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5000. THE PREPARATION OF CIC PROBLEMS FOR TRAINING.
In preparing CIC problems the first thing to bear in mind is the object of the problem. Each problem should be so designed that some definite object is stressed by working the problem. Once the object is decided on, the next step is to get a general outline of the problem. Decide how involved or how simple it is desired to make it. Now work out the bearings and ranges of the target relative to own ship's track. The simplest way to work this out is to set up the problem on a range keeper and record generated ranges and bearings at the times desired.
It should be borne in mind that real radar tracking carried on in CIC has two characteristics that should be included in the problems. Time intervals may vary. It is the exception than the rule when the interval is an even minute or when all the reports are made on the minute. Due to bearing errors mostly and to some extent range errors, a good track of a raid plotted from radar ranges is seldom a perfectly straight line -even though the target steers a steady course. Consequently, a more interesting problem results if the time intervals vary and the bearings and ranges are so selected that the raid's track becomes a slightly wavy line rather than an absolutely straight line. After the bearings and ranges are determined the rest of the job consists of correlating logical reports which would be associated with the plot.
The "Canned Problems" presented in the problem section illustrate the results of this reasoning. These problems were made up to bring out the fundamentals of CIC operations to CIC teams just forming. For personnel that have had considerable experience, these problems are too simple. More complex problems should be made up as the training progresses. The best aid to making a good problem is keen imagination on the part of the person making up the problem. To maintain a CIC crew in constant readiness requires constant drill. This drill must be so planned and executed that keen interest is maintained by the CIC teams.
The following remarks are quoted from DesPac's CIC Bulletin #1-44 of 17 February 1944:
"Many destroyers fail to realize the excellent training facilities aboard ship in the Rangekeepers or Computers. This is evidenced by the constant demand on the Radar Operator's School for plotting training. The desire for training is commendable, but the failure to recognize and utilize their own facilities is inexcusable. No ship should go to routine General Quarters without prosecuting some form of training. Attention is directed to part VI of Pac 10 (USF 10A also) which states in part that all members of CIC teams will be trained to utmost perfection. Commanding Officers will initiate immediate steps to comply with directive.
Very realistic conduct of a torpedo (or any other) duel can be simulated by stationing one officer in 'plot' to conduct the enemy tactics while CIC and Conn maneuver own ship. In such an arrangement it is only necessary to have phones between the surface plotting team and the computer. The JX is a suggested circuit. The complete torpedo control problem can be very realistically simulated by such an arrangement. This drill has the added advantage of being able to accurately determine the outcome of the duel. And too, torpedo director, radar, DRT, and IC casualties can easily be run into the problem. Such training is invaluable and must be used to the fullest
--68--
extent. The results of CIC tracking exercises in the Hawaiian Area leave much to be desired. It showed the perfectly obvious to all concerned that the best equipped CIC in the fleet "is no better than its ability to obtain a correct solution. With this in mind, Commanding Officers should constantly check the plotting ability of their CIC teams by means of generated ranges and bearings. Any failure to obtain a reasonably accurate solution should require immediate investigation."
The above remarks can be made applicable to any ship.
--69--
APPENDIX A
PROBLEMS
--A-1--
DRILL PROBLEMS.
Finding speed, time or distance when two of these values are given and the third unknown:
D = S × T, or S = D/T, or T = D/S.
D = Distance traveled, expressed in miles or yards. S Speed or rate of travel, expressed in knots. T Time of travel, expressed in hours or minutes.
Example:
If S = 15 knots, T = 2 hours, then D will equal 30 miles or 60, 000 yards. And if D = 52 miles and T = 2 hours, then S will equal 16 knots.
Find the missing part below:
SPEED TIME DISTANCE 1. 15 knots 8 hours ? 2. ? 4 hours 17 miles 3. 30 knots ? 20 miles 4. 7 knots ? 26 miles 5. 22 knots 30 minutes ? yards 6. ? 45 minutes 15 miles 7. 22 knots ? 1000 yards 8. ? 3 minutes 1500 yards 9. 19 knots ? 1900 yards 10. 13 knots 6 minutes ? yards 1° = 60'
1' = 60"
° = degree of arc
' = minute of arc
" = second of arc1. Add: 125°30' 25" to 23° 54' 56"
2. Add: 35°42' 15" to 330° 19* 15"
3. Add: 22°59' 59" to 68° 25' 32"
4. Subtract:85° 15' 23" from 135° 46' 56"
5. Subtract:108° 34' 14" from 22° 32' 10"
6. Subtract:122° 23' 24" from 15° 26' 28"
7. Subtract: 99° 45' 20" from 1° 2' 26"
8. Add: 102° 14' 15" to 32° 14' 15"
9. Add: 82°59' 22" to 270° 19' 52"
10. Subtract: 85° 11' 21" from 270° 18' 19"
DEAD RECKONING.
Initial point "A", time 1400, make a DR plot of the movements of the
--A-2--
ship if she was maneuvered as follows: 1400 ship on course 091°(T) , speed 10 knots; 14150 changes course to 039°. She steams for 8 miles on course 039° then changes course to 120°(T) and steams at 30 knots until 1630.
Find:
- Distance traveled from 1400 to 1430.
- Time ship changed course to 120°.
- Total distance traveled.
- Range and hearing of final position with respect to initial position.
Initial point "A" time 0900, ship on course 270° (T) , speed 15 knots. Make a DR plot of the movement of the ship as follows:
0930 change speed to 30 knots.
0954 change course to 120°(T).
1030 change course to 060°(T).
1045 change speed to 10 knots.
1100 end of track.Find from plot the total distance traveled and range and true bearing of 1100 position from 0900 position.
Initial point "A" time 0954, ship on course 090°(T) , speed 10 knots. Make a DR plot of the movement of the ship as follows:
0956 change course to 096°(T).
0959 change speed to 15 knots
1007 change course to 080°(T)
1012 change course to 075°(T)
1018 change speed to 12 knots
1027 change course to 090°(T)
1032 change course to 098°(T)
1037 change speed to 10 knots
1054 End of problem.Find from plot the total distance traveled and course and speed made good from initial point "A".
Make a DR plot of a ship starting from point "A" at time 1600 and underway on the following course and speeds:
1600 course 240° speed 12 knots.
1612 change course to 270°(T) speed to 6 knots.
1615 change speed to 10 knots.
1620 change course to 060°(T).
1636 increase speed to 15 knots.
1642 change course to 115° (T) speed to 10 knots.
1650 change course to 090°(T).
1700 End of problem at point "B".
--A-3--
Find from plot the total distance traveled, and the bearing and range of "B" and "A".
Make a DR plot of a ship starting from point "A" at time 0600 and underway on the following courses and speeds:
0600 course 200°(T) speed 18 knots.
0608 change course to 320°(T).
0618 change course to 080°(T) speed to 10 knots.
0630 change course to 150°(T).
0640 change speed to 5 knots; course to 000°(T).
0655 change course to 345 (T).
0710 End of problem at point "B".Find the total distance traveled, and bearing and range of "B" and "A".
Make a DR plot of a ship starting from point "A" at time 1000 and underway on the following courses and speeds:
1000 Course 350°(T), speed 20 knots'.
1007 Change course to 093°(T).
1011 Change speed to 15 knots.
1015 Change course to 244°(T), speed to 21 knots.
1021 Change course to 154°(T).
1028 Change course to 270°(T), speed to 12 knots.
1040 Change course to 005°(T).
1045 What course will have to be taken at this time to return to point "A", and at 12 knots, how long will it take?Make a DR plot of a ship starting from point "A" at time 1800 and underway on the following courses and speeds:
2330 Course 040°(T), speed 18 knots.
2342 Course 272°(T), speed 15 knots.
2352 Course 118° (T), speed 15 knots.
2400 Change speed to 12 knots.
0010 Course 185° (T).
0015 Course 255°(T), speed 15 knots.
0033 Course 345°(T), speed 18 knots.
0045 End of problem at point "B".What is the bearing and range of "B" from "A"? At what time after 2350 was the ship closest to point "A"?
Plot the following zigzag plan on a base course of 040°(T), speed of ship 18 knots.
Base Course for 4 minutes:
20° left of base course for 6 minutes.
10° left of base course for 5 minutes.
30° right of base course for 4 minutes.
--A-4--
Base course for 4 minutes:
10° right of base course for 5 minutes.
30° left of base course for 4 minutes.Base course for 6 minutes:,
20° right of base course for 6 minutes.
Find the speed made good.Plot the following zigzag plan on a base course of 300°(T), speed of ship 15 knots:
10° right of base course for 6 minutes.
Base course for 5 minutes.
25° left of base course for 6 minutes.
15° left of base course for 5 minutes.Base course for 4 minutes.
15° right of base course for 5 minutes.
10° left of base course for 6 minutes.
25° right of base course for 6 minutes.
Find the speed made good.
SURFACE PLOTTING PROBLEMS.
For use on both DRT and polar coordinate plots. Plot and find courses and speeds of the raids. On summary surface plot, note how changes of course of own ship or of raid affect the plot.
Problem 1.
