f Hll 1111 II -I 1 .,. ')( ... --~· - ~- -...... ~.- .· ~ : _._ .. ENTER THE FOLLOWmG COHRECTIONS BEFORE WORKmG PROBLEMS. THEN R&VIOVE THESE SHEETS
Yl'age 3: In line two of th~ first paragraph following the first diagram C:t'oss out the word -- "nmt" • v:. Page 4: .Paragraph comrnenc'ing with, "Selection and Use of Scales" - change the last sente!!ce to read, "true bearings are shown on the outside of the tenth range circle and reciprocal bearings on the inside "•
vpage 5: Column 2, the second line should be made to re.ad, 11.them down the' scale, placing the +eft leg on 3 "• vragol4: Column 1, paragraph 3, line 2 .... _ change the capital 11 G11 , to a small 11 g 11 •
~age 15: The last word in the first paragraph should. be "closing" instead of 11 opening n. /_ Page 16: Problem 21, following the letters 11 TBS 11 insert: 11 Henry, this is Trojan. Exec~t·e . upon receipt. 4 Ans Posit".
V'Page 17: Problem 26. The sentence beginning with ''At 1326 11 should read: "At 1326 the s.G. reports Jig at 250 - 28900; 11
~~'Page 21: In the first paragraph, line five, insert the word 11 or 11 between "course speed 11 • ./ Page 24: Second paragraph - Co.rrect the third sentence to read: "From the time the rudder is put over, until the time the ship settles on its new course, the distance it moves towards its origin~ head ing is knovm as advpnce. 11
In the first diagram cross out the last two ships at the end of the tum.
11 In column 2, paragraph. 3, insert the words 11 are made , between 11 speed as 11 in the last line.
)Page .25: In the definitions below the table the figures for standard rudder should be "20° - 22o u.
J Page 27: The ar-J.gle geM2 should be labeled "Target Angle 11 instead of 11 Track Angle "• JPage 28: Columu 2, paragraph 3, .insert a conuna at the end of line 7. j Page 31: In the diagram, the length of the G-M2 line should be "20000n yards instead of 11 90000".
J Page 32: First paragraph, second line should read 11 e •••• m is 30 mots and cuts g •••• m at de sired course "•
Problem 72 insert the word "bcenn between 11 has ordered11 in line eight. •. ·I' ...... "'~ . ~-.:
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ANSWERS TO . PROBLEMS
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Note: Tolerances as to error are indicated 074-077; 136-140; 12500-13500. (31) 041-045; throughout these answer sheets. In cases where 5-7; 244-247; 18-21; 269-273; 17200-18400; 347- the data are purposely inadequate for a precise. 351; 8000; 089-093. (32) 101-105; 2982; 094- answer, the tolerances indicated are very broad. 097. (33) 281-285; 135-139; 1734-1738. (34) Obviously in practice such solutions would be 228-231; 088-092; 145-150 minutes. (35) 070- reworked as additional information became 074; 11-15 minutes; 327-331; 21-25 minutes. available. (36) 306-310; 11-14 minutes ; 030-034; 17-21 minutes; 41-45 minutes. (37) 098-102; ~;2.2 1. Relative Plot Problems: /0'/0 -toclc{'i;'j 2'1 tit 11m. (38) 045-049; 23-27. (39) more 11 than one course is necessary ; 293-294 ; 1128- (1) 178-184; Mioo. (2) 333-339; 3800- 1132. (40) 118-122; 24-28; 0640-0644; 0710- 4600; 0450-0456; ahead; 9900-11100; 0510- 0714; 0719-0721. (41) 246-250; 26-30; 0935; 0518. (3) 009-015; 3700-4200; 0929-0935; 095.; 233-237; 26.5-28.5; 10()7-1011. ( 42) 239- astern; 12200-13300; 0945-0951. ( 4) · 281~287; 243; 18-20; 342-344; 7700-8200; 0056-0058. 11500-12500; 2319-2325; ahead; 13700-15400; (43) 257-261; 59-63 minutes; 269-272; 26-30 2329-2335. (5) 152-158; 11200-12200; 2149- minutes; 282-286; 11-14 minutes. (44) 115-118; 2155; ahead; 11200-11800; 2147-2153. (6) star- 127-131; 12-15 minutes. (45) 114-118; 23-27. board; 143-147 minutes; 29300-29700. (7} (46) 339-343; 24-26. (47) 230-234; 200-204; abeam; 31000-31700; 325-331; 77-83 minutes. 1828-1832. (48) 256-260; 271-275; 1546-1550. (8) starboard; 3000-3700; 347-353; 2208-2216. (49) 298-302; 338-342; 1116-1119. (50) 000- (9) 095-102; 10900-11700. (10) collision; 0900- 003; 10.5-12.5. (51) 155-159; 9-12; 317-321; 0907. (11) 10-14 minutes; 4600-5300. (12) 245- 3-4. (52) 072-076; 003-007; 1lJ8-1202. (53) 248; 243-246. 220-224; 0417-0421.
II. Course and Speed Problems: IV. Advance and Transfer Problems:
(13) 000-004; 23-27. (14) 348-354; 30-33. (54) 081-085; 4400-4800; 249-253; 4-5 min (15) 265-271; 18-22; 315-321; 16100-17000. utes; (55) 303-307; · 4300-4600; 4-6 minutes; (16) 212-218; 30-35; 301-307; 10200-11300; 104-108. (56) 173-178; 0827-0831. (57) 333- 0440-0447; 099-108; 11-13; 082-086; 7700-830Q; 337; 4-5 minutes. (58) Right to 192-196 or 210- 0506-0510. (17) 065-069; 11-12; 176-180; 9400- 214; 4.5-5 minutes. 9800; 1003-1005. V. Torpedo Approach Course and Firing III. Ship Maneuvering Problems: Problems:
(18) 153-157; 24-26. (19) 002-004; 26-28. (59) 067-070. (60) 338-342; 3700-4100; 3-4 (20) 200-204; 14-17 minutes. (21) 182-186; 13- minutes. (61) 250-253; 3700-4000. (62) 053- 093/-17. (22) 040-044; 17-20 minutes. (23) 028-032; 056; 2-3 minutes. (63) 028-032; 3200-3400. 09.35 19-22; 013-017; ,a& B9 mi!'utiiss. (24) 262-265; (64) 329-332; 0142-0144. (65) 8300-8800; 157- 15-!7; 148-152. (25) 031-035; 24-27; 20-24. 161; 57-61. (66) 5000-5300; 069-072; 070. (67) (26) 135-139_; 15-19; 180-184. (27) 123-126; 144-147; 55-59; 38-42. (68) 271-275; 061-065. 23-26; 050-054. (28) 0037-0041; 274-284. (29) (69) 128-132; 6000-6400; 324-328; 3-4 minutes. 217-220-; 25-28; 078-082; 15800-16400; 148-152; (70) 218-222; 194-196; 2.2-2.6 minutes. (71) 5200-5600. (30) 147-151; 8-11; 103-108; 22000- 359-003; 090; 6-7 minutes; '6990 788Q; e9e 12- 23000; 290; 20.4-20.7; collision; 1632-1634; .a & mirdeii i 10900 1150@ 1 2@9 ill8ll, :zgg ggi, r fooo-f300 .I• Jf#l.J.S-ItD')S'.~ C. I. C. Information CONFIDENTIAL
VI. Retirement Course Problems: 154.; 175-177; because the fish would be chasing (72) 184-188; 13-15 minutes. (73) 142-146 · us m; yes; yes; 104-106; 0331; no. (94) 334- 10-13 minutes; 311-316. (74) 014-018; 21-25; 336; 22.5-24.5; no; 348-350; 28.5-30.5; 112-114; 016-020; 1100-1106; 301-304; 12-13 minutes; 8500-8700; 129-131. (95-96) 325-327; 332-334; 11,200; 143-147. (75) 046-050; 20-23; 059-063; 8900-9100; 355-357; 188-190; 0347-0349; 0351- 0115-0119; 136-140; 3.1-3.3; 4800; 5200-5600. 0352. (97-98) 224-226; 221.5-223-5; 200-202; 266-270. , 343-345; 1.4-1.8 minutes.
VII. Advanced Ship Maneuvering Problems: IX. Wind and Aircraft Problems: (76) 067-069. (77) 047-049 or 097-099. (78) (99) 359-001, 11-13; 305-307, 24-25; 297-300, 270; 285-288; when other ships in your division 17-19; 089-091, 20-22; none. (100) Heading have completed column movement to 270 and 095-097; T.G.S. 145-147 K. (101) Heading 263- you see on PPI that they are in column astern 265; T.G.S. 171-173 K. (102) Heading 041-043; of you on that course. (79) 165-167. (80) 7.5- T.G.S. 137-139 k.; Drift angle: 6-8L. (103) 8.5 minutes. (81) 21-24; 161-163. (82) 099-101; Heading 319-321; T.G.S. 164.5-166.5 k; Drift 2-3 minutes. (83) HALFORD cannot reach sta angle 4-6 L; (104) Heading 212-214; Time out tion using 20 knots; 224-228. (84) 239-243. (85) 72-73 minutes; Drift angle 6-8 R. (105) Head 051-054. (86) 026-028 or 296-299. (87) 239-241; ing 055-057; drift angle 5-7 L; time 77-78 min 20-22. (88) 0659-0701; 135-137. (89) 070-072; utes. (106) True wind 039-041; 24 k; course 338-340; 19-21. 275-277. (107) Wind 179-181, 24 k.; heading 259-261. (108) True heading out 312-314; mag VIII. Torpedo Problems: netic 302-304; true heading in 140-142; mag netic 130-132; time to turn 73.5-75.5 minutes; (90) 133-136; 12,700-13,000; 139-141; 5500- total time out: 2 hours 57 minutes. (109) From 5700; 251-254, 8500-8700; yes; no; can't fire 00-05; course 127-131; From 05-06'~ course 135- outside of D.E.R.; 284-286; 5000-5200. (91) 139; From 06-09; course 127-131. (110) From 085-087; 15,000-15,200; 353-355; 9600-9800; 1225-1227; course 323-325; From 1227-1234; 332-334; 5100-5300; yes; no; 129-131; 082-084. course 301-303; From 1234-1235; course 006- (92) 164-166; yes; 148-150; 9400-9600; 131- 008; From 1235-1238.5; course 025-{}27; From 133; 159-161; 0713-0714. (93) 142-144; no; 151- 1238.5-1243.5; course 006-008. CONTENTS
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Page Introduction to the Maneuvering Board 1 The Relative Plot and Its Uses 5 Problems in Relative Movement 8 Simple Course and Speed Problems 10 Ship Maneuvering Problems 12 "Phantom Ship" Maneuvers 21 Mananeuvering Board Problems 17 Advance and Transfer . 24 Problems Involving Advance and Transfer 25 Torpedo Approach Course and Firing Problems . 25 Retirement Course Problems 31 Ship Maneuvering-Advanced 34 Torpedo Problems (with TERI) 44 Simple Aircraft Problems 48
This Syllabus is classified "Confidential" due to the inclusion of torpedo information, General Signal Book signals, and general tactical doctrine from USF lOA. CONFIDENTIAL C. I. C. Information 1
INTRODUCTION TO THE MANEUVERING BOARD
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It is the purpose of this course to review The first of these may be illustrated by the briefly maneuvering board theory and practice results obtained from the Dead Reckoning and to indicate a few of the ways in which it Tracer. Here we get a true picture of two or can be used to advantage in eie work. The more ships as they move over the earth. If we maneuvering board (HO 2665a) is simply a use a chart over the DRT, we can see just how miniature polar coordinate chart; it provides they move with respect to the area in which a quick means of getting· solutions to .move they are operating. We cah also develop a navi ments by both surface and air targets. gational plot on the maneuvering board itself. This may be done by representing the earth as In view of the growing importance of eie being in the center of the board and drawing as the nerve center of every ship having one, lines from the center representing the known it is desirable that all eie Watch Officers have courses of the ship; the length of the lines a knowledge of the maneuvering board. There may be determined by reference to the known are many functions which ere can perform to speeds and times on each course. Some maneu assist in the smooth functioning of ship maneu vers may be worked out by means of a naviga vers and related activities. For example, eie tional plot alone, while others are capable of can make suggestions to the conning officer as solution by combining the three types of plots to the course and speed to be used in taking listed above. However, for the most part, ship station and/ or in changing station. After hav maneuvering problems can usually be solved ing suggested a course, Watch Officer can use by using the relative plot and vector diagram the maneuvering board to determine whether in conjunGtion with one another. or not the course is being made good. In the case of destroyers and destroyer escorts, ere Many solutions which can be developed on can work out target approach courses and the maneuvering board can also be worked out speeds in connection with torpedo fire and shore on the DRT. While it may not always be true, bombardments. It may also suggest base tor it will usually be found that such solutions can pedo courses to be used in firing. be gotten ~ore quickly from the maneuvering board than from the DRT. Moreover, at certain These are only a few of the many ways in times it may be desirable to keep the DRT free which a knowledge of the maneuvering board of the lines, designations, etc., which would will be of benefit to eie Watch Officers. ·M~my result from using it for this purpose. commanding officers will expect this kind of information from eie and will assume that its The Relative Plot involves the idea of rela personnel are equipped to give it. It will readily tive motion. The point of origin of the plot is be seen, therefore, that it is important for you assumed to be fixed, although the ship repre to know how to develop speedly solutions to sented is actually in motion. Thus, if we con various kinds of ship maneuvering problems. sider our own ship to be in the center of the plot and wish to know what a ship observed Types of Plots - Basically, there are three in adjacent waters is doing, the relative plot kinds of plots used in navigation and in solving will define that ship's motion with respect to maneuvering problems. These are: us. It should be kept in mind that both ships are actually moving over the earth. The relative (1) Navigational or geographic plot plot then does not give us a true picture of (2)_ Relative plot just what is happening (as is the case with the DRT), but shows us the relationship of two (3) Vector diagram (also known as speed ships in movement. Despite the fact that both triangle) ships are in motion, we always assume one of 2 C. I. C. Information CONFIDENTIAL them to be stationary in the center (point of G origin) of the relative plot. Point of origin ---- Which ship is placed at the point of origin will depend upon tlie articular _prob1em at M2 hand and the purpose for which the relative plot will be used. Tlie fo owing ruTes-of-thumb M1 will prove usef"uT: It is emphasized that M1 .. M2 does not show the way in which the maneuvering ship is mov (1) ing over the earth; it shows only apparent movement or how that ship is moving with (2) respect to the ship at the origin (G). The idea of relative motion is illustrated per (3) base course, fectly by the operation of the PPI scope (Plan Position Indicator). In order to understand relative motion in relation to the PPI two very (4) on guide, place important points must be remembered: the ship on which the PPI is located is always at the center of that PPI; all movement of targets These simple rules may be summed up, in nega on the PPI is relative movement-this applies tive fashion, by saying that t~ship do~ the to both surface and air targets. Ranges and maneuvering- is not laced at tne omt of bearings of air targets obtained from a PPI origm. are usually considered to give true course and As will be seen from practice exercises in speed. This is done because of the great dis cluded in this syllabus, each of these methods parity between the speed of air targets and the of locating the point or origin will present some ship represented in the center of the PPI; the advantages. In modern practice most of the error introduced by ignoring the ship's speed bearings and ranges used in maneuvering board is considered negligible for some purposes. solutions are obtained from radars. It must -be To see how the PPI illustrates relative mo remembered that these are always (or nearly tion let us consider the following situation: always) true bearings. Therefore, if you have placed a ship other than your own at the center f-- Target closing of the relative plot, you must use reciprocal Assume own ship's: us bearings in locating your relative movement course 000 ° line. speed 25 The first position of a maneuvering unit lo - PPI cated from the point of origin on the plot is Our Ship usually designated Ml. The second position is indicated M2, etc. The ship at the point of ori gin is customarily designated as the guide and is labeled G. This designation of guide is simply From this we can see that there are at least a convention; it is not to be confused with the four possibilities as to the nature of the target Fleet guide. Ml and M2 are located in range and is movement. from point G. The resulting line, Ml .. M2, is (1) It could be ship dead in the water, or an called the relative movement line and defines: island or reef. (1) The direction of relative motion by its (2) It could be a. ship on our course (000°) slope or inclination and direction from at any speed under 25 knots. (Obviously M1 toward M2. if it were going more than 25 knots it would appear to be opening; if its speed (2) The distance of relative motion by its were exactly 25 knots, it would appear length. to be stationary). The direction of relative movement will obvi (3) It could be a ship on course 180° at any ously be from M1 toward M2. Capital letters. speed. are used for the center of the plot (G) and for ( 4) Whatever it is, we are on a collision the other ship's successive positions (Ml ... course because it has a constant bearing M2). The folllowing will illustrate: angle. CONFIDENTIAL C. I. C. Inforfll.ation 3
If we assume further that in Cases 2 and 3 it (1) e ... g vector has a speed of 15 knots, we can tell the relative speed: (a) Length represents true speed of guide over the earth.
