGB 614, 304; FD, 56; interest in splash spotting and MGB 657, 304; MGB 680, 304 height determination, 65; at Swanage Motor Launches, 108, 213, 215, 221, 301 trials, 69, 114; type 281 preferred to Motor Torpedo Boats, 302; lightweight type 279 in fighter defence of Fleet, aerial, 301; type 286,108; type 268,234; 117; plans for 2nd generation 10cm surface force direction, 87, 220, 302-3, warning radar, 177-8; vocal on 305-{i; in 'Neptune', 220; in operations requirements, 181 off Elba, 202-3; in Scharnhorst and Naval Staff Requirements, relative Gneiscnau Channel dash, 131; Free priorities, 26, 27; aircraft warning French, 306; 7th Flotilla, 301; 8th range, 28; aerials on directors, 44; post• Flotilla, 301; 28th Flotilla, 304; MTB 35, Dunkirk call for radar for seaborne 301; MTB 680, 305; Vosper (US) MTBs, invasion interception, 57; no specific 304 commitment to lOcm, 69; gunnery M-type transmission units, 95 requirements, 103, 105, 135; third Munich crisis, 25 generation gunnery radar, 256; high Murray, Captain A.J.L., Captain of HMSS, priority for bearing accuracy, 106; 'full 1937,18,19-20 facilities for FD to be fitted' not a Myngs, HMS (destroyer), 229 'requirement', 152; specialized TI set, 364 General Index

Naval Staff Requiremcnts (cont.) Norfolk, Virginia (US Navy Yard), 117,201 182; defcnce of Flcet against air attack, Norfolk, HMS (cruiser), radar fittings, 91, 186; heightfinding with type 277 seen 188, 232, 233; damaged at Scapa, 49; in as a bonus, 196; directed and Bismarck and Prinz Eugen action, 91, 92, controllcd projcctilcs, 225, 226, 257; TI, 93, 97; in Scharnhorst action, 188; in 226-7, 258-9; delay in dcfining 'Spcllbindcr', 232, 233, 234; and type priorities in submarine radar, 296; type 273, 188; and type 274, 232; and type 274, 183--4; typcs 294/5, 186, 187; typc 277,233 960, 186; type 990, 186 Norland, HMS (trawler), 87-8 navigation, beacons, 217, 221, 250, 277; in Normandie (French liner), 17 coastal craft, 301; in fog, 279; homing, Normandy Invasion, see 'Neptune', 279; IFF as beacon, 141; charts for 'Ovcrlord' radar, 214, 215; PPI 'reflectoscope', 215, Norris, Captain C.F.W., 230 221; landmarks, 215-7; for merchant North Africa, convoys, 147; 'Torch', 156 navy, 235, 253, 254; navigational North Cape (Norway), action off, 138-41 leadcr, 221; navigational marks, 221; Northstcad, RAF station, 228 near land, 52, 171, 174,210,232; radio Norway and Norwcgian Coast, Norwegian aids, 217, 254; in station kecping, 146, Campaign (1940), 52, 55-6; proof that 152-3; type 78T, 217; type 79B, 171; FD is possible at sea, 56-7; barrage fire type 286, 254; type 291U, 301; type SJ, devised, 137; success in heightfinding, 301; see also blind pilotage, and 284; night actions off coast, 224, 228- 'Consol', Dccca Navigation and 'Gce' 30, 232-4; Norwegian Lcads, 228-9, in Typc Dcsignation Indcx 232; type 291W in attack off Navigation Division, Admiralty, 206 coast, 296-8 Navigation School, see Dryad Nutbourne, HMSS/ ASE extension, 20, 79, Nelson, HMS (battleship), 29, 30, 59, 64, 72 90,101 'Neptune', Operation (assault phase of 'Ovcrlord', invasion of N. Europc), gencral, 191,193,208-10; navy's O'Bricn W.J. (Dccca Company), 213 function in assult, 209, 217; radar O'Carrol, Able Seaman (RDF) T., 116 aspects of planning, 209-10, 211; Ocean, HMS (light fleet carrier), 201, 243, 'Bigot', 209; radar aids for navigation 243, 256, 344 in assault, 213-17; radar charts, 214, '0' class dcstroycrs, 306 215; PPI predictions, 215, 216; RCM, Occan Boarding Vessels (OBVs), 100 210-11,230-1; air defcnce of beaches, Ohio, (tanker), 156 217-19; glidcr bombs, 219; surface Okinawa, Operation 'Iceberg', 232, 248 radar covcr, 220; anti-E-boat patrols, Oliphant, Professor M.L.E. (Birmingham 311; gunncry sets handicappcd, 219 Univcrsity), 67, 156 Nestor, HMAS (destroyer), 60 Onslaught, HMS (destroyer), 232 Nethcrbutton, Orkney (RAF CH station), 30, Onslow, HMS (dcstroycr), 158, 232, 233 49 Onslow Road, Southsea, HMSS Extension, Newark, HMS (destroyer, ex-USN), 279 44,89, 101, 102, 103 Newcastle, HMS (cruiscr), 258, 259 Olltario, HMCS (cruiser), 238, 242, 258 'Newt', Operation, (coastal forccs actions off opcrating factors, time to warm up in Elba), 302, 303, 306 switching on, 103, 129; periodic need New York (US battleship), 15 to cool down, 295 Nicholl, Captain A.D., 153 Operational Research Department, Nigeria, HMS (cruiscr), 64, 154, 156 Admiralty, 215 night fightcr control, 172, 191, 242 Operations Room, 239, 269 Night Fightcr School (RN), Drcm, 312 Operators, radar, spccialist Branchcs for Nimitz, Admiral Chester, USN, 232 operators, 112; RC and RP ratings, 208; Noble, H. (HMSS/ ASE), 266 responsibilities for operators, 206; Noble, Lieutenant John, 234 radar school set up, 206; Radar Noble, Admiral Sir Pcrcy, C-in-C Wcstcrn Training Flotilla, 206; need to selcct Approachcs Command, 79, 276 opcrators for heightfinding, 280; Noise Investigation Bureau (NIB), 117 Operators honoured, see below; Suffolk nomenclature of radar sets, 13, 179-80, 293, practises tactical use of radar, 91; 'Pip, 301,340 Squcak and Wilfred', 127; bcam Nore Command, 87, 131 switching aids operator, 135-6; choice General Index 365

of mode of using type 281, 169; and navy begins to advance, 162; type 277 blind fire, 136, 137; sets manned for as low air cover, 196; plans for Pacific long periods in BPP, 248; automatic theatre, 237; 'Bubbly' and 'Knobbly', tracking eases load, 258-9; in Battle of 237; Indomitable in action, 291; true Cape Matapan, 75, 76; in Battle of heightfinder in action, 291; cm gunnery Atlantic, SO; in 'Halberd', 112; in radar arrives as war ends, 233 Hesperus, 115; in Marigold, 115-16; in Pacific Fleet, see British Pacific Fleet Campbell, 131-2; shell damage in Duke Paddon, Sub-Lieutenant Stuart E. RCNVR of York, 189; in Scharnhorst action, 189; (later Rear-Admiral, RCN), Bismarck in sinking of Haguro, 244-7 action, 89, 95-6; sinking of Prince of operators, radar, honoured, A.B. Craig, 75, Wales, 124, 125; in Warspite, 159-60 76; E. McKay, 189; J. Morgan, 116; T. Palembang, Sumatra, Operation O'Connell, 116; N. Poole, 244, 247; J.W. 'Meridian', 232 Sheard, 115; S.A. Stevens, 189 Palomares, HMS (fighter direction ship), Orchis, HMS (corvette), 72, 84-8, lIS, 147, British radar fitted, 169, 242; American 276 radar fitted, 201, 242, 344; torpedoed, Orfordness, RAF radar trials station, 1935, 6, 174; hit mine at Anzio, 191; too slow 8; work at 25m, 11; Wright's view on for Pacific, 241; to Massawa by V-J short wavelengths for navy, 11-12; Day, 242; and height finding, 333 Tizard Committee support, 7; needs Parry, Sub-Lieutenant John, RNVR, 120 HMSS help with valves, 8, 10; HMSS Pas de Calais, jammimg of radar guiding liaison, 10, 11, 12; preliminary naval German guns, 212 requirements for radar, 11 Patia, HMS (fighter catapult ship), 81 Oribi, HMS (destroyer), 139 Patrol Torpedo Boats (US), use of PT boat Orion, HMS (cruiser), 73, 75, 77 Combat Information Centre, 302-3; OrisSQ, HMS (minesweeper), 278 Allied cooperation off Guernsey, 306; Orton, Sub-Lieutenant R. RNVR, 86 in Adriatic, 304; off Elba, 302; in 'Gun', Orwell, HMS (destroyer), 232, 233 302; in 'Newt', 302; 15th PT Squadron outside contractors (USN), 304; PT 218, 302-3 general, work to outside firms, 17,25, Paul, Commander R.T., (ANCXF), 209 166, 256; meeting with contractors, 'Pedestal', see convoys, Malta 166; industrial development starting Pegasus, HMS (fighter catapult ship), 80-1 from scratch, 61; magnetrons, 12, 20, Penelope, HMS (cruiser), 153 67; six makers for merchant navy performance meter, 282, 289 radar, 254; review of cooperation, periscope, detection, 68; radar, 300 267 Periwinkle, HMS (corvette), 85 specific firms, Alien West, 39, 156, 158; Perth, HMAS (cruiser), 77 Birmingham University, 12, 67; PP, see prefabrication BTH, 45, 187; A.C. Cossor, 45; Decca phase shifting, 107 Company, 213; Elliott Bros., 4; EMI, Phillips, Admiral Sir Tom, 122, 124, 125 109, 227; Perranti, 166; GEC, 20" 45; Philips Ltd,39 Gramophone Co. Ltd. (part of EMI), Philippine Sea, Battle of, 191 166; Howard Grubb Parsons, 187; Phoebe, HMS (cruiser), 41, 64, 65, 73 Vickers-Armstrong, 187 'Phoney War', 45, 52 specific sets, type 79, 22; type 262, 242; 'pickets', radar, 250, 251 types 271/3Q, 156, 158; type 282, pilotage, see blind pilotage 45; types 294/5, 187; type 960, 186, Piorun (Polish destroyer), 230 259; type 992,227; TIU3, 227; JE PPI, Pizey, Captain Mark, 131 109 'plan-packed' radar sets, 149 'Overlord', Operation (invasion of Northern Plan Position Indicator (pPI), see displays Europe); 191, 209, 217; see also Plessey,l44 'Neptune' plots and plotting, Action Information Owen, e.S. (HMSS/ASE), 69 Centre, 182; ARL Table, 132; automatic plotting table, 205, 220, 306; British Assault Area plot, 220; 'clutter' on Pacific, essentially an air war to RN, 206, screens, 171; coasta I forces in 226, 232, 247; Pacific War, 99, 122-6, 'Neptune', 220; echo amplitude, 250, 128, 191, 232, 244-51, 298; Japanese 287; filtered, 220; height, 288, 289-90; Fleet withdraws to Pacific, 152; US intercept, 171, 172, 205; PPI, 171, 182; 366 General Index