Own ship's initial course and speed: 015°(T), 15 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Able 002 9100 10 Able 140 1720 01 " 005 8160 11 " 160 2600 02 " 007 7220 12 " 172 3620 03 " 012 6360 122 (Own ship changes course to 320°(T)). 04 " 017 5500 13 Able 172 4700 05 " 024 4660 14 " 172 5800 06 " 033 3960 15 " 172 6860 07 " 042 2880 16 " 172 7940 08 " 058 1920 17 " 173 9100 09 " 096 1400 18 " 172 10240
--A-5--
Problem 2.
Own ship's initial course and speed: 100°(T), 18 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Baker 048 4900 082 (Own ship's speed to 21 kts.) 01 " 046 4660 09 Baker 039 2780 02 " 045 4400 10 " 036 2500 03 " 044 4180 11 " 034 2280 04 " 043 3920 12 " 028 1980 05 " 040 3700 13 " 024 1740 06 " 040 3500 14 " 016 1500 07 " 040 3320 15 " 008 1280 08 " 040 3120 16 " 355 1160 Problem 3.
Own ship's initial course and speed: 220°(T) 20 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Charlie 272 9160 09 Charlie 308 3420 01 " 274 8460 10 " 325 3140 02 " 275 7800 11 " 342 3100 03 " 278 7240 12 ii. 000 3380 04 " 280 6600 122 (Own ship's course to 200°(T)). 042 (Own ship's course to 230°(T)). 13 Charlie 008 3680 14 " 015 4400 05 Charlie 283 5900 15 " 018 5180 06 " 286 5220 16 " 024 6000 07 " 290 4660 17 ii. 025 6680 08 " 295 4000 Problem 4.
Own ship's initial course and speed: 150° (T) 18 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Dog 282 4040 10 Dog 208 1600 01 " 280 3720 102 (Own ship come to course 180° (T) 20 knots.) 02 " 280 3440 03 " 278 3160 11 Dog 186 1440 04 " 275 2840 12 " 165 1460 05 " 272 2560 13 " 148 1640 052 (Own ship slow to 10 kts.) 14 " 135 1900 06 Dog 270 2300 15 " 124 2360 07 " 258 1900 16 " 102 2820 08 " 245 1640 17 " 090 3600 09 " 225 1600 18 " 082 1180 19 " 075 5400 --A-6--
Problem. 5.
Own ship's initial course and speed: 080°(T) 12 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Easy 058 19,000 092 Easy 045 11,220 003 " 056 18,400 103 " 042 10,640 013 " 051 17,600 113 " 040 10,000 021 " 055 17,200 122 " 034 9,160 03 " 051 16,600 13 " 032 8,840 041 " 052 15,600 132 (Own ship 's course to 080° (T.) 05 " 052 15,000 053 " 050 14,200 14 Easy 026 8,520 071 " 048 13,000 152 " 018 8,180 072 (Own ship 's course to 065°(T)). 161 " 014 8,000 081 Easy 048 12,800 17 " 010 8,000 09 " 045 12,000 Problem 6.
(2 targets). Own ship's initial course and speed, 015°(T) 15 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Fox 204 3720 01 " 203 3600 02 " 204 3500 03 " 203 3420 04 " 202 3320 05 " 202 3200 052 Item 348 3300 06 " 202 3120 062 " 344 2880 07 " 200 3020 072 338 2500 08 " 200 3520 082 " 330 2200 09 " 200 4000 092 " 320 1820 10 " 200 4480 102 Cease 305 tracking 1600 (101 Own ship changes course to 320°(T)). 11 Fox 192 4820 12 " 188 5140 13 182 5200 14 " 178 5260 142 Item 175 1500 15 " 172 5400 16 166 5560 17 " 162 5800 18 " 158 6040 182 " 155 3300 19 " 155 6320 20 150 6580 --A-7--
Problem 7.
(2 targets). Own ship's course 060°(T), 12 knots.
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 George 150 8000 002 King 031 7000 01 " 150 8020 012 " 034 6780 02 " 150 8080 022 " 036 6500 03 " 150 8000 032 " 040 6320 04 " 150 8040 042 " 042 6120 05 " 150 7980 052 Hi 045 5680 06 " 150 8000 062 " 048 5300 07 " 150 8000 071 " 051 4900 (072 Own ship 's course change to 108°(T)). 08 George 150 7800 082 King 056 4240 09 " 148 7360 092 " 056 3700 10 " 150 6940 102 " 054 3220 11 " 152 6520 112 " 055 2700 12 " 150 6200 122 " 056 2220 13 " 150 5660 132 " 055 1650 14 " 152 5240 142 " 055 1300 (143 Own ship 's course change to 060°(T)). 15 George 152 5000 152 King 072 840 16 " 150 5020 162 " 110 600 17 " 150 4980 172 " 156 720 18 " 152 5000 182 " 180 1080 19 " 150 5000 192 " 188 1560 Problem 8.
(3 targets.) Own ship's course and speed 030°(T). 15 knots.
TIME RAID BEAR. RANGE TIME RAID BEAR. RANGE TIME RAID BEAR. RANGE 00 Item 315 22,300 01 " 314 21,700 012 Jig 202 21,400 02 " 312 20,800 022 " 205 17,000 03 " 310 20,100 032 " 210 13,000 04 " 310 19,200 042 " 222 9,100 05 " 308 18,600 052 " 245 5,800 06 " 307 18,000 062 " 291 5,000 07 " 302 17,500 072 " 326 7,500 08 " 300 17,200 082 " 342 11,200 Cease tracking (082 Own ship change course and speed to 180°(T) 18 knots.) 09 Item 300 17,100 10 " 298 17,200 11 " 298 17,100 113 King 136 11,000 12 " 298 17,000 123 " 132 10,800 --A-8--
Problem 8. (Cont'd)
TIME RAID BEAR. RANGE TIME RAID BEAR. RANGE TIME RAID BEAR. RANGE 13 Item 300 16,800 133 King 130 11,000 14 " 302 16,600 143 " 125 11,300 15 " 304 16,300 153 " 122 11,300 16 " 305 16,000 163 " 116 11,500 17 " 306 15,900 Cease tracking 18 " 308 15,500 19 " 310 15,400 20 " 312 15,100 5140. RELATIVE: MOVEMENT AND MANEUVERING BOARD PROBLEMS.
5141. Given the following courses and speeds for own ship with the target's relative movement, find the course and speed of the target for each of the following:
Problem 1. O.S.C. 060°(T), speed 15 knots. Time 1121.
Target bears 010°(T) 7600 yards. Time 1127.
Target bears 024°(T) 6500 yards.Problem 2. O.S.C. 035°(T), speed 9 knots. Time 0335.
Target bears 045°(T) 7650 yards. Time 0340.
Target bears 062°(T) 5100 yards.Problem 3. O.S.C. 287°(t), speed 20 knots. Time 1400.
Target bears 260°(T) 17, 600 yards. Time 1404.
Target bears 270°(T) 15, 200 yards.Problem.4. O.S.C. 020°(T), speed 17 knots. Time 0910.
Target bears 040° (T-) 19, 000 yards. Time 0915.
Target bears 054° (T) 16, 300 yards.Problem 5. O.S.C. 025°(T), speed 15 knots. Time 0445.
Target bears 012° (T) 9100 yards. Time 0448.
Target bears 022°(T) 6360 yards.Problem 6. O.S.C. 330°(T), speed 15 knots. Time 12152.
Target bears 182° 7700 -yards. Time 1218.
Target bears 182° 10, 240 yards.Problem 7. O.S.C. 090°(T), speed 18 knots. Time 1120.
Target bears 038° (T) 4900 yards. Time 1124^.
Target bears 032°(T), 3800 yards.Problem 8. O.S.C. 075°(T), 12 knots. Time 1300.
Target bears 053°(T), 19,000 yards. Time 1304.
Target bears 047°(T), 15,600 yards.Problem 9. O.S.C. 255°(T). speed 20 knots. Time 10212.
Target bears 323°(T), 8,520 yards. Time 1025.
Target bears 343°(T), 10,000 yards.Problem 10. O.S.C. 170° (T). speed 18 knots. Timp 1609.
Target bears 290°(T), 17,100 yards. Time 1614.
Target bears 292°(T), 16,600 yards.--A-9--
5142. Given the course of the guide (GC) and the speed of the guide (GS), and own ship's course (OSC), find the necessary speed for executing each of the following maneuvers and the time required.