Case I Case II Case HI (b) ~lope indicates true course of guide. 0 (2) g ... m vector 0 9 (a) Length represents the relative # 4 speed, or speed of maneuvering unit • with respect to the guide. 25 kts .. 25 kts. 25 kts. 0 0 6 (b) Slope represents the direction of relative movement. R.S. 25 kts. R..S. 10 kts. R.S. 40 kts. (3) e ... m vector A little thinking about relative movement (a) Length represents true speed of will show that there are~.only two situations maneuverin.g unit over the earth. where the. maneuvering ship will not crab along (b) Slope indicates true course of ma the relative movement line. This occurs when neuvering unit. the maneuvering ships at the point of origin are on the same course or reciprocal courses. In putting these vectors together to construct In all other cases the maneuvering ship will a vector diagram, the following rule may prove crab along the relative movement line. Thus: useful: the head of the vector represents the unit doing the movmg and the tail of the vector ..:::J::F represents the umt w1th respect to which the movement IS takmg place. It is of the utmost importance to observe that the slope of the g ... m line is the same as that of the M1 ... M2 line. This fact gives the clue to the relationship which exists be PPI Scope our tween the relative plot and the vector diagram. • ship The slope of both of these lines, it will be re called, gives the direction of relative movement. In other words, in the case of both plots, this M2 ~~~~~--M1 connecting link describes the movement of the maneuvering unit with respect to the guide. assume our ship's. From what has thus far been said about con course 000° structing the vector diagram, it will be seen speed 25 that the procedure to follow will ordinarily he this: In this case the maneuvering unit is on course (1) Draw the e ... g vector from the data 315°, while its apparent movem~t from the ship in the center is from East to West. It is given. not on course 270°; this would be true only 'if (2) the ship in the center were also on course 270° or 090.
(3) If either the course or speed of the ma neuvering unit are known, the third side of the speed triangle or diagram may automatically be drawn in. This third side will become the e ... m line. The The vector diagram has as its principal pur point at which it bisects the line that pose the solving for courses ana speeds.. As will has been drawn from g (parallel to Ml l5e seen-rater, !,t gives solutions when used in ... M2) becomes m. conJtmctiQn with the relative plot. The vector ( 4) If neither course nor speed of the ma diagram is made up of three vectors as follows: neuvering unit are known (as is the 4 C. I. .C. Information CONFlDENTIAL
usual case), but the time traveled along relative distance (the length of M1 ... M2). We M1 ... M2 is given, then find the relative wish to find the time the maneuver will take. speed (see explanation below). If we lay a ruler from 10 knots on the speed (5) Since the length of g ... m represents scale, through 10,000 yards on the distance relative speed, lay off the relative speed scale, and read the answer on the time scale we found from point g and locate m. will find it to be 30 minutes. This may als~ be done by placing one leg of a pair of dividers (6) Having performed step 5, the third side at 10,000 yards, adjusting them to cut the speed of the triangle may be automatically scale at 10 knots, and swinging them to cut the drawn in. Normally the solution required time scale (in diagonal fashion) : this is per will be the course and speed of the ma haps more accurate and somewhat faster. Had neuvering unit (or target): this is given our known factors been 30 minutes and 10,000 by e ... m. yards, we could have found relative speed in the same way; similarly, if we had been given The vector diagram does not give any infor time and relative speed, we could have found mabon as to di~tanees, It g1ve~ only courses relative distance. and speeds. It IS Important to remember this. The following illustration will indicate the way One of the most common errors made by be in which the vector diagram is constructed and ginners in the use of the maneuvering board the information it contains: is m1xmg relative an actrrat speeds and dis tances. It should be constantly borne in mind g Relative course and speed ffiat no actual distances will ordinarily be used in getting a solution. Both the M1 ... M2 line m and the g ... m vector are in relative terms and the application of either of them to a prob lem of the kind described here will result in an answer in relative terms. Selection and Use of S.cales-The maneuver ing board has 10 range divisions, each being one-half inch. Bearings are marked every 10 degrees; true bearings are shown on the out side of the tenth range circle and rel~•e bear- ings on the inside. '6C ~~c/JL.. The board has four scales shown on the sides: Time Problems and Their Solution-Very 2 to 1, 3 to 1, 4 to 1, and 5 to 1. These are de often maneuvering board problems require so signed to insure quick solutions and scales lutions as to time the maneuver will take, dis other than these should rarely, if ever, be used. tance run, and/or relative speed involved. This In selecting a distance scale no particular prob type of problem may be solved by the simple lems are posed. However, speed scales should be selected (a) so that they are not so small d distance as to result in inaccQracies, and (b) so that formula t =-(time=----). In maneu they are not so large as to cause the solution s speed to run off the board. This will usually be accom plished if a medium scale is selected; one which vering board terminology this becomes falls on the 3, 4, 5, 6, or 7 circle will usually M1 ... M2 (relative distance) give satisfactory results, though this will ob t = viously depend upon the nature of each prob g ... m (relative speed) lem. It is obvious that if any two of these factors Scale errors are very common and care must are known, the third one may be easily ob be exercise 1014 G 090o - 16.600 yds. Ml M2 M3 @ --•--~-~~-----r/ ~--.,._. ___ -~.! / _,.,;-- 1\()() -.gu;\s o/.-.-... - 1"1 Ao _-1'Z. _.-/,.._ ()l't; --- / @ 1001- o~· 1.---- //~~/ ~ / \::)\:5 / "-; //0/ / ,.<;, CD 1ooo -v ~"" E As G moves North, M moves East. M drops assigning G a fixed position in the center of in bearing and increases in range. The same the board and measuring off the ranges and information is plotted on a maneuvering board, bearings (1), (2), (3) therefrom: in the form of a relative plot, by arbitradly · / )' o~·/ ~~// ~\:5 j ~\:5 j /// ~ / \::)bi:// "" '\]'o.s. -- fA\ tzl\vv J ---- - 'J:;I / 1"11\0- --- /' ®3~---- -\~~--:_-__-:_ __ @~~9~:_-=~6~~.!~~- ---__ ~ M3 G I . ----- This gives a relative movement line for M of A relative wovement line has distance and di M1 ... M2 ... M3, the apparent movement of rection. Direction may be determined by mov M as viewed from G, although actually moving ing, with parallel rulers, the slope of M1 ..• ~ast. 6 C. I. C. Information CONFIDENTIAL M2 ... M3 to the center point and reading the and M3, the relative speed may be computed heading at the circumference of the azimuth· by the usual time-distance-speed formula or by circle. The following will illustrate: the use of the scales provided at the bottom M1 of the maneuvering board. ...,______M2 1\ Once the direction of a relative movement ! I t----!!3 line and the relative speed are known, we can I I I I I I I I predict: I I I I I I I I (1) Where and when that ship will be in 1 relation to the guide at all times. f f I (2) Whether it has passed or will pass ahead G~~ I or astern, on the quarter, abeam of the guide, etc., and when (3) Its closest range to the guide, at what bearing and when. Distance of the relative movement may be de This is accomplished by projecting the relative termined by measuring the actual distance be movement line in its known direction at the tween M1 and M3 using the same scale as was rate of relative speed with which the maneu used to measure ranges and bearings. With dis vering ship moves along that line. tance and the known time elapsed between M1 M1 at 1000 M3 at 1014 EXAMPLES: '- M1 at 1000 ' ' ' ' ' ' ' ' ' 'M2 at 1007 ' ' ' ' I. Where will M be at 1021? ' ' Known: rate of relative speed- ' 25 knots direction of M1 ... ' -..., M3 at 1014 M3-127° time for com ' putation-7 minutes ' ' . By simple computation, distance equals 6000 ' yards (approximately). Measure off 6000 yards at 1021) from M3 in direction of 127°. The range aml ',,~4 bearing of M4 from G is the point at which M will be at 1021. ' 127° CONFIDENTIAL C. I. C. Information 7 II. Will M pass ahead, astern or abeam of G? 000° f",M5 M has already passed ahead of G as may be seen from a back track of the relative move ' ment line, and is now opening constantly. ' To determine the time, measure M5 ... ' ' Ml for relative distance and with the ' known relative speed compute the ' ' time at which M was at M5. To ' ' determine the range at this ' time measure the distance ' ' G ... M5. ' ' Ml ' ' ' ' ' ' ' ' ' ' 'M2 ' ' ' ' ' ' G ' ' M3 ' 'It III. What and when is the closest range at which M passes G? Drop a perpendicular line to ' '-... M6 the relative movement line ,.... (ox: an extensiOn thereof) / '- Ml / from the center of the plot. I G ... M6 gives the range I and bearing at which M / is closest to G. Time / is c o m p u· t e d as / above in Example II. / I I I M3 G 8 C. I. C. Information CONFIDENTIAL Your CIC has the following SG readings Range ------at (time) ------· set up on a mooring board. 1020: 097°• ~; .wB&: ~97~-34100; 4:030. 0980- Pass (ahead or astern) ------32000; ~: 099° 28000. The Captain is visiting CIC and asks you what the range Range ------at (time) ------· and bearing of the other ship will be at the point of closest contact. What will you 5. You are on watch in the CIC of the SUM tell him? NER in the early part of the first watch. She is on course 150-speed 20. At 2105 Bearing_____ /f!__t/J______Range ____~):.5_(p ____ _ the SG operator reports a surface contact at 091-26500, which you immediately re Your ship is on course 040 °-speed 15. At port to the OD as surface contact ABLE. 0424 the SG reports a surface contact at At 2106 the SG reports ABLE at 091- 262 ° 18700 which you report to the 25800. At 2107 the bearing and range are bridge as surface contact DOG. At~ reported as 092-25600. The OD has asked SG reports DOG at 263°-l330tr; at 0427 you for a report on the contact as soon as the bearing and range have changed to possible. You give him the following: as4o 1269Q. DOG bears 290°-SO~· yards at 0444. At 0445 you make a report to the Point of closest contact: Bearing ______bridge including the following information: Range ------at (time) ------Point of closest contact: Bearing _$__~-~---- Range ___'/_'/{)()___ at (time) ___ ¢(__ 'i5J,.5. Pass (_ahead or astern) ------ Range ------at (time) ------· Pass ahead or astern _ek~- _ Range_IJQL)_O @ Your surface search radar has furnished at (time) ___ ¢$_/b______, you with enough plots to show an uniden tified ship bearing~ to have a You are on course 261)10-speed 15, in the &.1 relative movement line of 260°-relative J early hours of the forenoon watch in CIC. speed 5 knots. Your CVE is on a course of Visibility is pour. At 0911 the SG reports 075-speed 17. The OD asks CIC whether a surface contact at~22-100. You re we will pass to port or starboard of the port this to the bridge as surface contact other ship, how long it will take , J pass, CHARLIE. At 0913 the bearing and range and by what distance we will clear. have changed to 298 ° 20800.. CHARLIE bears 298°, Fange l'+SOO at 0916. At 0917 Pass £(o.At._ .cu.J __ Time --~--:_?} ______you make a report to the bridge including the following: . ;), q d)(/)(b Distance ------· Point of closest contact: Bearing __¢Lk, ___ _ (f) You are on watch in the CIC of the U.S.S. SUWANEE (CVE) enroute from Manus to Range ___ !.(_¢.__(/!. ______at (time) _¢_9_$__'1:-:; __ , Pearl. The SUWANEE is heading 235°• speed 19. Radar control has given you the ~ following ranges arrd bearings on an un Pass ahead or astern ------· identified surface craft: 0310 :...Q05=39500; 0315: 604 38800~ 0320: 002 31900; Range __ at (time) /3__ ------· ...... _¢_'fffi.... 0325: 000 3700&; 0330: ~g 36200. The 4. Your ship is on course 310° -speed 24 Bridge calls you and asks: whether the toward the close of the first watch. At ship will cross astern or ahead of the SU 2302 the SG reports a surface contact at WANEE, the closest range it will come to 236°_-19100, which you report to the the SUWANEE, the bearing at the closest Bridge as surface contact BAKER. At 2303 point and the time of closest contact. SG reports BAKER at 237-18700; at 2304 SG reports BAKER at 239-18100. At Ahead or astern .4:1.£!._ ..... :! Closest range 2305 you make a report to the Bridge which includes the following information: .... 'i __ fP. ___ Bearing at closest point:~-~£ Point of closest contact: Bearing ------Time ___ ¢__fi_,J_ ------· CONFIDENTIAL C. I. C. Information 9 8. Cruising from San Diego to Pearl on a ~seee : at 0818 SG reports EASY at 050 - CVE, on course 245-speed 16, your SG 23000. At 0819 you make a report to the reports the following readings on a surface OD which includes the following: contact: 1945: 075--40000; 1950: 075- 38600; 1955: 075-37400; 2000: 07 4-36,- Pass (ahead or astern) _t;;-_Q_ k _ ~JS.t.DIJ/ at 000; 2005: 074-34900; 2010: 074-33500. The OD at that time asks you for the fol (time) lowing information: Will the ship pass to ------~- 9--~-'i : .£______. port or starboard? At what time and bear~ @ Your carrier is on course 250 - speed 15. ing will it be closest to your CVE? What You have an escort at 300 - 12000 on will you tell him? course 000- speed 12. The Bridge asks CIC how long it will ta.ke, and the distance own Port or starboard ··------· ship will be astern of escort if own ship takes course 300 - speed 30. Closest range ------Bearing at I Time ./;(.______Distance astern _'l_f.P_¢?____ . closest point ------Time ------· SIMPLE COURSE AND SPEED PROBLEMS {({(})}) SOLVING FOR COURSES AND SPEEDS face contact at -168 - 84~60. You report this to the bridge over 21 MC as contact The true course and true speed of a maneu GEORGE. The Captain asks for a course vering ship may be determined when the direc and speed of the contact. At 1013 GEORGE is reported at ;J,ij7 33200; at 1026 the SG tion of its relative movement line and the speed reports GEORGE at ~- 2'r200. at which it moves over that line (i.e., relative speed) are known. There are four fairly simple Course ... $..5.:?...... Speed _}/...... steps involved in this type of solution: @)~ship is on course 350- speed 15. At (1) Construct the guide's vector, e ... g, at ~the SG reports a surface contact at the center of the mooring board. .(H2 27GG& which you report to the bridge as contact FOX. Bridge asks for a course (2) Transfer, with parallel rulers, the direc and speed on FOX and the point of closest tion or slope of the relative movement contact. At 0911 SG reports FOX at~- line tog at the head of thee ... g vector ~ at 0912 bearing and ra~ave and draw from g, a line of indefinite ex changed to~Q19 26499 and at ~the tension along the slope and in the same bearing is t0069 , r&nge-.2200&. At 0921 you direction. make a report to the bridge as follows: (3) From g measure on the line of indefinite extension the speed at which the maneu Course ....6.'1 ..¢. .. Speed .. /.9J.S. ... Point vering ship moves over the relative movement line (i.e., relative speed). of closest contact: Bearing .... Mark this point m; g ... m then is the 3.../.1...... relative course and relative speed vector. Range ...... /6~.?(/)tb . ( 4) Connect m with the center of the board, e. The vector e ... m, thus constructed, @) e ship is on course 030 - speed 20. At 42 SG picks up a contact at 916 .. 34600-:- gives the maneuvering ship's true speed ·s contact is designated contact WIL by the length and its true course by its LIAM. Bridge asks for course and speed direction. and point of closest contact. At 042~ reports WILLIAM at 6-l-a 3326&; at 427 @ Your ship is on course 350 - speed 30. At WILLIAM is at Ql4 313091' At 0428 1115 the SG reports a surface contact at make a report to the bridge including the ~ 21?66, which you report to the bridge following: as contact HOW. The bridge asks for a course and speed on' HOW. At 1118 HOW ,2 " ?) , is reported at~ At 1139 the SG Course ...... /.?...... Speed ...... !.~---······· reports HOW at~. Point of closest contact: Bearing ...... -: .. Course ....¢.(/).¢...... Speed --~---············ Range .l.O.L ,_ ...... Time .... ¢.?. .... '!.'!...... @ You are on watch in the CIC of the USS At({f4M the SG reports WILLIAM at~ INGRAHAM which is on course 020 - ~ at 0433 _AR reports WILLIAM at speed 20. At 1011 your SG reports a sur- 013 - 24700; at '{_43~ contact is (H4 23590. C. I. C. Information 11 You make a second report including: you report X RAY at 140- 21500 and in clude the following: New co.urse ...¢ ..'1..~ ------New speed L~!. f.. . Course ____(j)(p~···------Speed ------''· ----S'------The bridge informs you that your own ship Point of closest contact: Bearing __ f/?...4_} _~ will change course to 080- speed 30 at 0940 and asks what effect the change will have on X RAY's track. You give the bridge the Range .. '91!-!i.~ ------Time ...fP..