HOVERING CRAFT \ &

THE INTERNATIONAL REVIEW OF AIR CUSHION AND

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Volume 5 Nqmnea I I

KALERGHI PLIBLICATICINS I AUGUST 1966 d

The SR.N5, the wo~ld'sfirst military , is revolutionising logistics, carrying 15 fully-equipped troops or 2 tons of stores at cruising speeds up to 62 knots. In use with the U.S. , and during operational trials with the British Forces in Borneo, it has proved to be unaffected by tide I state, underwater defences, shallows and the many obstacles which previously meant inaccessibility. Its work rate is many times that of conventional of comparable size and its amphibious capability gives maximum freedom of choice of operating routes and landing points. Patrols, trooping, supply, casualty evacuation, amphibious assault, search . .. and rescue, anti-submarine warfare, will all be transformed by British hovercraft. In addition to their operations with the British Forces in Borneo, SR.N5 hovercraft are in service with the U.S. Navy. Both the 7-ton SR.N5 and the %ton SR.N6 with its much larger capacity are now available from the world's first hovercraft production line. Modern fighting forces have a : .-.-- - completely new weapon.

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1*c ,.1 A*&" / ,n,,- .,. , .,, ,,,5,,.,3 A....AC. ,,",.,O british hovercraft corporation limited I.L.ac,.~ nrll ,> I I* YEOVIL HOVERING CRAFT & HYDROFOIL

FOUNDED OCTOBER 1961

J~t!ion Rice, (left), Frrirbrr~zks attortacy, and Larry Lwdry, At~~:irorcrgeb~r.ritze.vs man, displuy a modal of the 18 posscnger 1tovo.cralr their new organisariot~ Skimmers Iltc. il ill bring lo First Hovering Craft & Hydrofoil Monthly in the V'orld Ancltoragc this month. See be101 for jro/ltc,r rletrtils

F any further evidence was needed of the vxhe of the June The result is a 30-day experinlent at Cook Inlet jointly I Hovershow, it is provided by a news report from far-off carricd out by Skimmers, Inc., a firm established by Rice and Alaska. There, an 18-passenger hovercraft has just started an Landry for the purpose, and Bell Aerosystems, the American operation unique in American history. The two men licensees of Westland. behind the experiment found their inspiration in Britain and Two hovercraft have been taking part in the experiment. particularly at the Hovershow. Each can carry 18 passengers or 5 tons of freight. This is the Their names are Julian Rice and Larry Landry. They had first hovercraft commercial charter operation in the Western for some time been considering how best a transport business Hemisphere. 1 h could function in the difficult conditions to be found at the "We believe the introduction OF hovercraft in Alaska will of Anchorage, Alaska. Oil Installations in Cook Inlet revolutionize the transportation industry particularly in those needed a reliable transport service of passengers and freight areas previously inaccessible by conventional modes of trans- which could operate on winter ice as well as choppy summer portation," says Mr. Landry. waters. Rice and Landry knew of the hovercraft service between "The two craft are equipped Lo operate under 'zero-zero' Oakland and San Francisco, the only such service in the conditions. Weather, for all practical purposes, will be no United States. ,But in California there are no ice hazards and obstacle in our operation," he said. the craft in use there are for passengers only. To find if there The port commission at Anchorage has welcomed the was a suitable hovercraft for Alaskan conditions they decided project. It promises to improve transport in the area and to to come to Britain to consult the hovercraft pioneers. They assist in (he exploration and exploitation of natural resources visited Westland Aircralt Ltd., and other firms. They were and the development of isolated territories across the inlet. impressed. But no final decision was taken. They returned to Such is [he hope. It is too early yet to speak of fulfilrnenl. Anchorage, looked at their problem again, and then returned to But this is a pioneering enterprise that can at once be Britain for the Hovershow. There, the superb demonstrations commended and should hearten all those who made the first they saw helped to make up their minds. Hovershow possible. IN THIS ISSUE ~ August 1966 Vol 5, NO 1 l 1 People and Projects 4 Editor ; The Wave Resistance of a JUANITA KALERGHI Compartmented Cushion 6 HOVERING CRAFT AND HYDROFOIL is produced by Kale~ghi Prrblicntiorrr, .SO-(.! lllrrrrdlo,d Srr-ccr, Lo,rrlo,r. Spearheads LVI Tcleplione WELbeck 8678, l'rirrteil in Grew Urirairr Potential 10 IIY Vrllrers Publicatiorrs. Lorrdoii, NW.5. A~irrr,alsrtl~sorp- [ion: Five Girineas UK and equivnlerrr overseas. USA Letters to the Editor 11 and Canada $15. There ore twelve issrres arrnrmlly. The History of Hydrofoils 14 Contents of this issue are rhe copyrifiht of KnleryItr Publicafions. Permission ro rcprodrrce pictrrres and texr The Small Hydrofoil Prototype car1 be granted orrly under \vrirtr.n ogreetnent. Extracrs to the Stryela 16 or conrrr~ents rnay be made with dire rrckt~o~vledgenrer~r to Hoverins CroJl and Hydrofoil. The Hovercraft and Problems of ADVERTISING REPRESENTATlVES Port Development 18 GREAT BRlTAIN & EUROPE: Iritcrrrorionol Graphic Press Lld, 2 Dyers , Lo~rdorr. ECI; JAPAN: 1 Across the Channel by Hovercraft 21 Japan Trade Service Lld, Masami Brrilding. 1-30 Ka~rrlrr Jimboclto, Chiyoda-ku, Tokyo, Japan; HOLLAND: Norway's Hovercraft Legislation 22 G. Arnold Tcesirrg, Amsterdam-2, Krrber7ssrranr 68, Holland A Revolution in Transport 26

COVER PICTIJRE: An rrrrist's impression of /lie protolype hydrofoil gunboar desigrred urid co~rsrructc,d by Crrtmrnotz Aircrufr for tl?c US Nuvy. The cruft is 22 rn 86 long, with o 6 rn 70 beum und rr 57 ton displtrcernertr. The foilborrr:, l>roprrlsior~system ~11ill be mcritrlrrincd by o 3,600 Irp rnorinr vcwion of the Rolls-Royce "Tynr," gus trrrbine erzgitic. A drtr~l.ingof the cltginc, rrppctrrs 011 pogc 5. Mr Htrrold Wilsotr, rlrc Brirish Prinie Minisrcr, l)t.escri/ed Mr Kosy~ir~.R~tssiior Prerrrier, ~c.irlr u modcl of n Wcs~lund hoi~er- c.r-crff ~.lretrIro visilcd tlrc Rritisli lrrdrrs~rirrl Exlrihiriotr in Mosco11. on ~lrc17/11 Jrrlv, 1966

People and Projects

The noei~tgContpany, . Washington. are constl-ucting The ,folloil.itt~ i.s hnserl or1 (1 sltor-I trrriclc by 111.o Sovicv a hydrofoil gunboat for the US Na\y. Designated PGH?, the ctigitrcers, N. Zulslov,ski~urld .T. Mnl'cliik, it1 rlrc Jrrtie ti~tt7ih~r craft has a length of 71 ft (21.64 m), a beam of 25 ft (7.62 m) of Ryechnoy Transport, monrhly orgurz of rlrc, Millistry of rlrc and a displacement ol' about 60 tons. The propulsion system River Flee/ oJ /he Urtssinrr Fcdrruriorr of .Soriali.st Kepublics: takes the form of water jets. Water is drawn through rear struts One of the psoblcrns facing the operators ol' hydrofoil pa,;- into a centrifugal pump and is ejected rhrough nozzles near the senger services on the Volga and other ercat rivers of the USSR stern. One of the major advantages claimed for this systeni is (especially during thc summer season, whcn they work to capa- its simplicity in operation and maintenance. A water jet does city) is that of keeping the cntire fleer in scrviccable condition no( require a complicated power transmission system and there- without withdrawing units from servicc. This involvcs frequent fore eliminates any nssociatcd lubrication problems. The engine docking of units during thc night. when the services are. for the is directly connected lo the pumps and forms an easily acces- most part at any rate, suspended, and in the normal way tlierc sible, compact uni~. have been occasions \\.hex damage has bcen done to the The water jet will be used for propulsion \\hen the cral't is vcsscls' hulls, more particularly in thz blu(l of the bow. using its conventional hull and when using the I'oils. In the In order to eliminate the risk of such damage. the Volgograd former condition a Buehler centrifugal pump will be driven by (formerly Stalingrad) Section of the Gor'ki C'cntral Design a 150 hp diesel engine. and in thc latter casc a Byron Jac!;son Bureau has introduced the use of a floating crane with a lift punip will be powcrcd by a gas turbine. ol' 42 tons for lifting tlic hydrofoil vessel out of the water and Three fully submerged foils will support the craft at high placing it on keel-blocks in a lighter alongside, and replacing speeds and are fully retractable for slow-speed operation. Their if in the water aftcr cxamin:~tion and, if neccss;irp, repair. stability will be controlled by an automatic electronic system. The floating crane used for this purpose is one of an exist- With the exception ol the foils and struts, which are stainless ing type known as !he "Staryy Burlak", reinl'orced with longi- steel, the hydrofoil is of aluminium construction. Armament tudinal beams and with supporting pillars undcr thc winches. will comprise a 40 mrn gun forward, an 8 1 mm mortar aft, and Such a crane can lift vessels of the 12nketu and Meteor types, twin 50 calibre machine-guns on each side of the bridge. carrying 66 and 150 passengers respectivcly. which are at * * * present in use on the rivers of the USSR. Hard ballast weighing During its first year of operations. , which 30 Ions is provided ;IS counterbalance for the vesscl lil'ted, and operates services across . has carried 302,640 pas- by this means the change of trim when lifting a vcssel of the J sengers on 15,000 trips involving 61,000 miles between , larger Meteor type is kept to 0.12 m (4) in). The original , Sandown and Gosport. using two Westland SR.N6 crane used for this service. at the port oi Volgograd (Stalin- craft. grad) in 1964, was hand-operated, but in 1965 it was fitted * * * with electric power, ptovidcd by a Type DCi-25 dicsel generator A couple of enthurias!ic young constructors. I. Galkin and Yu. Chaban. at the Icrasnoye Sormovo shipyard at Cior'ki. on the Kiver Vclg;i. main hydrofoil dcvclopmcnt centre in thc USSR. have spent the last year a catamaran yacht on hydrol'oils, the Atrclr-on~cdu.which is now in use and has sho\vn itself considerably faster than a similar yacht \vithout hydw- foils. No details of' the size, etc. of this novel yacht have been published yet. but thc short report :tbo~~tit published in Iz~~ycstiytrol' July 15th states that the designers are so cncour- aged by their success that they are now building "a younger brother" - t\vice the bize.

A tyrc-shaped rubber tube which has been successfully tcstcd on a 5 fl flying model at Wright Patterson Air Force Rase. Ohio. promises to allo\v heavy to land on ice, swamp, descrt or ploughl;~nd. without requiring prepared runways. Designed by Bell Aerosyslerns, the rubber tube is inflated before landing, and the perforations create an air cushion which cnablcs thc z~ircraft to float several inchcs ;tbovc tlic ground. Braking is by revcrsc tlirllst of the jets. and for linal braking some of the airjcts arc: cut olT. and special friction shoes skid along the ground to bring the aircraft to a halt. During llight the deflated tube is suckcd close against the f uselagc. Engineers claini that the flexible cushion will allo\v landings even over obstacles I X in high.

7'li(, /lotr/itrg rrorle dt,.ti,qrlcrI hy tl~c(;or'Xi Ci*nlrtrl 1)csigtl H~oetrrr. Volgoyrc~cl,liftitrg tr Ir?~drofoilorrt of tllc, rc,(rto.

One man using an air cushion system dcvclopcd by thc Clark Equipmen1 Company of Buchanan. ~Michigan.can mo\.c a1 ound pallets. loaded with goods weighing 3 or more tons. Pallets operated by thc system must be connected to an 80-100 Ibs. per sq. inch compressed air line and operation can only take place on smooth. level Iloors. controlled from a console on the deck of thc cranc pontoon. It is understood that the company is dcvelopi~ig ;I hand This lifts at a speed ol' 0.18 mimin (7 in'min). and transfers truck which will compress its own air and thus bc flcc of air the hydrofoil vessel Srom the water to the keel-blocks in a hose length limitations. lighter alongside. or vice versa, in ;ibout fifty minutes. Since rhe introdi~ction of this crane, no difliculty is csperi- cnced in completing the examination and requisite repair of hydrofoil vessels overnight, i.e. without taking thcm out of service. In between whiles. howcvcr. the cranc is being used for minor services, with displacement vessels as well as those with hydrofoils, such as lifting the bow or the stern for es;~rninationand adjustment or repair of the unclcrwatcr fittings - -s. propeller shafts, bzarings and foil systems- operations which can oilen be carried out in a matter of a Sew minutes.

A Is 3d stamp bearing ;i picture of an SR.N6 ho\rercraft is lo bc issued on Septcmbci- 19th. 1965. The Post Oflice will proviclc a lirst day covcr service on special cnvclopcs. as well as i~cccptaddressed cnvclopcs sent to thcm. Thc postmark will be Edinburgh.

Acccpt;~ncctrials of the hydrol'oil vessel H.Y I/ictoritr, built by M;~rylandShipbuilding and Drydock Company for North- west Hydrofoil Lines, Inc. Seattle, Washington, have been schcdulcd for August 16th and 17th. 1966 on the Kent Island Measured h,lile Coursc on Chesapeake Bay. Rolls-Royce Tync Mk 621 110 The Wave Resistance of a Compartmented Cushion

T. K. S. Murthy, MSc, MA, DIC, CEng, AFRAeS, AMRINA Vickers Ltd

3. STEPPED CUSllION

This article contains one possible explanation of the When thece is a pressure differential on either side of reason why hovercraft sometimes have difficulty in accclera- the transverse stability skirt the cushion originally con- ting through the hump. It is shown from theoretical taining uniform pressure becomes asteppedcushion (n, a;~). considerations that when a pressure differential exists The induced wave formation is now altered and it may there- between the two compartments of a conventional hovercraft fore be expected that the wave resistance and the moment cushinn with a transverse stability skirt, the wave resist- due to wave resistance will be different. ance is increased at all speeds, the increase being high enough at some low speeds prior to the hump to make the thrust power based on the hump resistance of the uniform cushiori possihly inadequate to accelerate through that speed. The requircmcnts of pitch stiffness and of low wave The formula for the wave resistance, R,,, of a stepped rcsistance appcar to be contradictory, but as very low cushion with equal compartments (+, : J) can be derived as: prpssurc ratios do not appear to be tlesirablc from con- sidcrations of the latter, it may he possible to effect a compromise I,y installing pressure relief valves between thc two coml,artmcnts. This sturiy is based on two-dimensiolial theury 1)ut the where W is the weight supported by the cushion. usual wavc slu11e limitations on wave resistance at low L the length of the cushion, speeds have riot beer1 included. Thr general trcnd is Iio\v- B the width ever likely to be as presented. and F = g~/v'.