Problem 1. GC = 15 knots. Own ship must move from 12, 000 yards on the starboard bow to 6, 000 yards on the starboard beam of guide. O.S.C. = 000°(T). Find speed and time. Problem 2, GC = 130° (T), GS = 25 knots. Own ship must move" from 6, 000 yards dead ahead'of guide to 5, 000 yards on port beam, using a true course at right angles to guide's course. Find speed and time. Problem 3. GC = 130°(T), GS = 25 knots. Own ship must move from 5, 000 yards on port beam to 3, 000 yards dead astern of guide. OSC = 180°(T). Find speed and time. Problem 4. GC = 130°(T), GS = 25 knots. Own ship must go from 3, 000 yards astern to 5, 000 yards on starboard beam of guide. OSC = 140°(T). Find speed and time. Problem 5. GC = 130°(T), GS = 25 knots. Own ship must move from 5, 000 yards on starboard beam to 6, 000 yards dead ahead of guide, using course of 120°(T). Find speed and time. Find the total time that was necessary for the maneuvering ship to circle the guide, on the courses and speeds in problems 2-5. Problem 6, GC = 328°(T), GS = 18 knots. Own ship must go from 14, 000 yards on the Dort bow to 14, 000 yards on the starboard beam. OSC = 030° (T). Find speed and time. Problem 7. GC = 265° (T), GS = 16 knots. Own ship must move from a position bearing 060° relative from the guide, 9, 000 yards, to a position bearing 120° relative from the guide, 4, 000 yards. OSC = 140°(T). Find speed and time. Problem 8. GC = 180°(T), GS = 10 knots. Own ship must move from 7, 000 yards 180° (R) to 2, 000 yards 330°(R) from the guide. OSC = 178° (T). Find speed and time. Problem 9. GC = 184°(T), GS = 25 knots. Own ship must move from 030°(R), 10, 400 yards from the guide, to 261°(T), 12, 700 yards, from the guide. OSC = 250°(T). Find the speed and time. Problem 10. GC = 122° (T), GS = 20 knots. Own ship must move from guide's starboard bow, 8, 200 yards, to a position alongside the guide. OSC = 090°(T). Find the speed and time. 5143. Given the course of the guide (GC), the speed of the guide (GS), and own ship's speed (OSS), find the course or courses for executing the following maneuvers, and the times required.
Problem 1. GC = 300°(T), GS = 18 knots. Own ship must go from 270°(T), 10 miles, from the guide to 7 miles on the port quarter of the guide at a speed of 20 knots. Find the course and time required. --A-10--
Problem 2. GC = 280°(T), GS = 25 knots. Own ship is dead ahead of guide, 12, 400 yards, and is ordered to go to a position 8, 000 yards on the guide's starboard beam, using a speed of 15 knots. Find the two possible courses and the time required for each. Problem 3. GC = 095°(T), GS = 22 knots. Own ship must go from 350°(R) at 15, 000 yards to 315°(R) at 7, 500 yards from the guide, using a speed of 12 knots. Find the two courses possible and the time required for each. Problem 4. GC = 045°(T), GS = 20 knots. Own ship must move from 315°(T), 7, 300 yards, to 220°(T), 7, 000 yards, at a speed of 15 knots. Find the course and the time required. Problem 5. GC = 240°(T), GS = 12 knots. Own ship must move from five miles on the starboard bow of guide to one mile on the starboard beam at the slowest possible speed. Find the course and the time required. Problem 6. GC = 240°(T), GS = 12 knots. Own ship must move from five miles on the starboard bow of the guide to one mile on the starboard beam in the shortest possible time, using 10 knots. Find the course and the time required. Problem 7. GC = 160° (T), GS = 20 knots. Own ship must go from 000°(T), 8, 000 yards, to 270°(T), 4, 000 yards from the guide, using a speed of 25 knots. Find the course and the time required. Problem 8. GC = 340°(T), GS = 18 knots. Own ship must go from 090° (R), 8, 500, to 180°(R), 6, 000 yards, from the guide, using a speed of 18 knots. Find the course and the time required. Problem 9. GC = 020°(T), GS = 16 knots. Own ship must zigzag at a speed of 20 knots, always staying on the port beam of the guide. What courses must it use, and how fast will it be opening or closing the range from the guide? Problem 10. GC = 115°(T), GS = 22 knots. Own ship must go from dead ahead of guide, 4 miles, to the port beam of the guide, 4 miles, using 18 knots. Find the course that will complete the maneuver in the longest time and the time required. 5144. Given the course of the guide (GC), the speed of the guide (GS), and the time in which the maneuver must be completed, find the courses and speeds necessary to-execute the following maneuvers.
Problem 1. GC = 210°(T), GS = 15 knots. Own ship must move from dead ahead of guide, 7, 000 yards, to 060°(R), 7, 000 yards, in ten minutes. Find the course and speed. Problem 2. GC = 315°(T), GS = 18 knots. Own ship must move from 285°(T), 19, 000 yards, to 180°(T), 14, 000 yards, from guide is twenty minutes. Find course and speed. --A-11--
Problem 3. GC = 145°(T), GS = 29 knots. Own ship must move from 10 miles on the port beam to one mile on the port beam of the guide in one hour. Find course and speed. Problem 4. GC = 110°(T), GS = 10 knots. Own ship is on guide's port bow at 4,000 yards, and must go alongside of guide in twenty minutes. Find course and speed. Problem 5. GC = 050°(T), GS = 22 knots. Own ship must go from dead astern, 5,500 yards, to 270°(R), 5,000 yards, from guide 35 minutes. Find the course and speed. Problem 6. GC = 005°(T), GS = 25 knots. Own ship must move from 040°(R), five miles, to 080°(R), six miles in 12 minutes. Find the course and speed required. Problem 7. GC =, 225°(T), GS = 12 knots. Own ship must move from 020°(T), 7,000 yards, to 160°(T), 4,000 yards from guide in twenty minutes. Find the course and speed required. Problem 8. GC = 000°(T), GS = 25 knots. Own ship must go from dead ahead of guide, 12,500 yards, to starboard beam, 8,000 yards, in fifteen minutes. Find the course and speed required. Problem 9. GC = 185°(T), GS = 16 knots. Own ship must move from 180° (T), 4½ miles, to 140° (T), 4 miles, from the guide in ten minutes. Find the required course and speed. Problem 10. GC = 295°(T), GS = 22 knots. Own ship must move from 350°(R), 7 miles, to 315° (R), 3½ miles, in ten minutes. Find the course and speed. 5145. Determining How Close a Contact Will Pass.
Problem 1. Own ship on 090°, 25 knots. Contact tracked on 120°, 30 knots. Present radar bearing and range is 350, 18, 000 yards. How close will contact pass to your ship? In how many minutes? Problem 2. Own ship on 355°, 21 knots. Contact track on 180°, 18 knots. Present radar bearing and range is 020°, 28, 000 yards. How close will contact pass to your ship, in how many minutes, and at what bearing? Problem 3. Contact on 291°, 28 knots. Present range and bearing of contact from you is 130° -- 10, 000 yards. Own ship on 290°, 20 knots. How close will contact pass to you, in how many-minutes, at what bearing? Problem 4. Own ship on 148°, 14 knots. Contact tracked on 190°, 8 knots. Present range and bearing is 190°, 22, 000 yards. Will contact come any closer to your ship? Problem 5. Own ship on 185°, 21 knots. Friendly ship on 060°, 15 knots. Present range and bearing 200°; 8, 000. How close will friendly ship pass to your own? What relative bearing will he be closest? --A-12--
Problem 6. Own ship on 350°, 18 knots. Friendly ship on 325°, 14 knots. Present position of friendly is 080°, 10, 000 yards. How close will friendly ship pass to own ship, what.relative bearing, and at what time? Problem 7. Contact tracked on 180°, 16 knots. Own ship on 090°, 12 knots. Present range and bearing is 042°, 20, 000 yards. How close will target pass to you and in how many minutes? 5146. Torpedo Attack Problems.
Problem 1. Own ship's initial course = 040°(T), speed = 32 knots. Target bears 020° (T), 19, 000 yards, at 2224. Target's course and speed = 120° (T), 18 knots. Execute collision course at 2227. Fire as soon as target is within range of high speed torpedo (46 knots, run of 6, 000 yards). Problem 2. Own ship's speed = 16 knots. Target's course and speed = 060° (T), 10 knots. Target will bear 210°(T), 16, 200 yards, at 0645, when own ship will execute approach course. We want to fire on a target angle of 300°(T), with intermediate speed torpedo (33 knots, range of 9200 yards), near limit of torpedo range. Find: Approach course for own ship, time of firing, torpedo course, expected time of hitting. Problem 3. Own ship's Speed = 30 knots. Target's course and speed = 270°(T), 30 knots. Target will bear 110°(T), 20, 000 yards, at 0210. Own ship will go on a collision course at 0210, until a course of 090°(T) will put own ship bearing 330° (T), 5, 000 yards, from target, the firing point. Find: Collision course, time of executing course of 090°(T), time of firing, torpedo course using high speed torpedo (46 knots). Problem 4. Own ship's speed = 25 knots. Target's course and speed = 010, 20 knots. Target will bear 140°(T), 18, 600 yards, at 0415, when own ship will execute approach course. Own ship will fire when target angle is 310°, range to target = 5, 000 yards, using high speed torpedo (46 knots, range at 6, 000 yards). Limits of the tube train: 260° and 280° (R). No gyro angle for torpedoes, (i.e. firing course must be nearly at right angles to torpedo course). Own ship must be on firing course 2 minutes before firing. Find: Approach course, firing course, time of executing firing course, time of firing, torpedo course, time of hitting. 5147. Approach, BTC, Retirement Courses and "Cross The T" Course
Start near bottom in the middle of your plotting sheet. Scale 2000 yds/in. DR own task force on C000 S15.