plots and plotting (cont.) sunk in Gulf of Siam, 99, 122, 124-5, pre-radar, 121-2; range, 43; saturated, 126; and Admiral Phiilips, 124; and 154, 171; Skiatron, 172, 172; tactical, type 273, 112; and type 273P, 157; and 226, 229; Onuel/ and Onslow in night type 281, 94-5, 124; and type 284, 93, action, 244; Scharnhorst action 95,124 controlled from plot, 190; in Battle of Prinz Eugen (German cruiser), in action with Barents Sea, 158-9; in Scharnhorst/ Bismarck, 91, 92, 93, 96; on Channel Gneisenau action, 131-2; in sinking of dash with Scharnhorst and Gneisenau, liagur~244-6,246-7 128,131 Pola (Italian cruiser), 76 private firms, see outside contractors polarization, 260, 274 production of radar equipment, HMSS Polish forces, 230 method, 21, 22; 1942, 'production Pollard, P.E. (Army scientist), 3, 108 year', 135; prefabrication, 149, 151, 158, Pollock, Commander David, RNVR, 64, 196; plan packing, 149; ships fitted, 171-2,250 100-1; type 79, 21, 22; type 268, 234, Pol/ux, HMS (radar training ship), 235, 237, 305; type 271, 84, 87 252,253,254 Projects, 'Bubbly', upgrading existing pom-pom control, 103, 186 warning sets, 237, 238, 240 'Knobbly', pom-pom director, 43, 44, 58, 59, 61, 104 fitting-out of long-range LSFs, 237, 241 Poole, Dorset, Decca station, 213 propagation, 20; see also anomalous Poole, Ordinary Seaman (Radar) Norman, propagation 244, 246,247 Proteus, HMS (submarine), 293 Porter, Sub-Lieutenant (Sp.) G. (later Sir proximity fuze (VT fuze), 257, 268 George), 164 Pryce, M.H.L. (HMSS/ ASE), 34 Portsmouth, C-in-C, 23, 220; dispersal of 'Puffin' class corvettes, 126 HMSS, 101-2; first air raid, 41; HMSS pulse length, choice, 105, 157; type 271Q/ extensions in area, 115; radar courses 2730, 157; type 274, 184; type 284/5, for General Service Officers, 113; visits 105; type 294/5, 187; type 960, 259; by Churchill and Somerville, 35; type type GL Mark 1,40; merchant navy 79 in operation ashore, 57 radar, 235 Portsmouth Dockyard, 17,29,30 pulsed radar, 3 Post Office experience, 7 Pumphrey, R.J. (HMSS/ ASE), 34 Potenti/la, HMS (corvette), 146 Puncher, HMS (escort carrier), 312 Pound, Admiral Sir Dudley, C-in-C Pursuer, HMS (escort carrier), 169 Mediterranean, 1936-39; First Sea Purvls, M.K.(Admiralty naval constructor), Lord and Chief of Naval Staff, 49 1939--43, 77 Power, Captain M.L., sinking of Haguro, 244,246 power, see transmitter Queen Elizabeth, HMS (battleship), 76, 244 Pozarica HMS (auxiliary AA ship), 332 Queen Mary, 5.5., 53, 279 PPI, see displays prefabrication, 149, 151, 158, 1% Premier, HMS (escort carrier), 233 Press Reports, 178; Daily Mail, 230; Daily radar Sketch, 252; Daily Telegraph, 22; The general, acronym, xix; definition, xix, 162; Times, 4 elements, xix; invention of, 2; a Pridham-Whippell, Vice-Admiral H.D., 75 beacon to the enemy, 11, 26, 54; a Prince of Wales, HMS (battleship), 104, 123; source of information, 203; first big ship with lOcm surface 'essential' equipment for the Navy, warning radar, 183; first with multiple 181, 270; breakdowns, 276-7; suite of radar, 89; first production calibration flights, 288-90; chart of model type 281, 90; first type 273 Normandy coast, 214, 215; huts see fitting, 110; sets fitted, 89, 93, 104, 112, radar offices; landmarks, 215-17; 123, 15~; into action with civilian lantern see aerials; performance contractors on board, 91; Bismarck meter, 282, 289; tactical use of, 175, action, 91, 93, 94, 96; damage to ship 195; see also accuracy, and radar, 94; Churchill to USA, 110; discrimination, development, radar detection of submarine, 112; errors, limitations, maintenance, General Index 367

priorities, reliability, secrecy and Radar Plot Ratings (RP ratings), 208 security Radar Research and Development applications, see beginnings of radar, Establishment (Army), 33 bombardment, coast defence, Radar Training Flotilla, 206 collision avoidance, dive bombers, radar training sight (RTS), 136 gunnery, height determination, radio communications, 190 homing, jet-propelled aircraft, radio countermeasures (RCM), general, 116, merchant ships, navigation, station• 209, 210, 211, 267 keeping, submarines, warning, Radio Equipment Department, weather, W /T silence Admiralty, 206 beacons, in navigation, 141, 221, 250, 277; radio guidance, see glider-bomb, guided channel-marking in 'Neptune', 217; missiles and radio-guided bomb priority replacement, 163; see also radio-guided bomb, FX.I400, 176, 192 IFF beacons identified on pp. 341-.3 radio mechanics, telegraphists, 27; radar countermeasures, Graf Spee, 49; officer initially sole radar technician, beginnings, 81-.3; RCM Section, 89; Radio Mechanics Branch formed, HMSS, 81, 116; search receiver, 93; 112; training, 208; frozen gearbox off increasing importance, 267; radio North Cape, 139; mentioned in war at Dover, 116-17; enemy-radar despatches, 189; in sinking of monitoring station, 117; 'Neptune', Haguro, 246 209, 210; 'Fortitude', 210-2 radio 'silence', 131, 174 offices/huts and their environment, radio telegraphy (R/T), 278 difficulty of 272 tuning, 109; abaft radome, 202, 311, 318 bridge to minimize blast, 112, 115, Raleigh, Lieutenant M.G., RNVR, 305 130; prefabricated huts, 149, 151; Ramillies, HMS (battleship), 112 shell damage, 189; wiring tidied up Ramsay, Admiral Sir Bertram, 110, 209 in 'Bubbly', 238; temperature, 190, Randall, J.T. (Birmingham University), 12, 262; no air-conditiOning, 239 67,84,156 ranging, 103, 199,229; 'Combined range of detection wireless rangefinder & lookout', 40; aircraft, prewar trial, 4; Tizard for gyro sights, 166; cm radar gives Committee set target, 7; Orfordness greater accuracy, 222; Glorious sunk result, 8; preliminary naval at 14 miles, 55; in Battle of Cape requirements, 11; TI requirements, Matapan, 76; type 281 used for 226-7; see also types 79, 273, 277, 280, surface ranging in Bismarck action, 281,285,286, SM-l, SJ 95-6; in Trinidad off North Cape, E-boats,58 139, 141; in night action, 229; in shell land, 86, 199 spotting, 280 low-flying aircraft, lllustrious defines the security and radar 'silence', cm radar problem, 65; TI requirements, 226-7; safer, 54; in Mediterranean, 64; 50cm radar trials, 27; see also types normal policy, 73, 271; in Bismarck 11,79,271,279,281,286, GCI, SM-l action, 93; in Prince of Wales in Gulf radars,54 of Siam, 124 responders, 159 set type designation, see Type ships, preliminary naval requirement, 11; Designation Index ASV demonstration, 58; Swanage Radar Control Ratings (RC ratings), 208 trials, 274-5; ,5Ocm trials, 27; Radar ('R') Division/Department of progress 1941-42, 181; TI HMSS,20, 208 requirements, 226-7; see also types Radar Display Room, 203, 205, 239, 261, 262, 79, 271, 272, 273, 274, 277, 279, 281, 289,318 284, 285, 286, 290, 293, NT 271, SJ Radar Maintenance Room, 256 shell splashes, 65, 140,232 radar maintenance ship, 247 submarines, Swanage trials, 69, 70, 274-5; radar mechanics see Radio Mechanics TI requirements, 226-7; HP/OF, 143; Radar Officers, earliest RDF Officers from see also types 271, 273, 281, 284, 285, RNVR, 112; Canadian recruits, 113, 286,SJ 265; training, 113; first MBE, 51; freeing rangefinding equipment, radar, 103, 136, frozen aerial gearbox, 139; restoration 225; optical, limitations, 140, 159 of shell-damage, 273, 189; transfer at Range Transmission Units, 227 sea, 164 range-rate, 24, 106, 136, 137, 138 368 General Index ranging panels, from type GL Mark I, 40; no Rodney, HMS (battleship), 31; one of first longer fitted in type 279, 65; for types two ships fitted with radar, 1, 25, 26, 271/2/3,110; L 22,137; L 24, 135, 138; 27,29; radar sets fitted, 21, 24, 31, 41, type 972 modified for surveying, 235 100; detected Sheffield's radar at 100 Rasenack, Lieutenant F.W. (German miles, 26, 54; radar silence, 54; radar Navy),45 operational at outbreak of WW2, 30; rate-aiding, 138, 318; rate-aided handwheel detected air attack at Scapa, 30, 32; control, 105-6, 137 near miss by bombs, 49, 50; Norwegian Rawlings, Admiral Sir H. Bernard, 56, 248 Campaign, 52; Home Fleet, 72; and Rawlinson. J.o.S. (HMSS/ ASE), 165, 266; height estimation trials, 285 Eastney, 26, 39, 40, 57; lecture to Fleet, 'rolling platform', 242, 261 87; Deputy Head of radar at ASE, 208 Roma (Italian battleship), 176 Raynsford, Lieutenant A.E.M. (Application Roosevelt, Franklin Delano, President of Officer), 86 USA, 71, 72 RCM Section, HMSS/ ASE, 81, 116 Rosenthal, Sub-Lieutenant M., RCNVR RC ratings, 208 (later Hartley), 90 RDF, superseded by 'radar' (1943), xix, 116; RoskiJJ, Captain Step hen, (author of 'War at see also radar Sea'), and gunnery, 44; cited as source, RDF Branch, Royal Navy, 112 95, 120, 192,209,228 RDF ('R') Division, HMSS, 20, 57, 132 Ross, Alfred W. (HMSS/ ASE), 266; aerials, RDF Officers, see Radar Officers 20, 21, 43, 58, 79, 260, 301; echo RDT (Italian radar), xix strength changes with range, 284-5; in Ready, HMS (minesweeper), 230--1 planning of 'Neptune', 209-10 receivers, radar, first HMSS version on trial, Rosyth Escort Force, 109, 127 15; design from scratch, 22; redesign rotating aerial, see aerial for short pulse lengths, 40; Marconi, Rowe, A.P., 5,6,8 45; lOcm receivers now probable, 68; Rowley, B.G.H., (HMSS/ ASE), 89 mount early stages near aerial, 83, 184, Roxburgh, Lieutenant John c.Y., (later Vice- 223-4; crystal detectors, 84; lOcm Admiral Sir John), 298-300 prototype, 178; improved sensitivity, Royal Air Force 135; Decca Receiver QM2, 221; search general, bombing German coastal radar receiver SN 4, 298; German search in 'Fortitude', 210--11; Coastal receiver:Metox',142 Command, 96, 129, 142, 296; night• recruitment, see staffing fighter training, 228; Stanmore filter 'reflectoscope', 215, 221 room, 179; 24 Sector, 220; 218 and reliability of radar sets, high priority, 163; 617 Squadrons, 210 needs more technical staff at comparison with RN, concentration on sea, 276--7; reports, 276--7, 298 fighter interception of attacking Remote [Gun] Training Unit, 136 aircraft, 28, 56; RAF prewar needs Renown, HMS (battlecruiser), 55, 61, 112, paramount, 32-3; RN started 154 development at lower priority, 265; Renwick, Lieutenant J. RNR, 115 RAF higher priority access to 3cm repair ships, 247 magnetrons, 296 Repulse, HMS (battlecruiser), Home Fleet, collaboration with RN, interservice air 72; in sinking of Bismarck, 91; type 273 and surface radar cover for Scapa ranges, 110; radar sets fitted, 125; sunk, naval base, 30, 38, 49, 50; ASV trial 99, 122, 124-6 at Lee-on-Solent, 58; Carlisle trains rescue ships, 143, 146 with RAF Gladiators, 62; no RAF Resolution, HMS (battleship), 112 support off Greece and Crete, 77; Revenge, HMS (battleship), 112 shared cost of magnetrons, 84; Ripley, HMS (destroyer, ex-USN), 279 5charn/lOrst and GneisenulI Channel 'River' class frigates, 196 dash, 131; in Largs in 'Neptune', 219; River Plate, Battle of, 30, 45-9 RAF control teams assist in 'Husky' Roberts, Lieutenant (Sp.) F.R., RNVR, 151 and 'Neptune', 174, 217, FD ships Robinson, Commander C.V. (Signal School for controlling naval and RAF Ship Fitting Section), 88, 88 aircraft, 241, 242; in CAMs in Rochester, HMS (sloop), 109, 144, 164 convoys, 81 Rocket Landing Craft, 199, 215 radar, research staff to Bawdsey Manor, Rocking/lam, HMS (destroyer, ex-USN), 279 12; Home Chain development, 17-18; General Index 369