This is based on two-dimensional theory. It is known that three-dimensional theory yields lower values for the wave resistance in the case of a simple cushion (uniform The wave resistance of the general type of tandem cushiol~ continuouscushion)depending on the B/L ratio and a similar (L, ; -) can be derived from first prir~ciplesusing two- effect may be expected in the case of a stepped cushion. dimensional theory. The notation (7., ' ; .-) is used to clcnotc a composite cushion consisting of two pressure bands The result corresponding to Equation (1) for a simple cushion of the same dimensions (i.e. when the craft is at a moving in tandem and extellding from 0 to 7.L and from 3L level trim or when the stability skirt is ineffective) is to L where L is the total length of the tandem cushion, the origin being taken at the leading edge of the front cushion. The two bands are assumed to be moving together at a speed V along the negative direction of the x-axis. The ratio of the pressure in the rear cushion to that in the front is r,

but in the case of a twin tandem cushion, i.e. when the .The propulsive power is usually based on R,,, and we will iI bands are of equal length, (1 + 3) equals urlity, and 3 can have to examine the increase in resistance, if any. given I then be simply the pressure ratio between the two cushions by Equation (1) due to the possible adverse interference for all the results are valid when 3 is replaced by 1/~and between the separate wave trains induced by the two com- 1 I when the motion is along the positive direction of the partments at different pressures. x-axis. Since A conventional hovercraft cushion with a transverse 1 t a' t 2mcosF/2 ( (1 t u)~. stability skirt achieves its pitch stiffness from the efficiency of this skirt in creating a pressure differential between the compartments on either side particularly when it is clear from Equation (1) that 4' the trim of the craft alters, for the pressure in the down- going compartment is expected to rise and produce a re- storing moment. The maximum value of 1 - cos F/2 is 2 and therefore which is positive or negative according as (1 - u)' $ 40, i.e. u + l/u 5 6. Thus, when u lies between 0.172 and 5.828. u + l/u < 6 and R, is a minimum. If. on the other hand, u < 0.172 or > 5.828, u + l/u > 6 and R, is a maximum. In either case. I giving an upper bound for the resistance. (5) 5. VARIATION OF RESIST4NCE WITH SPEED a2RW - 1 When (1 - u) = 4u, i.e. when u = 0.172 or 5.828, ,- 0. The maximum andminimum values of resistance are obtained ?F I by differentiating the RHS of Equation (1) with respect to and it is'necessary to examine the higher differential V or, what is virtually the same thing, by differentiating coefficients. with respect to F, and setting the result equal to zero. Now, I Now

But The turning points of R, are therefore given by - u) cos F/2 + 2u cos F F aF' (1 + u)~ 1 = (A) sin - = 0 2

F (1 -T)~ and (6) cos - = - -, provided (1 - 7)' < la 2 40 a negative quantity. The resistance is therefore a maximum r U To see whether these reoresent maxima or minima we must and has the value

evaluate -a 2~,v ;iF2 . it Now Case B (1 - u)~ (1 - u)' cos F/2 = - -, defined for -61, e 4u

Case (A) F F sin - = 0 when - = nn where n takes the 2 2 Ci values 0.1.2, -- and cos F/2 = T 1 according as n is odd or even. (1 - G-)2 Ii which is negative if -< 1. R, is therefore a 40- maximum and has the value w2 (1 t u)~ R = -- (maw!) gpL2'

when F takes the values I sinF/2 = 0, cosF/2 = +I, sinF = 0, cosF = +1 . a2RW = 2W2 - a tive quantity . 2F2 ~PL~B'

The resistance is therefore a minimum and, in fact, equal to zero. Thus (1 - u)~ If, however, -= 1, cos F/2 -1, and this case Rs(rnin) = 0 when F = 4pn , p = 0 . 1, -,9 ---- (4) - 4u reduces to case A(ii). Case ,i(ii) I It will be seen that by setting u = 0 or 9 in Equation (5), we derive -16~ sinF/2 : 0, cosF/2 = -1, sinF = 0, cosF = t1 . Rw = I (max) gpLZB the same as the result obtained from the basic Equation (1) or from Equation (3). This is the maximum resistance of either the front or the rear compartment when the adjacent compartment is empty. Also, setting CJ = 1 in Equation (7) gives 4w2/gp~'B as the maximum resistance of a uniform cushion without compart- ments, which is a well-known result, as can also be seen from Equation (2).

6. SUMMARY OF RESULTS

(1) For all 5, Rw(min) = 0, when F = 4~77, i.e. at Froude Nos. 0.282, 0.199, 0.163, 0.141, 0.125. --- Figure I

W'/~~L'B)fluctuates from 4.0 to zero, but when the pressure when F = 2(2p + l)~ ratio between the two compartments is, say. 0.5, the maximum resistance is slightly increased to 4.4; the minimum is not i.e. at Froude Nos. 0.399, 0.230, 0.178, always zero but about 1.7 at some speeds. When the pressure 0.151, 0.133, --- ratio is 0.172 the maximum resistance is doubled and the value increases sharply to four times the normal value when w2 (1 + 512 CT approaches zero. This is easy to understand for when the , when craft is borne on the front (or rear) cushion only the cushion pressure is doubled while the length is halved. If the transverse stability skirt is fully effective a pressure ratio will certainly be developed when the craft pitches nose-up or nose down. Figure 2 shows that although the hollows of the resistance curve for a uniform cushion at F = 477 and 8n are still hollows for all values of CT., the hollows which existed previously at F = 2n and 6n are now humps of very high magnitude when (T < 0.172. For when F = 2(2p t 1)~ higher values of CT app,roaching unity there are still i secondary hollows at these values of F with humps on either d: i.e. at Froude Nos. 0.399, 0.230, 0.178. side, but the resistance at these hollows is not zero as in \ 0.151, 0.133, --- the case of a uniform cushion but can assume very high values approaching twice the hump value of the resistance of the basic cushion. It is clear therefore when the cushion is non-uniform with the two compartments at different pressures, the average value of the resistance is very much higher than in (5) u = 0 (Front cushion only) 16w2 the case of a uniform cushion. When the craft starts from -- -do- 'w 'w (,ax) - gpL2 rest with a uniform cushion the changing pattern of the induced waves sets up a pitch oscillation (as is amply shown in trials) and this in turn produces a pressure ratio (6) u = m (Rear cushion only) causing a large increase in resistance. This is probably -do- -do- one reason why some hovercraft do not pass through the hump easily even when adequate thrust power is provided on the (7) u = 1 Uniform cushion basis of Rw,. 4w2 - - at F (2p t l)n Rw(max) - gpL2g =

i. e. at Froude Nos. 0.564, 0.326, 0.252, 0.213, 0.188. ---

7. DISCUSSION

The Froude Numbers indicated in paragraph 5 are based on the length of the complete cushion even when one of the compartments is empty (u = 0 or m). The regimes for u can be simplified by defining cr as the ratio (less than unity) of the pressures in the two compartments for, as stated in paragraph 2, all the results are true when l/u is sub- stituted for u. Figure 1 has been plotted showing the variation of maximum and minimum resistance for all values of u ranging from 0 to 1.0.

IIC 1 A study of Figure 1 reveals some interesting features. 0.1. 0 20 "7'Fm"Dt No O" .The wave resistance of a uniform cushion (in terms of Figure 2 A The ahove study is hasetl on two-dime~~slonaltlicol'j arid LEOPOLDO RODRIQUEZ is applicnble to a hovercraft with two equal length com- partments dlvided by a tral~sversestability skirt amidships SHIPYARD operating over calm, tlecl) water. A corngarison wlth a 111li- form cushion shows that the aave resistance is likely to he MESSINA - ITALY higlier at ~)racticallyall speeds belo\' the hump when the c~)ml)artme~itsarc at different pressures. The rrql~ircments of pitch stiffness ant1 lo\v save resistance apprnr therefore to be contratlictor?. hut it may be 1)ossihle to install pressure relief valves hetseen the two compartments so that the pressure ratio dro~lsno lorver than that required for Licensed by Supramar A.G. Zug-Switzerland adequate pitch stiffness. It is knowri that certain limitatioris on the theoretical The results for a unlform cushion (two-dimensional theory) can be irngosed from consiclerations of maximnm wave slope arid Greatest Experience similar limitatiolls car1 possihly he imposeti in the case of in a stepl)ed cushion. The trerid will very likely be the same as that resented hereill. Hydrofoil Building THE RODRIQUEZ HISTORY OF Hydrofoil Across The World's Seas AIR CUSHION in 18 Countries VEHICLES

LESLIE HAYWARD

KALERGHI PUBLICATIONS

U I<. and Europe 5s. 6d. (incl. postage) Canada and the U.S.A. $1.25 (incl. postage)

ANY KIND of I I REPAIRS British Rail Hovercraft Ltd

invites 1.43. R .li. IfiTDSON to On the 7.30 to mmx

xxx Returning 16.00 Sou thamp ton to Cowes date Monday to Friday 1.8.66. - 5.8.6h.inc The first season ticket for Monday to Friday 8.6.66. -12.866.inc the British Rail Hovercraft service between Sou thamp- ton and Cowes has been issued to Mr R. H. Hudson, Conditions : Issued subject to the conditions and regulations of Br~t~shRa11 Hovercraft L~m~ted Export Sales Director of appearing in their publications and notices Dimplex Ltd, the South- ampton manufacturers of heating appliances Seaspeed Spearheads British Rail Potential A Cadman Clinton CEng, FRAeS, FBIS, MSEE

OUTHAMPTON. the premier passenger port and gateway to the It was an enthusiastic party that met at the BR Seaspeed S world, has a long and lively history of pioneering maritime Terminal, Southampton, where the blue-and-white Seaspeed projects and adventures. Notably, in education and training was waiting, and it was here that Mr Stanley Raymond, Chair- there is the School of Navigation with courses for naval archi- man of the British Rail Board, accompanied by Dr Sydney tects and marine engineers, and at the University advanced Jones, Chairman of British Rail Hovercraft Ltd, opened the research includes sail design for yachts, propulsion, and the new service. The Mayor of Southampton, Alderman S. M. G. hydrodynamics of hovercrai't. Mitchell, with other civic guests, warmly supported the enter- Probably there has been nothing quite so exceptional as prise. Later the party embarked in the Seaspeed for Cowes. the rapid evolution of the hovercraft in this area. Here Mr escorted by a party of journalists in another N.b, the two Christophe,. Cockerell, the inventor and developer. had the craft keeping station at 50 knots across the Solent, sailing a ideas (covering the fields of science; engineering and practical dog-leg course to the Cowes Terminal. operations), formed Hovercraft Ltd, and then became Technical The welcoming party on the Island was headed by Mr L. G. Director of the Government-sponsored Hovercraft Develop- Daish. Chairman of the Urban District Council, and Mr L. H. ment Ltd at Hythe. Here he continued with a staff for several Baines, Clerk of the County Council, and there were also patient years through consecutive stages of successful design, some members of the British hovercraft industry. The warmth leading to the present generation of craft of which the N.6 of the welcome was increased by the shrill shouts of children is p~obablythe best known. The craft was built at Cowes by behind the wire fences. British Hovercraft Corporation, who are now on the way with While both terminals have waiting rooms with the usual the 160 ton N.4 planned for the cross-Channel service in 1968. offices: Cowes also has accommodation for crews and main- Not leas: in contributing to the success has been the many tenance stafl'. Self-contained parks adjoin each place. hours of testing in the local sea states in the Solent, where The staff at the terminals, in nautical blue uniform, includes shoit steep waves, sudden squalls and the wash of big hostesses issuing tickets and assisting passengers, and a beach- have irnposed the most severe conditions. master with his assistants to deal with traffic control and One of the most promising transport developments started general servicing. on July 5th when British Rail linked their system by Seaspeed Displayed in the waiting rooms are the Conditions of hovercraft to the . While this is in the nature of Carriage end pictorial instructions for fitting a life-saving an exploratory service for obtaining experience with passengers jacket, but in the fairing above the Seaspecd cabin there is the and freight, analysing loads. speeds. power, maintenance and large inflatable raft in case of emergency. d efficiency, it will be a guide to the projected operation to Refuelling may take place at either terminal, but mainten- of the N.4 in 1968. In fact the conditions in the Solent, ance and inspection are undertaken at Cowes, where lifting with N.6, when scaled up are directly comparable with those tackle at the end of the apron is available when required. As on the French route. the British Hovercraft Corporation works are just across the river, any special facilities or spares are quickly available. It was important to have a terminal adjoining the rail Maintenance costs at present are high, but it was hoped that station at to provide a second link with Cowes these wou!d reduce and fit in the economic plan. this year, and it was hoped to find a suitable piece of adjacent At the present time the N.6 was hired and the manufacturers beach, since it was not at all satisfactory to have a journey keep in close. touch with the operations. from the station. With this kind of development in view, the After the lunch at Cowes, Mr Raymond emphasised that the company would discover the snags in public service conditions; Sccrsprcd service was a small start, a small addition to their these could then be reviewed with the designers and develop- national services, and he hoped that it would introduce success- ment engineers so that improvements could be made. All this fully the new transport era. It was just over 100 years ago that would be valuable for the N.4, which has been ordered, and the railway started in the Island, and about twenty years later it is hoped that the first off the production line will have the that ships were introduced. BR livery. Ships had been used to link up many of our off-shore islands, There was every hope that the twenty-minute service open- and there was every prospect, first of all to introduce more ing to the public on July 6th would encourage the people from hovercraft links with the Island, and then with the more the Island to visit Southampton in greater numbers, for shop- distant ones like the Channel Islands, the Scillies, Ireland and ping and entertainment and possibly to explore the beauty of so on round the coast. . There seemed to be little doubt that there would British Rail were the largest concern in the world operating be many visitors to the attractive Island. short sea routes, and it was necessary to try out the new form While Mr Raymond was speaking a hovercraft passed close of transportation to see what it could do. as BR were the inshore: the noise was slightly noticeable, although a bus largest potential users of hovercraft. starting away in low gear really was disturbing. It was important that transport should be modernised to meet The noise question was considered by Mr Raymond to be the demand for rapid travel, and so this small start with the a tractable problem, bearing in mind that the N.6 was the Sraspr~dlink will help. It is also necessary to find out if the prototype of more sophisticated designs. The N.6 was a new new service could be used efficiently all the year round, and noise to many, and it was hoped that there would not be too what developments there might be for freight. The planning much discussion about it as, according to the sound recordings proposes to deal with night operations as the shorter days made and compared with some and lorries, the hover- approach, and also the question of improved at slow craft was less noisy The work being done by the development speeds in congested areas. teams to meet the operators' demands should much reduce the In referring to the Island's rail system. Mr Raymond said noisiness of the next generation of craft; as well as that of the that the route between Ryde and Shanklin would be electrified later models of the N.6. In any case travel noise was tedious and some of the London Transport District Railway stock and fatiguing, and the Board also had made great efforts to would be used. During the preparations for the Seaspeed reduce noise in trains and had succeeded quite well on the service BR had operated from the beach at the Hovershow electric rail services to Manchester. and on one day carried more than 2,000 people; this was a Passenger comfort studies would include air-conditioning. slight indication of the interest. seating, ease of entry and exit, and lighting. In order to investigate the whole problem the Board had While the terminals are suitable for the present conditions, hived off [his separate small operating company, now consisting more sophisticated layouts are planned where the hovercraft of about thirty people, young men and women keen on the will be guided to the ramp and up to the covered arrival bay, job. Mr C. A. Brindle was the manager, and in the course of so that passengers will be close to tht: facilities and amenities some four months all the planning, training, technical and of a first-class terminal. There will be a modern freight- commercial negotiations had been undertaken and achieved, handling system dovetailed into the national trunk network. not least being the certification of the route. The manager had The application of the air cushion principle to the handling of qualified as a driver and had taken the engine course. freight is a "must" for the future. While the Board would support the new company, it was Seaspeed establishes the first rail-hovercraft link to the Isle vilal that it felt free to develop in every way and to find out of Wight, and BR claim that the journey from London to what it was worth commercially. Cowes is completed in just ilnder two hours.