1700 few strangers 098 21500 01 098 21200 The raid has been designated Raid "Easy"' 02 099 20900 03 099 20600 Raid "Easy" consists of 3CA and 4 DD 04 099 20300 05 100 20000 Should have a good course and speed on target --A-13--
Figure on the maneuvering board your course to cross the target's T at 12000 yards using a speed of 25kt. Turn to that course at time 1705/ (030)
06 101 19400 07 102½ 18700 Find an approach course for the DD's in your formation to get to 60° 5000 yards on the target's bow using 30kts. Draw in that course line lightly. (C097)
08 104½ 18100 FR 144 1000 09 106 17500 10 108 16800 FR 145 3000 11 110 16300 12 112 15700 FR 145 5200 13 114 15100 14 116 14700 FR 145 7200 15 119 14100 16 122 13700 FR 145½ 9200 17 125 13200 At time 17 find the BTC for your friendly DD's to fire 45kt torpedoes. (BTC 064) Find the retirement course they should take to 15000 yards in minimum time using 30kt. (C203) Draw that retirement course in lightly.
18 128 12800 FR 154 11300 19 131 12500 FR 20 135 12000 FR 166 13800 21 138 12000 22 142 11800 FR 174 16800 At time 22 all enemy ships are disposed of. The friendly DD's (what's left of them) will rendezvous at a point "X ray" which now bears 296 22000 from the DD and 249 19500 from the heavy units of your task force. What speed must the DD's make to reach point "X ray" simultaneously if the heavy units travel at 25kt? (S 28.2) Time of rendezvous? (1745.6)
5148. Approach, BTC, Retirement Courses.
Start below and to the left of the center of your plotting sheet. Scale 2000 yds/in. DR your own ship, a DD, on C 027 S 20 for 6 or 8 minutes.
00 Screen clear 01 Few strangers 006 15900 02 007½ 15200 The raid has been designated Raid "Able" 03 009 14700 Lookout reports raid consists of 2 CL's 04 010½ 14100 05 012 13500 06 014 13000 At time 06 you are ordered to make an approach using 30 kts to 60° 5000 yds on Raid "Abie's" bow. Determine your approach course and DR your ship for 12 minutes on that course. (C 065)
--A-14--
07 013½ 12400 The lookout reports that the enemy has O. F. 08 012½ 11900 09 011½ 11400 10 010½ 10900 Lookout reports an enemy change of course 11 011 10000 Own main battery opens fire 12 011 9000 13 011 8100 Lookout reports one enemy CL burning 14 011 7200 15 011½ 6250 Lookout reports one enemy CL sunk 16 012 5350 You are hit by enemy gunfire Fire 45 kt torpedoes. Find the BTC. (BTC 046) Find the retirement course to 20000 yards using speed 30. DR own ship on retirement course for 5 min. (C 270)
17 030i 5500 Time to expect torpedo hits (19.3) 18 047 6200 19 060 7400 20 Screen clear Raid "Able" 00-10 C 094 S 18 10-20 C 123 S 27 5149. Torpedo Approach, Base Torpedo, and Retirement Course s Using The Relative Plot Method.
1. Target course and speed has been determined from the DRT as C060 S20. Ranges and bearings on the target develop as follows:
30 020 9700 31 013 9300 32 006 9000 At time 32 find course to approach to 5000 yds 60° on the target's nearest bow using 30kt. (C053)
33 003 8300 34 359 7700 35 356 7200 From your torpedo effective range device you find you are now in intermediate speed range (torpedo speed 33kt). What BTC would you fire on to secure hits? (BTC 028)
36 351½ 6800 37 347 6200 38 342 5000 39 336½ 5500 From the effective range device you are still in intermediate torpedo speed range. What BTC should you use to secure hits? (BTC 013-014)
40 328 5250 41 322 5200 42 315 5000 43 308 5000 You are now within high speed torpedo range (45kt). What BTC should be used? (BTC 332-333)
What course to retire in minimum time to 9000 yards using 30kt? (C 164-165)
--A-15--
2. Target course and speed from the DRT is C300 S 24.
00 209 18000 01 206 17200 02 202 16500 Find approach course to 5000 yds 50° on target's bow using a speed of 30kt. (C268)
03 201½ 15800 04 201 15100 05 200½ 14500 06 200 13700 From the torpedo effective range device you have come into low speed torpedo range (torpedo speed). Find the BTC if you were hit by enemy gunfire to get rid of them. (BTC 261)
07 199 13000 08 198 12300 09 197½ 11500 10 197 11000 11 196 10200 You are now in intermediate speed range. BTC if torpedoes were fired now? (3TC 240)
12 194½ 9400 13 193 8600 14 192 7800 15 190 7200 What BTC would you fire intermediate speed torpedoes? (33kt) (BTC 233)
16 187 6500 17 185 5700 18 180 5000 Fire high speed torpedoes now that you have reached the desired tiring point. BTC? (BTC 208)
What course to retire in minimum time to 15000 yards using 30kt? (C076) 3. Target course and speed as determined from the DRT is C140 S18.
20 355 18200 21 000 18000 22 005 17800 What course would you take to approach to 5000 yds 60"° on the target's bow using 30kt? (C022)
23 006 16600 24 006 15200 25 007 14000 From the torpedo effective range device you are now in low speed tor-pedo^range (torpedo speed 27kt). What BTC should you. fire your torpedoes on? (BTC 036)
26 007 12700 27 008 11400 28 009 10300 You have now come into intermediate speed range (33kt). What BTC to fire torpedoes? (BTC 033)
29 012 9100 30 013 7600 You are still in intermediate speed range, what BTC would you fire on now? (BTC 038) Assuming that you will be in high speed range (45kt) at time 32, what will the BTC be at that time? (BTC 040)
31 016 6200 32 020 5000 --A-16--
Figure a BTC from this 32 position. Does it check with the one obtained by DR-ing your position ahead? What is the retirement course to open the range to 20000 yards in minimum time using 30kt? (C281)
5200. CIC DRILL PROBIEMS.
5201. The object of the following problem is to:
Exercise personnel in plotting radar contacts.
Exercise personnel in proper sound powered procedure.
To give CIC simple problems to solve on a maneuvering board.
To train CIC personnel to coordinate lookout reports with radar reports.
5210. Drill Problem No. 1.
The tactical situation: You are approaching Casablanca. Friendly contacts are expected. Visibility ten miles. The following sound powered phone circuits are manned: Evaluator's circuits, Surface search radar circuit, Lookout circuit. Own ship's course 090, speed 30 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure A.
Figure A--A-17--
PROBLEM NO. 1.
01 Conn- Combat: Raid "A" bearing 154 range 11.800 022 Conn- Combat: Ship reported by lookouts is Raid "A" bearing 1564 range 10200 04 Conn- Combat: Raid "A" identified by lookouts as USS Brooklyn is on collision course 042 speed 30 12 Conn- Combat: USS Brooklyn is changing course to port, will pass well astern of us 13 Conn-Combat: USS Brooklyn on course 334 speed 30 19 Conn- Combat: USS Brooklyn is changing course to starboard. 21 Conn- Combat: USS Brooklyn on course 070 speed 30 Lookout Circuit:
02 Conn- Surface lookout forward: Ship on horizon at relative bearing 062 03 Conn- Surface lookout forward: Ship relative bearing 060 is USS Brooklyn 18 Conn- Surface lookout aft: USS Brooklyn disappearing relative bearing 206 Surface Search Radar Circuit:
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 A 154 11800 15 A 284 4100 01 " 154 11000 16 " 290 5700 02 " 154 10200 17 292 7400 03 " 153 9350 18 " 294 9100 04 " 153 8600 19 " 295 10100 05 " 153 7700 20 " 297 10300 061 " 152 6600 21 " 298 10500 07 " 152 6100 22 " 300 10700 08 " 151 5300 23 " 301 11000 09 " 151 4500 24 " 302 11200 10 " 150 3800 25 " 304 11450 11 " 147 2900 262 " 305 11800 12 " 169 1600 27 " 306 11900 132 " 256 1800 28 " 307 12200 14 " 273 2500 29 " 308 12500 30 " 309 12800 PROBLEM NO. 2.
The Tactical Situation:
You are a single ship operating in Chesapeake Bay. Tt is important to keep a careful track of any other ship picked up by radar. The visibility is now 6 miles, but we are expecting fog to set in. There are two cruisers reported to be making firing runs in this general area. The following sound powered phone circuits are manned: Evaluator' circuit, Surface search radar circuit, Lookout circuit. Own ship's course 065, speed 20 knots. Suggested plotting scale 1000 yards = 1 inch This problem will develop as illustrated in Figure B.
--A-18--
Figure BEvaluator's Circuit:
01 Conn- Combat: Raid "A" true bearing 027 range 16500 04 Conn- Combat: Raid "A" course 180 speed 30 05 Conn- Combat: Smoke on horizon reported by lookouts is evidently Raid "A"' 06 Conn- Combat: Lookouts have sighted Raid "A" 06½ Conn- Combat: Raid "A" has changed course to the right to 210 speed still 30 07 Conn- Combat: Lookouts have identified Raid "A" as the Mobile. 15 Combat- Conn: Range and bearing on the Mobile? 15½ Combat- Conn: Mobile true bearing 248 range 7500 22 Conn- Combat: Mobile has changed course to the left to speed still 30 26 Conn- Combat: Ship sighted by lookouts is the Mobile, bearing 219, range 11800 30 END OF PROBLEM. --A-19--
PROBLEM NO. 2 (cont).