~ -~-f..... following information: 7J ~ DD is on course 160 - speed 18. At X RAY's point of closest contact: ~your SG picks up a surface contact at 8299& which you report to the bridge Bearing __ __/ _2_ _y______Range ___?_i; _¢__4?_ __ as contact X RAY. The OD wants to know the course and speed of the target. At 0930 at (time) ___ 1_(/)__f/ltJ ...... 12 C. I. C. Information CONFIDENTIAL SHIP MANEUVERING PROBLEMS ((((}}}} SHIP MANEUVERING (a) Connect the original position and the final position of the maneuvering unit, Maneuvering the ship is one of the most which provides the relative movement. common problems that the ere is called upon line. to solve. Fundamentally, all such problems are solved in the same manner-by the correct use (b) Advance the slope of the relative move of the relative movement line and the vector ment line to its parallel position as a rel diag.ram. In this section the following types of ative course and speed line. common maneuvering problems will be pre-. (c) If the time of the maneuver is known, sen ted: compute relative speed for one hour and 1. A maneuver from one known position to lay off the amount on relative course and another known position within a specified speed line-the point thus determined time, together with its corollary problem, provides course and speed for the ma a maneuver from one known position to neuver; if speed of maneuver is known, another known position at a specified lay off this amount from the center of speed. the board so that it crosses the relative speed line-the point thus determined 2. A maneuver to intercept another ship. provides course for the maneuver. 3. A maneuver to avoid collision with an A maneuver to intercept a ship is similar other ship. to the maneuver of a ship from one designated 4. A maneuver whereby a ship opens and position to another. In such problems the same closes on a given bearing at a specified factors are konwn and designated (see para speed or in a specified time. (Known as graph above). The key to the problem is sim an "Out and In" maneuver.) ple: (a) .the target ship becomes the guide, which means that the position of your ship 5. A maneuver whereby a ship leaves its must be plotted in relation to it; (b) the final station to proceed to a specified point and position of the maneuvering unit is the point return to station, using a specified speed .of interception-which is always in the center or time. of the plotting board. If these two factors are 6. A maneuver whereby a ship must pass remembered·an interception maneuver becomes a specified point inside or outside a speci a simple maneuver from one position to another fied range from a guide. (Known as a position. "Limiting Range" maneuver.) Maneuvering to avoid collision can be accom Maneuvering a ship from one position to an plished in two ways: either by a change of other in a specified time, or at a specified speed course or by a change of speed. In all such is the fundamental maneuver upon which all problems the course and speed both of your maneuvering is based, and is most often en own ship, and of the target ship, and the posi countered in shifting station. In all such prob tion of the target ship are known factors. The lems the course and speed of the guide ship distance by which collision will be averted, and and the original position of the maneuvering the time at which a change of course and/ or ship are always known. Likewise, the final po speed will occur is designated. One point of im sition of the maneuvering ship is always desig portance needs to be stressed. Remember that nated. The technique of solving such problems since it is assumed that the target ship will consists of three simple steps: not change course or speed, it becomes the CONFIDENTIAL C. I. C. Information 13 guide, and your ship the maneuvering unit in the solution of the problem. In solving the problem (1) Position your ship on the reciprocal of the range and bearing of the other, placing the other in the center of the plot. (2) From the new position "M" extend a line tangent to a circle about the center with a radius equal to the range at which you desire- to pass. 7000 Yds. The point at which the tangent touches c ! the circle becomes L Other M2 Ship M2 (3) Transfer the slope of Ml ... M2 to the head of the guide's vector (the other ship's true course and speed vector) and from g construct a line of indefinite extension. g 030° cv I~ "'14:-~ // e / / / / / / / // Ml ,,/ / / ~ ..... / M2 - .... ._:-_ (4) Where a true speed specified or a true course to steer specified cuts the line of indefinite extension, in either case determines the m position of the relative speed line. The e ... m vector is then constructed. (a) Speed 20 (b) Course 060 specified specified 030° 030° _, 060° I I 20 Knot Circle r e e 14 C. I. C. Information CONFIDENTIAL • It will be noted that in constructing the M1 to be attained. The guide's course and speed are ... M2 relative movement line, that two solu always known. In the solution of the problem tions are possible in many cases. Which will be the length of the relative movement line is gen selected will be determined by instructions erally not essential. The slope of the relative from the bridge, the position of other ships movement line is determined by the bearing in the vicinity, land masses in the area, devia upon which the maneuvering ship is to open tion from ship's base course and other variables. and close. The first step is to transfer the slope of the relative movement line to the head of The Out and In maneuver is most often en the guide's vector (e ... g) and from g draw a countered in scouting. In such cases a ship is line of indefinite extension in both directions. directed to open and close on a specified bear For example, suppose fleet course is 350 (T), ing from the guide with two of the three fol speed 12 knots. M, bearing 055 (T), 5 miles lowing conditions also specified-(a) speed to from G, is ordered to scout outward on bearing be used; (b) time for the maneuver; (c) range 055 (T) and to be back on station in 3 hours. I I ,ts 0 \~ Slope of \~ Relative Movement o\ '£1 Line 1/ •e If the speed to be used is specified then the line of indefinite extension from 0 is cut in two places and labelled m, (or ml ~nd m2). 18 Knot Circle Slope of Relative Movement Line M 272° 18 Knots The two e ... m vectors (or e •.. m1, e ... m2) provide the ratio for determining how m2) thus constructed give the course out and much of the total time available will be spent the course in. In this case 018 (T) is the course out and 272 (T) the course in. The relative going out and how much in returning. One sim speed vectors OUT (g ... ml) and IN (g ... ple formula is as follows: CONFIDENTIAL C. I. C. Information 15 Relative Speed Out (g ... ml) be computed into the problem by way of a geo graphic advance of G's position or retraction Total Relative Speed (g ... ml + g ... m2) of M's position. With this position found, M's the fraction of the total time to be spent relative movement line to return to position in 9p9RiRg. c c..OS/NC can be determined and his course and speed If the distance to open is specified, then the found in the usual manner. relative movement line will have Ml and M2 positions and the problem of time becomes one There are many variations of limiting range of simple relative distance and relative speed maneuvers. But they all have certain known solution. factors: the course and speed of the guide, and Caution: Do not confuse this situation with the range by which the maneuver is limited: one in which a maneuvering ship is directed The problem is to draw the relative movement to scout a geographic point. Example-A DD line inside or outside the limit of the ranges bearing 090 (T), 2,000 yards is directed to in given. The key to the solution is to use the vestigate wreckage in the water at a point data determined from this segment of the line, bearing 120 (T), 10 miles from the guide at to determine the unknown factors. For ex that particular time. ample: If a ship is ordered to stay within a specified range at a specified speed, the time .A maneuver whereby a ship leaves its sta of the maneuver will be determined by the tion to proceed to a specified point, and then length of that relative movement line inside returns to its station at a specified speed and/ or the range. Similarly, if a ship is ordered to stay in a specified time, also involves the creation of outside a specified range at a specified speed two vector diagrams. The outgoing maneuver (maneuver to avoid a collision is a case in is solved by using the bearing of the specified point), the time of the maneuver will be deter point as M's outgoing course. With this M's mined by the length of the relative movement relative movement line can be constructed as line drawn from a known point to where it he opens on the guide. His relative movement makes a tangent with the limiting range circle. line to regain position is identical with his out If this is kept in mind the slope and length of going relative movement line except that direc the relative movement line will be correctly tion is reversed. If M remains at the specified drawn, and advanced properly to form the rel point for any period of time the amount of the ative course and speed line from which the so guide's progress, for that period of time, must lution is determined. ,...... / -- ...... / 2 3 4 = / ' 11-P M M M M's I .20001 Yds. ' \ relative movement I \ M2 -M3 = ·M's relative I \ movement within a lim I · G I I I iting range of 2000 yds. I The distance M2 - M3 \ I and the time for staying I within range gives M's relative speed for the ...... __ _ whole relative movement. M4 16 C. I. C. Information CONFIDENTIAL 18. A carrier and its escort are on course 150 22. Your carrier is on course 090, speed 15. - speed 18; escort is 3000 yards astern. You have an escort at 030- 8000 on course The Captain orders the escort to take po 090 speed 10. Bridge asks ere what course sition broad on the starboard bow of the to steer to come astern of the escort 4000 carrier, distance 2000 yards, and to ac yards, without changing speed. Bridge also complish the maneuver in 20 minutes. wants to know how long the maneuver will Bridge of escort asks ere for course and take. Your reply: speed. Course _____ (P_':/._2______Time /?_$~ Course ______Speed ------23. You are i)fl watch in the ere when the 19. Your CV is on course 020 - speed 10. You S.G. reports a skunk a~ yards have an escort at 000 R600 on same at 0813. At 0856 the bearing and range course and speed. Bridge asks for course has changed to 320 16,661Y" yards. Our and speed to come up to position 4000 gyro indicates a course of 045 and the pit yards on escort's port beam. The Captain log shows 15 knotS'. The bridge asks you wants to complete the maneuver in 15 for a course to get on the target's nearest minutes. bow at 6,000 yards, using 30 knots. You ...... are also requested to give the bridge the Course ___ ¢_¢__:J______Speed ___ fd_(e_~_,P. ______time of arrival at the new position. 20. A carrier and its escort are on course 220, tP3 Course ------Speed ------Our Avoiding Course ____ /!/_(______CONFIDENTIAL C. I. r. Information 17 MANEUVERING 8 OARD PROBLEMS 25. Your ship is on course 110, speed 15. At closes to ~ards". In the first half 1418 the S. G. reports a surface contact at hour of ~tch the S. G. has given 180 - 24000 which you report to the bridge you the following ranges and bearin n as contact King. The bridge asks for an unidentified surface craft: at 005 course and speed. At 1419 the S. G. re Q66, 41!:156~ yards; at 0"010 -~lb.~~ltr ports King at 180- 23100; at 1420 the S. G. yards; at 0015 - 269, 243~ yards; at 0020- reports King at 180 - 22200. The bridge 264, 39488 yards; at 0025 - 26~, B66QO yds. asks you for speed to use in order to pass The 0. D. at 0025 asks (1) when should ahead of King and come no closer than the Captain be called? (2) Give me a 4000 yards. No change is to be made in course to ateer to remain 10000 yards from course and the change in speed is to occur the stranger with as little possible devia in five minutes. You'r reply: tion from base course, with the maneuver to start at 0035. What would you tell him? Kings' Course ...... Speed ...... Call Captain at ...... t/)l/).~.9-~ ...S...... Our Speed to avoid King ...... ~ K.s- 26. Your ship is on course 200, speed 20. At AvOidmg course ...... 1325 the S. G. reports a surface contact 29. Your ship is on course 140, speed 20. At at 269 295ee- which you report to the 1646 the S. G. reports contact at~ bridge as contact Jig. The bridge asks for R. 1I ~199 -~vhich you report as surface contact course and speed. At 1326 the S. G.(:itMU: J/:/i' Mike. The bridge asks for Mike's course ..If ~ at 1327 the S. G. reports Jig at ~- and speed. At 1647 S. G. reports Mike _,- ~~ee. The bridge asks for a course to at 080 - 29200; 64 the S. G. reports ~ steer to pass ahead of Jig and to come no Mike at 080 - 10 he bridge informs ->- closer than 4000 yards, no change to be you that the shi ll change course to made in speed, course change to be made 090, speed 20 at 1700 and asks: "Where in fifteen minutes. Your replies: will Mike be then, d what will be the ~ jft; r closest point of contact on the new Jig's Course .. ./..e.J.(L ... Speed ...... !...... course?" Your replies: Our Avoiding Course ...... /..23...... Mike's Course .2.J...t .. Speed _;;?__~-~ .. f. 27. Your ship is on course 050, speed 15. At At 1700 Mike will be at Bearing.. l/).f:.4>...... 1531 the S. G. reports contact at 84(1--.. 31200, which you report to the bridge as Range.Lf.P..2.f/t. contact Love. The bridge asks for course and speed. At 1532 the S. G. reports Love Closest point of Contact Bearing.. ./..£./.. .. at 340 - 30400; at 1533 the S. G. reports Love at 340 - 295.00. The bridge asks for Range .. S~-r--~· course to steer to pass ahead of Love and no closer than 8000 yards if we increase 30. Your ship is on course 040, speed 16 knots. speed to 25 knots in five minutes. Your At 1601 the S. G. reports two contacts, one reply: at 063 - 30,500 yards, the second at 080 - 32,000 yards. You report these to the Love's Course .. /~.. ~-- Speed --~-;{ .... . bridge designating the first (closer) con tact as ABLE and the second (farther) Our A voiding Course ...... fi!.S.L ...... contact as CHARLIE. The bridge requests CIC to furnish course and speed for both 28. Relieving the CIC Watch on an unescorted contacts and the closest point at which CVE enroute from Pearl to Espiritu you each will · come to your ship. At 0602 the are given the following information. Base S. G. reports ABLE at 064 - 30,100 and Course 215, speed 17 knots. The night CHARLIE at 080 - 31,000. At 0603 the order book contains the following: "(1) Do S. G. reports ABLE at 065 - 29700 and w the ship to come any closer than CHARLIE at 080 - 30,000. At 1605 ABLE yards to any other vessel. (2) bears 067° - 28,700. Your 1606 report to 6:n the Captain in the event any ship the Bridge will be as follows: 18 C. I. C. Information CONFIDENTIAL ae. The U.S.S. CHICAGO, on which you have ABLE's Course ______Speed the CIC watch, is steaming from Saipan to Eniwetok and your clipboard shows the ABLE's closest point to us: Bearing______following information: (1) "Base course - 095, Speed 22. (2) Enemy surface unit Range ______reported 300 miles northeast of your 2400 position." At 0045 your S. G. reports an CHARLIE's Course ______Speed ______unidentified target bearing 925, 44,600 ·yards. On reporting this to the O.D. he tells you to develop a course and speed on CHARLIE's closest point to us: Bearing___ _ the target as soon as possible and to com pute an interception course using 32.5 Time ______knots. In the next 20 minutes the S. G. The Bridge then asks CIC for a new course gives you the following ranges and bear to the right of the present course, increas ings on the unidentified ship: At 0056 - ing speed to 20 knots, a voiding CHARLIE 027, 44500 yards; at 0055 - 029, 44300 by 4,000 yards, and passing clear of ABLE, yards; at 0100 - 031, 44200 yards; at 0105 the change to be made at 1615. CIC is also - 9BB, 4 ieee yards. What information requested to furnish the closest points at would you give the Bridge: which the two ships will pass us with our Target's Course _j_{/)_~____ , Speed _}_ ZEBRA's closest point, Range ------Time to turn ------· 35. A carrier and its escort are on course oooo, Bearing______speed 20; escort is 3000 yards ahead of the CONFIDENTIAL C. I. C. Information 19 carrier. The carrier orders the escort to 38. A task force is on course 020, speed 16. investigate contact bearing 060° (T), A carrier 2000 yards from the fleet center, 14000 yards from the carrier, and then to bearing 090 relative, is ordered to turn into return to position, using 30 knots. The the wind to launch planes, and return to Bridge asks CIC for courses out and in station. The Air Officer estimates that it and time for each leg of the maneuver. will take 20 minutes to launch planes. Wind is coming from 310 (T), at 12 knots. Course out...... --··------Time out·------·-····----· 30 knots across the deck is required to launch planes safely. The bridge asks for Course in ------Time in ------· course to steer and speed to return to sta 36. You are in station 6330 in an anti-sub tion 30 minutes after planes are launched. marine screen. Base course is 000° (T), speed 20 knots. A patrol plane reports Course ------·------Speed ------··------wreckage in water bearing 315 (T) dis 39. Your DD 558 is in position 5250 on a tant 10 