LETTERS TO THE EDITOR

Dear Editor, If the case for a show at regular intervals is accepted in ITH the first hovercraft show behind us, this is as good general, then the question of location inevitably follows. Much W a time as any to consider what may be done in the can depend on the choice of venue, and for this such things future in the way of shows and exhibitions. For the time being as local population density, availability and adequacy of accom- it is a hard job putting over the argument for such a novel modation as well as the sufficiency of the show area and form of , and it will be so for some time to come- facilities have to be considered. Thus. as much for domestic particularly so far as civil operators are concerned. and human reasons as for any other, cities and shows become What then may be done to propagate interest and involve- synonymous with each other: the Auto Show - London; Aero ment in the future? Obviously the maximum use must be Show - Paris; Trade Fair - Hanover; Induslrial Fair - Leip- made of the usual press, radio and television outlets, with zig; Film Festival - Cannes, etc - all international events. So news. features and discussions being widely disseminated at far as hovercraft are concerned I would like to suggest Venice home and abroad. As useful as these are, there is no substitute for earnest consideration and propose a combined Hovercraft for a live show with which to generate interest. There are two and Hydrofoil Show. reasons for this. First, the show itself, as well as the partici- Of course there are sure to be protagonists for holding the pants and personalities, becomes a local feature. Secondly, live show in the UK and others who will insist on an all-British activities draw a great deal of public interest, and particularly event after the style of the past SBAC shows. These insular so if speed can be effectively demonstrated. minds should be silenced from the start, for nothing is more damaging to an industry and its image as seen from abroad First. the list given of SR.N6 operators does not, I thin^. than a purely national show. We have nothing to lose but give due eminence to the performance of Hovertravel Ltd, who everything to gain by backing an international event. What is have operated a continuous service since , and have more, we have no really suitable display site within the British to date carried over 3.003,000 passengers, and are at present Isles. running at up to 3,000 -paying passengers per day and The unique city ol Venice provides a natural arena with have completed over 3,400 operational hours. Figures for all adequate Facilities For demonstrations, fuelling and engineering other operators can only be a small fraction of these, and installations. and a good comn~unications system connecting would make interesting reading! Notable omissions from with the rest of Europe. Many ships use the port and they Sarony's list are ScanHover and San Francisco Oakland Heli- would be able to off-load their charges straight into the lagoon. copters Inc, although they are not UK operators. The benefit As a city, Venice has a large number of alternative attractions to the industry of the valuable developments carried out on the for thc leisure hours and for entertaining. Timing would have Solent run is now being, I believe, recognised by the British to be chosen to avoid clashing with the high summer tourist Hovercraft Corporation and surely cannot be overstated. trafic. Late August or early September would probably be the Secondly, the article, while purporting to be a "Planner's best time, and the city authorities would undoubtedly welcome Guide". misses surely the fundamental point of hoverport the event as an aid towards extending their useful business design. which is the ability of the craft to operate without season. A bi-annual air show is there during September and it at all! In other words, terminals must be of minimum cost and may be possible to arrange a joint effort. so sited that they take full advantage of all the hovercraft's Apart From the internal aspccts of this city. its geographical natural advantages. The siting of the apron to take advantage location makes it an excellent base for prospective hovercraft of natural gradients is of first importance. This would reduce operators. A nominal 100 mile (160 km) range goes beyond the cost on the figures quoted to £140,000, which I think is Ravenna to Kimini on the Italian coast - a popular holiday nearer the mark. area. Trieste is only about two-thirds of this distance away, and Mr Sarony's other criteria for planning I completely concur the Yugoslav maicland a little less. Additionally, a service with; they are in fact exactly similar to those for modern working in this area would comc to the notice of interested , although as yet on a much smaller scale. The areas parties in Greece, Turkey and the Aegean area in general. involved for hoveiports are in fact insignificant when compared A glance at the map and only a slight knowledge of the area to even a sniall domestic . show that the Adriatic and Mediterranean regions hold more Thirdly, in the discourse on ramps. I cannot see why a prospects for hovercraft and hydrofoil operation than many dished ramp should not have a fiat bottom, and in the remarks other parts of the world. The tremendous holiday traffic now on noise, following my own experience with noise recordings being generated as millions of Europeans migrate towards the of both N.2 and early N.5s in 1964, taken in conjunction with sun and the sea offers an untapped potential. Some of the Hovercraft Developn~entLtd. the problem is not only in the probable routes are perhaps a little too long for the present close proximity of the terminal but over the surrounding area generation of hovercraft. but those capable of 200 miles of. say, half a mile radius; when baffles such as are proposed (320 km) will be able to cope with them. in the article would have little or no effect until the craft is Even if the major hovercraft manufacturers feel that a "in" the ramp. This has been fully discussed in articles pub- Venetian venture is not worth their while, the smaller ones lished in this very journal by Wheeler. Donno and Trillo in may think otherwise. Many vessels of a variety of type and 1965. Vol 5 Nos 1 and 3. size provide day-to-day transportation there either as public The solution to the problcm of large aprons put forward in utilities or as personal . The city is rich and exists the article is certainly ingenious and worthy of further studies. as three main entities - the Lido, which emphasises beach and It is perhaps relevant that no actual costs are mentioned and, water sports; the main city as a tourist attraction: and a port as an engineer, such a system to cater for an approach speed and industrial area on the mainland. The international airport of even 13 knots with an acceptable deceleration would seem is also on the mainland. For commercial reasons, the fastest quite an undertaking for the 160 ton SR.N4. It should not be transportation system is required, and hovercraft can provide forgotten that every force has an equal and opposite reaction, this. It is significant that there is a regular hydrofoil service and the engineering problems do not stop with a jet of water. bet~veenVenice and Trieste which is operated by a Rodriquez Finally. may I refer to the summary. All publications of vessel. large-scale hoverports have in fact been "artistic"; no further comment is necessary. However, if one studies the photograph Yours faithfully. on page 24 of your July issue, of the Association of Consulting Engineers' stand, all the models on display show the sea level at dead low water. as also did the model on the BHC stand. Mr Saronv asks the question: "What proposals have been put forward to date?" If he was inside the industry he would perhaps be a littlz more informed, and would quote other newspapers than the Evening Standard and Illustrated London News. It is a pity that the author has confused selling his patented scheme with criticising other schemes and with writing an article titled "A Planner's Notes for Guidance". Yours faithfully, .A. W. GRINYER,BSc(Eng). AMICE

Dear Editor. OUR magazine continues to give excellent coverage to Y hovercraft affairs, and its photographic presentation is second to none. I partic~~larlyliked the display of Hovershow 66 exhibition stands, which after all were the basis of the Show. As a civil engineer concerned with the rather primitive existing terminal designs and also with more sophisticated future layouts, may I add certain remarks to the article on "Hoverports - A Planner's Notes for Guidance" by Peter Sarony. Dear Editor, complex built out over unstable mud or ground, necessitating I am saddened that Mr. Grinyer, who is "in the industry", piled foundations, as could be the case if a Hoverport were to should so readily have misinterpreted both my text and my be built over the mud banks in Outer Harbour. motives, and I welcome the opportunity of answering his As I believe I explained to Mr. Grinyer's associates at the criticisms for the benefit of those who may be misled by them. Hovershow, and as is no secret to anyone who attended Firstly, the terminal schemes I described have been Browndown or read the numerous accounts of my system in evolved concurrently with Craft developments over a six-year a variety of technical journals and newspapers (e.g. Daily period and stem from original research and analysis into Telegruph, Evening Stundard, Southern Echo, etc.) the com- hovercraft and their operation. Assistance from Hovercraft parative costs on this oiled basis. for the Hoverwavs and ramps Development Ltd., and operators such as British United complete, are approxikately &1:250,090 for the large concrete Airways have enabled us to prepare detailed Design Studies platforms, and continuous ramp designs, as against f120,OOO and Reports on international (e.g. Cross Channel) hovercraft for the containment system which I support, and I do agree services from that time to date. that this IS highly relevant. The suggestion for a flat bottomed ramp is not new, and is Secondly, my paper was in no way intended to belittle the generally accepted by the Industry as being unworkable, not worthy and well-praised performance of Mr. Grinyer's com- only for the reasons I mentioned, but also because of the pany, Hovertravel. The point I was making is that British Rail width required for the Tidal section. This has to be sufficient Hovercraft and Townsend Hover would almost certainly for the Craft to be manoeuvred onto it at any state of the not have come into existence anything like so early had the tide. and thus, apart from the expense, could allow the Craft Swedish shipping interests not entered their Cross Channel to work up a dangerous lateral speed. service so decisively to U.K. waters, rightly or wrongly not- The comment on noise is not in conflict with my statements. withstanding the earlier commencement in service of Clyde It may well be objectionable to the ear within a half-mile of Hover Ferries and Hovertravel. the source, but excessive noise is at a peak when climbing a In further clarification, the list was a synopsis of the "state ramp, due to the use of maximum power during this of the market" at that time and refers specifically to those manoeuvre. It is therefore at this time that the reduction at running or intending to run within or to-and-from U.K. waters. source can be effected by the acoustic baffles. Incidentally, the passenger figures Mr. Grinyer gives for Since designers of existing SR.N6 facilities did not anticipate Hovertravel are impressive, but it is perhaps unfair baldly to the lateral instability factor. the three incidents of Craft being compare these to those of other Operators, for on a Cross- smashed against obstructions were not obviated by the intro- Channel service of, say, 27 n. miles far fewer loads can be duction of such a guidance system as the one I propose, (a carried per day than on a sheltered water service such as a fact which I had declined to reinforce). It is perhaps, therefore. Solent crossing of perhaps only 4.3 n. miles. This is especially not surprising that Mr. Grinyer does not believe that these so if one compares different factors within "Turnaround", incidents dictate a basic planning requirement when considering involving such important differences as passports, customs, docking systems for the 160-ton SR.N4 Craft, with the vastly immigration, etc. None of which apply to a domestic increased moment which will be involved. If he considers turnaround. the desired action to be one of a deflective nature, 1 think he T nonetheless agree that other Operators' figures might well will grasp more of the fundamentals of the system. He need be of interest to some, and in this respect I would welcome not be too concerned that the forces involved are impossible Mr. Grinyer's clarification of his own statistics: namely, 3,000 to absorb within a swing of 10 feet, if he compares the moment passengers per day x 400 days = 3,000,000 carried! It would taken up by a short action on the shock absorbers, via the appear that even if two SR.N6 Craft each transported a fresh point loaded tyres on a Boeing 707 jet, weighing many tons load every 10 minutes at a 100% load factor every time, 6,579 and landing at a speed of over 100 knots. operating hours would be required to carry 3,000,000 passen- As Architects our Code precludes us from being as deeply gers. Alternatively, if 3,000 passengers are carried every day, involved with certain companies as Mr. Grinyer appears to be it would take 1,000 days to move 3,000,000 people. I believe with Hovertravel, and I had not considered any disadvantage Mr. Grinyer has misread the figures: to my knowledge, that this may represent. Hovertravel carried a total of 337,818 passengers up to 9th Although labelled by him as "ingenuous", 1 am pleased to August, 1966. note that this Gentleman considers the ideas worthy of the Mr. Grinyer is also apparently confused about various com- further studies being carried out by the team of Engineers and panies' policies. He must surely either advocate that inter- Scientists who continue to be engaged upon this, and I would national services should be run from bare beach terminal sites add that should Mr. Grinyer see any room for improvement or recognise with me the need for the most careful planning that has not been already implemented, we should naturally be of a terminal complex. He seems already to be doing the latter most interested to discuss these ideas with him. Perhaps, to by assisting in the design of "more sophisticated terminal this end, he could well benefit from studying the article in layouts", which he later describes as "artistic". This may aptly criticism more carefully. describe other schemes with which he has been involved and which do not appear to recognise that a Hoverport design Yours faithfully, involves intricate planning of the main buildings and not simply ramps and block plans. Our own designs are in fine PETER P. B. SARONY. Dip.Arch., A.R.1.B.A details and in some cases have been advanced to working drawing stage. Generally, I contend that the hovercraft image is no more impaired by advocating the provision of sophisticated hover- ports than the aircraft image was damaged by the construction of sophisticated airports. Cost is, of course, of great importance, especially when considering SR.N4 facilities. but I would certainly not advise an Operator to choose a site by virtue of a convenient existing gradient alone. If the cost of improving road and rail cor?nec- tions to such a site is included, the cost would soar above any m saving by using such a gradient. In any case, a reduction on one system by virtue of an existing gradient effects a propor- tionate reduction on the system I propose by the same means. 1 have therefore illustrated a hypothetical case in the article, embracing the most adverse and typical conditions which are likely to prevail: namely, a restricted site area, with the whole The History