Surface Search Radar Circuit;
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 A 027 16500 16 A 244 9000 01 " 027 15100 17 " 241 10500 022 " 027 13000 182 " 238 12800 03 " 027 12200 19 " 237 13600 04 " 027 10750 20 " 236 14700 05 " 028 9500 21 " 233 14200 06 " 023 8000 22 " 231 13550 07 " 018 6550 23 " 227 12900 08 " 010 5200 24 " 223 12300 091 " 350 3800 25 " 219 11800 10 " 334 3200 262 " 212 11100 11 " 305 3050 27 " 210 10950 12 " 279 3650 28 " 205 10650 13 " 264 4750 29 " 200 10400 14 " 254 6100 30 " 194 10300 15 " 248 7500 PROBLEM NO. 3.
The Tactical Situation:
You have just left Norfolk. Friendly contacts are expected. The visibility is four miles. The following sound powered phone circuits are manned: Evaluator's circuit, Lookout circuit, Surface search radar circuit. Own ship's course 040 speed 20 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure C.
Figure C--A-20--
PROBLEM NO. 3 (cont).
Evaluator's Circuit:
002 Conn- Combat: Raid "A" at true bearing 311 range 10500 022 Conn- Combat: Ship reported by lookouts is Raid "A" 03 Conn- Combat: Raid "B" at true bearing 120 range 4750 042 Conn- Combat: Raid "A" identified by lookouts as USS Terror is on course 340 speed 15. She will pass astern of us. 07 Conn- Combat: Raid "B" on collision course 090 30 knots. 082 Conn- Combat: Cruiser reported by lookouts is Raid "B". We do not have the sailboat by radar. 102 Conn- Combat: Raid "B" identified by lookouts as USS Mobile is still on collision course. We will collide in four minutes if we don't change our course. 11 Combat- Conn: Coming right to 085 12 Combat- Conn: Steady on 085 14 Conn- Combat: On present course the Mobile should pass clear of us by one half a mile. 22 Conn- Combat: Mobile appears to be changing course to port 24 Conn- Combat: Mobile is on course 000 speed 30 Lookout Circuit:
02 Conn- Surface lookouts forward: Ship on relative bearing 075 is USS Terror 04 Conn- Surface lookouts forward: Ship on relative bearing 084 07 Conn- Surface lookouts forward: Sailboat 180 R 08 Conn- Surface lookouts forward: American cruiser bearing 265 10 Conn- Surface lookouts forward: is USS Mobile Ship on relative bearing 270 15 Conn- Surface lookouts aft: Have lost sight of USS Terror 26 Conn- Surface lookouts aft: Have lost sight of USS Mobile Surface Search Radar Circuit:
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 A 311 10500 072 B 157 2550 01 A 312 9850 081 A 312 4550 02 A 312 9100 082 B 174 2350 022 B 120 4750 09 A 312 4250 03 A 312 8200 092 B 191 2400 032 B 125 4200 101 A 315 3350 04 A 312 7750 102 B 204 2400 042 B 131 3700 11 A 315 2900 051 A 312 7050 11 B2 217 2750 052 B 138 3250 12 A 313 2200 06 A 312 6350 12 B 225 3300 062 B 148 3000 13 A 319 1850 07 A 313 5600 132 B 240 3700 --A-21--
PROBLEM NO. 3 (cont).
Surface Search Radar Circuit (cont):
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 14 A 325 1600 22 B2 280 10950 142 B 249 4350 23 A 352 2800 15 A 335 1400 23 B2 281 11900 152 B 257 5000 24 A 343 3700 16 A 349 1200 24 B2 282 12700 162 B 263 5700 25 A 340 4800 17 A 002 1150 25 B2 284 13600 173 B 270 7000 26 A 337 6000 18 A 021 1150 26 B2 284 14500 182 B 271 7400 27 A 336 7100 19 A 034 1300 27 B2 285 15400 192 B 274 8200 28 A 334 8250 20 A 046 1400 28 B2 286 16300 203 B2 277 9450 29 A 334 9450 21 A 037 1500 29 B2 286 17300 21 B2 278 10000 30 A 332 10500 22 A 007 1800 30 B2 287 18100 PROBLEM NO. 4.
The Tactical Situation:
You are approaching Bermuda. It is a brilliant night. The visibility is 3 miles. Moon is at 100 true. The following sound powered phone circuits are manned: Evaluator's circuit, Surface search radar circuit, Lookout circuit. Own ship's course 090 speed 30 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure D.
Figure D--A-22--
PROBLEM NO. 4 (cont).
Evaluator's Circuit:
01 Conn- Combat: Raid "A" at true bearing 102 range '23200 closing fast 04 Conn- Combat: Raid "A" on course 280 speed 30 should pass one mile off our starboard beam in ten minutes. 062 Conn- Combat: Ship sighted by lookouts is Raid "A" 09 Combat- Conn: Coming left to 060 10 Combat- Conn: Steady on course 060 12 Conn- Combat: Raid "A" identified by lookouts as USS Porter 17 Conn- Combat: Raid "B" at true bearing 076 range 13600 172 Conn- Combat: USS Porter is changing course to port 182 Conn- Combat: Raid "B" is on collision course 290 speed 15. The USS Porter is on course 254 speed 30 19 Combat- Conn: Coming right to 110 20 Combat- Conn: Steady on course 110 222 Conn- Combat: Ship just reported by lookouts is Raid "B" 242 Conn- Combat: Raid "B" identified by lookouts as merchant ship Lookout Circuit:
06 Conn- Surface lookouts forward: Ship in path of moon about 6 miles 11 Conn- Surface lookouts forward: Ship now at relative bearing 080 is USS Porter 22 Conn- Surface lookouts forward: Ship on relative bearing 040 about 3 miles 242 Conn- Surface lookouts foreward: Ship on port beam is a merchant ship Surface Search Radar Circuit:
Time Raid Bearing Range Time Raid Bearing Range 01 A 102 23200 15 A 226 6200 02 " 103 21000 16 232 7800 03 " 103 19200 162 B 078 13100 04 " 104 17200 17 A 236 9700 05 " 105 15000 172 B 078 11800 06 " 106 13500 18 A 239 11700 07 " 108 11400 182 B 077 10900 08 " 111 9500 19 A 239 13600 09 " 116 7200 192 B 076 9000 10 " 121 5800 20 A 240 15800 11 " 137 4600 202 B 073 7800 12 " 161 3900 211 A 243 17600 13 " 189 3900 212 B 064 6600 14 " 212 4900 22 A 246 19000 --A-23--
PROBLEM NO. 4 (cont).
Surface Search Radar Circuit (cont).
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 222 B 054 5800 25 A 252 24300 23 A 249 20800 252 B 004 5100 232 B 037 5000 262 B 349 5600 24 A 251 22400 272 B 348 6400 242 B 022 4800 282 B 332 7200 292 B 323 8700 PROBLEM NO. 5.
The tactical situation:
You are leaving Charleston. The day is overcast, visibility five miles. Squall forming in the northwest. The following sound powered phone circuits are manned: Evaluator's circuit, Lookout circuit, Surface search radar circuit. Own ship's course 045 speed 30 knots. Suggested plotting scale 2000 yards = 1 inch. This problem will develop as illustrated in Figure E.
Figure E--A-24--
PROBLEM NO. 5 (cont).
Evaluator's Circuit:
002 Conn- Combat: Raid "A" at true bearing 020 range 16550 04 Conn- Combat: Raid "A"' course 165 speed 30 042 Conn- Combat: Ship just reported by lookouts is Raid "A"' 062 Conn- Combat: Raid "A" identified by lookouts as LCI will pass 1000 yards astern of us 09 Conn- Combat: Raid "B" at true bearing 045 range '21900 13 Conn- Combat: Raid "B" on collision course 225 speed 10 143 Conn- Combat: Raid "C" bearing 092 range '21650 16 Combat- Conn: Coming right 090 16 Combat- Conn: Steady on course 090 172 Conn- Combat: Ship just reported by lookouts is Raid "B" 19 Conn- Combat: Raid "C" shows a very erratic plot and appears to be ionized clouds. 20^ Conn- Combat: Raid "B" identified by lookouts as tanker Lookout Circuit
04 Conn- Surface lookouts forward: Ship at relative bearing 330 about 5 miles 06 Conn- Surface lookouts forward: Ship at relative bearing 325 is an LCI 17 Conn- Surface lookouts forward: Ship at relative bearing 310 about 5 miles IB Conn- Surface lookouts forward: Ship at relative bearing 295 is a tanker Surface Search Radar Circuit:
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 A 020 16550 13 A 210 2400 01 A 020 15150 132 B 045 15300 02 A 020 13700 14 A 207 3800 03 A 019 12200 141 B 045 13900 04 A 018 10850 142 C 052 21650 05 A 019 9400 15 A 205 5300 06 A 018 7900 151 B 046 12700 07 A 017 6600 152 C 055 20450 08 A 016 5050 16 A 204 6700 082 B 046 21900 161 B 045 11300 09 A 015 3500 162 C 052 18700 092 B 045 20600 17 A 208 7700 10 A 010 2200 171 B 041 10300 102 B 045 19400 172 C 055 17900 11 A 349 700 18 A 212 8800 112 B 046 17950 181 B 036 9350 12 A 225 1050 182 C 047 17700 122 B 043 16600 19 A 215 9550 --A-25--
PROBLEM NO. 5 (cont).