airborne radar detects Home Fleet boosts Navy's confidence, 50; HMSS beyond visual range, 18; Fort technical staff presence, 89 Wallington CH station, 57; height Sceptre, HMS (submarine), 296-8 determination, 284; type ASV Mk.l, Scharnhorst (German battle cruiser), Seetakt 58; type AI Mk.VIII, 228; type GCI, radar, 55, 188; hit by Renown off 81,242, 284; type H 2S, 199,221 Lofoten Islands, 55; from Kiel towards Royal Aircraft Establishment, 192 Atlantic, 77; Channel passage with Royal Canadian Navy Volunteer Gneisenau, 128-9; detected by Duke of Reserve, 62 York, 181, 188; sunk, 162, 188-9, 190; Royal Marine Barracks, Eastney, 13 and type 273Q, 181, 188 Royal Naval Air Station, Yeovilton, 119-20 Scheldt Estuary, 221-2; first convoy to Royal Naval Aircraft Direction Centre, Antwerp, 99; type 971, 199, 221; Kete, 263, 263 pilotage, 221, 235; Decca chain, 221 Royal Naval Barracks, Portsmouth, HMSS Schepke, Joachim, (U-boat captain), 80 workshops and extra laboratories, 12, schnorkel, 191, 235, 268, 305 87; wavelengths below 23cm, 17; Scientific Research and Experiment HMSS dispersed, 101 Department, Admiralty, Alder's Royal Naval Night Fighter School, proposal, 3; Tizard Committee, 7; Drem, 312 Orfordness demonstration, 8, 11; trials Royal Netherlands Navy, 860 Squadron, 311 needed, 16; review of priorities, 19; Royal Oak, HMS (battleship), 32 contract with GEC, 20; CVD Royal Savereign, HMS (battleship), 112, 132 Committee formed, 25; central Royalist, HMS (cruiser), 227 recruiting for radar workers, 34; 'Ruler' class escort carriers, 169 enthusiasm for centimetric radar, 67 Ruyter, Nikolas, 1 Scorcher, HMS (submarine), 294 Scorpion, HMS (destroyer), 189 Scott (Greenock) shipyard, 86 Scott, Lieutenant-Commander Peter, SA (ship to aircraft) radar (UK), 40, 163; for RNVR, 305, 306 USA radar, see Type Designation Scourge, HMS (destroyer), 193 Index Scylla, HMS (cruiser), 220 Sabang, attacked by Eastern Fleet, 191 Seacat, surface to air missile, 256, 270 St John's, Newfoundland, radar Sea Dart, 272 beacon, 277, 279 Seafire aircraft, 174 Sakashimo Gunto airfields neutralized, 248 'seaguard' submarine radar, 296, 300 Salamander, HMS (minesweeper), 149 Sea Harrier, aircraft, 270, 271, 272, 273 Salerno landings (Operation Sea King missile system, 270 'Avalanche'), 162, 173, 174-6 'Search' radar, see warning radar Salisbury class aircraft direction frigates, 264 'search-and-Iock-on' radar, 185, 256 Salt burn, HMS (trials vessel, minesweeper), searchlight control, 24 16, 17, 19, 21, 179 Searle, Commander M.W. StL. (later Rear- Sardonyx, HMS (destroyer), 27, 40, 43, 78, 79, Admiral), 49-50 80 Sea Wolf, guided missile, 272-3 Saunders, Captain L.S., 139-40 Seaslug, surface to air missile, 257 Saumarez, HMS (destroyer), 244, 246 secrecy and security, pre-war, 2; remote Savannah, (US cruiser), 175, 176 locations, 6; liaison problems within Sayers, J. (Birmingham University), 156 HMSS, 8, 10, 15; liaison problems with S-band, see wavelength, IOcm other Departments, 16,35; liaison scanner, aerial, 199 problems with industry, 20, 22, 23, 26; scanning, electronic, 258 problems in recruitment, 38-9; scanning radar for fall of shot hindrance to flow of information on determination, 224-5 enemy radar, 49; hindrance in use Scapa Flow, location of only radar-fitted within navy, 54; radar in sinking vessel ships at outbreak of WW2, 30; RAF air• destroyed, 52, 54; swept away within warning cover, 30, 49; interservice air Fleet, 132; 'Bigot', 209, 215; in & surface radar cover, 38; Royal Oak 'Neptune', 209, 213; type 79X, 17 torpedoed, 32; Iron Duke beached, 32; Sector displays, see displays temporarily abandoned, 32, 49; air SeIsey Bill, type 277T trials, 178 attack on Fleet, 49; Curlew's radar semiconductors, 262 370 General Index