Figure 81. Cosmos L)y~~umicslrlc

N March 26t11, 1963, Cosmos Dynamics Inc of Newton 0 Upper Falls, Massachusetts, USA, applied for US Patent 3,164,119, which relates to transversely arranged foils connected to the structure of the craft in spaced parallel relationship. As shown in Fig 81, water sk~s,which may be used in conjunction with marine craft, water-based aircraft, etc, support a V-shaped strut carrying a boom structure which in turn carries front and rear foils. The front foil, attached to the upper side of the boom, has a positive lift effect, and the rear foil, attached to the underside of the boom. has a negative lift effect. Various types of foils and carry- Hydrofoils ing struts may be used. It will be remembered from prior disclosures that attempts have already been made to improve the perform- v (Part X) ance of hydrofoils under cav~tatingconditions by "ventilat- ing" the foils. United States Patent 3,221,698 in the name of James Turner discloses a system for controlling the operational depth of hydrofoils using a somewhat similar principle. As shown in Fig 82, the foils have a number of spoiler apertures in the upper surfaces so that when air under pressure is passed through the apertures a cavitation bubble is formed. Air is supplied from a fan having a gas discharge rate at a preselected fan speed related to the submerged depth of the foil and to the load response characteristic of the fan. Jn operation, the pressure of the air source is set for the desired depth of operation of the foil. An increasing amount of air is discharged through the apertures as the hydrofo~l depth decreases due to the decrease in external pressure, and a decrease in the amount of air being discharged takes place when the depth of hydrofoil increases. Details are given in the patent speci- fication of a number of alternative embodiments of various types of apertures in various locations. Richard Barkley of Palo Alto, California, obtained the grant of US Patent 3,213,818 for proposals put forward in h-ovember 1963. Tandem-type foils are supported on front , and rear pairs of struts. A fixed foil is supported betwecn a pair of struts, the foil set at some predetermined angle. Dihedral foils, movable from a position parallel with the main foil to a raised position, are pivotally mountcd to the lower ends of the support struts. It is claimed that this type of foil arrangement has ~ncreasedroll stability over the conventional aileron-type control hydrofoils. By indepen- dent or simultaneous control in opposite directions- decreasing the dihedral of one foil while increasing the dihedral of the opposite foil -roll control is attained. Vertical lift provided by the movable foils may also be controlled, The control mechanism, extending through the Figrrrc 83. R. E. Bobcles foil supports, may be operated hydraulically, pneumatically or electrically. description of US Patent Specification 3,241,511 in the R. E. Bowles of Silver Springs, Maryland, filed a specifi- name of Otto Drtina of Cleveland, Ohio. cation, US Patent 3,209.714, on October 14th, 1963, for a A surface-piercing, concave-disc type of hydrofoil has fluid control system for foils in which a minimum number been proposed by the Sturgeon Brothers of Seattle, Wash- of moving parts are required. Pressures are directly moni- ington, and is the subject of US Patent 3,237,582, which torcd to effect foil lift. thereby eliminating the conversion was issued on March lst, 1966. It is suggested that this of pressure to electrical signals which have to be recon- type of foil automatically sheds itself of debris. to a great verted by servo systems to alter the angle of attack of the extent overcomes the problem of skin friction, and elimin- foils. ates cavitation. A bearing assembly inside the housing supporting the foil shaft is suspended from the hull of the The system senses foil lift conditions relevant to the craft by swinging links and a shock absorber assembly. local dynamic conditions of the water and the static pres- A foil disc mounted on the base of the outwardly inclined sure at foil level relative to depth. The static pressure is shaft has a concave lower surface. The axis of rotation of damped and averaged to eliminate high-frequency pressure the disc converges upwardly and rearwardly in relation to fluctuations due to choppy water. The static and dynamic the hull of the craft so that the wetted surfaces of the disc 1 -* fluid pressure signals are combined with a fluid pressure move in rotation with the flow of water to reduce skin related to a required depth selected on a control and the i friction. resultant pressures are amplified to produce an output Considerable hydrofoil development has been carried out which operates directly on the foil by action or reaction by the Russians. In 1957 work was completed on their first to adjust its position and maintain a constant depth and multi-seat passenger hydrofoil, the 90 ft long Raketa. This lift. The control system can also add in a signal derived single-screw craft, capable of carrying sixty-six passengers from a fluid gyroscope and related to pitch and roll to at a speed of 45 mph, has a displacement draught of 6 ft improve stability. and a foilborne draught of 3%ft. The Raketa was initially Fig 83 shows a hydrofoil craft employing three indepen- powered by an 800 hp diesel, but this has been changed to dently servoed hydrofoils, and Fig 84 illustrates diagram- a more economical 1,000 hp diesel. , atically a pure fluid computing and amplifying system Upon completion of the Raketa, Alekseyev's team incorporated in a foil which produces reactive and pressure designed and built the Meteor. This craft made its first effects to alter the position of the foil. public appearance in Moscow during the summer of 1960. A static sensor projects from the foil support and a The Meteor, 112 ft long and displacing 52 tons, has a dynamic or lift sensor extends forward from the foil. The foilborne draught of 4 ft and is capable of carrying 150 dynamic sensor contains pure fluid amplifiers which send passengers at a speed of 50 mph, power being provided by amplified signals into a summation amplifier which adds in two 850 hp diesels turning twin screws. The control cabin, signals from the static sensor, the depth selector and a pitch and roll transducer. The resultant is amplified to produce maximum gain of fluid flow, and the fluid issues from ports above and below the rear of the foil, causing a reaction which in turn corrects the angle of the foil. The specification gives many variations and modifications of the control system and details are given of the con- struction and operation of the fluid amplifiers, which do not include any moving parts. It is known that considerable experimental work has been carried out by Bowles on this type of apparatus on behalf of the . Retractable, resiliently-mounted, variable angle, steerable foils of submersible or ladder type form a part of the Figure 84. R. E. Bowles set well forward for good visibility, is equipped with an seagoing Russian hydrofoils are the Strela, carrying ninety- automated control system enabling the craft to be piloted two passengers ; the Dolphin, a small turbojet craft ; the by one person. Vikhr, a 300-passenger craft; and the Cosmos. In November 1961 the Sputnik, a still larger craft Russian Raketa hydrofoils have done service in Hungary 4 capable of carrying 300 passengers, made its appearance. but a Hungarian-designed craft, Fecske (Swallow), similar Sputnik is 165 ft long and displaces 100 tons. Power is to the Raketa and carrying sixty passengers, is now known provided from 750 hp diesels driving four propellers and to be in service. gives the craft a top speed of 50 mph. The hull is of alloy The Japanese, one of the latest entrants into the hydro- construction and the hydrofoils are of stainless steel. Pas- foil field, already produce the largest range of hydrofoil sengers are accommodated in three saloons, and facilities craft in the world. aboard include a promenade deck and a restaurant. The decision to manufacture hydrofoils was taken in It has been stated that the running costs of this craft 1960, and since then the rate of develo~menthas been are fourteen times lower than the best ship of the Volga quite remarkable. Hydrofoils are now in regular use in Shipping Line. nine major areas in Japan: Nagasaki, Kagoshima, Beppu, The smallest Russian hydrofoil, Molnia, is a six-seater Setonaikai, Kobe, Lake Biva, Tokyo and Matsushima. pleasure craft fitted with a 90 hp engine that provides a To interest ship operators in hydrofoils, six main manu- speed of 40 mph. facturers joined forces to publish a sales brochure laying One of the most recent Russian hydrofoils to go on out details of areas where services were, or were to be, scheduled service is the Chaika. Intended for commuter provided, and also the types of craft available and the and pleasure services, it has a range of 310 miles. Power advantages of hydrofoils over conventional craft. The is supplied from a 1,200 hp diesel engine arranged to drive manufacturers concerned were: Hitachi, Ishikawajima- a two-stage pump providing water jet propulsion. Thirty Harima, Mitsubishi, Shina Mitsubishi, Shin Meiwa and passengers can be carried at a top speed of 60 knots. The Uraga. hull of this 86 ft craft, displacing 143 tons, is built in Japanese manufacturers build many different hydrofoil three sections divided by companionways ; the bow section craft including the PT-3, PT-20, PT-35 and PT-50, con- is occupied by the control cabin, the centre section pro- structed by Hitachi under licence from Supramar. vides the passenger compartment and the stern section Mitsubishi build the MH-60, a 95 ft craft powered by houses the engine. The water jet system, besides providing two 1,500 hp diesels and capable of carrying 168 passen- propulsion, can also be used in conjunction with bow and gers. They also build the MH-30, an eighty-passenger craft stern rudders for manoeuvring, and by using a deflector powered by a 1,500 hp diesel giving 40 knots, and the plate across the water jet nozzle, a zero turning circle can MH-3, powered by a 280 hp engine and capable of carrying be attained. Originally the hull, struts and foils were built twenty-one passengers at 40 knots. & of light alloy but this was later almost entirely replaced Ishikawajima-Harima build a smaller range of craft, the with stainless steel to improve reliability and endurance. largest being the IHF-8, powered by two 280 hp diesels Motor ship Mir was launched in the autumn of 1961. and capable of carrying thirty-four passengers at 65 knots, Provided with stainless steel V foils and a lighter alloy as well as the 1HF-3, carrying thirteen passengers, and the hull, this open-sea craft has a cruising speed of 45 mph. 1HI Runabout 16, 2 small pleasure craft. Autumn 1961 also saw the launching of the seagoing Shin Meiwa build three different versions of the Konleta (or Comet), the largest seagoing hydrofoil craft fourteen-passenger SF-30. of its time. The Kometa's foils, like those of the Mir, are Uraga produce the Sea Bird, a four-seater powered by similar in shape to the wings of a sea bird. The Kometa a 75 hp engine giving 55 knots; and Shin Mitsubishi pro- has a speed of 45 mph and carries 150 passengers. Other duce the MHF-4, a six-seater craft capable of 65 knots.

The Small Hydrofoil Prototype to the Stryela

Translarior~from Rrrssian of an article in the May 1966 nrrmber of the Sovret morlrhly magazine Sudostroyeniye (No j), organ of the Minisrry of rhe Shipbuilding Zndrrsrry of the USSR, and the A. N. Krylov by E. A. Aframeyev Scientific and Trchnical Society of the Shipbuilding Zndusrry, (pp 57-59) hy Co~rlmandrrEdgar P. Yorm~,RN lretd).

- Figure I. General view of the motorboat from the side PRINCIPAL PARTICULARS, ETC ! Length overall ...... 9.60111 (31ft6in) Length between perpendiculars 8.70 m (28 ft 6+ in) 'F Maximum breadth (at forward

bilge) ~ ...... 1.67 m (5 ft in) I-Ieight of side (freeboard) : Stem ...... 1.34 m (4 ft 43 in) Transom ...... 0.77 m (2 ft 6+ in) Draught at rest: Hull ...... 0.35 m (1 ft la in) Foils ...... 0.65 m (2ft 1Qin) Propellers ...... 0.78 m (2 ft 63 in) Draught under way (pro- pellers) ...... 0.35 m (1 ft 1) in) Displacement (without crew or passengers) ...... 1.650 kg (3,638 1b - about If tons) Crew ...... Four Maximum speed ...... 50 km/ h (about 31 knots)

HE hull is of wood, and has two continuous bulkheads Figure 2. View of the motorbout from ahead T which separate the forward and zfter parts from the pas- senger and engine compartments. Over the engine compartment (9+ in), and are situated under the after foil so as to avoid the there is a removable hatch. to facilitate access to the engines, possibility of their drawing in air from the atmosphere. The and two ventilating cowls run up through the raised deck there. propeller shafts are held in position by three single-stayed one on each side. The petrol tanks are situated in the forward brackets streamlined with pressed Goodrich rubber. compartment, some distance from the engines, to reduce fire In order to prevent air being sucked into the propellers, the risk. brackets are fitted with thin washers. and similar washers on The boat is controlled and steered from the port side of the the rudders prevent interruption of the stream and ensure that front of the passenger compartment, each motor being separ- there is sufficient submerged surface when the boat is foilborne. ately controlled. There are the same indicators of cooling-water In order to reduce the resistance produced by the propeller- temperature and lubricating oil pressure as in a motor car, shaft brackets, the middle stays of the after foil and of the but in addition to these there is an electric tachometer with rudder are placed one behind the other, but are not made into two needles, to indicate the number of revolutions, and the a single structure, so as to ensure that it is possible to change position of the rudder is indicated on the steering wheel. All the position of the foil. For it must be taken into account, -4 excepting the last of these are mounted on a dashboard in front when building any boat, that one may have to change the foil of the coxswain. system. because it is impossible in practice to determine by The middle part of the boat is designed to take the coxswain calculation the correct angle of attack taking into account all and three passengers, but an overload of up to two more the constructional peculiarities of this or that boat. persons is permissible. The foil systems of the EK-4 are secured to the hull by The hull is typical of a sports boat: 2. sharp bow; fine frames bolts runnlng into the curved seams of the flanges of the side forward. broadening out aft; maximum width in the middle; brackets, and to the stays, by semi-flush large-diameter screws and a transom stern. Spray-shields with angular profiles are which serve also as the rotating axis of the entire foil. This mounted along the sides of the fore part. The fineness of the system of securing facilitates making change$ of the angle of forward frames reduces the effect of wave shock, while the attack of the foils while testing and perfecting them. sharp lines of the hull reduce the resistance when the boat is The EK-4 boat has stood up to hard testing conditions and becoming foilborne. The lines and the relative proportions may be recommended as a reliable and very seaworthy high- which have been selected ensure satisfactory trim when running speed craft. at $peed and great lateral stability when becoming foilborne. The foil system is made of an alloy AMr5B. The load on the forward and after foils is approximately equal. Several types of forward foil have been tried with the same after foil, the one described here being the simplest for plotting curves to show good characteristics for resistance and for stability. Both the forward and the after foils are fitted with inclined stabilisers, as shown in Figs I ;nd 2 and these provide con- siderably increased lateral stability when the boat is becoming foilborne and when she is foilborne. The forward foil system includes two intermediate inclined planes running along the sides of the boat which enter the water directly the stream of water over the main lifting surface is interrupted an3 limit the sinkage of the foil by providing additional lift. It takes the boat 20-25 sec to become foilborne from rest, the hull becoming completely clear of the water at a speed of 30-32 km/h (18.6-19.9 knots). (See Fig 3.) The foil system guarantees stability at a speed of 40 km/h ,+ (24.8 knots) on all courses with waves of 0.5-0.7 m (1 ft 74 in- 2 ft 3; in) in height and excellent manoeuvrability, almost with any heel. The turning circle is reduced by iitting two small fins on the forward foil, just below the flat part where it joins the Figure 3. Running churucteristics of the bout: ng - No of stabilisers. revolutions per minute of the propeller shafts; 9 - Trim of The propellers are three-bladed, with a diameter of 0 24 m the boat; v-Speed THE HOVERCRAFT AND PROBLEMS ^' PnRr