Surface Search Radar Circuit (cont),
Time Raid Bearing Range Time Raid Bearing Range 191 B 032 8450 25 A 220 15650 192 C 047 15550 252 B 334 6650 20 A 216 10550 26 A 222 16650 201 B 023 7600 262 B 323 7100 21 A 217 11500 27 A 221 17500 212 B 015 7050 272 B 314 7750 22 A 219 12500 28 A 224 18800 222 B 008 6600 282 B 309 8500 23 A 219 13550 29 A 223 19750 232 B 354 6400 292 B 302 9300 24 A 220 14600 30 A 224 20800 242 B 345 6400 302 B 297 10300 PROBLEM NO. 6.
The Tactical Situation:
You are a single destroyer operating in Solomon Islands area. The visibility is 6 miles. You are about 12 miles West of Shortland Island. The following sound powered phone circuits are manned: Evaluator's circuit, and Surface search radar circuit. Own ship's course 060, speed 30 knots. Suggested plotting scale 2000 yards = 1 inch. This problem will develop as illustrated in Figure F.
Figure FEvaluator's Circuit:
06 Conn- Surface lookouts forward: Ship on horizon at relative bearing 300 08 Conn- Surface lookouts forward: Ship at relative bearing 300 is USS John Paul Jones. 09 Conn- Control: Director of Raid "B" true bearing range 045 at range 16650 12 Conn- Surface: lookouts forward: Ship on horizon at relative bearing 000 --A-26--
PROBLEM NO. 6. (cont).
Evaluator's Circuit: (cont).
13 Conn- Surface lookouts forward: Jap destroyer at relative bearing OCO has opened fire on the John Paul Jones 14 Control- Conn: Commence firing target "B" 15 Combat- Conn: Coming left to 000 16 Combat- Conn: Steady on 000 162 Combat- Conn: Coming to 090 17 Combat- Conn: Steady on 090 18 Combat- Conn: Coming to 173 19 Combat- Conn: Steady on 173 26 Conn- Surface lookouts forward: Two direct hits on Jap destroyer 30 Conn- Surface lookouts forward: Jap destroyer sinking fast Surface Search Radar Circuit:
Time Raid Bearing Range Time Raid Bearing Range 00 A 359 18500 132 B 068 11700 01 " 359 17400 14 A 355 4700 02 A 358 16400 142 B 073 11300 022 Land from 070 to true bearing 130
approximate range 24,00015 A 356 3900 03 A 358 15350 152 B 079 10750 032 B 037 20700 16 A 353 3150 04 A 359 13300 162 B 086 10400 042 B 039 19600 17 A 019 1900 05 A 359 13200 172 B 095 11100 052 B 040 18600 18 A 045 1100 06 A 356 12400 182 B 103 11200 062 B 043 17600 19 A 040 1500 07 A 356 11300 192 B 103 11150 072 B 045 16650 20 A 043 2400 08 A 357 10250 202 B 103 10600 082 B 049 15700 21 " 105 10000 09 A 356 9200 22 " 105 9300 092 B 051 14800 23 " 105 8900 10 A 355 8200 24 " 106 8400 102 B 053 13900 25 " 107 7800 11 A 355 7150 26 " 107 7300 112 B 059 13100 27 " 109 6800 12 A 353 6250 28 " 100 6450 122 B 062 12400 29 " 090 6500 30 " 080 6400 --A-27--
PROBLEM NO. 7.
The Tactical Situation:
In this problem your own ship is the guide. You have in company, a DE who is not radar equipped. Your captain desires to maneuver the DE to various stations. Your captain will call on you for courses and speeds that he will use to signal to the DE in order that that ship may take the various stations. The following sound powered phone circuits are manned: Evaluator's circuit, and Surface search radar circuit. Own ship's course 090, speed 15 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure G.
Figure GEvaluator's Circuit:
00 Combat- Conn: What is the necessary course and speed for the DE to take station one mile on my starboard quarter, using 5 minutes to complete the maneuver? 04* Conn- Combat: Course for DE is 062, speed 7g knots. 05 Combat- Conn: What is the necessary course and speed for the DE to take station one mile on our port quarter, using 4 minutes to complete maneuver? 11* Conn- Combat: Course for DE is 035, speed 26 knots. 16 Combat- Conn: What is the necessary course and speed for DE to take station two miles on my port quarter, completing maneuver 6 minutes from now? 16* Conn- Combat: Course for DE is 038, speed 10½ knots. 17 Combat- Conn: When DE gets on station two miles on my port quarter; what will be the necessary course for her to take station one mile on my port beam, using maximum speed, 32½ knots? 20* Conn- Combat: Course for DE is 098 * These are the reports that Conn should expect from Combat. --A-28--
PROBLEM NO. 7. (cont).
Evaluator's Circuit: (cont).
21 Combat- Conn: When DE arrives on station, what course should she steer to come alongside and deliver mail, using a speed of 21 knots? 23* Conn- Combat: Course for DE to come alongside, 135 30 END OF PROBLEM * These are the reports that Conn should expect from Combat. Surface Search Radar Circuit:
Time Raid Bearing Range Time Raid Bearing Range 00 A 180 2000 15 A 297 1500 01 " 180 2100 16 " 315 2000 02 " 181 2000 17 " 315 2400 03 " 180 2100 18 " 316 2750 04 " 180 2000 19 " 315 3200 05 " 189 1850 20 " 315 3600 06 " 199 1850 21 " 316 4000 07 " 208 1850 22 " 320 3600 08 " 218 1800 23 " 326 3050 09 " 225 2000 24 " 333 2600 10 " 226 2000 25 " 345 2400 11 " 225 2000 26 " 000 2000 12 " 225 2000 27 000 1500 13 " 244 1550 28 " 000 1000 14 " 271 1400 29 " 000 500 30 " Within minimum range PROBLEM NO. 8.
The Tactical Situation:
You are on patrol in Caroline Islands area; time, midnight; visibility 300 yards. The sound powered phone circuits to be manned are: Evaluator's circuit and Surface search radar circuit. Own ship's course 090, speed 30. Suggested plotting scale, 2000 yards = 1 inch. This problem will develop as illustrated in Figure H.
Figure H--A-29--
PROBLEM NO. 8. (cont).
Evaluator's Circuit:
08 Conn- Control: Director on Raid "A" at true bearing 971 ranee 16.000. 10 Conn- Control: Ready to open fire Raid "A". 11 Control- Conn: Commence firing. 11½ Conn- Surface lookouts forward: Explosions on ship at relative bearing 340. 13 Conn- Surface lookouts forward: Explosions on ship at relative bearing 000. 20 Combat- Conn: Coming right to 145. 21 Combat- Conn: Steady on 145. 24 Conn- Surface lookouts forward: Explosions on ship at relative bearing 350. Surface Search Radar Circuit:
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 02 A 064 25200 143 C 094 12400 03 " 065 23700 15 A 098 9000 04 " 066 22100 152 B 039 6050 05 " 067 20650 153 C 095 12450 052 B 063 18350 16 A 105 8600 06 A 068 19050 162 B 024 6200 062 B 063 16850 163 C 095 12300 07 A 069 17600 17 A 110 8400 072 B 065 15400 172 B 010 6900 073 C 077 19000 173 C 096 12300 08 A 072 16200 18 A 116 8200 082 B 066 13800 182 B 000 7700 083 C 078 17600 183 C 097 12300 09 A 073 14600 19 A 123 8200 092 B 064 12400 192 B 351 8750 093 C 082 16200 193 C 098 12300 10 A 075 13400 20 A 130 8400 102 B 071 10800 202 B 345 9900 103 C 085 14850 203 C 099 12300 11 A 078 11750 21 A 136 8600 112 B 073 9200 213 C 100 12300 113 C 088 13550 221 A 136 8600 12 A 083 10300 223 C 096 12550 122 B 076 7800 231 A 136 8600 123 C 092 12300 24 A 136 8700 13 A 087 9800 25 A 136 8600 132 B 067 9900 26 A 136 8600 133 C 093 12300 27 A 136 8600 14 A 092 9400 28 A 136 8600 142 B 054 6300 29 A 136 8700 --A-30--
PROBLEM NO. 9.
The Tactical Situation:
You are searching for a submarine reported to be in this region. It is night, no moon, visibility about 3 miles. The sound powered phone circuits to be manned are the Command circuit and Surface search radar circuits. Own ship's course 090, speed 15. Suggested plotting scales: 1000 yards 1 inch, 200 yards = 1 inch. This problem will develop as illustrated in Figure I.