Sellllell, HMS (cutter, ex-USN), 116 radar, 10; Orfordness trials, 11; need to Shakespeare, HMS (submarine), 295-6 justify effort, 15-6; priorities, 18, 19, Sheard, Leading Seaman (RDF) J.W., 115 296; naval uses of radar, 23; enlarged Shearing, G. (HMSS/ ASE), Chief Scientist, Valve Section, 24-5; staffing criteria, Experimental Department, 7. 16, 19; 25; demonstration of lOcm radar, 68; Tizard Committee, 7; Orfordness bulk order for type 271, 84; type 281 on visit, 6, 8, 10 loan to US, 90; no action until staff Sheffield, HMS (cruiser), early radar-fitted requirement defined, 296; ship, 1,21,24,27,29; type 79 sea trials, responsibility for radar transferred to 25, 26; exercising in aircraft detection, DRE,206 26; radar operational at outbreak of Signal School, see H.M. Signal School WW2, 30; first naval shots of war, 30; Sinker, AB (Radar) A.J., 97 Norwegian Campaign, 52; near miss Sirius, HMS (cruiser), 208 by FAA torpedo, 308; Force H, 61-2, Sirte, second Battle of, 128, 152 74; sinking of Bismarck, 96; Battle of Skiatron, see displays Barents Sea, 158-9; sinking of Skinner, H.W.B., (TRE), crystal mixer valve, Schamhorst, 188; and plotting, 159; and 67, 68, 69; advocates 10cm radar, 68; radar silence, 54; and FD, 96; and type report on Swanage trials, 274-5; tribute 79Y, 25; and type 252 IFF, 159 by Dr Landale, 84 shell fuzes, 137, 138 Skua aircraft, 30 shell splash spotting and ranging, Skyhawk, Argentinian aircraft, 272 detectable by radar, 65, 136; remote sloops, 195, 276, 342 display for fire control, 136; expanded Slough (NPL Radio Department), 6, 8, 10, range display, 184; in action, 139-40, 274 188,222,232,246; spotting approach of SM 79 aircraft (italian), 63, 175 enemy shells, 300; conical scanning, Small Wiirzburg, see Type Designation 224; type 271, 280; type 274,184,224-5, Index 232; type 284/M, 136, 232; type 930, Smiter class escort carriers, 201 255; type 931, 224-5, 255 Smith, W.H., see W. H. Smith Ltd. Sherbrooke, Captain R. StV., 158 Somerville, Admiral Sir James F., 36; Sherston, Professor, (Canada), 165 Experimental Commander HMSS 'Shingle', Operation, (Anzio landings), 191 (1919-20),3; coordinator of naval radar ship-fitting development, 32, 40, 41, 44, 265; general, at Alexandria, 73-4; dockyards, Inspector of Anti-aircraft Weapons & home and abroad, 88-9; HMSS Devices, 38; Force H, (1940-42), 61-2, backup, 185; Prillce of Wales a 74; C-in-C Eastern Fleet, (1942-44),128, challenge, 89; statistics, 100-1; 50cm 159-60,309-10; 'foster father' of naval improvements, 138; prefabrication radar, 33 and plan-packing, 149; planning, 'sonar', see asdic 149,211; lattice masts for HP/DF on 'Son ne', see 'Con sol' in Type Designation destroyers, 195; AIO, 205-6 Index 'Bubbly', 237-8, 240; CRBFD, 243; South Foreland, Type 271 used ashore, 110, 'Knobbly', 241; submarines, 293; see 129,305 also specific type references SOllthamptoll, HMS (cruiser), 56, 74 priorities, categories defined, 99; radar, SouthdoWIl, HMS (destroyer), 52, 59, 61, 66, 99; AA cruisers, 27, 63; modernising 89, 105 for BPF, 237; 'Bubbly' and South sea, Onslow Road, HMSS Extension, 'Knobbly', 237, 241; cm gunnery for 44, 89, 101, 103 BPF,242 Southsea Castle, 12, 17, 20, 59 shore radar, 100, 109-10 Spartall, HMS (cruiser), 192 Shuttleworth, Norman, (HMSS/ ASE), 266 Spearfish, HMS (submarine), 30 Sicily, convoy passes between Cape Bon 'Spellbinder' Operation (sweep off and Sicily, 63; Luftwaffe uses Sicilian Norway), 224, 232-3 airbases, 72, 74; invasion of Sicily, Sperry Ltd, Brentford, 255 Operation 'Husky', 174-6 Spezia, Italian Naval Base, 176 Signal Branch, Royal Navy, 3, 27, 206 'spider's web', 132, 171 Signal Department/Division, Admiralty, Spitfire aircraft, 129, 154 Alder's proposal to, 3; silica valves for splash-spotting, see shell splash spotting Orfordness, 8, 10; HMSS to start on spotter-reconnaissance catapult planes, 308 General Index 371 spotting tubes, 222 submarine threat, see U-boats Springbank, HMS (fighter catapult ship), SO, 'Substance', see convoys, Malta lOO Subtle, HMS (submarine), 244 Spruance, Admiral, USN, 248 Suffolk, HMS (cruiser), 133; fitted with type SS (ship to ship) radar (UK), 40, 41, 163 79,26, 27; other radar sets fitted, 91, 92, stabilization of aerials, see aerials 97; one of two ships operational with stabilization of directors, 184, 185, 187 radar at start of WW2, 30; Norwegian Stabilized tachymetric anti-aircraft gun Campaign, 52; Bismarck and Prinz (STAAG), 243; blind fire, 163, 185-6; Eugen action, 73, 91-8; and type 284, auto-following, 166; mount increases 91, 92, 93, 96, 97 error in aiming, 225; trials, 224, 242-3; Sumatra, 'Meridian', 232; air attack on oil first seaborne STAAG in Vanguard, refineries, 248 256; vibration problem, 256; type Sunderland aircraft, 280 262(1), 224, 242, 256 Super Etendard missile, 270, 272 Staff Requirements, see Naval Staff Superb, HMS (cruiser), 238, 255 Requirements super-refraction, see anomalous staffing of HMSS/ ASE, Wireless propagation Section,Torpedo School, 3; HMSS Surface Force direction, 87-8, 220, 302-3, encouraged to ask for more radar staff, 305-6 10; only four Scientific Officers on surface gunnery fire control, see WS radar radar in 1936, 13; need of more staff, surface to air missles, 12,1619,166; Swinton Committee calls Seacat, 256, 270 for enlarged Valve Section, 25; Seaslug, 257 increases granted, 10, 25, 28; recruiting surface warning radar, see warning radar scientists and engineers, 34-5; crash survey ships, 222 recruitment, 38-9; understaffed in Sutton tube (local oscillator), 69 comparison with TRE, 166; use of Sutton, RW. (HMSS/ ASE), Bristol, 67 outside contractors, 187; pressure Swanage, Dorset, AMRE becomes TRE, 33; causes teething troubles, 195; postwar IDem trials with submarine Usk, 52, 69; staff shortages, 262; senior civilian staff IDem aircraft echoes, 68; visits by (1945),88,165,266 Coales and naval officers, 68; HMSS/ Stalker, HMS (escort carrier), 174 TRE IDem trials, 69-71, 274-5; PPI Stanmore filter room (RAF), 179 development, lOB Starling, HMS (sloop), 164 Swiftsure, HMS (cruiser), 204, 205, 234 starshell, in sinking of Scharnhorst, 188; in Swinton Committee, Air Defence Sub• night actions off Norway, 229, 233, 234; committee of Committee for Imperial in sinking of Haguro, 246 Defence, political control over Tizard Statesman, HMS (submarine), 244 Committee,6-7; influential, 7; pressure station keeping, 146, 152-3 for common radar research station, 12; Steam Gunboat (5GB), 301 CH development success, 18; call for Steel, Lieutenant-Commander Ian, 209 enlarged HMSS Valve Section to step' marker, electronic; 137 supply all three Services, 24-5 Stevens, Lieutenant J.S., 298-300 Swinton, Lord (formerly Sir Philip Cunliffe• Stevens, AB (Radar) S.A., 189 Lister), Secretary of State for Air, St Margaret's Bay, RCM, 81 Chairman of Swinton Stockport, rescue ship, 146 Committee, 6 Stonecrop, HMS (corvette), 150 Swordfish aircraft, in sinking of Bismarck, Stork, HMS (sloop), 120, 277 96, 308; in Scharnhorst and Gneisenau Strahl (German trials vessel), 49 Channel dash, 129, 131; in shipborne Struszynski, W. (Polish engineer at ASE), convoy protection, 169; first U-boat 143, 144 sinking by aircraft by night, 3OS-9; lost Stuart Prince, HMS (fighter direction ship), in Ark Royal, 307; replaced by Albacore 169, 241, 242 aircraft, 309; ASV Mk1, 307; ASV U, submarine radar, 202, 293--8; sets fitted, 99, 308; ASV ON, 308; ASV XI, 311; lOB; see also types 267W /MW /PW, nickname 'Stringbag', 308 286W, 291W, S] Sydney, BPF base, 232, 237, 238, 247 submarines, Allied - specific, H.34 in trials Syfret, Vice Admiral E.N., 32, 154 with Army's Coastal Defence Set, 38; Symonds, A.A. (HMSS/ ASE), 20, 26, 266 Norwegian B.l in type 271 trials,86 Syrian campaign, 77 372 General Index

Tactical Division, Admiralty, 11 influence, 7; Swindon Committee tactical use of gunnery set, 91, 181-2 formed as political control, 6-7 tactical use of radar, 178, 195 mission to USA (1940), 71, 90,141 Tait, Lieutenant-Commander A.A., 115 Torbay, HMS (submarine), 295 'Talk Between Ships' (TBS) radio, 247 'Torch', Operation (invasion of N. Africa), Tank Landing Ship, LST 305 for FD in 128, 156 'Avalanche',174; as FDTs in 'Neptune', torpedo attacks, 217, 246 217; optimum aerial height for type torpedo bombers (Italian), 74 GCI radar, 284; converted to LSFs for Torpedo Branch, Admiralty, 2, 4 BPF,241-2 torpedo control, 132, 301 Tantallon, trials station, North Berwick, 261, Torpedo School, see VCr/lOll 262 torpedo, Mark Vlll, 304 Tapir, HMS (submarine), 298 Torpedoes and Mines Department, Taranto, attacks on Italian Fleet, 52, 54 Admiralty, 4 target indication, see gun direction Tovey, Admiral J.e., C-in-C Home Fleet at target-towing aircraft, 256 Bismarck action, 72, 91; type 273 to Task Force 37, 248 avoid U-boats, 112; type 273Q trials, Task Force 57, 248 157; 'T class submarines, 299 'Town' class destroyers (ex-USN), 66 teachers, 166 Tracker class escort ca rriers, 201 Tedder, Air Chief Marshal Sir Arthur W., Tracker, HMS (escort carrier), 168 Director General of R & 0 at the Air tracking of targets, 182, 256, 257 Ministry, 1938-40; Deputy Supreme Trafalgar, HMS (destroyer), 242 Commander,1943-45,33 training, radar course for General Service Teddington, Admiralty Gunnery Officers, 113; FD School formed, 119; Establishment, 256 reorganiza tion of responsibility, 206; Telecommunications Research RC and RP ratings and Radio Establishment, AMRE becomes TRE at Mechanics, 208; heightfinding Swanage, 33; crystal mixer, 67; initial operators, 289; sets for shore training, lOcm development for all Services, 68; 57,87, 100, 101, 158, 224; see also visits by HMSS staff, 68; technology Collingwood, Vulkyrie, Radar Training transfer to HMSS, 69; TRE/HMSS Flotilla 10cm trials on target detection, 69-71, Training and Staff Duties Division, 274-5; lock-follow Al radar for MGBs, Admiralty, 206 304-5; staffing comparison, 166; PPI, transmitters, radar, designed from scratch, 108/9 22; 4m model for Bawdsey trials, 15; Telegraphists, 112 calls for more power, 26-7, 105,177, TcIemobilscope, 2 180-1,187,199; Valve Section produces television, 20 higher powered valves, 26, 41; terminology - radar, xix transmitter valves, 180, 199, 261; first Terror, HMS (monitor), 77 kilowatt output, 27; magnetrons Thames, River, estuary survey, 254; Decca available, 68, 69, 156-7; coaxial cable chain, 222 melted, 156; distance from lOcm Theseus, HMS (light fleet carrier), 256 transmitter to aerial minimised, 83, Thomson, Sir George, 165 109,184,223-4; BTH contract, 187; Thomas Ward, Ltd, 48 GEC contracts, 22, 45; Swanage trials, Thrasher, HMS (submarine), 300 69; artificial loads in laboratory, 29; three-dimensional radar, 262, 264 Merchant Navy radar specification, Thruster, HMS (LST), 241 235; type 262, 185; type 271, 87, 109; Tiger class cruisers, 259, 260 type 274, 184, 223-4; type 275, 184, 185, Tiger, HMS (cruiser), 256 223-4; type 276,177,182; type 277,178, 'Tiger', Operation (passing forces through 181, 186, 199; type 282, 103; type 284, Mediterranean), 76 105; type 288, 105; type 286/PQ, 107, Tiptoe, HMS (submarine), 202, 298, 344 147; type 290,107; type 294, 186-7; type Tirpitz, (German battleship), 191, 309 295, 187; type 901, 257; type ASV IIN, Tit/ark (launch), 69, 70, 274-5 308 Tizard, Sir Henry T., 165 Transmitting Station (TS), telephone from Committee for Scientific Survey of Air RDF, 76; organizational problem, 95; Defence, 5-7; technical options, 6, 7; remote display in TS, 136, 185, 222; General Index 373