+,, . 'by

Secr-Lnrlrl Hccrrlq~ccrrrers, E1i:rrhcrh T(~rrttirtu1, Purr of A~~TIIYork (I'lro/o~rcrpl~bv cororesy of .Tccr-Lrr~~dScrvicc, Itrc trrld Porr of N~II.Yorli Alrrhoriry)

Dockside Trends and a hundrcd ycars heforc the full cost of their construction HI: trend in dockside "furniture"-- transit sheds. care- is recovcred - presupposing. ol' coursc, that c\lery c;~lcul;~ted assumption of th2 economists and finnncial experts hiis been T househ. ctc - has in rcccnt )( hccn towards ;I certain lightnes.; of dcsign. utilising materials such as alloy sheeting in correcl and that the traffic devclops in precisely the way antici- singlc-storied structures, cluitc distinct from the rnassivc multi- pated. The Southampton scherne. incidentally. is representalive storied reinl'orccd concrctc buildings of a Tew years ago. One in both scalc and cost of four or live sirnilar projects now under of the main reasons I'or this is the recognition that changes in consideration. thc practices of cargo handling and movement can. in a rcla- Taking another example. the original Tilbury Docks - part tivcly bhort number of years. render a huilding totally obsolctc. of the responsibility of the Port of London Authority - \\,ere One is then presented with !he choice either of modifying thc buili in the 1880s. and yet it is very doubtful \\,hether they most efficient and up-to-datc methods to suit the outdated build- made any profit at all until aftel. the second Worlil War. Thus ing. or of tearing down thc building and replacing it with the construction of a port elfectivcly locks up a very largc something more suitable. Thus niany dockside buildings no\\. capital sun1 for a great many ycars. Since it is virtually im- takc on an almost temporary air. as the pace of the develop- possible to make any radical alleratior. to a systcrn of docks. ment philosophy behind thcir construction is so great following especially impounded docks, once their layout and pattern is the many studies to which the industry has recently been cstahlished. the only guarantcc of security for thc invested suhjectcd. cap~tallies in the continuation. with only minor niotlification. of existing methods and types of shipping. Any basic change in Progress in Dock De..ign the dcvclopment of the vcsscls which arc to use thc facilities However. the dcsign of the actual clock itselr. whilst pro- must place thc invested capital at hazard. This fact is par- gressing in terms of layout and space utilisation, rcmains on a ticularly relevant when it is remen~beredthat thc economic lifc very massive and permanent scalc in most cases. For example. of the normal oceangoing ship is barcly one-third of the plans for the developmcnt of the Western Dock at South- accounting life of thc port facilities it uscs. In an age of amptc)n. mostly on an arca no\$! covcrcd by the waters of the euploding technological innovation such long-tcrm investments Redbridge Channel. envisage an expenditure of bout E65 become rnorc vulnerable almost day by day. millions, spread over a nunihcr oi' years. to produce only thirty or so berths. The project will enjoy no subsidies - charges will Vessel Changes - he tied directly to the cost of facilities used - so that to ensure At a time when this country is embarking on u port construc- ;I realistic return on capital whilst still remaining compctitivc. tion programme of unpreccdc~ited proportion. it is clear that it will be necessary to use the berths I'or anything bet\vecn fifty any hint of a change in the basic char;icteristics of dcep-sea ships must be closely investigated and an evaluation made of military purposes and surface effect ships for commercial any potential threat to the capital about to be invested. Upon operation. The initial recornmendation envisaged a 5,000 ton identification of such a change the gains likely to accrue to the ship capable of crossing the Atlantic in the mid-1973s at speeds ."P shipowners and shippers must be assessed. These will determine of up to 100 knots at a hoverheight of 20ft with a payload the likelihood of implementation of the change. The construc- of 2,000 tons. A nuclear power unit might be one of the possi- tion programme must then be re-examined and amended in the bilities studied. light of the direction and scale of change expected to occur to Using the above figures as a basis for calculation, and at the the vessels which in twenty or thirty years will be using the same time making a number of fairly sweeping assumptions, it ports. In the past year at least one such idea has been publi- is possible even at such an early stage to form some picture cised which clearly represents an identifiable and radical change of any gains likely to accrue to shipowners and shippers, at in the existing and developing conventional method of ocean least indirectly. As their costs are largely incurred in the use carriage of general cargo. This IS the atomic-powered ocean- of various capital assets, a computation of the likely capital 1 going high-capacity hovercraft. Whilst it is obvious that the costs involved may provide a sufficient yardstick for the pur- introduction on a large scalc of such craft would not drive pose required. Direct operating costs must remain unassessable, from the seas overnight all conventional vessels, it has been since the hovercraft postulated is merely a recommendation for predicted in some quarters that a very considerable impact development in years ahead. However, for the purposes of this could be made in about twenty years. They are therefore at exercise, they are assumed to be the same as for the sort of least a possibility worthy of examination in the time scale of container ship with which such hovercraft might compete. The the life of any new port. exercise is based on a requirement to transport 6,650,000 tons of dry cargo per annum each way across the Atlantic, and The Hovercraft examines three possibilities - moderately improved conven- It is now practically certain that in 1968 at least one tional ships. container ships, and hovercraft equipped with cross-Channel vehicle ferry service will be in operation using specialised containers, together with major ancillary require- hovercraft instead of ships. The SR.N4 hovercraft now under ments, giving the benefit of any doubts which arise to the construction for this purpose will weigh about 160 tons, have a hovercraft. This is particularly so at stage 19 of the study, payload of 30 cars and about 250 passengers, and will offer where it is necessary to assume a capital cost per craft. The a comfortable ride in all bat the roughest Channel conditions. figure of £5,000,000 used in the calculation is probably very It will thus be in direct competition with present vehicle ferry low, and depends largely on research and development costs operators. The pattern of commercial hovercraft operations in being spread over a far greater number of craft than would be the future will be greatly influenced by the experience gained required for this route and trade. Various estimates for small in 1968. M: , inventor of the hovercraft, numbers of such vehicles range up to totals of f20,000,000 per has suggested that only the selection :bnd proving of economic craft --a figure anticipated by Christopher Cockerell in his routes now delays development of evzr larger hovercraft. All historic paper to the Royal Society of Arts in 1960 and current technical details appear to be surmountable. One shipping com- still in the thinking of naval experts both in this country and pany is convinced to the extent of putting £2 million into the America. However, any figure higher than that used in the testing of the Ran~sgate- route, and further orders for exercise would only further substantiate the ultimate conclusion hovercraft of a similar size have been quick to follow. of this paper. * If the service is a comlnercial success - and it is to be Although the crew of each hovercraft may only be fifteen in emphasised that operations on this scale will be the first that number (assumed) in comparison with the crew of each con- most hovercraft enthusiasts consider capable of going beyond tainer ship of, say. thirty men, it is probable that a number of the experimental stage -then many more cross-Channel hover- additional complete relief crews would be required to maintain ? craft services will soon be introduced. The economic range and such an intensive schedule of operations, and since also at least size of thc vehicles available will govern choice of route, and some members of the hovercraft crew might also have to be thesc are likely to increase steadily as manufacturers gain qualificd nuclear engineers on a substantially higher pay scale, experience from the research likely to be required to develop i~ is probably favouring the hovercraft to assume identical , military hovercraft, in which there now appears to be very crew costs. Similarly, although any nuclear fuel consumption considerable intcrest. In fact it seems probable that the real of the hovercraft is likely to be purely nominal, other main- spur to development will come from that quarter henceforth. tenance costs, to skirts for instance, are likely to redress the Already several types of military vehiclc are being contem- balance. All of these factors are apparently appreciated by plated. A logistic support or fast patrol capacity would call for the US Maritime Administrator, Mr Nicholas Johnson, who a hovercraft in the order of about 400 tons, which might be acknowledges that large savings are not expected directly. The available within five yeai-s. whilst a frigate-sized vessel of benefits which he identifies are of an indirect nature, i.e.: between 1,000 and 1.500 tons is under consideration as a later (a) Higher utilisation of crews and equipment: possibility. It was lccently indicated by Mr Lewis Boddington. Assistant Managing Director (Technical) of the British Hover- (b) No locks required for docking; craft Corporation. that projections of up to 4,000 tons, with a (c) No canals required to serve inland cities; payload ol' 1,600 tons and a range of 1,0:0 nautical miles at (d) Projects such as a second cutting to supplement the a cruising speed of 40 to SO knots do not seem impracticable. Panama Canal or widening of tht: Suez Canal and St Such vehicles amear. . cauable of otferinrr- serious cornvetition Lawrence Seaway would be unnccessary; to conventional shipping on all British-Continental routes. (e) Greatly increased transit speeds wouid allow : Preliminary American studies have shown that hovercraft for (i) reduced stockpiles; transoccan use appear to be economically and theoretically (ii) reduced interest on capital goods (cargo); sound, technically feasible. insensitive to the labour rate differ- (iii) reduced insurance on volume of goods both in cntial between American laF3ur and foreign competition, and transit and stockpiled; have vehicle characteristics zapable of restoring the US Mer- (iv) increased number of departures and hence better chant Marine to its original vigorous state without requiring and more flexible service; Government subsidy to survive. Recently a special committee (v) increased chance of higher load factor per container of technical advisers recommended that the US Department of each trip. Commcrce, through the Maritime Administration. should spon- The last point is of great practical significance, since it is sor a $70 million research programme on the important techno- unlikely that the containel ship would sail regularly with all logical problems at present likely to impede a commercially containers fully loaded. The assembly of 10,640 tons of cargo 74 competitive operation The Naval Ship Systems Command to be available precisely as required during the very tight turn- (formerly the Bureau of Ships) has also proposed extensive round schedule of the container ship would in itself require an research and development of air cushion vehicles, and a joint extremely efficient and expcnsivly equipped back-up organisa- naval/commercial programme seems likely to emerge. The tion. Additionally there is great attraction in the type of main aim of this will be to determine the technological feasi- development to be anticipated in other fields which a move bility of building multi-thousand ton air cushion ships for in this direction would appear likely to precipitate. It would only require a latter-day Henry Ford to produce a "Model 7" of only ten years' standing. The introduction of a lactor for hovercraft, for instance, and the entire transportation network depreciation definitely substantiates this view. The decision of of the world could be revolutionised. Bridges on the scale of the US Department of Commerce will doubtless settle the ques- the Forth and Severn Road Bridges would be unnecessary, as tion, and it will be interesting to see what weight is attached ' would the . Underdeveloped countries would to the military aspect of such vehicles, where a different order 4 no longer be obliged to lay down precious millions on an infra- of priorities may prevail. Nevertheless. for short sea cargo and structure of enormously expensive concrete roads and steel ferry services the hovercraft certainly appears much more likely permanent way when grass tracks would serve as well. Of to supersede all other types of shipping, and for this reason course hovercraft as we now know them are noisy, and research it should be studied and anticipated now. Convenient sites, a aimed at greatly reducing this nuisance is already showing signs even several miles inland, with clear access routes to the sea i of success, but compared with the sonic boom of the Concorde should not be wasted or pre-empted for other purposes. and I now under construction, even present noise levels are compara- future coastal development and protection works on these I tively insignificant. With such virtually unlimited possibilities routes should reflect the need for shallow sloping embank- i of revising old notions on the whole field of transportation, it ments with no sudden drops or other awkward barriers. Berths would not be long before the skill of man began to put hover- constructed for conventional short sea ferries will be totally craft to uses such as the few here touched upon. Indeed, British unsuitable for handling hovercraft, but fortunately these are firms such as Britten-Norman and Manx Hovercat are making usually of a much !ess massive and permanent construction in moves in such directions more likely day by day. themselves, and this fact in conjunction with their ability,

However, in the context of deep-sea general cargo move- normally, to produce a much higher throughput and rate of I ment, a saving on capital costs of such a marginal nature as return anyway, has resulted in their accounting life being much that indicated by the theoretical exercise seems unlikely to shorter than that of the deep-sea berths. Obviously when the provide adequate incentive to justify the change, which would economic life of berth and ship are practically the same, the have to be in the face of the current momentum towards con- risk to capital invested in the berth is minimal, and the only tainer ships as postulated, and across the barrier of an enor- danger lies in over-provision of such berths vis-ci-vis ferry ship mous and indeterminate research programme on an invention buildings, which is not too difficult to avoid.