miles from your guide. The OTC screen. Your CIC clip board contains a dis directs you to leave station immediately patch to the effect that fleet axis and and proceed at maximum speed to investi course is 270, and speed is 20 knots. It gate. Your Captain asks you for course to also has a dispatch with special task force steer to reach the area and the time, using cruising instructions one of which states 35 knots. He further states that he will that a clearance of 1000 yards between search the area for ten minutes and then vessels shall be maintained in all maneu rejoin the formation, taking his original vers. At 1120 the OTC signals DD 558 as station all at maximum speed. He wants follows: "Cross ahead of guide and search to know what course will be and the total bearing 310 (T) 8 to 12 miles for plane time you will be out of formation. wreckage." The OD calls CIC for a course, To reach the area: using 30 knots. What would you give him? When would you be nearest the guide? Course Time -·------· Inform the OOD ------·--·------··-··------···· To rejoin: Course ·--··----·····------Time --·-----··-·-·-----· First Course ·------·-·---·------Time ·------·-· 40. A carrier and its escort are on course 130, Total time out ______, speed 18. The escort is broad on the car 37. Your DD is serving as plane guard for a rier's starboard quarter, distant 8 miles. CVL and is now on station 1000 yards on At 0600 the carrier sends the following the port quarter of that ship. The CVL's TBS transmission: "Snapper this is Bull base course is 090 (T), speed 18 knots. At dog. Posit 0. Tack. 8 Tack. Jig 0605. Over.'' 1012 the carrier gives two blasts of her Your bridge asks CIC for a course and whistle and the OOD of your ship comes to speed to carry out the above order and port on course 000 (T), same speed. After also to remain within three miles range of steadying on course 000 (T), he notices the carrier for a period of thirty minutes that the CVL has not changed course. Un to send and receive blinker messages, re certain as to what the CVL is going to do, questing you to specify the time of arrival he continues on his present course. The at the three mile range, time of leaving OTC calls on the TBS indicating that the the three mile range and time of arrival on carrier will not change course and ordering station. the DD to resume original station. Five minutes have elapsed since we have Course ·------·------····- Speed ...... changed course. The OOD calls CIC for course and speed to get back on station Times: Arrival at 3 mile range...... as soon as possible. The engineering con dition is 32. (Maximum speed 22 knots). Leaving three mile range ...... The OOD requests CIC to notify the OTC On station of the time when the DD will be back on station. 41. A carrier and its escort are on course 230, speed 18. The escort is broad on the car Course ------··--· Speed ______Time ...... rier's port quarter, distant 8 miles. At 20 C. I. C. Information CONFIDENTIAL 0900 the carrier sends the following mes 289 - 31000 yards. What heading will you sage on the TBS: "Bantam this is Bear give the Captain? If he asks when you will cat. Take position 4 miles ahead, coming be dead ahead of the· CA what time will within 2 mile range in 30 minutes, remain you give him? At what distance will you ing within ~ mile range for 20 minutes to cross ahead of the CA? receive flaghoist message. Execute in 5 minutes, OVER." Your Bridge asks for CA's course ------Speed ______courses and speeds to carry out the order, the time of arrival at 2 mile range, bearing Interception course ______: ______from the carrier at that time, and time of arrival on station. Range when CB is dead ahead Original Course ______Speed ______of the CA _____ :______Time when the CB will be Time of arrival at 2 mile range ______dead ahead of the CA ------Bearing at 2 mile range ------43. Your DD-661, enroute to Davao from Second Course ______Speed ------Guam picks up a Jap armed merchantman. The recognition officer identified it as a Time of arrival on station ------ship mounting 3 inch guns with a maxi~ mum effective range of 12000 yards. The 42. The U.S.S. ALASKA (CB) has been dis OD calls CIC and makes the following patched to patrol on enemy anchorage for statement: "We wish to close to 13000 the purpose of interception of a TONE yards and no closer, using 30 knots. We Class CA which has suffered battle dam wish to get on true bearing 220 from the age. It is known that its No. 1 and No. 2 target, at which point we will parallel the turrets are out of commission and that at target's course, and the CO does not _want last reports its top speed was 20 knots. The to use more than four headings to com ALASKA's gyro repeater reads 350 and its plete the maneuver. We will use 30 knots. pitometer log 25. At 0030 the S.G. oper Will you prepare the data as soon as pos a tor reports a skunk bearing 020 - 42000 sible? The DRT plotter says that the Jap yards. Your OD orders General Quarters, is on course 270 at 21 knots. The SG gives notified the engine room to prepare to a present range and bearing of the Jap make flank speed (35 knots) and tells ere as 275 (T), 21000 yards. What course and to develop course and speed on the target times of change would you give the as soon as possible. At 0032 the S.C. re bridge? · ports the skunk to bear 020 - 39000 yards and at 0034 to bear 020 - 37200 yards. The Captain then says to CIC: "Give me a Course !______Time on Course ------heading to meet the following conditions: (1) Stay 25000 yards outside the known Course 2 ------Time on Course ------shore batteries: (2) Start the maneuver at 0039.5; (3) Use 35 knots; (4) Cross ahead Course 3 ______Time on Course ------of the CA." Your DRT plotter tells you that at 0039.5 the shore batteries will bear Course 4 (270) CONFIDENTIAL C. I. C. Information 21 PHANTOM SHIP MANEUVERS There is one type of maneuvering problem problem in this way the initial and final posi which involves a maneuver from one known tions of the maneuvering unit are connected position in relation to a guide to another posi to form the relative movement line and the tion in relation to the guide, ~jlich is com procedure for maneuvering from one known plica ted by a change of coursf~peed by the position to another known position is followed. guide during the maneuver. This is called the When the guide changes course a new initial "phantom ship maneuver", since the solution position is created - tha~ position upon the rela may involve the use of a fictitious or phantom tive movement line held by the maneuvering ship. unit at the time of change. A new final posi tion is also created in relation to the guide. The simplest method for solving such prob These are then connected to form a new rela lems is to use two courses for the maneuvering tive movement line, and once more the pro- unit. Actually this is the only method that can be used when a change by the guide is made cedure for maneuvering from one known point without previous announcement and the man to another is followed. In effect two vector dia euver has already been started. In solving the grams are used to solve the problem. m Guide's Original Course Guide's Second Course First Relative Movement Line - ~m ~ - M's Second Course Ml Second Relative Movement Line M2 If, however, the course change of the guide that this method can be used only when the is known in advance the maneuver can be exe time that the maneuvering unit begins the cuted without a second change of course by the maneuver, and the time when the maneuvering maneuvering unit. The problem is solved by unit ends its maneuver are both known. If only the use of an average course and speed of the one is known another method, known as the guide. The guide is moved along the maneuver "Offset" method must be used. This will be ing board on his original course and speed for considered elsewhere. the time which he will be on that course and speed and his position plotted geographically, The type of problem discussed in the prev and from that point moved on his second course ious pa~arraph can also be solved by a geo and speed in like manner. The result will give. graphic ~ : . , c as follows. The gUide's track, the guide's average course and speed. For ex starting at the center of the board, is plotted ample if the guide is on course 000 - 12 knots geographically. The maneuvering unit's initial for 20 minutes, and then shifts course to 040 - position is laid off geographically from the 18 knots for 30 minutes, the guide's average guide's initial position and the maneuvering course and speed will be 028 - 14.4 knots, or to unit's final position laid off geographically from be more accurate, the course and speed of the the guide's final position. The maneuvering phantom guide is 028 - 14.4 knots. When this unit's initial a1'd final positions are connected is known, the relative movement line in rela and this line gives the geographic track that tion to the phantom guide is drawn and again the unit will make. Its direction gives the the procedure for maneuvering from one known course to steer. Its length gives the actual dis point to another is followed. Note, however, tance the maneuvering unit must make. 22 C. I. C. Information CONFIDENTIAL Maneuvering Unit's Final Position -----·/ Maneuvering Unit's Actual Track and True Heading e MI ·.----- Maneuvering Units Initial Positiol} @ Your destroyer, the U.S.S. CONY, is acting pickets will assume their stations. BING as plane guard bearing 170 relative, 1000 HAM take position 180, relative, 16000 yards astern of the CVL PRINCETON yards ... " At 1800 the BINGHAM is in which is headed 100 into the wind at 27 daylight cruising position bearing 270 rel knots. The PRINCETON hauls down the ative, 5500 yards from the guide. Fleet FOX flag and your OD has asked you for course and speed are 090 - 18 knots. Sun a course to resume the CONY's normal set is at 1810 and at 1805 the OD asks for cruising position which is 090 relative, his course to assume night station, at pres 5000 yards. You are to use 30 knots. What ent speed. What would you give him? At would you give him? After 2 minutes the 1815 the OTC makes the following TBS CVL flies the signal MIKE spe_ed one seven transmission: "Hello, Stablemate this is and your OD cuts the CONY's speed to 22; Blinker. Execute upon receipt. Turn 3. How would you revise the CONY's course? Sparkplug acknowledge, over." (Stable When will you be on station?· mate is collective call to whole unit). Your OD asks you for a revised course. What Course to take 5090//~Revised course .It9 . would you give him? When would you be on station? Time of arrival __ ___ //,__ £______· ______0 r1gma.. I course_. ~~2______R.ev1se d course ...<.v ~J..3... 45. A carrier and its escort are on course 090 - speed 16. Carrier is dead ahead of escort 8 miles. At 1200 carrier signals escort that @ ~~:: ~::t~:~::. ~~~~s: ~~i;~~so~. it intends to shift course 45 ° to the right has been detached from a task force to at 1230 and increase speed to 20 knots. pick up a Victor Fox pilot in the water. Carrier orders escort to take station broad At 1455 you have the man aboard and are on the starboard bow, distance 4 miles, to ready to proceed to resume your station arrive at 1300. The maneuver is to begin which is 090 relative, 5000 yards from .the at once. Your OD asks for: guide. The task force is on course 265 - speed 20. The SG operator reports the Course ____ ------Speed ------guide bearing 286 - 24006. The OD calls 46. A carrier and its escort are on course 050 - CIC and asks for his course to regain sta speed 18. Carrier bears 310, 6 miles from tion using 28 knots. After proceeding for escort. At 1100 the carrier signals that it 15 minutes on the given course, the OTC intends to shift course to 000 - speed 18 at makes the following TBS transmission: 1110. The carrier orders your ship to take "Hello, Rathole (collective call) this is position broad on the port beam, 4000. Bearcat. Execute upon receipt. Corpen 3. yards. The maneuver is to begin imme Elmer acknowledge, over." The OD then diately and you are to reach station by asks you if he should revise his course. 1130. The OD asks CIC for: What answer would you give him? When would you be on station? Course to steer ______Speed to use ---·-··--·-- Original Course.~S?'Revised course_ ~).) @ Your destroyer, the U.S.S. BINGHAM, has the following operation order. "At sunset Time on station ______/_~_ :(p ______CONFIDENTIAL C. I. C. Information 23 tiaJ A carrier and its escort are on course 290 - @ A carrier and its escort are on course 090 - V speed 20. At 1045 the carrier bears~ speed 15. The carrier bears 040 - 16000 ri>oOO"Yards from the escort when the es from escort. At 1100 the carrier signals cort is ordered to take position 2000" yards on the port beam of carrier in shortest the escort to take position at 090 (relative) possible time. Your ship, the escort, has - 4000 yards. The escort is ordered to use 34 knots available. The Bridge asks CIC 24 knots and to begin ·the maneuver at for a course. Ten minutes after execution 1115. At 1130 the carrier shifts course to of order is begun, the carrier changes 000° and signals the escort to take posi course to 000 °. The OD asks you for a new course and time of arrival on station. tion 270 (relative) - 4000 yards. What courses will the escort use? How long be Original course ~_Q(._ New course J.. .'/J2 fore the escort will arrive on station? Time on station ______//__/_)______First course rP'l'/ Second course _(/)_6 50. Your ship, the U.S.S. WADSWORTH, has been acting as a night picket ship bearing Time of arrival _____j __?.:- ___ ADVANCE AND TRANSFER {({(}}}} Thus far it has been assumed that a maneu A subsidiary element i~ a turning maneuver vering ship turns and changes speed instantly. is that the speed of the turning ship drops Such is not the case. This conclusion would while making a turn. Information concerning mean that a maneuvering ship would go from this factor is usually included with advance · ~ ts present station to its new station without and transfer data in publications. r 'taking into account advance and transfer. This may be done in the case of some maneuvers, In solving mooring board problems at sea, but there are many situations where it will be due allowance for advance and transfer must necessary to allow for these factors. be made in many cases. This may be done by turning early to allow for advance and by off When rudder is put over on a ship under way, setting the relative movement line to allow for the ship continues on its course for a short transfer. The manner in which these factors interval of time, then enters its turn for an are taken into account may be shown as fol other interval of time, until the new course is lows: attained and the rudder has been set amidships. While in its turn inertia carries it, with dimin ishing force, in the direction of its original Desired t..- Turn Early to allow course, and the turning movement carries it in Heading ~ for advance the direction of its new course. From the time the rudder is put over, until the time the ship Offset to j.-..:l~ M12 settles on its new course, the distance it moves I allow for I advance. For the same period of time, the transfer distance it moves towards its new course is J. This Relative Movement line known as transfer. These factors may be illus I will be made good. trated as follows: I I Present I Heading Rudder Moving . As a matter of practice, the ma;neuvering unit's progress along the relative movement line is checked periodically by ranges and bear ings on the guide and modifications of M's Transfer course and speedV CONFIDENTIAL C. I. C. Information 25 The following table of advance and transfer public Turn Speed Rudder Angle* Advance Transfer** 180° 15 Half-standard 500 1400 180° 20 do 550 1200 180° 15 Standard 400 800 180° 20 do 350 800 180° 15 Full 300 700 180° 20 do 300 700 * Half-standard is avJJ.roximately 15°-17 ° ; standard approximately 20 °-22,K"; full approxi mately 30°. ** Transfer for 90 ° turn is approximately half that of figures in this column. 54. Your DD 599 has received the following Range: ······· ··········- -··-- ·········--- · (from guide) flag hoist message: "9 Posit tack line 4". You have the guide's course as 180, speed Time: ...... Course ...... 12 knots, and the S.G. has the guide bear ing 270, 8000 yards. Your C.O. desires a 56 .. Your 445 class DD, on heading 030 at precision maneuver and tells CIC to in speed of 14 knots is approaching a forma clude transfer and advance in its solution, tion which it is to join, and receives the using half standard rudder. The can is on following blinker message at 0805; "As course 250, speed 24 knots. To what point sume station 5030 at 0830. Fleet course would you offset your M2 position to com and axis 190, speed 14". The bridge reads pensate for advance and transfer? What the message to you and says that it is • course would you steer to make good your desired to start the maneuver at 0810. offset relative movement line? How long Your DRT plotter tells you that the guide would you steam on that course before will bear 110, 7000 yards at 0810. The OD putting over your rudder to come to 180? tells you to incorporate transfer and ad vance elements in your solution using Offset point: Bearing ---·-··· -· ··-- ······················ standard rudder and any speed up to 24 knots. What course and speed would you give the bridge? How long would you Range ...... (from guide) steam on that course ? Course to steer ······------·---·· Time ...... Course ...... Time ...... 