radar panels integral with 1'5, 223; in type 271 successes, 116, 276, 277-a; Battle of Cape Matapan, 76; in sinking 'Ultra' assists counteractions, 114; of Bismarck, 95; off North Cape, 140; in escort carrier Audacity, 119-20; night action off Norway, 229 Coastal Command success and U• trawlers, 87-a, 296, 297, 306 boat response, 142-3; threat Treasury, H.M., 10, 12 contained, 177; schnorkel threat, Trenchant, HMS (submarine), 295, 300 191,235; HP/DF, 143-7, RAF ASV trials of radar sets, in Ambuscade, 107, 147; in radar, 99; type 273, 112; type 286/ Barfleur, 184, 224; in Carlisle, 43; in M/P, 115; type 972, 235 CuracOR, 44, in Curlew, SO; in Dido, 41, specific, U.32, 80; U.73, 154; U.93, 115; 65, 90; in Fleetwood, 254; in Gardenia, 84; U.99, 80; U.100, 79, 80; U.131, 120; in Hood, in Indomitable, 172-3; in Janus, U.433, 115; U.451, 309; U.751, 120 183; in King George V, 66, 105,157; in Uganda, HMS (cruiser), 175, 176 Marigold, 157; in MGB 614, 304; in Ulster Queen, HMS (fighter direction ship), Nelson, 59; in Ocean, 243; in Orchis, 86; radar sets fitted, 169, 227, 242; Sicily in Prince of Wales, 110; in Pollux, 235; in landings, 174; Anzio landings, 191; Saltburn, 16; in Sardonyx, 27, 40, 43; in landings on South of France, 227-a; Sheffield, 26; in Southdown, 66, 105; in German evacuation of Crete, 228; not Tuscan, 180; in Verity, 52; first fast enough for Pacific, 241; and FD, experimental gunnery set, 103; early 191, 228, 242 50cm set, 27, 40, 172; barrage control, 'Ultra', 114, 188, 320 43; Skiatron, 172; tilted cheese aerial, Unicorn, HMS (maintenance carrier), 169, 182; merchant navy radar, 254; cruiser 174 to be made available, 19; shore trials, United Kingdom Conference on Radio for 178; trials station, 102, 261, 262; see also Marine Transport, 235 individual types United States Navy, RN/USN cooperation, 'Tribal' class destroyers, 66 90, 220, 290, 306; Secretary of the Trier, P. (ASE), 34 Navy, 90; Naval Attache, 80; Trinidad, HMS (cruiser), 128, 138-40 Technical Liaison Officer, 90; loan of Triumph, HMS (light fleet carrier), 243, 243, type 281, 90; coastguard cutters, 116; 256 convoy escorts, 99, 116; ship repairs, Troubridge, Rear-Admiral T.H., 227-a 117; US Commander of Landing Craft Trump, HMS (submarine), 202, 298, 344 Bases in Europe, 211; starts to push Trumpeter, HMS (escort carrier), 233 Japanese back in Pacific, 162; BPF Tuckwood, Ordinary Seaman CF., 97 joins US Pacific Fleet, 232; BPF Tumult, HMS (destroyer), 148 operating with US 3rd and 5th Fleets, Tuna, HMS (submarine), 298 247, 248; 'picket' early warning 'Tungsten', Operation (FAA attacks against system, 250; US and UK navies Tirpitz in Altenfjord), 191 complementary in heightfinding Turpin, HMS (submarine), 298-300, 299 accuracy, 251; US/UK Task Force Tuscan, HMS (destroyer), lOO, 195 (Japan), 251; submarines with type SJ, type designation of radio/radar equipment, 295--6, 298; PT Boats with type SO see Type Designation Index radar, 301-6 Tyrrhenian Sea submarine patrols, 295 United States of America, Tizard Mission discloses secrets, 71; Lend Lease Bill, 90; repairs to UK ships, 75, 117; type U-boats 281 loaned for study, 90; UK IFF general, Royal Oak sunk, 32; attacks adopted by US Forces, 141; K-band intensify, 72; Battle of Atlantic, 77- components for type 931, 224 81, 113-16; convoy battles and HP/ Universal Display Unit, 261, 262 DF, 142-7; tactics, 77, 142, 143, 268; Ure, W. (HMSS), 15, 19, 20 Focke Wulf locates targets, 80; navy Usk, HMS (submarine), 52, 69, 274, 275 needs lOcrn radar, 66; detection at night, 276; first sinking attributable to type 286, 72, 79-aO; first sinking Valiant, HMS (battleship), early radar through type 271, 99, 115; first fitting, 27, 30, 52; radar sets fitted, 27, sinking at night by aircraft with 55, 73, 75, 76, 132, 190; Force H, 61, 63; direct radar assistance, 309; type 271 Mediterranean Fleet, 53; detected air acclaimed by Navy, 86-7, 113-14; attack on lllustrious, 74; Battle of Cape 374 General Index

Valiant, HMS (battleship) (cont.) Vickers Armstrong, Crayford, 187 Matapan, 75, 76; and FD, 74, 98; and Victorious, HMS (fleet carrier), 155, 197; sets height estimation, 190, 285; and type fitted, 117,197,201,264; first 279,55, 75, 76, 190 operational lOcm warning set, 196; Valkyrie, HMS (radar training school), 206 sinking of Bismarck, 91, 96; only modern Valve Group (HMSS) (Bristol), 37, 67 carrier operational at end of 1941,117; Valve Section, HMSS, 8, 24-5, 26, 37 Home Fleet, 152; in 'Pedestal', 154, 287; valves in 'Berserk', 154; prototype ADR, 156; general, valves and the CVD Committee, hit by kamikaze attack, 248; first type 22-3; inter-service development 984 fitted, 264; and height estimation, responsibility, 67; post-WWl valve 285, 286, 289; and FD, 152 research, 8-10, 34; Air Ministry Vidette, HMS (destroyer), 115 seeks help, 8, 10; manufacturers, 8; Vigilant, HMS (destroyer), 244, 245, 247 silica valves for over 7m 'Vigorous' (Malta convoy), 128, 153 wavelength, 15; several hundred Vindex, HMS (escort carrier), 166, 238 kilowatts power available around Virago, HMS (destroyer), 180, 244, 245, 246 3m,27; IMW possible, 41; 2MW not Viscount, HMS (destroyer), 146 reached, 199; higher power still visual detection, binoculars, 1, 7; Tizard sought, 261; design, 156; efficiency, Committee reviews alternatives, 7; 156; heat from valve made UDU RAF detect Scharnhorst and Gneisenau impracticable, 262 Channel dash, 129; shell-splash magnetron, Birmingham University spotting, 224; radar range supported research, 67, 84; GEC improvement, visual fire decisions, 229; submarines 68, 70, 84; sample to USA, 71; preferred visual observation of Swanage trials, 69, 274-5; Navy and aircraft, 296 RAF share costs, 84; strapped Vivian, Rear-Admiral J.G.P., 54 magnetron CV 56, 156, 157; more V-J Day, 232, 252 power, 180; RAF priority in use of Volunteer, HMS (destroyer), 79 3cm magnetrons, 296; E 1198, 274; Vosper MTB, 304 NT 98,156 VT fuze, see proximity fuze other values, crystal mixer, 67, 69, 84, 109, 274; diode switch, 90; klystron, 67, WA radar, see warning radar 70,317; 'micropup', 22-3 Wake-Walker, Rear-Admiral W.F., 91, 97 Vanessa, HMS (destroyer), 279 Wa1cheren Island, key to River Scheldt, 221 Vanguard, HMS (battleship), 243, 255, 256, Walker, Commander F.J., 120, 164 259 Walker, Vice-Admiral H.T.C., 244 Vanoc, HMS (destroyer), 72, 79, 80, 115 Walker, HMS (destroyer), 79, 80, 279 V-E Day, 232, 238, 244 Wal/ace, HMS (AA destroyer), 109 Vega-Helguara, Julio, 48 Walrus, aircraft, 58, 124,308; nickname, Veintecinquo Mayo (Argentinian carrier, ex- 'Shagba!',308 Venerable), 271 War Office, 3, 33 Venerable, HMS (light fleet carriers), 238, 240 warming up time for radar sets, 103, 129 Vengeance, HMS (light fleet carrier), 238 warning radar Ventnor, Isle of Wight, radar sites, 129, 178 general, limited range by end of 1941, Venus, HMS (destroyer), 244, 245, 246 122; in large ships, 73, 122, 203; in Verity, HMS (destroyer), 52, 58 small ships, 57, 58, 107, 108, 122; as Vernon, HMS (Torpedo School), 2-3, 49 part of a system, 203; responsibility Vertical Coverage Diagram, 174, 283, 286, after reorganisation, 206; 288 'Bubbly'update, 237-40 Verulam, HMS (destroyer), 229, 244, 246 aircraft, the AA problem, 4; RDF possible, very high frequency radio, 156, 210 6; Daventry experiment, 6; initial Vetch, HMS (corvette), 277 requirements, 7; Orfordness Vian, Rear-Admiral Sir Philip, second Battle demonstration, 8; preliminary naval of Sirte, 152; in 'Vigorous', 153; requirements, 11; first sea trial type Salerno, 174; Normandy, 220; BPF, 248, 79X, 16; priority for 7.5m, 21; 251 progress report, 23; type 79 ranges, Vichy French bombers, 62 25, 26; no plans for sets in carriers, Vickers, Ltd, 4 28; first skirmish involving radar, General Index 375