INITIAL CAPITAL COST OF SYSTEMS TO MOVE 6,650,000 TONS GENERAL CARGO 1JSIEUROPE AND RETURN PER ANNUM

Cotlvetlrional Container Derail Ship Ship 1. Assumed nominal disposable load per craft ...... 6,650 tons 15,200 tons 2,000 tons 2. Unladen weight per container (if used) - 2.5 tons 0.5 ton 3. Container type, dimensions and nominal loaded weight ...... IS0 stackable Aircraft type non-stackable 20x 8 x 8ft-20tons 10 x 8 x 8ft-10tons No of containers per craft - aboard ... 760 246 No of containers per craft - ashore ... 3,040 2,460 Cost per container ...... f700 f 250 Capital cost of containers per craft employed ...... Actual cargo carried per round trip (assuming containers 80°/, full by weight) 13,300 tons 21,283 tons 3,739.2 tons No of round trips required per annum 1,000 625 3,557 Rate of cargo handling per 12 hr day ... 1,000 tons/day 1,045 tons/ hour 664.2 tons/ hour Craft's turn-round time ...... 13+ days 2 days 6 hours Craft's average speed ...... 17 knots 22 knots 100 knots Transatlantic voyage - 3,000 nm ... 7f days 5) days 30 hours Round trip of craft ...... 42 days 15f days 3 days Rotation period per set of containers at each terminal ...... 31 days 15 davs - assumed packed and returned quicker (size) 16. No of days required per annum ... 9,688 10.671 17. No of craft required per annum (365 days) ...... 18. Add 10"h (maintenance, etc) ...... 19. Cost per craft ...... 20. Capital cost of total craft ...... 21. Total containers required ..... 22. Capital cost of total containers ... 23. Days at berth per round trip (12 hr day) 24. Days at berth per annum ...... 25. Maximum workdays per berth per annum ...... 280 26. Assumed berth occupancy ...... 30% -higher density 27. Actual days working to craft per berth containers per annum ...... 84 28. Total berths required (US and Europe) 32 29. Required throughput per berth per annum ...... 168,000 tons 1,053,360 tons 1,339,328 tons 30. Cost per berth ...... f 1,750,000 £2,500,000 £1,000~000 31. Capital cost of total berths ...... f 283,500,000 f 80,030,000 f 22,000,000 32. Capital cost, berths + containers + craft f411,500,000 f 226.820,000 f 207,295,000 ACROSS THE CHANNEL BY HOVERCRAFT Leslie Colquhoun GM, DFC, DFM Chief of Operations

HE captures the imagination probably looks at wave predictions the same pattern emerges. Statistically T more than any other slretch of water in the world. For the wave heights were expected to be 4 ft or less for 81 9; of centuries it has presented a challenge that has proved irresist- the time at the East Goodwin Light Vessel. Our actual experi- ible. and the stories of human bravery and endeavour are ence based on figures given us twicz a day from the East legendary. People have crossed it on beds, in barrels, ships, Goodwin Light Vessel were that for only 48.6% of the time canoes, aircraft, balloons and gliders, and of course it has been were waves of 4 ft or less. Waves of over 6 ft were reported swum; perhaps there remains only one thing left, to walk across for 20.4"/, of the month, whereas the equivalent statistical figure it or of course to go by hovercraft. The walking will have to is only 7.3%. Natu~allyin any statistical information there are wait for the tunnel but the hovercraft like other forms of trans- bound to be good averages and bad averages; it is unfortunate port has in 1966 become old hat. although occasionally spiced that July proved a bad average. with adventure. So Par we have carried 6,000 people across the Channel, It was in 1959 that the first hovercraft, the SR.Nl, crossed despite the fact that at ihe moment out of the possible four betweer! Calais and >nd so celebrated the fiftieth anni- scheduied return trips per day we have been forced to cancel versary of Rleriot's adveriturous crossing. This was an epic 48% due to weather conditions. "first" and a pioneering effort in the true vein. It was fitting The varies between 40 and 50% on that Mr Cockerell who invented the hovercra.ft as we know it each Channel crossing but on a good weather week has reached should have been a member of the crew, albeit a wet one, since 62O6. With the French and British holiday periods coinciding for most of the voyage he was oulside the cabin attending to in late July and August even this figure might be exceeded. the trim of the craft. Now, seven years after this adventurous Day excursion passengers from Ramsgate have formed 80-907, crossing, Hoverlloyd are running a scheduled passenger service of our fare-paying passengers and it is significant that of all between Ramsgate and Calais using the thirty-six-seat SR.N6. the tickets sold at least 80-85% of them have been sold from With such a small craft the service is run subject to weather Ramsgate. Our experience and that of other cross-Channel conditions; pleasure-boat accidents have featured too promin- conventional ferry operators indicates that the French day ently this summer to take any risks with passenger safety. tripper is a rare bird that not even the novelty of hovercraft travel can bring to light. Could not our immigration and When in 1965 the news was released that Hoverlloyd - then rererred to under the names of its parent companies. Swedish Cusloms habits be to some extent responsible? English day Lloyd and Swedish America Line- had signed contracts for trippers are welcomed with a minimum of fuss in France, and I am sure that if these conditions were reciprocated it might be ,- the chartering of two SR.N4s and two SR.N6s to carry out cross-Channel hovercraft services, there was jubilation that at possible to effect an improvement. This comment, of course. last a breakthrough had occurred, and the future outlook of does not refer specifically to Ramsgate. [he hovercraft industry brightened considerably. However, there It must be quite obvious to any reader that !he cross-Channel were many whose enthusiasm for the project was dulled by the service must be running at a financial loss. This of course is news that the service was to be initially operated with the true and indeed a loss was expected, but such losses must be SR.N6. They rightly considered that this craft was too small set against the invaluable experience we are gaining. It can be to cope with the sea states that would be experienced in the stated quite unequivocably that Hoverlloyd's operating experi- Channel even on relatively calm days. ence is now seco~idto none. The operation embraces all facets of hovercraft operations such as navigational problems, open- At Hoverlloyd we were, and are, well aware of the limita- water operations, overland operations (Goodwin Sands). oper- tions of the SR.N6 and with three months' operating experience ating in and out of crowded harbours and, perhaps most behind us we know some of the vagaries of the Channel. As important of all, the 153 miles that we are away from the a craft we have foalnd that the SR.N6 will cope with waves up manufacturer means that we must be capable of tackling all to 8 ft high and winds of up to Force 6-7, but as a passenger- maintenance problems on the site. At least two days would be carrying vehicle these limits must be more severe simply required to return a craft to the British Hovercraft Corporation because above all else the safety of the passengers must be at Cowes for the rectification of a defect. This of course does considered, and secondly some thought must be given to their not mean that the British Hovercraft Corporation does not comfort. There is a tremendous difference between putting up give us any assistance. On the technical and design side there with dillcult conditions !'or a few minutes on a run across the is the closest co-operation; since what we are learning is of Solent and in enduring the same for fifty minutes to an hour tremendous importance to the design of SR.N4, particularly in on the Channel. relation to the skirts, even at this late stage. Experience on the route has shown us that winds of above It can be seen, therefore, that our endeavours in 1966 and 15 knots will generate sea states in the English Channel that 1967 are an essential build-up to the great moment in May are unacceptable on these counts. This of course puts a very 1968 when we take delivery of our first SR.N4 complete with severe limitation on operations. StatisticaIly it can be proved its permit for cross-Channel operations. Our hoverterminal and that using :I 15 knot wind and 4 ft wave height as passenger- operating team will be ready and fully trained for such a carrying limits it should be possible to operate Channel cross- moment. We are very conscious of the fact that as the first ings for 60°!, of the days of May to September inclusive, and cross-Channel operators of the SR.N4, and indeed of the this was the basis on which the service was planned. Our SR.N6. the success of the hovercraft industry rests upon the experience in May and June was in line with this forecast, but outcome of our efforts. Should we fail or give up in our July 1966 - as any luckless holidaymaker will confirm - has endeavours, heavy suspicion will have been aroused amongst been a month well below the statistical average; as a result, in other potential operators at present sitting on the fence. The July, Channel operations were possible on only fifteen out of importance of these two critical years, 1966 and 1967, thus

A [he possible thirty-one days. becomes more heavily underlined. I - If one briefly considers the statistics for July. our figures The experience so gained will help the major task of intro- taken from visual observations on weather forecasts show that ducing the SR.N4 on to the Channel route in 1968. With this wind forces of less than Beaufort Force 3 were experienced for craft Hoverlloyd hope to reap the reward of these early only 3-3.S0:, of the time. Thc statistical average based on obser- pioneering efforts and give passengers the reliable, fast cross- vations for the past thirty years gives a figure of 67% If one Channel service that they are seeking. 22