55. Your DD is approaching a Jap transport to 57. fire a salvo of torpedoes. The Jap is on Your Fletcher class DD is on station 5210 000, at 20 knots and your ship on 090 at in a screen at 1400. Fleet course is 270 30 knots. The CO wishes to fire when the and speed is 20 knots. The OTC makes the Jap bears 130 (T) 4000 yards and wishes following TBS transmission: "Ragtail to be on a course parallel to the Jap when (your call), this is Bruiser. At 1410 change station to 5150 using maximum he fires. If the Jap presently bears 130 (T), 10000 yards, to what point would you speed. Over". Your OD wilcos and asks offset your M2 position to allow for your for a heading to use at 33 knots. Assum advance and transfer in turning to 000, ing that standard rudder was used and using standard rudder? How long would that you were required to compute trans you steam on your offset relative move fer and advance into your solution what ment line before putting over rudder to course would you give him and what time come to course 000? On what course? to steer that course? Offset point: Bearing ...... Course Time ...... 26 C. I. C. Information CONFIDENTIAL 58. Your DD is on station 6300. The forma 25 knots, standard rudder and incorporat tion is on base course of 030, speed 15. At ing the ship's turning characteristics in 0330 the TBS blares in CIC: "Hickory your solution. What course would you give (Your DD) this is Magellan (OTC). Posit. him? How long should he steer that Your station is 6220. Expedite. Over". course? Your OD wishes to get on station as soon as possible and asks you for a course using Course ...... Time ...... CONFIDENTIAL C. I. C. Information 27 TORPEDO APPROACH COURSE AND FIRING PROBLEMS {{{{)})} THE TORPEDO PROBLEM point where torpedoes may be effectively fired. However, there is one important difference: the There are three more or less distinct steps M2 position in the approach course problem involved in the solution of the average torpedo will not be precisely defined. Instead, the bridge problem: (1) the approach course (2) the tor will indicate certain conditions for firing and pedo base course, and (3) the retirement the M2 position will be determined from these course. This section will offer a brief explana conditions. tion of some considerations involved in the first two steps. Conditions which are commonly specified in making an approach are: (1) the track angle, In developing the relative plot in a torpedo and (2) the speed of torpedoes. This is all the problem, the target is placed at the point of information that is needed; the track angle will origin and the relative movement line applies define the bearing of M2 from the target and to own ship. In setting up the relative move the torpedo speed will give the range of M2 ment line for the approach course, advance and from the target. transfer should be taken into account in order to insure a correct solution (see page 44). The The following illustration will serve to show relative plot in the approach course problem is the meaning of track angle and its relationship basically the same as that for any simple man to the approach course and firing problem. It euver; the problem is simply to go from the will also show how torpedo speed affects the point where the target was first picked up to a location of the M2 position. g Track Angle B.T.C. &"Dist. Run M2 f--L------..---.,. (Firing Point of Point) Impact e In this illustration it will be observed that (a) Track angle is always measured from the vector diagram and the navigational plot the target's heading clockwise around to have been combined on the same background the torpedo track (BTC). in order to depict the interrelation between the two types of solutions. The following points of (b) Obviously, the track angle specified will analysis are of principle importance at this determine the slope of the torpedo's stage of the students' progress: track (or base torpedo course). Thus, 28 C. I. C. Information CONFIDENTIAL for a track angle of 90 degrees the base then becomes the line of sight and the torpedo course must be 270° regardless point at which it cuts the effective range of the speed of torpedoes fired. becomes M2. (c) The torpedo track (BTC) in the naviga (f) It will be observed that M2 may also be tional plot will be parallel to the base located by using a given target angle in torpedo course in the vector diagram. conjunction with doctrine effective range. (d) The distance between the firing point (M2) and the point of c on tact is Solving for the base torpedo course in the the actual distance the torpedo must vector diagram becomes relatively simple once run to hit. This actual distance must the M2 position is determined. The M3 posi not be greater than 80 per cent of the tion is always at the center of the relative plot total torpedo range. The corresponding and the M2-M3 line defines the apparent range of own ship to target at time of movement of the torpedo with respect to the firing is known as "Doctrine Effective target. The M2-M3 line is transferred to g""' Range." It will be observed that doc and m will fall at the point where the torpe trine effective range is measured along does' speed cuts the g-m line. The e-m vec the Line of Sight and the relative, move tor then gives base torpedo course. This is the ment line. manner in which a torpedo problem would be solved if the bridge specified a given bearing (e) It follows that the M2 position in the on which to fire; the range of the firing point approach course may be determined by from the target would still be determined by transferring the slope of the relative reference to the actual distance the torpedo course and speed vector to point e ; this would run. The following table gives necessary data on torpedo speeds and ranges for the Mark 15 torpedo: 80% of Total Range Total Range Speed Knots (yards) (yards) Low 27 11,200 14,000 Intermediate 33.5 7,360 9,200 High 45 4,800 6,000 /'ficiJ Two minutes before your Captain has pedoes at the instant range and bearing. '-.~7 brought his DD to a position bearing 260 (true), 3500 yards from an enemy trans Base torpedo Course -----~_q_4} ______port which is on course 290-speed 18, a shell knocks out the communications be Distance to run to tween the Bridge and torpedo fire control -~-'l~!hime hit~_t.S:.~. stations. One minute before the DD reaches firing position, torpedo control @ The CO of DD 401 is directing his ship to calls CIC and asks for a check on the true a point on the port bow of the Jap AP torpedo course for firing high speed tor MOANA MARU, 5000 yards. He has or pedoes. What would you give? dered CIC to plot the course to fire a half salvo of intermediate speed torpedoes. The T. Torp. Course: ______DRT plotters have given you the target's fl;?_f?.~------course and speed at 138-17. When CO calls you for base torpedo course and dis @ Your DD 660 has maneuvered to a posi tance of torpedo run, what will you give tion bearing 45° relative on the port bow him? of the ARGENTINE MARU at 5000 yards. Your DRT plots have given you a courl?e ~ 5J. of 225°-speed 16 for the target. The Base torpedo course ...... Evaluator has asked you for a course to fire a half-salvo of intermediate speed tor- Distance to run ~.6..d>.... CONFIDENTIAL C. I. C. Information 29 ·C) &" Your CIC on the USS McCALL has been Range ___?_fo _ _/) _(L ___ _Bearing __ _! _.?J ______instructed to prepare a firing course for an intermediate speed torpedo. The McCALL Target angle ____ iJ_s_ __ ,______, is to fire from 30° on the port bow of a Jap merchantman at a range of 4000 yards. @ The CIC on DD 488 has been given the fol Your DRT plotters report course and speed lowing instructions from the Bridge: A of target to be 280-18. What course would high speed torpedo salvo is to be fired at a you give the Bridge? How long would the Jap seaplane tender. The CO specifies a torpedoes run to hit? 90° track angle and doctrine effective range. Your DRT plotter tells you that the Base torpedo course _____ Jap is on course 180, speed 16. At what {j)_~i range and bearing of the Jap from you would you tell the Bridge to fire? What Time to hit _:2_~--S.-~- -· would the target angle be? @ The USS LANSDOWNE on which you are CIC Watch Officer is making a torpedo run Range _;£_/_(~.!__, __ Bearing ____ ¢)_2_rp _____ on a Jap oiler. The Bridge calls CIC to say that it plans to fire a half-salvo of inter f'::\. Target angle ______t/J.?t/1------· mediate speed torpedoes at the target when it bears 015 - 4500. Your plots have '-VFive minutes before coming into position given a heading of 160 and speed of 15 bearing 310 (true) - 4000 from an enemy knots. Your plot also shows that at 1910 oiler on course 270, .speed 20, the Bridge the target will bear 015-4500. What base calls for CIC and asks for the true tor torpedo course would you give the Bridge? pedo course on which to fire a half-salvo How far will the. torpedoes run? of high speed torpedoes. What would you give them? What track angle would go Base torpedo course _d)_'l! __ i_ __ __ , with your solution? What target angle? Distance to run --~(/!-~,,_, True torp. courseL4{R- Track angle __~"4 @ Your Fletcher Class DD is standing by to Targ~t angle --- -~ - ~ --~------· fire a salvo of high speed torpedoes at the Jap cruiser MOGAMI when it bears 040 @Your Skipper is maneuvering his DD to (relative), 4000 yards on your starboard position bearing 070 (true) from an enemy bow. Your pitometer log reads 30 and your merchant raider which is on course 030 - gyro repeater shows 27(}. The DRT plot speed 20. He suddenly calls CIC and asks ters have estimated the cruiser's course for a check on (1) the true torpedo course as 080, speed 20. From the DRT you es for firing intermediate speed torpedoes, timate that the ·DD will be in firing posi and (2) the track angle. What would you tion at 0141. The Captain has asked you tell him? for the torpedoes' course and when they will hit. True torp. course.~.2.~ rack angle t{){p_~ ~3 ~ Your CIC in DD 583 has been instructed Base torpedo course ------· by the Bridge to prepare a torpedo course to meet the following situation. It is Time of hit ___t/?_/!1_~~_7. planned to fire high speed torpedoes on ~ DD 590 is being sent on a torpedo run to target angle of 40° on the starboard bow sink a damaged Jap CA. There is a possi of a Jap CVE. Your DRT plotter states bility that the Jap can still fire a part of that the CVE is on course 090- speed 19. his main battery so your CO wishes to go The Bridge wants to know our firing posi no closer than doctrine effective range for tion, torpedo course and time of torpedo an intermediate speed torpedo. He has in run. dicated that he wants to fire on a 90° 13 track angle. If your DRT shows the target Firing position_ki4__ 1_Torp. course_~ -~- W- to be on course 280 at a speed of 20 knots, Time ___ _~ _ !.______, what ~hould the target's range and bear ing be from the DD at the firing point? ® In a night engagement a Jap light cruiser What would the target angle be? has been partially disabled. Your DD (601) ,. ..: ., • 30 C. I. C. Information CONFIDENTIAL has been · 8ent in to make a torpedo run. bearing and range of Skunk as 050° - 10,- The skipper tells CIC that he wishes to 000. Bridge asks for a course to get into • fire. a salvo of intermediate speed tor position to fire a half-salvo of intermediate pedoes at a target angle of 325° from a speed torpedoes with a 270° track angle range of 4000 yards. Course and speed of from doctrine effective range. Your des the target have been reported by the DRT troyer has 30 knots availa4Jle. What ap plotter as 075- speed 24. What true bear proach course will you give? What course ing must the target be from us at the fir for torpedoes will you recommend? What ing point? What torpedo course would you will be the time of torpedo run? What will give the Bridge? What would be the time the doctrine effective range be? When will of run? we get to the f iring position? Bearing.2_'2 __¢_ ___ _Torp. Course/f_j_ ___ _ Approach course ____ (/)__ ___ ) BTC ______9_tJ)__ I Time. .. d..L, __~s______, Time of Torp. run ___/?._J ______~ Your DD has been tracking a target on the DRT for 10 minutes. Skunk's course and Doctrine Effect. Range __ ?_¢_¢-f--:------ speed have been reported to the bridge by CIC as 000°- 15. At 1605 the SG reports Time to fire _)_~~-~------· • CONFIDENTIAL C. I. C. Information 31 .•.. RETIREMENT COURSE PROBLEMS In order to determine a retirement course to open with gun fire. be used after firing torpedoes, certain condi tions must be specified or certain objectives Just as there is no single retirement course must be laid down. There is obviously no one solution, neither is there a single method of ar solution to a retirement course problem; the riving at a given solution. From a practical solution will depend upon a number of factors. standpoint, one of the most commonly used Among the conditions which may influence the techniques is simply to pjck a retirement course retirement course solution, the following may "by eye" from the situation as shown by DRT. be mentioned: However, there are several methods which have specific applicability to the maneuvering board. (1) It may be desired to open range and re Three of these will be briefly explained; all tire as quickly as possible, keeping own three are designed for use when it is simply ship clear of torpedo water, desired to open range. (2) It may be desired to get own ship into 1. The "X-Factor" method is designated to new firing position for torpedo fire, or enable you to open to a specific range in mini (3) It may be desired to get into position to mum time. Consider the following example: ui "0 ?-; 0 0 0 0 r-1 "'{. c,_'P· / ;_,""a.\)\) // e-'G M2 The solution is based on this formula: 15 Speed of G (a) Find the value of X. equal - X 20000 ----- times desired range 30 Sneed of M equal 10000 yds. equal X. In the above problem assume: G on 000 °-15 knots. M now bears 050, 9200 yds. (b) Locate X from G on target's course. This Captain .wants to retire to 20000 yards as point then serves as a guide in determining the quickly as possible. M has 30 knots available. slope of the relative movement line. The following steps indicate the method of (c) Extend a line from X through M1 to a solving. point 20000 yds. from G. This point will be M2• C. I. C. Information CONFIDENTIAL (d) Transfer relative movement line to g; is a simple rule-of-thumb which needs no spec ~ ... M is 30 knots and cuts g . . . M at desired ial explanation. course. 3. The "tangent method" is designed to give 2. Under the conditions specified, an ade the highest relative speed without closing range quate solution may be obtained by using the while retiring. Consider the following illustra reciprocal of the torpedoes' base course. This tion: g Target Course & Speed & Speed Note the following points in this solution: Retirement course ...... , Time ...... 73. Your DD is preparing to fire a salvo of in (1) A limiting range circle is drawn with termediate speed torpedoes at a Jap armed the radius G ... M. The maneuver must merchantman which is steaming on course be made so that the relative movement 210 (true) - speed 18. The salvo is to be line of own ship does not pass within the fired at a target angle of 330°. ere is circle. called upon for a retirement course to 16- (2) The relative movement line must be 000 yards using 27 knots. The Captain calls tangent to the limiting range circle at you and states that he wants to reach that point M. range in a minimum time. What course would you give him? When would the DD (3) Since no retirement range is specified, reach the desired range? What is. the track there will be no M2 position. angle of the torpedoes which were fired? ( 4) The balance of the solution is similar to that involved in any simple maneuver. Retirement course ...... Time ...... 72. Your DD, the McDONAUGH, has just Track angle ...... fired a salvo of high speed torpedoes at the Jap cruiser AGANA from a point 74. Your DD is operating in the Bonin Islands bearing 060 (true), 4000 yards. Your DRT south of Iwo Jima. At 0930 the SG picks plotter has given you the AGANA's course up a Skunk at 270-15000. At 1000 the and speed as 030 - 18. At the time, the range and bearing have changed to 300- area is closed in by fog and vtf·i ity is 10000. Your own gyro repeater shows limited to about 1 mile. CIC h dered 000°; pit log shows 17 knots. Captain calls to have. a retirement course o 20000 ere for an approach course to fire low yards plotted, using 36 knots. The man speed torpedoes on a 60 ° target angle from euver is to be performed in as short a doctrine effective range. Speed to use in time as possible. As the salvo is fired, the getting to firing point is 2'1 knots. Captain CO calls CIC for the course. How long will also wants to know when you will arrive it take to retire to the desired range? at firing point. In addition, he has asked CONFIDENTIAL C. I. C. Information 33 for the following: base torpedo course, range. You flre requested by the Evaluator time and distance of run, retirement course to give the approach course using 30 knots, which will not close range in retiring, us time of arrival at firing point, base tor ing 33 knots. pedo course, time of torpedo run, distance of torpedo run, and doctrine effective Target's course ______Target's speed ______range. Prior to arriving at the firing point the Captain calls ere and states that he Approach course ______Time of arrivaL ______wants to retire to 20,000 yards as quickly ' as possible after firing. Engineering con Torpedo base course ______Time of run ______dition is 31 (maximum available speed 33 knots). The Evaluator asks you for the Length of run ______Retirement course ______best retirement course under the condi tions specified by the Captain. 