Figure ICommand Circuit
06 Bridge- Surface lookouts forward: Surfaced submarine dead ahead 3i miles 07 Bridge- Surface lookouts forward: Submarine is submerging 08 Combat- Conn: Coming right to 144. 09 Sound contact left cut on 113, right cut on 127, range 2100. 10 Sound contact left cut on 112, right cut on 129, range 1750. 11 Sound contact left cut on 118, right cut on 132, range 1500. 12 Sound contact left cut on 121, right cut on 137, range 1200. 13 Sound contact left cut on 126, right cut on 146, range 900. 14 Sound contact left cut on 123, right cut on 143, range 650. 15 Sound contact left cut on 120, right cut on 141, range 500. 16 Sound contact left cut on 112, right cut on 138, range 250. 18 Releasing depth charges. --A-31--
PROBLEM NO. 9 (cont).
Surface Search Radar Circuit (21JS)
Time Raid Bearing Range Time Raid Bearing Range 04 A(Sm pip) 082 4350 262 C 245 2200 05 A 086 3750 27 B 312 3600 06 " 092 3300 272 C 258 2200 07 " 098 2800 28 B 312 4000 08 " 107 2400 282 C 270 2250 24 New contact 316 2300 29 B 310 4500 25 B(Sm pip) 315 2600 292 C 282 2400 252 New contact 233 2250 30 B 310 4900 26 B 314 3100 302 C 292 2700 PROBLEM NO. 10.
The Tactical Situation:
You are one of three destroyers escorting a carrier to New York from Norfolk. Due to engine breakdown you get behind and are now trying to find the carrier and resume station from the carrier at relative bearing 300° at 1400. The following sound powered phone circuits are manned: Captain's battle circuit, Surface search radar circuit, and Evaluator's circuit. Ship's course 090, speed 15 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure J.
Figure J--A-32--
PROBLEM NO. 10. (cont.)
Evaluator's Circuit:
04 Combat- Conn: Do you think Raid "A" is the carrier? 042 Conn- Combat: Affirmative 05 Combat- Conn: What course should I steer at 15 knots to take reauired station and how long will it take? 06 Conn- Combat: Suggest course 073. That would put us on station in 19 minutes. 12 Combat- Conn: What course should I steer now, at 15 knots, to take station and how long will it take? 13 Conn- Combat: Course 062 would put ub on station in 13 minutes. 16 Combat- Conn: What course should I steer now to take station at 15 knots, and how lone will it take? 162 Conn- Combat: Course 045 will put us on station in 11 minutes. 17 Combat- Conn: Coming left to 045, speed 15 knots. 18 Combat- Conn: Steady on course 045. 26 Conn- Surface lookouts forward: Destroyer 300 yards broad on starboard bow. Surface Search Radar Circuit (21JS)
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 A 123 15900 092 B 119 9300 oo2 B 122 14800 093 C 114 10900 01 A 122 15300 10 A 118 9650 OI2 B 122 14200 102 B 118 8600 02 A 122 14700 103 C 113 10300 022 B 121 13600 11 A 118 9000 03 A 122 14050 112 B 118 7850 032 B 121 13000 113 C 112 9800 04 A 122 13400 12 A 117 8500 042 B 120 12400 122 B 116 7400 043 C 117 13850 123 C 111 9000 05 A 121 12800 13 A 116 7800 052 B 120 11800 132 B 113 6700 053 C 117 13350 133 C 110 8400 06 A 121 12200 14 A 115 7100 062 B 120 11200 142 B 113 6050 063 C 116 12850 143 C 108 7800 07 A 120 11500 15 A 114 6500 072 B 120 10500 152 B 111 5400 073 C 118 12100 153 C 105 7200 08 A 120 10900 16 A 112 5850 082 B 120 9900 162 B 109 4800 083 C 115 11500 163 C 103 6600 09 A 119 10250 17 A 110 5200 --A-33--
PROBLEM NO. 10. (cont).
Surface Search Radar Circuit (21JS) (cont).
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 172 B 105 4200 233 C 099 3700 L73 C 101 6000 24 A 117 2550 18 A 108 4650 242 B 100 1400 182 B 100 3600 243 C 097 3300 183 099 5450 25 A 120 2250 19 A 109 4300 252 B 102 1200 192 B 102 3250 253 C, 096 3000 193 C 098 5100 26 A 124 1900 20 A 110 3950 262 Lost surface "B" 202 B 100 2900 263 C 096 2600 203 C 097 4750 27 A 129 1600 21 A 112 3600 272 C 094 2250 212 B 101 2500 28 A 135 1300 213 C 098 4400 282 C 092 1900 22 A 112 3250 29 A 149 1050 222 B 099 2150 292 C 092 1500 223 C 097 4050 30 A 165 900 23 A 115 2900 302 B 067 900 232 B 100 1800 303 C 090 1200 PROBLEM NO. 11.
The Tactical Situation:
You are a single ship operating in Chesapeake Bay, about to conduct a firing practice. There is a tug towing a target about two miles off your starboard bow. CIC must be prepared to give the captain the necessary courses and speeds for the tug to take various stations. A close search must be kept for any surface contacts which might foul the range. The sound powered phone circuits to be manned are the Evaluator's circuit, Lookout circuit and Surface search radar circuit. Own ship's course 090, speed 30. Suggested plotting scale: 1000 yards = 1 inch. This problem will develop as illustrated in Figure K.
--A-34--
PROBLEM NO. 11 (cont).
Figure KEvaluator's Circuit:
00 Combat- Conn: What course should tug steer to take station 4 miles on our starboard beam at a speed of 30 knots, and how long will the maneuver take? 02 Conn- Combat: Tug should steer 145, if she does she would be on station in 6 minutes 03 Conn- Combat: Tug is on course 145, speed 30, she will be on station in 5 minutes 07 Conn- Combat: Raid "B" true bearing 151 range 17500 10 Conn- Combat: Raid "B" course 315, speed 20. 11 Combat- Conn: Is the tug on station? (Answer affirmative) 14 Conn- Combat: Lookouts have sighted Raid "B". 141 Combat- Conn: Coming right to course 180. 142 Conn- Combat: Lookouts have identified Raid "B" as the Augusta. 15 Combat- Conn: Steady on course 180. 152 Combat- Conn: What course should tug steer to take station 4 miles on the starboard beam of the Augusta? 16 Conn- Combat: The Augusta has changed course to 270, speed 20. 17 Conn- Combat: Tug is on correct course 290, speed 30. She will be on new station in 3 minutes. --A-35--
PROBLEM NO. 11 (cont.)
Evaluator's Circuit (cont).
21 Conn- Combat: Tug is now on station 4 miles on the starboard beam of the Augusta. 28 Combat- Conn: Range and bearing on the Augusta. 29 Conn- Combat: The Augusta at true bearing 273 range 13600. 30 End of Problem. Lookout Circuit:
00 Conn- Surface lookouts forward: Tug and target at relative bearing 025, 1½ miles. 13 Conn- Surface lookouts aft: Ship on horizon at relative bearing 090. 14 Conn- Surface lookouts aft: Ship on horizon at relative bearing 090 is the Augusta. 22 Conn- Surface lookouts aft: Have lost sight of tug and target at relative bearing 110°. 27 Conn- Surface lookouts forward: Have lost sight of Augusta at relative bearing 085°. Surface Search Radar Circuit (21JS) :
Time Raid Bearing Range Time Raid Bearing Range 00 A 110 3800 153 B 202 13400 01 A 123 3800 16 A 218 6610 02 A 136 4050 162 B 206 12800 03 A 148 4400 17 A 231 6390 04 A 156 5000 173 B 212 12000 05 A 164 5675 18 A 247 6520 06 A 170 6400 182 B 216 11500 062 B 151 17500 19 A 260 7050 07 A 174 7175 192 B 222 11300 072 B 154 16400 20 A 270 7900 08 A 178 8000 202 B 229 11000 082 B 158 15300 21 A 279 8700 09 A 178 8000 212 B 235 10900 092 B 163 14400 22 A 284 9570 10 A 180 8000 222 B 242 10900 102 B 169 13700 23 A 289 10500 11 A 180 8000 232 B 247 11100 112 B 175 12900 24 A 292 11440 12 A 180 8000 242 B 253 11300 122 B 182 12900 25 A 295 12490 13 A 180 7800 252 B 259 11800 132 B 190 13000 26 A 297 13600 14 A 189 7150 262 B 264 12200 142 B 196 13400 27 A 299 14600 15 A 205 7390 272 B 265 12900 --A-36--
PROBLEM NO. 11 (cont.)
Surfaace Search Radar Circuit (21JS) (cont).
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 28 A 302 15700 292 B 278 14300 282 B 273 13600 30 A 305 17900 29 A 304 16800 PROBLEM NO. 12.
The Tactical Situation:
We are convoy USF 10 making arrival at Gibraltar. In addition to ships present, an American destroyer, the USS Flusser has joined company with us.' She has been assigned station 5000 yards of relative bearing 315° from us. The following sound powered phone circuits are manned: Evaluator's circuit, Surface search radar circuit, and TBS radio circuit. The TBS calls are: Rider = OTC; Spurs = Flusser. Own ship's course 090, speed 15 knots. Suggested plotting scale 1000 yards = 1 inch. This problem will develop as illustrated in Figure L.