30, 32; type 79 at sea in numbers, 39; escort in joining convoy, 279; type naval air-warning radar ashore, 57; 286P in Proteus, 293; type SJ in escort carrier concept, 119-20; radar Tiptoe, 298; US radars in UK ships, and PO, 117-19, 163, 173, 174, 177, 201-2; type 276, 196; type 2SOP, 79; 186; PO development, 199-201; PO see also WS sets noted in pp 340-4 ships, 241, 242; limited range by end combined air/surface craft, need, 40; sets 1941,122; radar for air defence, 169- fitted, 100; in 'Neptune', 219; in 73; second generation lOcm radar, convoy protection, 277; see also WC 177; tactical use of lOcm radar, 178; sets noted on pp. 340-4 in Carlisle, 43, 62-3; in Rodney, 49-50; Warrior, HMS (light fleet carrier), 256 in Force H, 61-2; in 'Excess', 74; in Warspite, HMS (battleship), radar sets fitted, sinking of Bismarck, 93; in Prince of 112,159-60; Battle of Cape Matapan, 75, Wales, 125; in Repulse, 126; plot 76; evacuation of Greece and Crete, 77; saturation in 'Pedestal', 154, 156; in damaged by radio controlled glider 'Husky', 174; in 'Avalanche', 174-5; bomb, 175, 176; and Somerville, 159-60 in 'Neptune', 219; type 271, 279-80; Watchman, HMS (destroyer), 109 in Proteus, 293; US radar in RN Waterlooville (HMS5 extension), 101 ships, 201, 202, 298; later water vapour in atmosphere, correction, 285 developments, 259, 260-1; see also Wat80n-Watt, R.A. (later Sir Robert), WA sets noted on pp. 340-4 National Physical Laboratory'S Radio low-flying aircraft, type 79 sea trials, 27; Department, 1935, 6; Daventry vulnerability to low flying, 65, 117; experiment 6; Chfordness, 8; and type 271Q 157; lOcm answer HMSS, 8, 10; Bawdsey, 12, 35; Director promising, 157; in 'Avalanche', 175; of Communications Development at type 277, 1%; type 286P, 293; RAF Air Ministry, 33, 37; presses for unified types 15 GCI and 11 early warning, radar research under Air Ministry 217; type SM-l, 196 control, 33-4; incognito, 252 submarines, type 281 trials, 65; type 284/ Wat80n, D. Stewart (HMSS/ ASE), 65,266 5 trials, 66; Swanage 10cm trials, 69, 'Wat80n effect', 279 70, 274-5; Battle of Atlantic, 77-81; waveguides, see aerial feed type 286M trials, 79; first U-boat wavelength sinking due to radar aid, SO; type centimetric radar (before WW2 the term 271 trials, 86, 87; in 'Halberd', 112; 'centimetric' included all first sinking due to type 271, 115-16; wavelengths below 1 metre): early convoy battles, 142-3, 277-8; work on communications, 15; GEC combination of radar, HF/DF, HE liaison, 20; accelerated research, 28; and asdic, 146; types 271Q/273Q Staff requirements for 50cm trials, 157; schnorkel threat, 191, 235, gunnery, 103; improvements in 268; type 286M, 115; type 286P, 115; 50cm gunnery, 102-7,222-4; birth of type SJ, 298 lOcm radar, 66-70; Swanage trials, surface craft, preliminary requirements, 69-70; development at lOcm, 83-88; 11; need for surface detection, 39-40; Orchis trials, 86; success at sea, 77, Swanage IOcm trials, 69-70, 274-5; SO, 109-12, 175; improved surface gunnery sets used for surface cover, 156-8; success against low• warning, 97; limited range of sets in flying aircraft, 175; variety of uses, use by end of 1941, 122, 132, 147; 158; Navy welcome, 156; value in development priorities, 163; plans Battle of Atlantic, 113-4; gunnery, for second generation sets, 177; 183-4, 242; plans for 2nd generation, improvements, 1942-3, 181; in Battle 177; reviews, 68, 180-1; for PO, 186, of Cape Matapan, 76; in sinking of 199; development priorities (IOcm, Bismarck, 94-6; in Sclutrnhorst and 3cm),163); Gneisenau Channel dash, 129, in 3cm gunnery radar, 242; see also specific North Sea operation, 131-2; off wavelengths (below) and type North Cape, 139-40; in Battle of numbers of required wavelengths Barents Sea, 158-9; in sinking of from pp. 340-4 Sclutrnhorst, 188; in 'Neptune', 209, 1.25cm (K-band), 184, 224, 255, 317 220; in night action off Norway, 229; 3cm (X-band), priority 'A', 163; search• in sinking of Haguro, 244-6; aid to and-Iock-on radar, 185; RAF trials, 376 General Index wavelength (cont.) for gun directing, 163; type 960 for 199; integrated with gunnery long range high cover, 199,201; system, 223-4; narrow beams for sector displays for heightfinding, good resolution, 226; surface 203; superior to US navy in high warning type 268, 234; merchant cover, 251; see also metric sets noted navy radar, 235, 254; type 971 in on pp. 341-3 Scheldt, 199, 221; type 972 for l.5m, Yeo's experiments, 15, 17, 18; aerial schnorkel threat, 235; type 267W design, 21; back echoes, 151; aerials hybrid set, 296, 298-300; type 268 for generally too high for best coastal forces, 304; US radars, 255, heightfinding, 284; beam width, 301; 304-5; type 262, 223, 242-3, 256; type ease of detection, 293-5, 301; cooling 901, 257; type 905, 258 time, 295; type 286M in convoy, 79; lOcm (S-band), 318; suitable wavelength, type 291 in operations, 219, 229; 67; initial TRE work, 68; RAF Army Coast defence set, 37-8; Army impetus, 70-1; Swanage trials, 52, Fire Control radar, 129-31; RAF 69, 274-5; breakthrough, 68; A/S ASV Mk I leading to type 286, 58; use, 22, 68, 70; limited against US radars, 169, 201, 251, 284; schnorkel, 235; jamming resistent, comparison US and UK equivalents, 129; elimination of back echoes, 151; 201, 251; shore beacons, 277; commom transmit and receive development of types 290/1, 107; working, 178; polarization, 260; 'airguard' part of hybrid type 267W, priorities, 163; main armament 296; see also sets noted in pp. 340-4 range-finder, 103; gunnery, 183-4, 3.5m, aerial design, 21; shorter 222-4, 254-6; weapon systems, 256- wavelength to suit naval staff 8; TI, 182, 226, 258-9; success at sea, requirements, 26-7; type 281's triple 109-10, 112, 162; for combined function, 40; 1940 view that naval operations, 199; in coastal forces, war would be won on 3.5m, 68; new 303; navigation, 215, 221; next set, type 960, planned, 186, 259; see generation, 159; review of also type 281 series development, 180-1; new 4m, chosen as maximum wavelength for generation warning sets, 195-9; shipborne aerials, 15; Yeo's 1936/7 shipfitting, 59-61, 149; ships fitted, experiments, 15, 17; type 79X sea general, 100, 132, 147, 149; US sets in trials, 16; abandonment, 19, 20 RN ships, 201-2, 251, 298; see also 5m,7 lOcm sets noted on pp. 340-4 7.5m, research switch to 7.Sm, 20; 16cm,17 technology well known, 22;highest 23cm, 17, 19, 20 priority, 21; aerial design, 21; type 50cm, in communications, 7; early 79X trial, 21; interference reduction, gunnery, 20, 21; early fire control 26; useful ranges on surface targets, radar, 28-9; new technology, 22, 44- 26; type 79Z meets required 5; priority, 44; industrial liaison, 22, performance despite constraints, 28; 44-5,61; gunnery radar to sea, 58, operational at outbreak of WW2, 39; 59-61,89; barrage control, 43, 44; move to shorter wavelengths for blind fire, 136-7; first lkW output, detection of surface and low-flying 27; sea trials, 40, 65-6; performance, targets, 40; see also types 79/279 66, 138; interference, 89; tactical use, below 20m, 8 97-8; ship fitting, 135; beam width, 20m-50m, 6, 11, 28 226; improvements in gunnery Wavell, General Sir Archibald Percy, C-in-C radar, 102, 138, 222; postwar, 254-6; Middle East, 1939-41, 73 see also types noted on pp. 340-4 WC radar, classification, 340; dual purpose 55cm, 188 set needed, 40; sets fitted, 100; in 57cm,48 'Neptune', 219; in convoy protection, 60cm, 17, 19,45,49 277; for TI, 258-9; see also WC sets 80cm, 45, 82, 188 noted on pp. 340-4 metric radar, development at 4m, 13-16; weather, effect on radar, 280; weather prewar progress, 28-9; Germany system detection, 201 denied air superiority in Wellington bomber, 142 Mediterranean, 162; difficulties in Western Approaches Command, general, use close to high land, 174, not ideal 127; Admiral Sir P. Noble appointed C- General Index 377

in-C, 79; C-in-C insists on radar, 144; Woodcock, HMS (sloop), 164 memo on radar, 147; type 271 trials, 71; Woolwich, 3, 12 priority fitting of type 271, 131 'Woolworth' carriers, 169 Western Desert campaign, 77, 153 workshops, see HMSS Western Ocean Meeting Point Wright, Charles S., Director of Scientific (WESTOMP), 279 Research at Admiralty (1934-46),3,9, Westminster, HMS (destroyer), 127 37, 165; Tizard Committee, 7; Whitton, AB (radar) G., 189 Orfordness 1iaIson, 8, 10, 12; separate W.H.Smith Ltd, Old Trafford, 149, 151 naval radar effort agreed, 12; lOcm Wicks, Warrant Observer Teddy, 64 radar, 11-12, 66, 67; progress from Wilkins, Amold F. (Group Leader at 1937, 19, 29, 265; GEC told of radar Bawdsey and Orfordness), 6, 8, 11 secret, 22-3; and Canadian graduates, WilIett, Captain Basil R., 88, 165; 113,265 Experimental Commander, HMSS Wright, G.M. (HMSS/ ASE), Chief Scientist (1932),18,19,23,24,29; Experimental ASE,165 Captain, HMSS (1939-41), 37, 40, 44, Wright, S.T. (HMSS/ ASE), 39 68, 69, 70, 81, 83, 84; Captain Women's Royal Naval Service: 215 Superintendent, ASE (1941-43), 102, WS radar: see warning radar - against 113, 114, 147; succeeded by Brooking surface craft in 1943, 211 W /T silence: 126 WilIiam-Powlett, Captain N.J.W., 36 Wylie, Commander F.J. (Experimental WilIiams, F.e. (RAF scientist), IFF, 173 Commander, HMSS, 1935-7): 15, 18, 19 'Window', 210, 219, 320 Whnperis,H.E.O)rrectorofScientiftc Research, Air Ministry, 1943), 5, 6, 8, 10 X-band, see wavelength - 3cm Wireless Commander (of HMSS), 3 Wireless Section (Torpedo School), 2, 3 'wireless rangefinder', 43 Yates, Captain Andrew V.S. (Application wireless telegraphy (W /T - morse), HMSS Officer, HMSS), 165; type 271 trials, 86; uses manufacturing methods type 271 on land, 110; prefabrication, developed for W /T in radar 149; Project 'Bubbly', 237, 238, 242 construction, 21; possible conflict with Yeo, R.A. (HMSS/ ASE), seconded to radar, 23; communications ship/ Orfordness, 10, 11; requirements of aircraft, 56, 64; iced feeders, 92; OF of naval radar, 11; at Eastney Fort East, W /T location, 279; W /T silence, 126 13, 15, 17,20; replaced on metric radar Witley, ASE radar laboratories/workshops, by Symonds, 20 101-2, 135 Yeovilton, Somerset, FD School, 119, 120 'wolf-packs', 77, 80 Yorke, Commander Philip, 75 Wolverine, HMS (destroyer), 278 Young, Commander R.T., 304 Wood, A.B., (ARL) (seconded to HMSS, 1937-39), infra-red detection, 7; Orfordness, 10; work below 23cm Zambesi, HMS (destroyer), 229 wavelength, 17 Zara (Italian cruiser), 76 Wood, Sir J

Notes: brief descriptive notes are given in Table of Type Numbers, pp. 340-4; notes on nomenclature appear on pp. 13, 179-80, 293,301.