For the Ministry of Transport : NORWAY'S HOVERCRAFT (2) Secretary (now Traffic Chief) at the Ministry of Trans- port,, Olav Haukvik, Oslo. LEGISLA TI0N For the Ministry of Fisheries : (3) First Secretary in the Directorate of Harbours, Erik Ministry of Trade and Shipping Reichborn Kjennerud, Oslo. For the Norwegian Federation of Ships' Masters and the ODELSTING BILL NO 26 Norwegian Association of Mates: ( 1965-1966) (4) Director of the Norwegian Federation of Ships' Masters, Henry Bjonness, Oslo. - ~ I For the Council of Hovercraft in Sunnmore : Re Temporary Law concerning Air Cushion Craft (5) Harbourmaster Leif Thue, Alesund. ECOMMENDATION from the Ministry of Trade and Shipping, For the Technical College of Norway, Trondheim : R March 18th, 1966, (6) Chief Engineer Harald Walderhaug, Trondheim. approved by Order in Council same day. Deputy members : or NO 1 : Deputy Director in the Directorate of Shipping, (Presented by the Minister, Kare Willoch.) Modolv Hareide, Oslo. I For No 2: Inspector of Coastal Shipping K. L. Bugge. In a letter of February 23rd the Directorate of Shipping Ministry of Transport, Oslo. submitted to the Ministry an Odelsting Bill draft for a tem- porary law concerning air cushion craft. The text in the present For No 4: Director of the Norwegian Association of Ships' Bill is in all essentials based on the draft received. Mates, Ole Tennfjord, Oslo. For No 5: Head of the Alesund College of Navigation. I. GENERAL OBSERVATIONS Knut Larsgaard, Alesund. For No 6: Professor at Norway's Technical College, J. K. I. Definition Lunde, Trondheim. Air cushion craft are characterised by the fact that they rest To reinforce the Committee in its consideration of special on a cushion of air when in motion. problems, the following were appointed : The craft are not intended or designed to move in water like For the Telegraph Board (problems of telecommunication): conventional craft, or on land or ice like ordinary vehicles. Inspector at the Telegraph Board, Rolf Antonsen, Oslo. They can, however, in an emergency, land in water and keep For the Roads Directorate (problems concerning operation afloat on tanks while moving at slow speed. Furthermore, the over land) : craft can in certain circumstances also move on (over) land and Departmental Director (now Traffic Director) in the ice. The ordinary operational field of the air cushion vehicle is, Roads Directorate, Rolf Normann Torgersen, Oslo. however, the air, with the craft freely raised above the surface Deputy: Chief Engineer in the Roads Directorate, Odd at a limited distance (height). Schoyen, Oslo. For the Directoiate of Aviation (technical aviation prob- 2. Introduction of Air Cushion Craft in Norway I lems) : I The air cushion craft known in this country have been Civil Engineer in the Directorate of Aviation. 0. E. 4 1 developed in recent years ir, England by Ltd. Kjolas, &lo. In Norway air cushion craft have been introduced by the The First Secretary in the Directorate of Shipping, G. A. I Messrs Scandinavian Hovercraft Promotion Ltd A/S, who Bull, was appointed Secretary of the Committee. I started a trial service in More and Romsdal in April 1965. The trial service was in operation -with some interruptions -until 5. Trial Service into September 1965, when the craft were transferred to Danish The trial service referred to with an air cushion craft at waters. More and Romsdal was started at Alesund on April 5th, 1965. A regular passenger service was opened on April 6th. On 3. Control of Air Cushion Craft Thursday, April 8th, 1965, the air cushion craft capsized during In 1964 the question of which administrative body should be a demonstration trip. The capsizing is thought to have been the given responsibility for the control of air cushion craft was result of several circumstances. It is assumed in the first place the subject of discussion in the Government. It was decided that the centre keel of the craft, during earlier manoeuvring that the Directorate of Shipping should be in charge of tech- on the landing stage, had received initial damage which then nical and safety control and also be responsible for rules of materially deteriorated when the pilot made three demonstra- navigation at sea for air cushion craft. tion emergency stops immediately before the craft capsizd. During the third demonstration emergency stop, which con- 4. Appointment of a Committee to Inquire into Problems in sisted of a pirouette manoeuvre, i.e. the craft in motion turned connection with Air Cushion Craft through 180" against its direction of travel, the craft lost stability. To assist the Directorate of Shipping, a Committee was The latter manoeuvre appears to have been unfortunate in appointed by Order in Council of January 15th, 1965, with the combination with a calm water surface on account of a special following terms of referencc : suction effect under the craft. The damage the craft suffered "To evaluate the technical, operative and practical aspects from the accident was so great that the craft had to be trans- of air cushion craft, and to submit a recommendation concern- ported back to Eng12nd for repair. ing the legal aspects, aspects of traffic, concession and liability A new trial service with an air cushion craft of a larger and related to these craft, and concerning the public control device improved type was inaugurated at the end of June 1965. Later which should be effected. The Committee shall further make an additional craft of this type was put on to the trial service. proposals for detailed lines of policy and possibly for tem- According to the reports which have been received, the trial porary regulations for the construction, arrangement, equip- service mentioned with air cushion craft in More and Romsdal ment, manning and operation, and for special precautions and has been dogged by major and minor sccidents. safety measures which should be effected to ensure a safe Apart from the capsizing on April 8th, 1965, grounding, service." collisions with people, fences, pontoons, etc, have occurred as The following were appointed as members of the Committee: well as several engine breakdowns and damage to the "apron" (the lower part of the craft). 4 For the Directorate of Shipping : It appears that the pilots of the air cushion craft have found (I) Director of Shipping, Neubert Wie, the Directorate of difficulty in retaining control of the craft during take-off and Shipping, Oslo, Chairman. landing. 6. Legal Problems 11. DRAFT FOR TEMPORARY LAW ON The first question that arose in preparing regulations for air AIR CCISHION CRAFT cushion crnft was whether the craft could be regarded as ships, 1. General aircraft or vehicles, or whether this was a question of a com- pletely new means of transport. Another question was whether In a preliminary recommendation the Committee has stated existing laws and regulations could be extended, or whether that it does not consider its work completed with the prepara- entirely new legislation was needed fo~.air cushion craft. tion of the temporary regulations, and that it considers its further task should be to follow the trial service, eventually The question was submitted to the Ministry of Justice by evaluate the establishment of other trial routes for air cushion the Directorate of Shipping, and the Ministry stated as follows: craft, and continue the inquiry into ths above-mentioned prob- "It must be considered doubtful whether air cushion craft, lems, in order, finally, to be able to make further proposals a:, described in the letter from the Directorate of Shipping, for a law and final regulations on air cushion craft. are covered by the concept of a ship as understood in the It should also be mentioned in this connection that IMCO Law on Seaworthiness. It is assumed, however, that it is (the International Maritime Council Organisation) has ap- defensible - until the question is further clarified -to inter- pointed a working committee to study the possibilities of pret the Law on Seaworthiness so that it applies also to air arriving at international agreement on air cushion craft. cushion craft? and it is assumed therefore that regulations The Committee has pointed out, however, that, in view of may be prepared for such devices under this law. in respect the events of the trial service with nir cushion craft in this of aspects connected with travel over open water. country, it would be desirable to ha-jc a law that could give "It is assumed that air cushion craft are beyond the the authorities clear powers to issue the necessary safety regu- concept of a ship as traditionally understood in maritime lations concerning the construction, arrangement, equipment, law. It therefore appears uncertain whether and to what safety measures, maintenance, control, manning, registering and extent air cushion craft come under the law of shipping, and marking of air cushion craft. and to stipulate conditions for the Ministry cannot make a definite statement on this point. concession and fol- approved insurance or other approved "The question can arise differently in relation to the security for coverage of compensation liability for damage and separate rulings of the law. It must be considered necessary loss arising from the use of the craft. to take legislative measlkres to solve the many doubtful The question of whether this law should also include rules problems connected with air cushion craft. This applies. about registration and mortgaging in order to allow sub- among other things. to eventual registration and mortgaging, mortgaging ol air cushion craft, and about compensation and to questions of liability towards passengers, goods and liability towards passengers, owners of goods and outside third outside third parties who sufrer damage. parties, has been submitted by the Directorate of Shipping to "Express provision for safety regulations - in the event, the legal department of the Ministry of Justice, who in a letter by addition to the law on seaworthiness-should be in- of December 15th, 1965: stated inter uiiu: cluded, when the matter is being regulated by law in other "Under any circumstances the Ministry of Justice consider respects. it unfortunate that rulings of a civil legal nature as men- "Attention is drawn to the fact that in the bill for a new tioned above should be given by means of delegated legis- law on road traffic it is stipulated in the motivation docu- lativc authority. ments that the law's concept or a vehicle can include air "Until the questions connected with air cushion craft ser- cushion craft used on land (and on ice). vice are further clarified and there is a better basis Tor "Accordingly, it would be reasonable to let the maritime passing suitable rules of law, it should, in respect of com- rulings include all traffic at sea. pensation problems, be left to the courts to decide on any "It would seem that a solution to the questions mentioned cases which may arise could best be established on an international basis (compare "Nor is there considered to be such a pressing need for conventions in the fields of shipping and aviation)." the financing of the service of such craft that the usual The Committee, whose mandate was inter uliu to consider legislative channels should not be used in giving rules for the legal problems connected with air cushion craft service, was sub-mortgaging. The same applies to rules of registration in of the opinion that it was not possible to work out proposals civil law - on the registering of title in aircraft (as a con- for laws intended to cover all aspects concerning air cushion dition of legal protection). For your information. we can tell craft before the trial service was due to start. This was due not you that we have learned that the Committee on Maritime only to the short time at their disposal, but also to lack of Law in a preliminary draft for revision of the legislation of knowledge of the air cushion craft. On the other hand the the shipping register, etc (recommendation Vl), have pro- Committee found it necessary to have further regulations for posed admission of air cushion craft to the shipping register the use of air cushion craft. The Committee therefore sought (among other things). to prepare temporary regulations for air cushion craft with "There is. however, no objection to rules on registering for reference to existing laws. public purposes being given by means of delegated legislative Temporary regulations for air cushion craft were prepared authority, and such powers should be included in the pro- by the Directorate of Shipping on April 2nd. 1965. These posed la* if such registration is considered necessary." regulations were in accordance with a draft prepared by the The Committee then przpared a proposal for a temporary Committee. law on air cushion craft giving the Sovereign powers to make On the basis of experienca gained during the first part of the the necessary rules. The draft has been submitted by the trial service, including. among other things, the breakdown in Directorate of Shipping to : April 1965, the Committee found that certain alterations should The Ministry of Transport. be made to the temporary regulations. New temporary regula- The Directorate of Aviation. tions were therefore prepared by the Directorate of Shipping The Ministry of Fisheries, and by this Department to: on June 18th, 1965, on the Committee's recommendation. The The Director of Harbours, regulations contain rules concerning definition, range of use. The Director of Lighthouses, passenger sertificatz. standard of craft, standards for pilot and The Director of Pilots, and crew. rules for steering and navigation, use of lights and The Director of Fisheries. machinery. maintenance, logbooks and surveys. The following are among the comments received : Several aspects of general importance have not been included From the Ministry of Transport : in the temporary regulations. such as the question of concession "We have no objection in principle to the draft. With for ~egularservice with air cushion craft, questions of registra- regard to the rules of concession for air cushion craft, it tion. mortgaging, liability towards passengers. goods and out- would be an advantage if the same terms are used as those side third parties who suffer damage, and, further, questions in used in the new transport law. The Ministry of Transport connection with landing stages and travel over land. The reason would therefore propose that para 2, section 4, should read: for this is that the Committee could find no basis in existing " 'The Sovereign can decide that a licence. against pay- laws for laying down rulings on these matters. ment of a fee. shall be required in order to run a regular air cushion craft transport service between places in Nor- of the Port Authorities, but only to have a supplemental way and between Norway and other countries. The expres- effect where the field of competence is insuflicient. sion "regular transport" is to be understood as this concept "The Director proposes that the term 'landing stage' in is defined in the law dated June 19th, 1964, No 7, on the draft be replaced by 'take-off and landing areas, etc'. Transport, para 2: section 2. The terms mentioned in para as the former expression in his opinion appears somewhat 3 of the same law can be established for such permission. restricted . . . 4 " 'The Sovereign can also decide that air cushion craft "The Ministry of Fisherics will, likc the Director of Har- cannot be used for other business activities within Nor- bours, propose that the term 'landing stage' in the draft be wegian territory without permission. . . .' " replaced by 'take-of and landing areas, etc'. We further From the Inspector of Coastal Shipping, K. L. Bugge, assume, like the Director, that the intention of the draft bill Ministry of Transport (deputy on the Committee for Traffic is not to limit the competence of the Port Authorities. but Chief. Olav Haugvik, Ministry of Transport): to have a supplementary effect in those cases where the ". . . I note the absence of rules allowing for making compctence of the Port Authorities is inadequate. In order to conditions in the certificate about speed limit. maximum exclude doubt we would propose that a rule which would permissible load, height of waves and wind force, and a read as follows 'For the establishment of take-off and landing limitation on the range of travel. Even though there is a areas. etc, the necessary permissions must be obtained in warrant in other laws and regulations for stipulating such accordance with the law on Port Authorities dated June 24th. conditions, they should be included for the sake of complete- 1933, paras 19 and 20, compare para 18' be included as a ness in order to have the rulings collected together under new section 4 of para 2 of the draft, or in the rulings which one heading." will be given with reference to para 2, section 3, of the draft. From the Directorate of Aviation : The same consideration may also apply in ]elation to other "In contrast to the law on aviation, which has no defini- laws, for instance the building law." tion of the conccpt of an aircraft, the submitted draft law 1n preparing the draft bill. the statements submitted have contains a definition of the concept of an air cushion craft. been taken into consideration and will be further considered The crilerion of definition is supposed to consist in the under comments on the separate paragraphs. technical 1 physical system - manifest in sn air cushion - 2. Comments on the Separnte Parilgraphs of the Draft Bill whereby the craft in motion is held up from the ea-th's surface. Such a system, however, might occur in many con- On para I nections which have hardly been intended to be included in The paragraph defines what is meant by air cushion craft. It the field of application of the new law. Tt is reported, for renders the law applicable to air cushion craft both on water instance, that an undercarriage for aircraft has been designed and on land. Within Norwegian territory the law applies on the air cushion principle to replace the usual under- whether the owner or user is Norwegian or a foreigner. The carriage with wheels or floats. Further, something similar is rulings in para 2, sections 1 and 2, also apply to craft which said to have been tried with rail vehicles. Tn other fields. too, are registered or owned in Norway and are used outside the the air cushion system has been utilised, for instance in kingdom. connection with loading and stowing and other examples of The Directorate of Aviation appears to consider that the handling goods. If the law on air cushion craft is to have a definition of the concept "air cushion craft" may prove to be definition. it should perhaps be considered that it be given too wide, and it is pointed out that an undercarriage for air- a limiting rule. . . . craft is said to have been constructed on the air cushion "The draft has no ruling that fully corresponds to the principle, and further that something similar is said to have w1 aviation law rulings on airworthiness, see Chapter TI1 of the been tried with rail vehicles. The Directorate of Shipping, 4 law. It would thus appear that there would be no powers to however, has on its part stated that there is little danger of I stipulate requirements relating to the operating conditions of doubt in interpretation in the cases mentioned. We consider I the air cushion craft, such as requirements on minimum that it would be natural not to consider either an aircraft weather conditions. loading, etc. dur~ngtake-off or landing, or a rail vehicle, as an air cushion ! "Finally, we mention that there is a notably stricter penal craft. However, should an aircraft manoeuvre on an air cushion 1 framework in aviation conditions than the one proposed in undercarriage over land or water, not in connection with take- ! the draft. compare Chapter XI11 of the law of aviation." off or landing, it is considered that it would be natural to From the Ministry of Fisheries: regard it as an air cushion craft. 1 "The draft Odelsting Bill has been submitted to the 1 Director of Harbours, the Director of Lighthouses, the 011para 2 Director of Pilots and the Director of Fisheries. It is proposed in this paragraph that the Sovereign be given "The Director of Harbours, in a letter dated January 24th, powers to issue any rulings that might be necessary to ensure a 1966. stated among other things that he is in some doubt as safe and reliable air cushion craft service in this kingdom and to whether the existing legislation is sufficient to enable the between Norway and foreign ports. The paragraph gives powers making of all the rules which might prove necessary in to prepare the necessary regulations concerning the construc- connection with the take-off and landing stages for air tion, arrangement, equipment. maintenance, control, manning, cushion craft. He refers to a letter dated May 31st, 1965. piloting, registration (for public purposes) and marking. from the Legal Department of the Ministry of Justice to the Furthermore, it is proposed that the Sovereign be empowered Ministry of Fisheries, stating that it is possible that the rule to issue rulings concerning landing stages. in para 19, section 1. point 3, in the law on Port Authorities In connection with the rernarks of the Directorate of Aviation oi June 24th: 1933, concerning the Harbour Board's power and Director of Coastal Shipping, K. L. Bugge, about powers to issue rulings about 'dimensions of materials, building to stipulate requirements for the operating conditions of air method and necessary safety measures' for buildings which cushion craft. for instance requirements relating to minimum are intended for or are open for general traffic, only gives weather conditions. loading, speed. etc, the Directorate of powers for rulings needed in respect of the general traffic Shipping has referred to para 2, section 2. in which it says that and not in respect of the air cushion craft itself. the Sovereign can issue rulings. inter alia, governing the piloting "The Director states that it is not thought possible to of air cushion craft. In the opinion of the Directorate of regulate further aspects of general significance in ports and Shipping the term "piloting" covers the right to specify such waters in this connection satisfactorily with reference to requirements relating to the operation conditions of the air existing legislation. He is. therefore, of the opinion that there cushion craft. is a need for special legislation, as proposed, for this means With regard to the proposal from the Directorate of Fisheries of transport. According to para 2 of the draft the Sovereign and the Director of Harbours about replacing the term "landing can issue rulings concerning the construction, arrangement, stage" with "take-off and landing areas". the Directorate of maintenance. control of, and equipment for landing stages Shipping maintains that the term "landing stages" must be for air cushion craft. The Director of Harbours assumes considered sufficiently comprehensive. The Directorate of Ship- that the intention of the law is not to limit the competence ping has also remarked, in connection with what was said by the Ministry of Fisheries and the Directorate ol' Harboul-s. that That Your Majesty approve and sign the submitted draft the intention of the draft bill is to obtain powers to prepare Bill to Parliament relating to a temporary law on air cushion the necessary regulations to ensure safe operation with air craft. cushion craft, and that there is no intention thereby to limit the field of competence of the Harbour Authorities. A member of the Air Cushion Craft Committee. Director We OLAV. King of Norway. R. Torgersen. in a statement to the Directorate of Shipping, hereby make known that: remarked : Parliament is invited to take measui-es for a temporary law ". . . In the thiyd sentence it is cmphasised that the law on air cushion craft in accordance with the submitted draft. also applies to landing stages, as air cushion craft as a rule Recommendation from the Ministry of Trade and Shipping will not land at a quay, but will have to be driven up on is attached in print. land at the end of a CI-ossing. It is, therefore, of special Issued at Oslo Palace, March 18th, 1966. importance to ensure that the landing stages are an appro- Under Our hand and the seal of the realm priate condition. OLAV "During the trial service considerjtion was given to using (L.S.) .- -- air cushion craft also for shorter traflic distances over land, for instance up to Vigra airfield from the seashore. In this Per Borten E. G. Asbj~rnsen connection we wish to point out that the new road traffic kst. law of June 18th, 1965, presupposes that the law's concept of a vehicle can also include air cushion craft, compare DRAET OF TEMPORARY LAW ON Odelsting Bill No 23 (1964-65), page 36. col 2. Some of the AIR CUSHION CRAFT conditions which it is intended to govern by the present bill Para 1 can thus to some extent be regulated with reference to the road traPfic law. This will not. however, apply to air cushion An air cushion craft (hovercraft) is understood in this law craft insofar as they are used at sea. It has, therefore. been to be a craft which, when in motion, rests on compressed air found most practical fo~the time being to give joint rulings between the underside of the craft and the surface over which for air cushion craft both when they are used at sea (on it is moving. The law applies to the operati~nof such craft water) and on land. thus I'or any operation overland which both on land and on water. might temporarily occur, for instance from landing stages to The operation of air cushion crart in this kingdom, including any nea by airfield or other terminal or stop for land traffic Norwegian territorial waters, can only take place in accordance or other traffic media. Should the question arise of traflic with this law and the regulations given under the law. rules in the ordinary sense for the more extensive use of air This applies even if the craft is registered abroad or the owner or user is a foreigner. cushion craft on land - including the question of such craCt in relation to other vehicles- it is assumed that it would The regulations issued according to para 2, sections I and 2, be natural to base such rules on the road traffic law and its apply also to air cushion craft which are registered or owned in Norway, and which are used outside the kingdom, when regulations." nothing else has been decided. and this is compatible with The Directorate ol' Shipping agreed with Director Torgersen foreign law. with regard to what was said about landing stages. Para 2 Air cushion craft shall satisfy the regulations issued by the The paragraph was formulated following a proposal from Sovereign concerning construction, arrangement and equipment. the Minister of Justice. It is proposed that the Sovereign be The Sovereign can issue regulations on the registration, given powers to establish conditions for concession and for marking, maintenance, control, manning and piloting of air approved Insurance or other approved security to cover com- cushion craft. pensation liability for damage and loss which might arise The Sovereign can also issue ~.egulationson the construc- through the use of the craft. As an example of the kind of tion, arrangement, maintenance. control of, and equipment for condition in question. reference is made to the law on transport landing stages for air cushion craft. dated June 19th. 1964, No 7. para 3, in respect of regular transport. and to para 5. last section, and para 6, fifth section, Para 3 of the law concerning goods and pasbenger transport respec- The Sovereign can decide that permission against payment of tively outside regular transport. a fee shall be required in order to operate a regular transport service with air cushion craft between places in Norway or The paragraph contains penalties for infringement of the law between Norway and other countries. "Regular transport" has the same meaning as in the law of June 19th. 1964, on Trans- or regulations made under the law. The proposed penal frame- work for infringement of rulings on air cushion craft is in port, para 2, section 2. The Sovereign can decide also that air accordance with the one which applies to a number of penalties cushion craft cannot be used for any other activity within concerning maritime conditions, compare Chapter 42 of the Norwegian territory unless permission is granted and a fee is penal code. Offences in maritime conditions, as regulations in paid. this chapter read according to the law of February 15th. 1963, Permission will be granted by the authority designated by the on alterations of regulations in the penal code. are (I) offences Sovereign. It is granted for a definite period and on the con- against morality. (2) crimes and misdemeanour in maritime ditions deemed necessary. Unless the Sovereign decides other- wise, it shall be a condition that there exist approved insurance matters. or other approved security to cover compensation liability for any damage that might arise through the use of the craft. This paragraph contains regulations about the coming into force of the law and its duration. Para 4 Deliberate or negligent infringement of this law or of the regulations or conditions laid down in accordance with the law, A draft for temporary law on air cushion craft has been will be punished by fines 01. up to three months' imprisonment. submitted to the Ministry of Justice for examination of the legal technicalities. In preparation of the final draft the com- Para 5 ments oC the Ministry of Justice have been taken into con- This law comes into force from the time of the Sovereign's sideration. decision and applies until further notice, but not exceeding The Ministry of Trade and Shipping recommends: December 31st, 1970. A Revolution in Transport