75. You have just relieved the midwatch in the Target's course ______Target's speed ______ere of the SUMMER operating in enemy waters when the SG reports "Skunk", bearing 150- 26000. At 0025 the bearing Approach course ...... Time of arrivaL ...... and range have changed to 140 - 24000. BTC ______Time of run ______Thirty minutes later the target is reported at 110 - 12000. Your present course is 090 - speed 20. The ship has gone to gen Distance of Run ------·------· eral quarters and you are Assistant Evalu ator in ere. The Captain tells ere he wants Doctrine Effective Range ------to fire high speed torpedoes with a track angle of 270° from doctrine effective Retirement course -··--··------·--·--·------· .. C. I. C. Information CONFIDENTIAL SHIP MANEUVERING-ADVANCED ««»» MANEUVERS IN LARGE DISPOSITIONS maneuvering unit's time of departure or time of arrival and time of guide's course This section is comprised largely of maneu and/ or a peed change are known. vers in large dispositions; problems in the sec All of the problems are designed to acquaint tion include: the student with some of the signals .necessary 1. Changes of fleet axis, rotation of fleet to carry out such maneuvers. axis, changes of fleet course (same axis Changes in Fleet Axis-Before getting into and change of axis) and related prob the subject of ·changing fleet axis, it is first lems. necessary to understand what the axis is and 2. Maneuvering bent line or arc screens. the purposes it serves. Fleet axis is the line of true bearing used as a reference line about 3. Change from A/ S screen to AA screen. which ships or groups of ships are stationed 4. Effect of zig-zag plans on maneuvering in formation. Let us first take a simple example board solutions. where fleet axis and fleet course are one and the same. Ships have been assigned the follow 5. Phantom ship maneuvers in which only ing stations: OOOT +B J ~1 G3 Ship No. 1: 000 Rela tive-5000 yds. I \ I Ship No. 2: 330 Rela ti ve-5000 yds. \ I Ship No. 3: 030 Relative-5000 yds. \ I \ I AB-Fleet course \ I \ I AB-Fleet axis \ I \e,~ Guide In the above illustration ships 1, 2 and 3 have Let us now assume that the fleet course is been assigned stations relative to the fleet 000 (T), but since enemy contact is expected axis. Since the guide's true course and the di from 045 (T), the OTC has made a signal that rection of the fleet axis are both 000 (T), it is the direction of the fleet axis is 045 (T). Let then obvious that ships' positions are in the us now examine the same formation under same relation to the guide as to the fleet axis. these changed conditions. CONI<'IDENTIAL C. I. C. Information 35 OOOT• B I ~ 2 045T /'/( c AC-Fleet axis I~ / I ..... go o / AB-Fleet course ..... j 1 ~ I /y~ I / \ 30o I / \ I / ' // ' ---~-~ 3 To sum up, you have the following condi A / ___ _... ---- tions to be dealt with: @ 1. The basic change of station problem, which will involve one or more relative Guide motion lines, to be executed in a given From this illustration we can readily see that time or at a given speed. ships 1, 2 and 3 have not changed station in re 2. The determination of the guide's average lation to the fleet axis, but have changed their course and speed for the time required stations relative to the guide. to complete the maneuver in case of zig To reiterate, then, the fleet axis is a line of zag. true bearing originating at fleet center and is 3. The laying out of the relative movement the reference line used by all ships in the form lines of all maneuvering units and the ation to determine their assigned positions. For solving of the maneuvering board prob example, if a ship is assigned a station 030 (R) lem for all units whose relative movement and the fleet axis is 045 (T), the ship will take lines cross your own. station bearing 075 (T) from the fleet center. The use of fleet axis, then, is to dispose the The examples used in this discussion were ships of a formation in any desired direction based on small formations for clarity, but the from the fleet center irrespective of the form- basic principles hold true for large formations ation course. · as well. The greater number of ships merely increases the chance of collision or embarrass Next, let us investigate the maneuvers re ment and requires more vigilance on your part. quired to rotate the fleet axis and the maneu Remember the job isn't done until your ship vering board problem involved. The maneuver is safely in her new position. ing board problems for each maneuvering unit will be a simple change of station problem. The Bent Line and Arc Screens--A typical ex Ml position will be your present station and ample of a bent line or arc screen is the A/S M2 will be determined by applying the amount screen. It is used when there are not enough of rotation in degrees (left or right) to the screening vessels to form a circular screen. As true bearing of your present position from the this particular type of screen is used to screen fleet center. The range of the new position re ahead of heavy vessels (along the line of ad mains unchanged by rotation of the axis. vance), it is obvious that screening units will have to reorient or rotate their positions any The conditions usually set forth in the exe time the fleet course and axis is changed. Also, cution of axis rotation are either a given speed as the screening ships are some several thou or a given time for the completion of the ma sand yards away from the guide, it can readily neuver. The maneuver may be complicated by be seen that an angular rotation of the axis the fact that the formation is zig-zagging. will involve an appreciable linear displacement And the maneuver will almost always be com of the screening stations and will require some plicated due to varying numbers of other ma time for the screen to assume new stations. neuvering units, any number of whose relative There are two general cases involved in reori movement lines may cross your own. enting screens of this type: 36 C. I. C. Information CONFIDENTIAL 1. Change of course and axis by from 110° the ship in the number one position in case of to 180°. In this case the ships turn back indi an odd number .of ships in the screen. If the vidually and proceed through disposition as di number of screening ships is an even number, rectly as possible to new stations. The new station for all ships will be reversed except for all stations will be reversed. -, /-, I I ,-, ,-, ,-, I 2 I 1 a I \ ~ 1 ~ I 3 ~ l -, I /-, 2 . I I I I I \ e I I -, I ,..I, I I /-, \ I I I \ "-' I 9 4 I I I 3 ~• II ~4 \ I I 5~ I I \ I I I I I \ \ I \ I ; + I I • I I \ \ I I \ '\ I \ \ I I I I I I I \ \ \ \ I I I I I \ \ I + I \ I I G3 I 4e \ • I I \ I I I \ I I I ~5 \ I I G4 I ~1 2G 3 @ e@ e1 Gz The signal necessary is "Corpen ...... before the time the signal is to be executed. William." The two methods of making the sig 2. Change of course and axis of less than nal are: (a) the executive method and (b) the 110°. In this method the ships merely rotate Jig (time) method. In the executive method their stations by the amount of the axis change all screening vessels commence reorienting as and maintain their present station numbers. soon as the signal is understood, the guide delays execution until the screening vessels The signal for this type maneuver is "Corpen have had time to get into their approximate ...... Queen." This signal can also be stations. In the Jig method the screening ves made by either the execute or Jig method, and sels commence their reorientation ten minutes as in the previous case, the ships will com- --~- 2 • A 3 2 i. A I . A -\ vE:::=>~ 1--- ] \ I B I \ I I \ I I \ I I \ I I \ I I \~/~ CONFIDENTIAL C. I. C. Information 37 mence their reorientation (a) in execute meth understood by maneuvering DD's, the possi od as soon as understood, and (b) in Jig method bility of a M.B. solution to clear all units is ten minutes before the signal is to be executed. quite complicated and at times impossible. In a case of this nature, both the best M.B. solu The maneuvering board problem involved is tion possible plus a good ship handler at the rather simple for the individual ship, being conn are required. simply a change of station with the guide on steady course and speed. The guide will be on Change of Disposition from A/S to A/ A steady course and speed due to the fact that Screen-First, let us examine these two forma even though a zig-zag is employed, it will be tions separately. An anti-submarine screen is ceased and base course resumed (a) in the case composed of sonar-equipped vessels (usually of execute method, when signal is two-blocked, DD's or DE's) in a semi-circular formation sta or (b) in the case of the Jig method, ten min tioned ahead of and along the line of advance utes before executing the signal. of ships being screened. The distance the anti submarine screen will be placed ahead of the The mooring board solution for changes of screened vessels will be determined by the course and axis of 110° to 180° will not usually number of ships in the anti-submarine screen involve crossing relative movement lines of the and will necessarily be a compromise between screening vessels and will require only that the maneuvering vessels remain clear of the heavy the two following conditions: ships during reorientation. The complexity of 1. The necessity for having the screen far this will be determined by the number of ships enough ahead of the screened vessels to in the main body and the amount of the course detect submarine contacts before they are change. within firing range of the large ships. The mooring board solution for reorientation 2. The necessity for covering the water to less than 110° will produce the same problems a sufficient range normal to the line of as were set forth in the section on rotation of advance to render improbable the possi the axis, except for the fact that the guide bility of a submarine getting into firing will be on steady course and speed. position after the anti-submarine screen The above discussion will hold good for situ has passed. ations when the main body is all the same type The two above conditions will necessarily be or remains at the same speed. But frequently tempered by the fact that the distance between the formation may consist of, for example, the ships in the screen must be such as to several columns of AP's followed by CA's or allow the sonar search coverage of the ships CL's, and due to submarine threat the CL's to overlap so that no contact will be allowed do not wish to slow to formation speed. To to slip through undetected. This distance will maintain' the positions astern they are forced be determined largely by the underwater sound to zig-zag. And as this zig-zag may not be fully conditions. 4 5 0 Guide 38 C. I. C. Information CONFIDENTIAL The anti-aircraft screen has as its objective in a circular disposition around the heavy the stationing of the light ships around the ships at a minimum range. The minimum range large ships to achieve the greatest possible is determined by the distance necessary to concentration of fire-power on any bearing. This permit the ships to maneuver radically in form is best accomplished by placing the light ships ation without undue risk of collision. e>'!.l I _,'I ,---+------t~2 ~' ~' I ..c>2 \ f I ~'C> \.~------~--~ I ..c:>l C>~ C> I \ \ .... ______I 5 ....C> / ~3 --~---'\ 1 ~ --- J ' I I --- ...... '- \ ,__ -- I C>"'3 ...... ----- ...... --t----- 'I C>;l The problem then of shifting from anti-sub what less than the total distance actually trav marine screen to anti-aircraft screen involves eled, and, therefore, the average speed made the shifting of the ships from a semi-circular good along the line of advance will also be less formation from 2000 to 6000 yards (approxi than the actual speed. The same is true for any mately) ahead of the guide ship to a circular portion of the zig-zag. formation 1500 to 2500 yards from the guide. In shifting from anti-submarine to anti-aircraft The effect of a zig-zag plan on a maneuvering screen, ships normally take the same numbered board solution, then, is to require: stations and the maneuver will almost always 1. A series of maneuvering board solutions be executed in a minimum time. -one for each successive heading of the guide, or Effect of Zig-Zag on Maneuvering Board Solutions-Zig-zagging is the steering of pre 2. A determination of the mean course and determined courses to the right and left of the speed over a given period of time (the base course to foil enemy submarines in their time allowed for the completion of the attempt to get into favorable firing position. maneuver) to be used as the guide's Zig-zag plans are so laid out that the base course and speed to execute the maneuver. course is made good over given periods of time (usually one or two hours). That is to say, that The first method requires no further expla at the end of the given period of time the ship nation as it is merely a succession of simple will be on the base course line projected from maneuvering board solutions. The second meth the starting point. It must be remembered, od .may be further clarified: The method used however, that ·part of the time the ship will be to determine the mean course and speed of the either to the right or the left of the base course guide first requires a given time in which to line. Therefore, from the starting point to any execute the maneuver. The guide's track is then particular position, the average course made plotted in navigationally commencing at the good is not the base course. center of the maneuvering board, and thus de termining the guide's position at the end of a Due to the fact that the ship is steering given time. The bearing of the final position courses to the right and left of the base course, of the guide from the center of the maneuver it should be evident that the distance made ing board will be the mean course. The distance good along the line of advance will be some- from the center of the maneuvering board to CONFIDENTIAL C. I. C. Information 39 the final position measured along a straight line connecting the two, divided by the time elapsed, will give the average speed. AB-for 5 min.- 5000 yds. OOOT BC-for 7 min.- 7000 yds. AC-for 12 min.-10000 yds. AB-030° T BC-070° T AC-050° T Therefore Average: Course = 050 10000 Speed 12 833 yds/min. 3 833 X = 25kts. 100 After the mean course and speed have been things, it will be possible to get a single cour~e determined, it is then a simple matter to solve and speed for the maneuver: the problem for a single course and speed. In using the single course and speed method, the 1. Time when guide will change course and/ following caution should be strictly observed. or speed (as a corollary, the time guide Since the guide's course and speed vector used will be on either old course or new course is fictitious (the guide is not actually moving will be known). down that line), it obviously follows that nei ther will the maneuvering ship move along the 2. Time when maneuver is to be started by relative motion line used in solving the problem. the maneuvering unit, or time when it Therefore, the relative motion line will not in must be in new position. These times are dicate the true ranges and bearings of t:qe ma referr,ed to as departure time and time neuvering unit from the guide during the of arrival. maneuver. The solution to the problem is slightly different Phantom Ship Maneuvers of a relatively for the case (a) where maneuvering unit's de simple nature were discussed on page :lfl. In parture time is known, and (b) where maneu this section attention will be turned to a more vering unit's time of arrival is known. These complex type of phantom ship problem. It cases will be separately analyzed. sometimes happens that guide will chang~ ' course and/or speed after having ordered a Let us assume the following situation: Guide maneuvering unit to take a new station; this is now on 000°, speed 16 and will change course may happen in such a way that the maneuver to 040°, speed 20 at 1120. M now bears 250° ing unit does not know how long the guide will (T), 6000 yards from the guide. At 1110 M be on both its old and new courses. However, is ordered to take . station at 320° (T), 5000 if the maneuvering unit knows the following yards, using speed of 25 knots. 40 C. I. C. Information CONFIDENTIAL m g~ This relative movement------·--~------~ line will be used. M11 Offset of 10 minutes at reiative speed of 12.4 kts = 4100 yards. (This offset parallel to g1 ... g2 and in direction from gl to g2). The following points in the solution should F-ince it is known that the real guide be noted: spends 10 minutes on the first leg. 1. An inspection should be made to deter 5. The offset is made for 10 minutes at the mine whether the maneuvering unit could relative speed represented by gl ... g2 take station before the guide changes (12.4 knots). This gives a relative dis course and speed. If it can, then obviously tance of 4100 yards. The offset is made the solution given here does not apply. parallel to g1 ... g2 and in the direction 2. The guide's original and new vectors are of g1 toward g2. laid out in the vector diagram. They are 6. The new (offset) relative movement line, then connected, forming g1 ... g2. This M'1 ... M2, is then transferred to point is the relative speed of the guide on the g2. This line is then cut at speed 25, giv new course and speed with respect to the ing a course for the maneuvering unit of original course and speed. 