Type Type 11, RAF early warning radar, 217 91, radar jammer, 116-17, 142,282,341 IS, RAF GCl, 217 241, interrogator, 142, 341 72/DM, aircraft homing beacon, 170, 310 242/M, interrogator, 119, 277, 281, 302, 341 78T, radar beacon, 217 243, interrogator, 119, 134, 341 79/X/Y/Z/M/B, WA radar, 341; early 244, interrogator, 341 days, 13; wavelength decision, 20; 245, interrogator, 341 aerials, 31, 170, 198, 241, 249; rotating 251/M/P, shipborne beacon, 163, 341 aerial, 17,21, 53; redesign, 26; not 252,IPF, 141, 159, 279,341 modified for PPI, 173; single mast 253/P, IPF,341 working, 89-90, lOS, 168; vertical 2535, IFF, 341 coverage diagram, 288; power, 26; 255, beacon,Ml priority, 16, 18, 19; secrecy, 17; 256, shore beacon, 341 document security, 39; manufacture, 257, carrier controlled approach radar, 341 21-2; trials, 16,21, 26, 40-1,50; ranges, 258, shore radar beacon, 341 aircraft, 16, 25, 26, 28, 30, 32, SO, 62, 259, shipborne beacon, 341 175; ranges, ships, 16; useful but 261/W, WS radar, 341 unreliable surface ranges, 26; reached 262/Q/X, GC radar

378 Type Designation Index 379

Type Type radar hut, 130, 131; cylindrical lantern, range, submarines, 112, 157; range, 85, 109, 111, ISO, 151; aerial remote aircraft, 157; gun blast problems, 158; from radar office, 109; prefabrication, maintenance at sea, 188, 189; PPI, 109; 149, 151, 158; an anti-U-boat weapon, developments, 177-8; in 'Avalanche', 86-7,146,276, 277; first U-boat sinking, 175; in Battle of Barents Sea, 158; in 99,115; beats 'wolf pack', 80; early 'Halberd', 112; in 'Husky', 174; in model to ADRDE, 109; first shore use Prince of Wales in Gulf of Siam, 124; in of naval radar, 109-10; shore model in sinking of Scharnhorst, 188, 189; and Dover Straits, 129; power, 87, 156, 180- Somerville, 160; dockyard fitting only, 1; ranges, ships, 86, 87, 88, 129, 131, 149; ships fitted, general, 100, 112, 131, 158, 279; ranges, aircraft, 157, 279-80; 158, 188; ships fitted, specific, 111, 112, ranges, submarines, 86, 87, 116, 146, 157, 158, 188, 229; Mark IV, 156, 177; 157, 277-8; performance improvement Mark V, 163, 177-8 181; comparison with lookout for 274, GS radar, 342; Staff requirements, 183; aircraft detection, 280; demand for priority, 223; operational, 163; aerials more sets, 114; naval appreciation, on main armament director, 183; 147-9; maintenance at sea, 131,276-7; aerials, 204, 239; power and pulse limitations, 280, 304; new magnetron length, 184; beam switching, 184, beam melts cable, 156; addition of accurate width, 184; performance, 184, 232; ranging panel, 110; suggested ranges, ships, 233; shell splash developments, 281; new designs, 156- spotting, 184, 224, 232; in 'Spellbinder', 7; in 'Avalanche', 175; in Battle of 232, 233; ships fitted, general, 224, 255; Atlantic, 113-14; in Battle of Barents ships fitted, specific, 224, 232, 242, 255; Sea, 158; in detecting fall of shot, 280; in service until 1963, 255; superseded, and height estimation, 279-80; in 257 homing, 279; in navigation, 87, 279; in 275, GA radar, 342; priority, 163; 'Neptune', 217; in North Sea destroyer supersedes type 285, 185; trials, 184, sortie, 131, 132; in 'Pedestal', 278; and 185, 223; auto-following, 166; blind PPI, 109, 281; and radar charts, 216; fire, 184, 185; conical scanning, 185; decision on use in larger ships, 110; system accuracy, 185, 225; low angle numbers fitted, 109, 135, 147; ships applications, 185; ships fitted, general, fitted, general, 100, 109, 132, 147, 158; 255; ships fitted, specific, 242, 255, 270; ships fitted, specific, 36, 109, 111, 112, fitted until late 19508, 255; basis for 115, 116, 130, 131, 148, 151, 158, 233, missile guidance, ~; replaced, 255; 278, 279, 280; conversion to type 273, superseded, 257 112; replaced, 193; plans for next 276, WS radar, 342; second generation set, generation, 177-8 177; concept, 179; differences from 272/M/P, WS radar, 342; prototytpe, 109; type 293, 195-6; aerial, 177, 180, 182, radar office, 119; aerial lantern, 133, 193, 194, 249; aerial speed, 178; 145, 168, 170, 207; use of lattice mast, common aerial working, 178; trials 180; 148; beam splitting, 110; plan packing replacement for types 271/2, 148, 177; scheme, 149; performance, 109; range, power, 181; basis ofTI radars, 179, 182; ships, 229; gun blast damage, 111, 112; performance, 180; tactical use, 178; air unsuitable for coastal forces, 304; in cover 179; trials of prototype, 180; user 'Avalanche', 175; use with radar reaction, 195; side echoes, 195; charts, 214-15; ships fitted, general, maintenance at sea, 195; teething 100, 109, 112; ships fitted, specific, troubles, 195; in 'Neptune', 220; use 169, 188, 229, 233; second generation, with radar charts, 214-15; ships fitted, 158, 177; replaced replaced types 276 general, 180, 195; ships fitted, specific, and 293, 193; Mark Ill, 177; Mark V, 169, 180, 195, 220, 229; obsolescent, 180; 163 superseded, 180 273/M/P/Q WS radar, 342; difference 277 /P/Q WS radar, 342; concept, 179; from type 271, 110; aerial, 123; new developments, 177-8; aerial, 197, 204, lantern, 134, 152; trials, 110, 157; first 236, 239, 241, 260; variable aerial fitting, 110; prototype, 156, 157, 158; speed, 178; larger aerials, 260; power, power, 180-1; performance, 110; 181; ranges, ships, 196,250; ranges, performance against aircraft, 175, 287- aircraft, 196, 233; limitations, 250; first 8; range, ships, 110, 157, 181, 188, 229; fittings, 180; to sea, 181; 380 Type Designation Index

Type Type 277 /P/Q WS radar (cont.) USA interest, 90; compared with type tactical use, 178; TI, 181; anti• 79B, 171; gunnery capability, 65, 94--6, submarine uses, 260; FD radar, 181, 118, 137, 138, 139; shell splash spotting, 261; heightfinding, 196, 199, 205, 259, 65; IFF, 205; radar silence, 93, 124; in 264, 288, 291; in landings in S. France, 'Avalanche', 175; in Bismarckaction,93, 227, 228; in 'Spellbinder', 233; in 94,95; in project 'Bubbly',238, 240; in 'Bubbly', 238; in 'Knobbly', 242; BPF 'Dragoon', 227; in 'Husky', 174; in picket, 251; use of radar charts, 218; 'Overlord', 210; in Prince of Wales, 124; ships fitted, general, 179, 180, 195, 1%, in Russian convoy, 138, 139; in sinking 260, 264; ships fitted, specific, 169, 227, of Scharnhorst, 188, 189; and FD, 163, 233,242,251,260 169 171, 175,186; and first raid on 277S, WS/low air cover radar, 342 Portsmouth,41; and height finding, 65, 277f, WS/low air cover radar, 178, 179,220, 175, 203, 205, 251, 282, 283, 285, 286, 342 287, 288, 289; ships fitted, general, 89, 277X, WS radar, 179-80 lOO, 117,244; ships fitted, specific, 41, 279/B/M, WA radar, 342; conversion from 43,64,90, 93, lOO, 138, 169, 171, 188, type 79,41; aerials,21, 53, 111, 133, 155, 227, 238, 240, 242, 251; replaced, 186, 203; receiving office, 118; ranges, ships, 259 73; spurious frequencies, 166; 282/M/P /Q GC radar, 342; genesis, 44; limitations, 117; gunnery capability, aerials,59, 103, 170, 197, 239, 249; trials, 43, 65, 76; single- masr working, 89-90, 58, 59; ready to fit, 66; fitting 93; surface plotting, 91; comparison completed, 222; power, 103, 105; pulse with type 281, 10~9, 117, 219; length, 103; performance, 103, 125; comparison with type 284, 91; in Battle ranging accuracy, 106, 137-8; bearing of Cape Matapan, 75, 76, 91; in FD, 153, accuracy, 106; beam Switching, 137; 169; in 'Harpoon', 153; in Norwegian surface weapons in AA barrages, 138; campaign, 55-6; in sinking of Bismarck, low priority maintenance, 125; further 91; ships fitted, general, 57, 73, 89, 100; developments, 103; modifications, 222; ships fitted, specific, 53, 55, 64, 73, 74, blind fire, 222; ships fitted, general, 75, 76-7, 90, 91, 111, 153, 169,251; see 101; ships fitted, specific, 89, 123, 138 also type 79 283/M, GB radar, 66, 106, 107, 138, 342 280, WA/GA radar, 342; aerials, 42; ranges, 284, GS radar, 342; aerials, Ill, 123, 133, 134; aircraft, 43, 62~; trials, 43; in Aden, power and pulse length, 105; range 62~; in Mediterranean, 43, 73; in discrimination, 105; precision ranging Norwegian campaign, 43; ships fitted, panel, 137-8; bearing accuracy, 106, specific, 42, 43, 62, 73, 81, 100; 135; beam Switching, 103, 106, 135; discontinued, 43 trials, 52, 59, 66, 105; ranges, ships, 59, 281/B/BM/BP/BQ WA radar, 342; triple 66, 105; ranges, submarines, 66; function, 40; started, 27; first models, limitations, 91, 110, 129, 160; mutual 41; first production model, 90; trials, interference, 89; blind fire, 229; shore 41, 52, 65, 90; production method, 22; installations, 129; shell-splash spotting, bulk order, 41; ship fitting policy, 41, 224; tactical use, 91, 97; in Battle of 117-8; numbers fitted, 89, 100; aerial Barents Sea, 159; in Bismarck action, 89, design, 21, 123, 134, 239, 241, 259, 260, 91, 93, 96, 96, 97; in Prince of Wales, 124; 262; single-mast version, 118, 166, 169, off North Cape, 138, 139, 140; in night 198, 204, 207, 249; beam switching, 40, action off Norway, 229; Scharnhorst 41, 137, 169; beam shaping, 163; silica and Gneisenau Channel passage, 129- valve developments, 41; ranges, ships, 31; in sinking of Scharnhorst, 188; and 65,%,139;ranges,submarines,65;air Somerville, 12~1; ships fitted, cover, 117, 251, 252; vertical cover general, 66, 89, 101, 188; ships fitted, diagrams, 169, 286, 288; PPI, 108-9, specific, 61,66, 76-7,89,93, 125, 138, 117, 171, 173; sector display, 205, 287; 188; next generation, 102, 103, 105; bearing accuracy, 137; land echoes, replaced, 224 219; operating conditions at sea, 139; 285/M/P/Q GA radar, 342; genesis, 40; modernization at sea, 238; replaces type 280, 43; development interference from communications, speed, 61; aerial on HA Director, 53, 210; design criticism, 90; limitations, 133, 134, 170, 204; aerial on 173, 174, 175; Rangefinder Director, 60, 145, 148; Type Designation Index 381