by Toivo J. Kaario

T. J. Kaario of Finiand built and tested his first ground etfect machine in Finland in 1935. The machire was 6 ft hy 8 ft and attuined a speed of 12 knots over ice on its first flight in late 1935.

LL bodies, except when on ballistic trajectories, are borne A single cushion will apparently have a stable attitude posi. A by auxiliary forces counteracting gravity. These are tion. By combining several compartments, stability about two the forces at contact points with other solid bodies or fluid horizontal axes is added into the system. At super-critical static or fluid dynamic forces. speeds, however, transverse walls would prevent the proper air In the past the introduction of steam power for propulsion flow. Experience with man-carrying craft and models has shown of ships and trains, the internal combustion engine, the aero- that a single, continuous wing of such aspect ratio (below one) plane and the mass production of automobiles, were some of has enough inherent stability for practical purposes. When the the most marked cornerstones in the development of transport. nose ascends, the ~ut-flowthrough the forward parts of the Compared with the classical systems, wheeled carriages, ships side gaps will increase as well as the pressure at the rear bottom 4 and sleds, the air cushion combines and advances some of the and the equilibrium will be re-established. most desirable properties. It behaves from some reasonable The stability in space, of a wing of such aspect ratio and speed upwards, on water surface as on a solid body. rectangular planeform would be questionable, especially with- It is not readily conceived that the ground effect has already out auxiliary pitch stabilisators (Mr J. F. Mowbray, Border- been in everyday use. The ground will reduce or prevent ver- town, USA, may not join to this opinion). A triangular delta tical velocities of air currents and will thus make the take-offs wing, on the contrary, has, as known, stability in a space. and landings of aircraft possible. This configuration, however, is unusable as a ram wing, For compensating a pressure differential in a gap there because the outlet channel or area is lacking, the two-dimen- should be a flow of fluid. The blow power per unit area of sional extensiveness in horizontal plane is necessary for a perfect nozzle is: stability. Dr A. Lippisch has turned the delta back to front np3/2 and found a form, the form of many flying animals, which is P/A = d2. - stable without auxiliary stabilisators both in a space and in the dT ground effect. On great seas. for waves, some altitude capability would be where S = density of fluid desirable. Jumping over a ship could be a better proposal than p = pressure dift'erentizl. turning or braking. The vehicle of Dr Lippisch has realised By use of inwards inclined peripheral jets the power is these outstanding features. reduced to 30-5076 of the value given above. For many reasons air cushions on land are best suited for The power to keep a given weight at a given height is pro- vehicles on special tracks. Curved track profile allows turns to portional to the wing loadir~g,and, at a given height and wing be run without side forces on carriages. The free air gap can loading, the power loading is proportional to the square root be quite small, )in or less. Elastic seals of labyrinth or some of the weight. other design will aid in closing the cushion. At occasional .At locomotion the dyna~nicpressurc of ambient air stream touching of the seals, only small forces are generated. For will decrease differential at the leading edge gap and the jet stability, the air cushion is directed in compartments. Oscilla- of the trailing edge delivers thrust power. On certain assump- tions of the carriages sideways and about vertical axis may be tions (unretarded longitudinal flow) the side gap blow power is prevented by small servo operated fins steered by gyroscopes, independent of speed. and friction couplings between the cars or by some other In a ram wing the cushion pressurc is upbrought by retarded suitable means. In side winds the train will take an inclined air flow. Pressure is reconverted to velocity before outlet. In position. Detracking barriers could be used on sides of the theory, leading and trailing edge blow powers are zero. track. The very small aspect ratio of the locomotive will The lift coeficient of a spherical half-ball lying on a plane prevent the lift-off even at great super-critical speeds. For surface is 0.68. Lift of spherical segments should be nearly operations on plain yards the centre compartments could be in proportional to the relative thickness. In a potential flow the a plane. The small leakage from these cells on the curved lift will not induce any drag. track may be allowed or prevented. - A lifting wing in a space is a circulation generator but in Safety precautions of the common railways are not coping close proximity to the ground, lift is achieved by ram and with the increase of speed. The safety height of a wheel flange displacement effects. is less than 1 in. There will always be a multitude of mecham ical components, axles. springs, wheels, lines, rollers of bearings left for payload. When the possible aerodynamic configuration and rails, for example, all of them important for survival. In would allow enough space for payload without drag or weight an air train these highly-stressed parts are substituted by a light penalties, all spared weight could be allocated for payload and p envelope of the cushion and by some fans and electric motors. the ratio payload to gross weight would increase sharply at which can all fail safely. An air propeller is an efficient means increasing gliding ratio. A pound of excessive weight in a long- of propulsion and good for braking also. Braking at small range commercial aircraft may cost about £250 and a pound speeds could be effected by shoes. The lift power is small in of drag £2,500 during the iifetime of the craft. Some propor- relation to the propulsive power, 150kW per car, for example. tional lift to drag ratios may be presented: 4-6, On water the gap between solid parts of the vehicle and air cushion vehicles at sub-critical speeds and hydrofoils 7-10, irregularities of water surface is either closed by elastic skirts aeroplanes 15-20, trains on railways at 60 miles/hr 200 and or sidewalls, or a vehicle, having generally fixed contours, will cargo ships 600. The minimum value for bridging the Atlantic proceed above the wave crests. Especially in the latter case with conventional power plants should be about 10. control of attitude and altitude is desirable. In close proximity On every flight an aircraft will experience two periods when i to the ground a separate control of positions of leading and accurate control in the proximity to the ground is necessary. j trailing edges may be required. A man-carrying vehicle of the These periods are short but the circulnstances are adverse. The author realised these design aims at super-critical speeds. The aircraft must follow a closely restricted path at its minimum machi~le had 3 rectangular platform 10 X 15 ft. The centre speed whereby its zerodynamic controls are most sluggish. Side of gravity was coincider with the geometric centre. In the winds may yet complicate the manoeuvres. front part of the wing was a controllable outlet and on the There art: fundamental diRerences in the functions of aero- trailing edge a flap. Two quantities are to be controlled. alti- planes and correspondingly of air cushion vehicles. The latter tude and pitch attitude, and there were two controls for the are inherently stable in a plane and should respond most imme- purpose, the tunnel Rap and the rear flap. In this particular diately to the demands of altitude and attitude corrections. machine a part of the propeller disc was blowing into a tunnel The poor gliding ratios of hydrodynamic planing boats and or the front part of the wing and flaps were in the rear end of floats and their great weight have restricted their use. The first this tunnel. The craft was flown on ice, water and snow- transoceanic aircraft were? however. flying boats. The excellent covered hills. The possibility to use variable ground contact all-metal Junkers planes with floats and single 300 hp engines forces. too. at either end of the craft, was useful for driving were operated in scheduled international passenger traffic in curves in restricted areas, in sharp turning or driving up or Finland, for instance. from the year 1923. down. The control of the pitch attitude is advantageous for At increasing speeds. benefits of the elastic members may attaining minimum drag. In the machine of the author this become questionable; but compared to the days of the piston was fully exploited. engines, there is an abundance of cheap power available for In a ran1 wing the streamlines are curving outwards and this installation. A new philosophy may be needed in evaluation of is necessary for stability. Fnr sparing power, peripheral jets air cushion systems for open seas. They may be considered to could be used on sides or, in a delta planform. some longi- take the role of bridges. The vehicles will have special duties tudinal jets. and transverse jets for control. Regulated outlets and destinations. For take-offs and brakings the levelness of in the forward part of the wing. as explained, could form the sheltered water areas could be used. other component of the attitude and altitude control. The last vehicle of the author had a form of skirtless pres- P A great virtue of the peripheral jet is the compactness of the sure chamber or bell. It performed starts from water to super- structure. A 20 ft gap of a large ship could be closed with a jet critical cruising speed, 50 knots. at power loading 20 lb/hp. of 4 it thickness, for instance. Such a jet is easily regulated by The power loading was not outstanding, but the span, 10 ft, was a flap valve small for an airborne 1,000 1b vehicle and other conditions If the space flight capability is needed once in a lifetime of a stated. lleet the effort may be justified. The water involves aspects of Floats, rigid pressure chambers, elastic skirts as flaps in efficiency and safety in a complicated manner. This complica- periphery and in immediate positions for stability, possibly of tion does not indicate any presence of difficulties but the wide air pressurz, chamber construction. peripheral air jets exhaust- scope of the various possibilities. ing from elastic bags, pace peripheral air jets or some com- An ocean-going fast ground etfect vehicle shall be large bination of these are the very elements of the new art of enough in the North Atlantic, 40" latitude. In winter the signifi- generating lift during starts or at intermediate speeds. Satis- cant wave height is given to be below 6 ft during half of the factory hydrodynamic gliding ability is. of course, always time. At wing loading 80lb/sq ft. span 30:) ft. average wing desirable in an emergency. length 200ft. free air gap 6ft. lift coefficient of the upper A low-flying airclaft or air cushion vehicle is the only means surface 0.15. speed 300 knots, power in the peripheral side jet which will cross the Atlantic in twelve hours at better gliding to power of a perfect nozzle 40":,. efficiency in jet generation and payload ratios than conventional aircraft. Twelve to fifteen 7OU,, and at the ratio calculated, turbulent skin friction drag to hours is a time interval which a passenger will readily endure act~~alparasite drag 0.7, the lift to drag ratio, comparable to without sleeping accommodation. The present aircraft are not the gliding ratio of an aircraft in gliding. is 47. When the wing enjoyable as passenger transport and lhey have a tendency to is of triangular form the actual span uill be somewhat greater. become yet more complicated and unaccountable. Although the The length must be specified for calculating the Reynolds favour of the air cushion is dependent of the general pattern number and skin friction. of traffic and may alter parameters. too. it presents paramount, The lift-to-drag ratio at super-critical speeds and simplifying fundamental benefits, small-power consumption, small struc- assumptions (neglecting !he lift of the upper side) is a function tural stresses and levelness of locomotion, for example, un- of the speed ratio E= critical speed (lift coefficient = I) to surpassed by any other . actual speed, of the gap ratio p = 2 x effective gap (perfect The general standard of safety of present systems is poor. nozzle) to span and of the parasite drag coefficient Cf. Especially private automobiles are dangerous to life and health. Some shift to common transport systems would be advan- tageous. Vertical take-off flight seems to suffer from severe limitations in cost, safety and noise attenuation. In theory only the straight line is the shortest one. Communities and their real At about 6 ft chord the induced drag in a space would be communicative possibilities have always been in creative inter- the same as the equivalent gap blow-power drag. Such a wing action. An air train represents general quality of transport would be. however, quite impractical in all other considerations. unknown hitherto. Air cushions will increase safety. economy There are other quantities as important as the gliding ratio; and convenience of passengers and light cargo transport. They stability. steerability. empty weight ratio and starting ability. will open up new areas for human habitation. They are to be for instance. may be mentioned. used wherc they are best suited. The propulsive airscrews begin Aircraft destined for oceanic ranges necd fuel loads up to to show good efficiencies from speeds 100 knots or milelhr half of the gross weight. Thus a small weight fraction only is upwards.