025 °. 3. Since it is not known how long the guide will remain on the new course at 20 knots, If the time of arrival of the maneuvering the e ... g2 vector represents the phan unit on its new :;;tation had been known rather tom guide as well as the real guide. (It than the time of departure, the following dif is assumed, of course,. that the guide will ferences in the solution would have applied. remain on the new course and speed long Assume: Guide now on 000 °, speed 16 knots enough for the maneuver to be made). and will change course at 040 °, speed 20 knots at 1120. M now bears 250° (T), 6000 yards 4. The M1 position is offset for the amount from the guide. M is ordered to take station of time the real guide and phantom guide 320° (T), 5000 ~·ards, using 25 knots and to be are not in company. This is 10 minutes, on 1~ew station at 1133. CONFIDENTIAL C. I. C. Information 41 m g2 Offset of 13 mins. at relative speed 12.4 kts = 5500 yds. ~~· ~ 0/ §I \:s This relative movement line will be used. Ml of~ 1. The M2 position has been offset by a rel (jj) Fleet course and axis 020 deg., speed 15. ative distance representing the time the Station of your ship, cruiser VICENNES, real guide and phantom guide were not in cruising disposition is 30 deg. relative in company. 3000 yds. from fleet guide. OTC hoists signal "XRay Form 065.V' The OOD asks 2. The e ... g1 vector represents both the real guide and the phantom guide, since you in CIC for a solution, using 10 knots the time that the real guide is on the as the VICENNES' speed for the man first course is not known. (Time on sec euver. What course would you give him? ond course is obviously 13 minutes). Course ...... l/!.~/.f:. ______3. The new (offset) relative movement line is applied to point ·g1 rather than g2 as (7y Fleet course and axis 000 deg., speed 18. in the former case. Your ship, cruiser MIAMI, is division guide for cruiser division 23. Fleet guide To sum up, the following rules should be kept is in carrier LEXINGTON, which bears in mind: 020 deg. (True) from you, interval 5000 (a) When the time of departure is known, the yds. Signal is put out by OTC over TBS, M1 position is offset and the relative move "Beetle (all ships) this is Granger. Exe ment line is extended from g2. cute to follow. 270 corpen Dog 17 tack Dog Roger Easy 50, over." What course would (b) When the time of arrival is known, the you in CIC first tell the OOD to come to M2 position is offset and the relative move an execution of the signal? What would ment line is extended from gl. be the second course you would tell him to come to, using 25 knots, to reach your (c) The offset is always made parallel to g1 new station? When would you tell him to ... g2 and in the direction from g1 toward do so, assuming it is night-time and visi g2. bility is poor? @ Fleet course and axis 120 deg., speed 15. Station of your ship, cruiser KALAMA First Course 1.'J..,;J; Second Course 2,_'{~ ZOO, 2000 yds. on starboard beam of guide. O'I'C hoists signal "060 corpen Time to commence second course . fl.~. Queen." OOD asks CIC for a course for the KALAMAZOO, using 20 knots for the maneuver. What course would you give him? 79. ;:~~r;;;; -c~:t:.•::~~~~ ; ·~~:~: ;·~~~~' 20. Destroyer Squadron 48 is exercising J 1fCourse ...... at maneuvers. Division 95 (4 ships) and r/?.fzf...... !l~ ~ J rr{1 42 C. I. C. Information CONFIDENTIAL DIVISIOn. . . 96 (4 Sh" IpS ) are S!"eJ!m!NClhsQJMIMg Ill 2 course and axis 220, speed 20. A large columns. Your ship is No. 4 in column in flight of bogies is picked up on the screen. DesDiv 96. Squad Dog is in USS ERBAN The OTC hoists ~ignal "Charlie form 5 DesDiv 95). Your Division has just car Victor." In AA disposition· 5V your sta ried out the signal 9 Form Div tack line tion is 4030. OOD asks CIC what course DRE 20 tack line DKJ 5. Squad Dog now will get the HALFORD to her new station o<;.e~ 4/ _ hoists Corpen 9. This signal is executed if she remains at 20 knots and how long it fiNS. Fo~ht and carried out. 'Reg9P 48 FePm is then will take. What do you tell him? hoisted. Your Captain asks for a course to get to new station using 25 knots and the Course ···-··--·------·--- Time ------·------·- time it will take you to get there. He also wishes to know what the R & B to guide 83. After you have reached your new station will be when we are on station. in AA disposition 5V (see problem 82), lookouts report that the bogies are a large Course ...... Time ...... flight of geese. The OTC hoists the signal "Charlie form 5 Roger." The OOD asks Range & Bearing to guide ...... CIC what course will get the HALFORD to station 7030 from her present station 80. Your ship, cruiser QUINCY is division # 4030 if she remains at 20 knots. What do guide for a division of cruisers in column. .. you tell him? What would be the course 2000 yards on your starboard beam is for 25 knots? (Fleet course and axis still fleet guide, cruiser BALTIMORE, leading 220, speed 20.) another column of cruisers. Fleet course and axis is 025 deg., speed 15. Signal is Answer ___ i ...... ______...... ___ .... __ _ hoisted and executed "Sopus turn 18". (This signal m~ans port colu.mn turns left, Course for 25 knots ...... starboard column turns right 180 degrees, then both columns converge, .each at an @ The destroyer ROSS is in station 11 in AS angle of 15 degrees from the new course, screen for a group of heavy ships in_ a until the leading ships of the two columns cruising disposition. Fleet course and axis are the same distance apart as they were 000 deg., speed 18. There are 13 destroyers originally). If tactical diameter of your ·in the screen and they are equally spaced ship is 1000 yards, also of guide ship, how from 5270 to 5090, the destroyer in station many minutes after you have turned 180 1 being at 5000. The force picks up on the degrees with standard rudder will it take SK screen a large flight of bogies. The before you and the guide ship are once OTC gives the signal to form an AA dis more 2000 yards apart? position. According to the doctrine of this force, 12 of the destroyers are to form a Time ...... circular screen on circle 4 for the AA dis position, the DD in station 13 moving in to 81. Your ship, destroyer MACDOUGAL, ·is at the center to stand by the carriers. The 6025, station 3 in a 9-ship screen. Fleet remaining 12 DD's are to be equally course and axis 000 deg., speed 15. OTC spaced, the DD in station 1 being at 4000. hoists signal "Corpen 160 William." Doc What course will bring the ROSS to her trine is for screening ship in station 3 to new station 11 if she uses 18 knots? turn right and proceed to station 2, 6335 on new axis, on a countermarch as soon as Course ... ____ -~ __ .... / __ .... ___ .. _.... _... _.... ___ . _. ______. signal is understood. OOD asks you in CIC for MACDOUGAL's course and mini The OSHKOSH is zig-zagging according to mum speed if she is to be on new station plan 6. Base course, fleet course, and fleet within 8 minutes of signal's being hoisted. axis 090 deg., speed 15. On this zig-zag (It is understood that signal will not be leg the OSHKOSH is 4000 yds., 120 deg. executed until destroyers are on new relative from fleet guide. The time is 1449. stations). The zig-zag course is 050 deg. (T). An island is off the starboard bow. The OTC hoists the signal "Turn Zebra Fox." It is Speed ----·-----·------· Course -----·-········--·--·--· executed. He ten hoists the signal "XRay- 82. Your destroyer, the HALFORD, has sta 050 Form." At 20 knots what course would tion 7030 in cruising disposition 5R. Fleet you in CIC recommend to the OOD to CONFIDENTIAL C. I. C. Information 43' bring the OSHKOSH to her new station? 88. DD 850, 20,000 yds. astern of guide, who is on course 110, speed 15, is ordered at Course ..- ...... c;P.5.3 ...... 0500 to resume original station 20,000 yards ahead of guide as quickly as pos @ The GRANT's station is 4020 on fleet sible. DD 850 only has boiler power avail course and axis 060 deg., speed 20. Force able for 26 knots. Guide will change to is zig-zagging according to plan 6. The course 160, speed 20, at 0600. When will time is 0810. Zig-zag course is 040 deg. DD 850 arrive on station? What cour-se (T). OTC hoists signal "Turn Zebra Fox." will put her there? He executes it and then hoists a signal ad dressed to the GRANT, "Form 18 tack Dog Love Uncle 1." What course would Time ...... Course ...... you in CIC tell the OOD to use at 15 knots to reach station? 89. The guide is on course 060 deg., speed 16. Your ship, the destroyer SNERD, is on Course .fk2..?...... {)!...... i ..?J'...... guide's port beam, distance 6 miles. You receive orders to take station dead ahead @ Fleet course and axis 340 deg., speed 16. of guide, distance 8 miles, and to pass Station of your ship, cruiser DENVER, is through a point bearing 090 deg. (T) dis bearing 310 deg. (T), distance 2500 yds. tant 15 miles from guide. You are to com from guide. Force is zig-zagging accord plete the maneuver in 4 hours or less, ing to plan 6. 'l'he Captain's night order using the minimum speed possible the book has the notation "2200 : 280 corpen the whole time. What are your first and Queen." If you are allowed to increase or second courses, what is your speed, and decrease speed 5 knots from 16 knots to how long will the maneuver take you? carry out any maneuvers, what course and speed would you as OOD of the DENVER use at 2200 to carry out the maneuver in 1st Course ...... 2nd Course ...... the shortest time? Course .. 2.//.~ ...... Speed .. ~!...... Speed ...... Time ...... • • 44 C. I. C. Information CONFIDENTIAL • TORPEDO PROBLEMS -ADVANCED ««»» The Torpedo problems included in this sec Torpedo Effective Range Indicator- The tion are designed primarily to train the Assist · TERI is a simple device designed primarily to ant Evaluator to determine approach courses, enable the M2 position in an approach course (i. e., the firing position) to be found. In per base torpedo courses, and retirement courses on forming this function, it takes into account the the maneuvering board. The use of the Tor variables of torpedo speed and target speed pedo Effective Range Indicator is recommended and course. With the TERI it is possible to for speedy solutions of the torpedo problems. find quickly the M2 position in an approach under either of the following conditions: (a) Problems 92-98 should be worked by~ follow- firing on a given track angle, or (b) firing on a . ing the times set forth i~~oblemS. given bearing. A sketch of the TERI is pre A brief explanation of the TERI follows: For sented below for study, together with an ex a more detailed one see "RAD FIVE." planation of the manner in which it is used: 270° Track angle t 280 ° Track angle 290 ° Track angle 5 70 ° Track t angle 80 ° Track a~gle 90 ° Track angle Scale of target speeds for intermediate SFJeed torpedoes. CONFIDENTIAL C. I. C. Information 45 Assume a target ship on course 000°, speed Intermediate Speed fish with an 80° 20 knots; your instructions are to find an ap proach course to fire intermediate speed tor Track angle ------· pedoes on a track angle of 80°. In using the If the range and the bearing to the target TERI for this solution, the following steps are 155 - 10,000, are we within effective range would be carried out: (1) Place the TERI on the maneuvering for a L.S. shot? ______An I.S. shot? ------board so that the 20 knot marker on The Captain wishes to know the course for the intermediate speed torpedo scale is an I.S. fish to be fired when the target bears at the center of the board; at the same 090° true at a range of 7360 yards. What would time, line up the scale with the target's heading ( 000 o) . Be certain that the center of the TERI is pointed in the you tell him? ------direction of the target's heading. He wishes to know the course for a high (2) Place pencil in hole designating 80° speed fish fired from doctrine effective range track angle and mark this point on the board. This point becomes M2 in the with a track angle of 90° ------ approach course. What would the doctrine effective range for (3) Lay out M1 position using a bearing and range which is still current and valid. this fish be? ------·· ( 4) Ml ... M2 will then represent the rela 91. You have a target on course 220°T- speed tive movement line for the approach 20 knots. The Captain wishes to know what course. From this point the solution is the Doctrine Effective Range and bearing to the same as that for any simple man the target would be for firing: low speed tor- euver. The user of the TERI is cautioned concerning pedoes with an 80° Track Angle, ------ the scale at which the device is laid out; for use on the small maneuvering board (HO ------; Intermediate speed torpedoes 2665a), the TERI is usually constructed at with a 290° Track Angle ______; 4,000 yards = 1 inch. It is imperative, there fore, that the Ml position be laid out on the High Speed Torpedoes with a 270° Track An- same scale. If this is not done it will obviously give a relative movement line with the wrong slope. gle ------· If the bearing and range to the target are It will be observed that the outside circle of 030-14,500 are you within Doctrine Effective the TERI gives the effective range for a low speed torpedo, the middle circle for an inter Range for a L.S. shot? ______. For an mediate speed torpedo, and the inside circle for a high speed torpedo. By reference to these circles in relation to own ship's present posi I.S. shot? ------· tion, it is possible to determine exactly when What is the course for an I.S. torpedo :fired own ship is within firing range of the target. from Doctrine Effective Range with a track Some TERI's are constructed with holes drilled for track angles to fire torpedoes from angle of 90°? ------the quarter of the target. In this case, the pro What is the course for a High Speed :fish cedure for finding the approach course is pre fired when the bearing and range to the target cisely the· same as that already outlined. 90. You have a target on course 015- speed 15 knots. The Captain wishes to know what the are 070°-6000? ------doctrine effective range and bearing to the tar 92. We are closing in on a crippled Jap cruiser get would be for firing Low Speed fish with a to make a high speed torpedo run from doctrine effective range with a 270° track angle. 