Type Type aerials, 123, 197, 239, 249; single aerial aerial, 100, 107, 260; power, 107: trials, operation, 105; trials, 52, 59, 65-6, 105; 107: compatible IFF, 141; ranges, ships, ship fitting, 222; variants on basic set, 158; in Battle of Barents Sea, 158; in 66; performance, 102-3, 105, 106, 135; convoy protection, 146, 277; in ranges, aircraft, 59, 66, 125; ranges, 'Harpoon', 153; ships fitted, general, ships, 66, 246; ranges, submarines, 66; 100; ships fitted, specific, 107, 153, 158; precision ranging panel, 138; power abandoned, 107 and pulse length, 105: beam width, 291/M, WC radar, 343; replaces types 286 107; staff requirements, 103; new and 290, 107; aerials, 21, 148, 260; version planned, 103; beam switching, power rotation, 260; trials, 107, 147; 103, 106, 107; bearing accuracy, 106, limitations, 151, 284; back echoes, 151; 135; TI, 226; target discrimination, 107; IFF, 141; compatible beacon, 217; in barrage fire control, 137; comparison convoy protection, 277; in sinking of with type 274, 232; in Barents Sea, 159; Scharnhorst, 189; ship-fitting policy, in Bismarck actions, 94; in blind fire, 293; ships fitted, general, 145; ships 230; in 'Harpoon', 153; in Prince of fitted, specific, 193, 219, 223, 229, 242; Wales, 125; on Russian convoy, 139-40: in service until 1950s, 107; criticism of in sinking of Haguro, 246: in sinking of 1ash-up',298 Scharnhorst, 188: and Somerville, 160: 291U, coastal forces WC radar, 301, 302, 303, ships fitted, general, 66, 89, 101: ships 343 fitted, specific, 61, 76, 89, 111, 134, 138, 291W, submarine WC radar, 343; aerial, 294; 193: superseded, 185: postwar usage, fear of detection by enemy, 293, 296; 255 comparison with type SI, 298; criticism 286/M/P/PQ, WC radar, 343: aerial design, of one modification, 298; in navigation, 260; aerial and height estimation, 284: 295, 300; in Tyrrhenian Sea, 295; ships aerial location compromise, 144: fitted, general, 293; ships fitted, 'bedstead'aerial, 60, 78, 130: trials on specifi~ 294, 295,296, 298, 300; new aerial design, 79, 301: lightweight superseded, 2296 aerial, 301: trials, 52, 58: power, 107: 293/M/P /Q WC/TI radar, 343; ranges, ships, 75, 79, 293; ranges, replacement for types 272 and 276,148, aircraft, 126, 293: ranges, submarines, 190,193,195: aerials, 179, ISO, 195, 196, 79, SO, 115; limitations, 79, 86, 114, 126; 197, 204, 227; comparison with type side and back echoes, 86, 126; 276, 195-6; sector display, 205; beam upgrading, 147; in Battle of Atlantic, width, 182, 258; ranges, ships, 244, 246; 79; in Battle of Barents Sea, 158: in in FD, 260; TI, 179, 183, 205, 224, 227, Battle of Cape Matapan, 75; in convoy 258; puts type 285 on target, 246; in protection, 277: in confused North Sea 'Bubbly', 238; in sinking of Haguro, 244, action, 131: in evacuation of Greece 246; ship fitting policy, 179, 183; ships and Crete, 77: and IFF, 141: in fitted, general, 260; ships fitted, navigation and station keeping, 86, specifi~ 229, 233,239, 270 277,279: in 'Substance', 110: in U-boat 294, WC/FD radar, 186, 187, 199,201,260-1, detection and sinking, 79, 115: first 343 experimental submarine version, 293: 295, WC/FD radar, 166, 186, 187,199, 201, same transmitter as ASV fi, 308; ships 260-1,343 fitted, general, 58, 61, 64, 77, 79, 81, 89, 650, jammer, 343 100, 109, 139, 147, 152, 153, 293, 301: 651, jammer, 192,343 ships fitted, specific, 58, 64, 73, 75, 79, 901, WA radar, 234, 257 81, 91, 125, 126, 127, 131, 279: replaced, 903, WA radar, 255 107 905, WA radar, 258 286U/MU/PU, coastal forces WC radar, 930, GS/splash radar, 255, 343 301,343 931, Canadian GS/splash radar, 184, 225, 286W, submarine WC radar, 107, 343 255,343 287, minewatch radar, 100, 110, 343 932, GS/splash radar, 255 288(1), GC radar, 343 941, interrogator, 343 288(2), GC radar, 343 951, beacon, 343 289, GA radar, 343 952, beacon, 343 290, WC radar, 343: replaced type 286, 147; 960/P, WA radar, 343; genesis, 186, 199,201; unrushed development, 90: Marconi development, 186, 259; 382 Type Designation Index

Type Type 960/P, WA radar (conI.) indicator, 87; German detection of ASV aerials, 259, 260, 261, 262, 263; pulse transmissions, 142; in sinking of length, 259; beam width, 259; range, Bismarck, 96, 308; in Orion, 75--6; in 290; trials, 261, 262; puts type 981 on Schamhorsl and Gneisenau Channel target, 262; ships fitted, general, 259, dash, 129; for reconnaissance and 260; ships fitted, specific, 259, 262, 264; shadowing, 23; in escort carriers, 311; towards type 984, 262; replaced, 259, in catapult planes, 308; in other 264 aircraft, 96, 142,307-12; Mk.II, 308, 344; 961, CCA radar, 344 Mk.IIN (naval variant), 308, 310, 312, 965, WA radar; 259, 260, 264 344; Mk.lll, 142-3; Mk.XI, 311-12, 344 970, WS radar, 199, 200, 215, 216, 343 CCA, 341, 343 971/M, WS radar, 199, 221, 235, 343 CD (Coast Defence - Army radar), 15, 37, 972, WS radar, 235, 237 163 974, navigational radar, 254 CD No.l, Mk.lV, (Army set), see Type NT 980, WC/FD radar, 344; replaces types 294/ 271 5, 201, 261; continuous aerial rotation, CH (Chain Home - RAF radar), progress, 199; aerial, 261; 'user friendly' panels, 18; valve needs, 24-5; performance, 28; 251; UDU, 261, 262; trials, 261, 262; stations, 30, 57 performance prediction, 262; decisions, CHL (Chain Home Low - RAF radar), 15, 262 163 981, heightfinder radar, 344; replaced types 'Coastwatcher' (German) radar, 233 294/5,201,261; stops on height 'Con sol' (German radio naVigational aid), bearing, 199; aerial, 261-2; 'user 234 friendly' panels, 261; UDU, 261, 262; Decca 12 radar, 254 range-height display, 261; trials, 261, Decca Navigator (Outfit QM), trials, 213; in 262; heightfinding, 199, 261, 291; slow 'Neptune' 200, 213; in Scheldt, 199, progress, 201; decisions, 262 221-2; comparison with 'Gee', 213; 982, FD radar, 262-3, 263, 264 ships fitted, genera\' 213; navigation 983, FD radar, 260, 262-3, 263, 264 aid,254 984, FD radar, 187, 262, 264 DEM (French radar), terminology, xix 990, WC radar, 186, 199,201,261, 344 FH3/4 (HFIDF), 144, 146 992/Q, TI radar, 227, 258-9, 260, 344 'Freya' (German radar), 116 993, TI radar, 259 FuMG38G, German radar, 45, 46, 47, 49 AI, RAF air interception (airborne) radar, FuMO (German radar), terminology, xix RAF chooses fighter interception, 28; FuM022, German radar, 73 1.5m wavelength, 15; lOcm desirable, FuM023, German radar, 94, 95 67; RAF makes 10cm set, 68; no pre• FuM027, German radar, 188 War FAA fittings, 129; production FVl (DF equipment), 233 priority, 308; Mark VI night-fighter GC!, RAF 1.5m ground control interception trials, 310; Mark VIII, 228; Mark X, (US radar, 218, 241; first night operation, 3cm SCR 720), 304-5; Mark XI, 310, 108; beam width, 108-9, 171; ranges on 311 low-flying aircraft, 217; in 'Avalanche', AlA radar, 312, 344 174; in CAMs, 81; in 'Dragoon', 191, AIF (lock-follow air interception 227; in German evacuation of Crete, radar),304 228; and heightfinding, 284; in AISF (lock-follow air interception 'Neptune', 217; for night interception, radar),304 242; Mark IIG, 141 AN/ APS-4, 312 'Gce' (Outfit QH), navigation aid, 212, 213; AN/ APS-6, 312 213; in Dieppe raid, 212; 9/42; in AN/SPG-34 (US 3cm GA radar), 255 'Neptune', 212, 213; risk from jammers, ASB, 312, 344 213 ASH radar, see AN/ APS-4 Giant Wiirzburg (German radar), 116, 233 ASV (RAF and naval versions), 344; GLl (Army gunlaying set), 40, 41-3, 81, frequency, 15,308,309,310; detected 342 Fleet beyond visual range, 18; H 2S, RAF airborne radar, lOcm set fitted for demonstration to navy, 58; C.S. Wright for use in small craft, 199, 200,215; talks with Bowen, 66--7; trials, 58; ASE with PPl, 215; in Schcldt Estuary, 221; aerials 58, 115; modified ASV Bomber Command priority for Type Designation Index 383

Type Type magnetrons, 296; developed, 229; 3cm radar, 195, 201; control of coastal set developed into type 971,199 forces, 220, 306; use with radar charts, Hohentwiel 55cm ASV (German), 188 214-15; ships fitted, 201 Mark 35 (US 3cm radar), 255 SM-l, FD radar (US), 344; aerial, 198, 241; NT271 (Army designation of type 271), 129, ranges, aircraft, 196, 201; comparison 131 with British radar, 196, 251; weather NT284 (Army designation of type 284), 129, systems detection, 201; in BPF, 250, 131 251; heightfinding, 198, 199, 201,250, QH, see 'Gee' 290, 291; ships fitted, specific, 201, 242 QM, see Decca Navigator Small Wiirzburg (German radar), 116 ROT (Italian radar), terminology, xix SN4, search receiver, 298 SA, WA radar, (US), 201, 202, 295, 344 SO, WS radar (US), 344; radome, 303; SCR 720, (US, 3cm AI radar), 304 comparison with type 291U, 301; 'Seetakt' German radar, aerials on gun benefit of hindsight, 305; unofficial directors, 44; in Battle of River Plate, Lend-Lease, 303; control of coastal 45; in Scharnhorst and Gneisenau, 55, 73, forces, 303; off Elba, 303; ships fitted, 108; in Bismark, 93; on French Channel general, 305; ships fitted, specific, 304 coast, 81, 82, 116; in radio war at 'Son ne' (German radio navigational aid), see Dover, 81-2, 116; aerials shot away, 'Consol' 188; ships fitted, 45, 55, 73, 93, 188; SP, postwar FD radar (US), 250, 251 type FuMG38G, 45; FuM023, 93; type SQ, WS radar (US portable), 240, 344 FuM027, 93, 188 SR radar (US), 15 SG, WS radar, (US), 167, 169, 198, 344 TIU/2/3, TIU, 121, 205; TIU", 183, 227, 258; SI, WA radar, (US), 202, 295, 298, 344 TIU3, 227, 258 SK, WA radar, (US), 344; aerials, 167, 241; Wiirzburg (German) radar, Small and Giant comparison withBritish sets, 15, 251, Wiirzburgs, 116 284; ships fitted, 169, 201, 242 YE, aircraft homing beacon (US), 167, 168, SL, WS radar, (US), 344; aerial, 202; 197,250 comparison of fitting with British XAF, US Navy air search radar, 15