270° track angle ------At time 0700 the cruiser bears 160°, range 20000. At time 0701; 160 - 19000; 0702: 160 - High Speed fish with a 290° track angle ______18000. The DRT plotting team reports the 46 C. I. C. Information CONFIDENTIAL cruiser to be on course 010° T at a speed of 15 trac~ angle. Captain wishes an approach course knots. The Captain calls down from the bridge at time 11. Own ship will use 20 knots. and asks for our approach course, the course At time 10 Able bears 118 - 17600. At time change to be made at time 0704. We are to 11 Able bears 117- 16,900. We change course to use a speed of 20 knots. This course will be ------ Ranges and bearings on Able are; 0312: At time 0703 bearing is 160, range 17000; 117.5 - 16000; 0313: 118 - 15100; 0314: 119 - 0704: 160 - 16000. At time 0704 we come to 14300; The Captain asks if we are within range the approach course. At 0705 the cruiser is at 159 - 14,900; 0706, for L.S. torpedoes ------· 158 - 13,900. The Captain asks if we are within 0315: 119 - 13500; 0316: 120 - 12,800. Cap tain says we will fire a half-salvo of L.S. fish range for a low speed torpedo. ------· when the target bears 123 if we will be within At a707 the cruiser bears 156 - 12,900. The Doctrine Effective Range. We report that the Captain wishes to know what the bearing and range will be when we get to Doctrine Effective torpedoes course should be ------· At 0317 Able bears 121 - 12000; 0318: 122.5 Range for an Intermediate Speed torpedo ______- 11500. The DRT plotters report target ap pears to be changing course to the left. The Captain says to belay firing the L.S. fish. 0319: Bearing, and range at 0708 are 154 - 11900; 124 - 10,800; 0320: 126 - 10,200. DRT plotters 0709: 153 - 10,900. Captain wishes to fire a report Able on course 195 - speed 15 knots. half-salvo of Intermediate Speed fish as soon as Captain says to close at 35 knots for a high we get to D.E.R. The course for these torpe- speed run with a 90° track angle. We will come to approach course at time 22. At time does will be: ------· 21 Able bears 128 - 9700; 0322: 130 - 9200. We At 0710 the bearing and range are 151 o - 9,900. The DRT plotters report that the target come to new approach course of ------may be swinging left. We hold fire on the tor 0323 Able is bearing 127- 8500. Combat asks pedoes. Bearing and range at time 11 are 150 bridge if we will be firing L.S. or I.S. torpe - 9000; 0712: 150 - 8,000. The target is now does while we are closing to the range for the on course 310°T at 20 knots. H.S. shot. Captain says that the track angle Captain says we will fire a half-salvo of High wouldn't be !IO good and besides there was a Speed fish as soon as we close to Doctrine Effec rather obvious reason for not firing low or in- tive Range. We will remain on present course termediate speed fish. What is this reason? ___ _ at present speed. The cruiser bears 150 - 6900 ------·------· at time 13. The BTC will be ______0324 Able bears 124 - 8000; 0325: 120 - 7 400; 0326: 116 - 7000; 0327: 112 - 6400; 0328: 107 and the time of firing will be ------· - 6000. Captain asks if we are in L.S. range · 93. Your ship has just picked up a surface con ------· Are we in I.S. range ------· tact bearing 121 - 22,000 yards. This contact Time 29 Able is at 101 - 5700. What will be is believed to be a crippled Jap cruiser which you have been ordered to finish off with tor the course for the H.S. Salvo? ______. pedoes. Your Captain asks CIC to advise him ·of target course and speed at the earliest pos How long before we fire (approx.) ? ______. sible moment. Time 0331: 086 - 5100; 0332: 079 - 5000. We At time 0307 target, which is now desig change course to 260 - speed is still 35 knots. nated as "Able", bears 120 - 20,000; at 0308 Able bears 083 - 5800 at time 0333. Captain Able is at 119 - 19,400; at 09 she bears 118.5 - wishes to know if we will be within range to 18500. The DRT plotters report Able's course fire Intermediate Speed fish when the target to be 240° - speed 15 knots. Bridge informs you on receipt of this information that we will bears 090°. ------· close to fire Intermediate Speed fish with a 90° 94. Three enemy destroyers escorting two CONFIDENTIAL C. I. C. Information 47 loaded transports have been sighted by patrol using 32 knots, change to be made at time 34. planes in the early afternoon. Your destroyer Bearing and range at 0334 are 321 o - 19,000. division has been sent to destroy them. It has been decided that the division will split into You change course to the left to ...... sections and make a coordinated torpedo at At 0335 the target is at 322° - 17,500; 0336: tack, your section attacking from the starboard 323° - 16,100. side of the enemy formation. Intermediate speed torpedoes are to be fired with a 70° track The Captain decides to fire a half-salvo of angle if possible. The division will split when I.S. torpedoes as soon as you close to Doctrine Div Dog sends the signal as to the time for Effective Range. firing torpedoes. You report to the bridge that the firing bear- At 0100 the contact was picked up by radar, ing will be ...... , range ...... , tracked and found to be on course 230°T, speed 15. At 0137 contact bears 030 ° - 22,000; 0138: with a BTC of ...... 030° - 21,500; 0139 : 030° - 21,000. Bertha (Div c:i Dog) sends the following message over TBS At 0337 the BB is at 324 o - 14,800. The Cap- C at 0139; "Daisy 2 (your section) this is Bertha. tain says he wishes to retire as quickly as pos- ~ William tack line Jig 0200, over." Your Cap sible to 18,000 yards after he has fired the ' tain acknowledges for the transmission and half-salvo of Intermediate Speed Torpedoes and C.:.. asks CIC for the approach course and speed, asks you for the retirement course. ~ change to be made at 0142. At 0140 the enemy At 0338 the target bears 325.50° - 13,400; · · formation is at 030° - 20,500; 0141: 030° - 0339: 326° - 12,100; 0340: 329° - 10,700; 0341: ~ 20,000; 0142: 030 ° - 19500. We swing left to 332° - 9,500. • ' our approach course of...... at speed At 0341.5 you swing left, fire torpedoes and ~ 0 ~ • come to a retirement course of ...... 1~ • The Captain asks what time the torpedoes-....; ~ We are at this point tracking the right hand I transport and are basing are calculations on its should reach the target. You tell him ...... ~ movement. At 0143 the target bears 031 o - ~ · 18,600. Captain asks if we are within range ························· You also add that we will be at ~ the desired 18,000 yard range at ...... for L.S. torpedoes...... 0144 target ~ ,~ 97-98. Your DD is closing in at 30 knots course ' · bears 033 ° - 17,600; 0145: 035° - 16,700; 0146: 173 °T on a crippled Jap cruiser to finish it off 037 ° - 15,900; 0147: 039 ° - 15,000; 0148: 042 ° 'N - 14,206. DRT plotters report target on course with torpedoes. Your Captain intends to fire~ ~ 240°T speed 12. Captain asks for new approach a half-salvo of high speed torpedoes from doc- • course and speed, the change to be made at trine effective range and retire as quickly as ~ ~ possible to 12,000 yards without closing the ~ time 50. At 49 the target bears 045 ° - 13,500; \:! at 0150: 049 ° - 12,700. We change course to range after he fires. At 0207 the target is bear-~ ~ - ing 225° - fc14 ,000; 0208: 226° - 23,000; 0209: ' Q ...... and speed to ...... Cap- 227° - 22,000; 0210: 228° - 21,000. DRT plotters 0.. tain asks what the firing bearing and range will report the target course as 080°T, speed 20. ~ Captain says we will fire a 290° track angle~ ~ be ...... What will the shot and will come to the approach course usintijg 30 knots at time 0212. At 0211 the cruiser is BTC be? ...... at 229° - 20,000 ;0212: 230° - 19,000. You com . 95-96. You are closing in on a crippled Jap BB right to course ...... At time 13 the cruiser~ to finish it off with a salvo of High Speed Tor half-salvo of I.S. fish when we get to doctrine pedoes which you intend to fire with a 90° effective range and then retire. You tell him track angle from Doctrine Effective Range. the firing bearing will be ...... ; BTC At 0330 the BB bears 330° - 21,500. The will be ...... and retirement course DRT plotters report her to be on course 100° - will be ...... At time 0216 the cruiser speed 16. At 0331 bearing and range are 328° bears 226 ° - 12,700. - 20,800; 0332: 326 ° - 20,200; 0333: 323.5 ° - You tell the Captain that you will reach the 19,500. firing bearing in about ...... minutes. The Captain asks for the approach course At 0217 the cruiser is at 224 ° - 11,000. 48 C. I. C. Information CONFIDENTIAL SIMPLE AIRCRAFT PROBLEMS {({(}}}} One of the simplest problems of this type (b) The vector e ... w represents the direc with which CIC personnel should be familiar is tion and speed of the wind over the that of the influence of wind on aircraft flight. earth. It is, therefore, the true wind. Before working problems of this kind, however, The e ... w vector may be easily found it will be important to know how to find the if the ship's course and speed and the true wind, given the relative wind. Simple wind direction and velocity of the apparent problems may be solved by using a vector dia wind are known. gram. Wind is always spoken of as blowing from a given direction (true or relative). A (c) If the direction and velocity of the true ship's anemometer shows the r~lative direction wind are known, as well as the ship's of wind and not the true direction. Relative course and speed, then the relative wind wind is also sometimes referred to as "appar (g ... w) is simply the resultant of the ent" wind or "wind across the deck." An illus two known forces (e ... g and e ... w). tration will serve to show how this type of problem may be solved: In plotting an aircraft's course or speed the following terms must be kept distinct: Assume the following: Your ship on course 000, speed 15. The apparent wind (from (1) True Air Speed (TAS) -the speed of the anemometer) is from 090, 20 knots. Find plane through the atmosphere. the true wind. (2) Ground Speed (GS) - the speed of the Direction & Velocity of plane over the ground. Apparent Wind (090 (5) Drift Angle - the difference in degrees between the heading and the track. 'H 0 In solving aircraft problems with the man euvering board, w representing the wind is e placed in the center of the board; e represent ing the earth is laid off from w in the direction from which the wind originates; p represents the plane. T AS is laid off from w ; GS is laid The following points should be noted: off from ef; heading is laid off from w and track from e. Thus, if the wind were from (a) The vector g ... w represents the direc tion and speed of the wind with respect 120 (T) and a plane were on heading of 270 to the ship. It is, therefore, relative (T) at a TAS of 100 knots the vector diagraf\1 wind. would• appear as foii'ows: CONFIDENTIAL C. I. C. Information 49 p TAS 100 Kts. Heading w 270 G.s.~ (136 Kts.) e ' 120 The vector w ... p equals heading and T AS. carrier situation, a vector must be added to The vector e ... p equals track and GS. account for the ship's movement. This is laid The angle WPE equals the drift angle in de off from e, in the direction of the ship's move grees, but the drift angle is actually right. ment. Thus in the above case if the flight was from a carrier making 20 knots on course 200 In operations from a moving base, the usual (T) the plot would be modiiied as follows: P Heading TAS 100 Kts. w ~ .... e "-~ s The vector s ... p gives the speed of opening and will be on 250 (T), at 20 knots from 1300 of the plane, (the relative speed) and the direc to 1500. At 1200 it orders a TBF flight over tion of relative movement. head to scout bearing 090 (T) and to return at 1500, using a TAS of 160 knots. The wind Point Option may be defined as the rendez is from 130 (T) 20 knots. vous point for a plane returning to its carrier. CIC may be of some aid to·its air group in this The ship's geographic point option can be regard. It can furnish the geographic point determined by dead reckoning the ship's pro option by dead reckoning in advance the ship's gress for the three hours. position at the time specified for the plane's return. If an aircraft's mission is purely scout By using an average guide vector (245-18 ing and no deviation from its courses and knots) the e . . . s and e . . . w vectors can be speeds is planned, CIC can give the pilot his constructed. headings out and in, time to turn and similar From · e the track direction can be extended data. In cases where the plane deviates from until it touches the TAS .circle and the point his planned courses and speeds, then the pilot marked p1 w ... p1 is the heading to use go must correct his own plot to compensate for ing out. time or distance lost. Connect s with pl. The vector s ... p1 repre Suppose the following problem: A CV is on sents the relative speed with which the plane course 200 (T) at 20 knots from 1200 to 1300 opens on the carrier. 50 C. I. C. Information CONFIDENTIAL To determine the course in, the s ... pl vector is extended in its reverse direction until it touches the 160 knot TAS circle on the opposite side of the plot. This point is marked p2. Con nect p2 with w and e. The vector w ... p2 gives the heading in and the vector e ... p2 the track in and the ground speed in. w Heading Out(095oT.) TAS (160) Track Out (090°T.) e G.S. (144) Relative Speed (Out) Time In (1 Hr. 29.5 Min.) T The time to turn may be solved graphically as follows: From p2, at any convenient angle, extend a line equal in scale to the total time. Mark its end T. Connect p1 with T. From s draw a line parallel to p1 T to the time line and mark the intersection tl. p2 ... t1 will be the measure of the time out and the time to turn. 99. With the following instrument data, fill in true wind~ Ship's Gyro Pit. Log Anemometer True Wind 270 12 315, 17 · ------,--- 000 15 090, 20 215 20 315, 25 045 15 270, 15 180 20 000, 20 100. The pilot of an F6F wishes to cruise at should the plane's heading "be? What will 160 knots, T.A.S. on course 090 (T). The be the ground speed of the plane? What wind is from 140 (T), 20 knots. What is the drift angle? heading should the F6F fly? What will be the true ground speed? Heading ------·------T.G.S. ------ Heading ------T.G.S. ------Drift Angle ------· 101. The pilot of an F6F wishes to cruise at 160 knots, T.A.S., on course 27 (T). The 103. A T.B.F. on A.S.P. wishes to make good wind is from 140 (T). What heading · a true course of 315 at 150 knots, T.A.S. should the F6F be on? What will be his The wind is from 090 (T), 22 knots. - true ground speed? What should his heading be? What will be his true ground speed? What is his Heading ------T.G.S. ------drift angle? 102. The pilot of an SB2c wishes to scout on a Heading ______·______T.G.S. ------f/&11PI~of 035, at 150 knots T.A.S. The aerologist informs the ready room that the wind is from 090 (T), 22 knots. What Drife Angle ------51 CONFIDENTIAL C. I. C. Information 104. In the Air Plot of a CV the following makes good 94 per cent of the base data has been posted: Wind from 110 course. Just before the TBF's take off, (T). Enemy airfield bears 220 (T), 200 the ready room calls your CIC for a check miles. The ready room calls and asks for of the heading the TBF's should take to a check on: True heading for TBFs at make good 320 (T) ; the heading they 160 knots T.A.S.; time out at 160 knots should use to return to the CV; the time T.A.S.; drift angle. they should turn. If there is a magnetic variation of 10 E, what magnetic head Heading. ______Time out ------ings would you have given? When would they return? Drift Angle ------True heading out ______Magnetic ------105. A TBF pilot returning from a strike wishes to reach a point bearing 050 (T), True heading in ------Magnetic ______190 miles (his D.R. position for his CV), from his present position. His data in Time to turn ______Total time out ______cludes information that the wind is from 110 (T), 20 knots and he plans to cruise 109. Your CVL is in normal daytime cruising at 160 knots. What heading should he position 1135 in T.F. 58.8. Engineering take? What will be his drift angle? condition is 31, all boilers lit off, 33 knots When will he arrive at .the carriers? available. Fleet axis is 090 (T), fleet course 090 (T), Speed 15 knots. The dis Heading ______Drift angle ------position is as follows: Guide, CV BEN NINGTON, fleet center; CVL BELLEAU Time ------WOOD (your ship), 1135; CVL PRINCE TON, 1225; BB MASSACHUSETTS, 106. The navigator of a PB4Y has his pilot 2000; BB NORTH CAROLINA, 2315; BB steer 180 (T), using 160 knots T.A.S. for WASHINGTON, 2045; CL COLUMBIA, 15 minutes and notes a drift angle of 5 2225; CL DENVER, 2135; DD FLETCH R; then 270 (T), using 160 knots T.A.S. ER, 3030; DD CONY, 3330; CL CLEVE for 15 minutes and notes a drift angle of LAND, 3270; CL MONTPELIER, 3090; 6 L. From these data what would the DD SUMNER, 3.5000; CL(AA) SAN true wind be? What heading should the JUAN, 3.5060; CL(AA) SAN DIEGO, PB4Y take to make good course 226 (T)? 3.5300; and the following screen: DD MCDONOUGH, 5.5000; DD SOMERS, True Wind ______knots. Course ______5.5340; DD STACK, 5.5020; DD STER 107. A PBM pilot having been airborne for 3 RETT, 5.5320; DD CONVERSE, 5.5040; hours on a long over-water hop on course DD DYSON, 6300; DD MAHAN, 6060; 270 (T), speed 140 knots T.A.S. decides DD BRADLEY, 6.5280; DD BATES, to check the true wind. He steers 315 (T) 6.5080; DD BENHAM, 6.5260; DD BAI for 15 minutes and his navigator deter LEY, 6.5100; DD DICKSON, 6240; DD mines that the drift angle is 6 R; then MEREDITH, 6120; DD MCCALL, 5.5220; for 15 minutes he steers 225 (T) and the DD ANDERSON, 5.5140; DD WILSON, navigator notes a drift angle of 8 R. What 5.5200; DD BAGLEY, 5.5160; and DD is the true wind? What heading should ISHERWOOD, 5.5180. The BELLEAU the plane take to make good 270 (T) ? WOOD is ordered to launch a C.A.P. of 8 VF using the BAKER method of launch Wind .. ______knots. Heading ______ing, with the following limitations: She is to open out on the starboard side of 108. A TBF scouting formation is to leave the formation and is not to drop below your CV one hour before dawn with in 180 (T) in bearing from the guide, start structions to search bearing 320 (T) for ing at 1200 and to be back on original a distance of 200 miles and then to re station by 1245, or as soon thereafter as turn to the CV. It is assumed that the possible. The wind is from 100 (T). The planes will cruise at 160 knots T.A.S. T.F.'s zig-zag plan has the following head Aerology gives you a wind from 225 (T), ings at the following times: 1200 - 1206, 22 knots. The CV is in formation on a 110 (T) ; 1206 - 1215, 080 (T) ; 1215 - base course of 100 (T), 18 knots. The 1222, 060 (T) ; 1222 - 1227, 090 (T); formation is zig-zagging on a plan that 1227 - 1235, 120 (T) ; 1235 - 1245, 085 52 C. I. C. Information CONFIDENTIAL (T). At speed 30, what courses would for the return trip. The rest of the force you suggest to the bridge to get outside meanwhile is still zig-zagging. (See the formation? problem 109 for headings.) What courses would you in CIC recommend to the From ______to ______Course bridge to get the BELLEAU WOOD back on station? Assume she passes between From ______to ______Course the same ships as on the trip out. From ______to______Course From ______to ______Course ------; 110. The CVL in problem 109 turns into the From ______to ______Course ------·-- --· ; wind when she gets outside the forma tion and at 1209 commences launching, still making 30 knots. It takes her 2 min From ...... to ... ~ - --· · ··· Course ·-·-····--·········· ; utes per plane to launch the C.A.P. She is to start the return to her original sta From ...... to ...... Course -- -- ····------·-··· ; tion in the formation as soon as she has launched the last plane, using 20 knots From ...... to ...... Course ··-···------········· Set up in Linotype and Photo-Litho&"raphed by Visual Education Department Fleet Service School• SCHOOLS AND TRAINING COMM.,ND U. S. NAVAL REPAIR BASE San Die&'O 36. California