Figure L--A-37--
PROBLEM NO. 12 (cont).
Evaluator's Circuit:
01 Bridge- Surface lookout forward: Destroyer at relative bearing 315 is USS Flusser.
Bridge Aye Aye05 Bridge- Surface lookout forward: Flusser seems to be changing course away from us. Target angle 180.
Bridge Aye Aye16 Bridge- Surface lookout forward: Flusser appears to be stopped near Spanish gunboat.
Bridge Aye Aye18 Bridge- Surface lookout forward: Buoy relative bearing 345
Bridge Aye Aye.19 Bridge- Surface lookout forward: Buoy relative bearing 015
Bridge Aye Aye.21 Bridge- Surface lookout aft: Flusser and Bruno underway. Flusser target angle 080.
Bridge Aye Aye.22 Bridge- Surface lookout aft: Bruno target angle 300 24 Bridge- Surface lookout forward: Flusser passing abeam to port, target angle 090 TBS Radio Circuit:
Time Message 00 "Hello, Spurs, this is Rider. How do you hear me? Over 002 This is Spurs. I hear you loud and clear. Reporting for duty. Over. 01 This is Rider. Roger 02 Hello, Spurs, this is Rider. Take station 315 Relative, 5000 yards from fleet center. Over 022 This is Spurs. Roger 04 Hello, Spurs, this is Rider. Veer out and investigate stranger bearing 041, 8 miles from me. Acknowledge. Over 041 This is Spurs. Wilco. Out 10 Hello, Rider, this is Spurs. Vessel is Spanish gunboat. Over 101 This is Rider. Roger 14 Hello, Rider, this is Spurs. Vessel identified as Spanish gunboat, Bruno, on neutrality patrol 141 This is Rider. Roger 15 Spurs, this is Rider. My compliments to Bruno and request her to stop or steer clear of me. Over 151 This is Spurs. Roger. Bruno is stopping. Out --A-38--
PROBLEM NO. 12 (cont.)
Surface Search Radar Circuit (21JS):
TIME RAID BEARING RANGE TIME RAID BEARING RANGE 00 Friend 046 5100 19 Small target 107 3600 01 " 041 4750 192 " " 078 4800 02 " 037 4400 20 " " 103 4600 022 New target 046 17500 202 PPI shows two columns of small targets ahead bearing 070 to 110 03 Fluss 036 4400 032 A 043 16100 21 Fluss 351 4900 04 Fluss 036 4400 212 A 337 4650 042 A 041 15100 22 Fluss 357 4700 05 Fluss 032 5100 222 A 326 4650 052 A 039 14800 23 Buoy 078 4600 06 Fluss 028 5900 232 A 316 4900 062 A 036 13300 24 Fluss 009 4450 07 Fluss 025 6600 242 Buoy 105 3850 072 A 035 12300 25 Fluss 016 4400 08 Fluss 023 7400 252 A 298 6000 082 A 034 11400 26 Fluss 024 4400 09 Fluss 024 8000 261 Buoy 078 4600 092 A 033 10500 262 A 292 6800 10 Fluss 024 8700 27 Fluss 028 4500 102 A 031 9600 271 Buoy 104 4100 11 Fluss 025 8500 272 A 298 7700 112 A 030 8700 28 Fluss 034 4150 12 Fluss 025 8100 282 A 285 8600 122 A 028 7800 29 Fluss 040 4800 13 Fluss 024 7300 292 A 283 9500 132 A 025 7000 30 Fluss 045 5000 14 Fluss 019 6450 302 PPI shows many small targets close in. Ranges and bearings will be given at ½ minute intervals. 142 A 021 6050 15 Fluss 015 5700 152 A 016 5350 31 Buoy 291 2700 16 Fluss 010 5050 312 " 250 3000 162 A 012 4800 32 " 304 1800 17 Fluss 004 5000 322 " 242 2000 171 New target 078 4600 33 " 333 1100 172 A 004 4600 332 " 217 1250 18 Fluss 358 5000 34 " 026 1100 181 Buoy 076 4200 342 " 164 1100 182 A 359 4700 --A-39--
PROBLEM NO. 13.
TEAM PRACTICE
Conditions: Start the DR plot below and to the left of center of your plotting sheet. Scale 2000 yds/in. Your destroyer "Garnet" is part of a small destroyer task group steaming in column 1000 yards apart. You expect to intercept two transports coming down from the North. A strong enemy task group is in the area and you do not wish to let your presence be known. "Emerald" is the leading DD (and guide) followed by your ship "Garnet, " 1000 yds astern, "Ruby" follows you 1000 yds astern. Your task group is on C027 speed 20. You do not know how long you will be on this course. Your present DR position, at 0100, is L10° 17'N? Lo167° 20'W.
0100 Screen clear of strangers "Emerald" Bearing 027 Range 1000, "Ruby" Bearing 208 Range 1000 01 Few small strangers, probably two, Bearing 006 Range 15900 02 Strangers Bearing 007½, Range 15200 The raid has been desig "Raid Fox" 03 Strangers Bearing 009 Range 14700 Evaluation using the intelligence dope shows Raid "Fox" is the two expected enemy transports. 04 Bearing 010½ Range 14100 Should have a C094 S18 on Raid "Fox" by now. 05 Bearing 012 Range 13500 TBS xmission "Do not execute Dog, standby to make William run on Raid Fox" Figure the approach course you would turn to at time 0106 using speed 30 to reach a position 60° 5000 yds on Raid Fox's nearest bow. DRT plotters check the solution on the DRT. 06 Bearing 014 Range 13000 TBS xmission "Standby to execute Corpen 065 speed 30 knots--standby execute" Plotters note that in a corpen movement the axis will change 07 Bearing 013½ Range 12400 08 Bearing 012½, Range 11900 At this time the bridge requests the time you will reach the position to fire torpedoes. 09 Bearing 011½, Range 11400 10 Bearing 010½, Range 10900 Raid Fox appears to be changing course, prepare to figure a new approach course to reach the firing point. 11 Bearing 011 Range 10000 12 Bearing 011 Range 9000 TBS xmission "Execute Dog only if our presence is detected--the present course change in all probability is part of their zig-zag plan" 13 Bearing 011 Range 8100 The bridge requests advice on the necessity of change of approach course to a favorable firing point. 14 Bearing 011 Range 7200 You should by now have an approximate course and speed on Raid Fox of C123 S27. You should have decided that your present approach course will place you in a favorable firing position. --A-40--
PROBLEM NO. 13 (cont.0
TEAM PRACTICE (cont.)
15 Bearing 011½ Range 6250 Figure a base torpedo course to fire a 45kt spread at time 16 st Raid Fox. 16 Bearing 012 Range 5350 Torpedoes away on BTC 046. Find the course to open the range in minimum time to 20000 yards using speed 30. Turn to course sjo speed go. 17 Bearing 030½ Range 5500 18 Bearing 047 Range 6200 At what time would you expect torpedo hits? 19 Bearing 060 Range 7400 Shortly after time 19 the lookout reports two explosions indicating torpedo hits on the transports. 20 TBS xmission "Secure problem, rotate positions for the next problem." PROBLEM NO. 14.
Team Practice
Conditions: Start your DRT plot near the bottom in the middle of your plotting sheet. Scale 2000 yds/in. Your cruiser "King" is part of a task force cruising on course 000 speed 15 in battle disposition 3S1. Enemy contact to the East is imminent. Plotters note particularly your disposition.
dd's Opal 1000 cruisers Ace 0000 Pearl 2000 King 1180 Garnet 3000 Queen 2180 Ruby 4000 Jack 3180 Emerald 5000 Circle spacing is 1000 yards. Fleet course and axis is 000. Your present DR position at 1700 is L2°03'N, Lo179°17'E/
1700 Few strangers Bearing 098 Range 21500 01 Strangers Bearing 098 Range 21200 The raid has been desig Raid "Easy" 02 Bearing 099 Range 20900 Reid Easy looks like 3 large and 4 small ships 03 Bearing 099 Range 20600 Ace's report over the TBS estimates the composition of Raid "Easy" as 3 cruisers and several DD's. 04 Bearing 099 Range 20300 Plotters convert this range and bearing to fleet center for an amplifying report to OTC. 05 Bearing 100 Range 20000 By this time you should have a good course and speed on the raid. Figure a course to cross the target's T at 12000 yds using speed 25. TBS xmission "Standby to execute Corpen 030 speed 25 at time 1705--standby execute." 06 Bearing 101 Bange 19400 TBS xmission "Destroyers make William, run on Raid Easy at time 1707" --A-41--
PROBLEM NO. 14 (cont.)
TEAM PRACTICE (cont.)
07 Bearing 102½ Range 18700 Find an approach course for your DD's in formation to reach 60° 5000 yds on the target's nearest bow using 30 kts. Draw in that course line lightly to check your solution against the plots that will follow. (097) 08 Bearing 104½ Range 18100 FR Bearing 144 Range 1000 The lookout reports our DD's making their torpedo run off to starboard about ½ mile. 09 Bearing 106 Range 17500 Your FDO reports a plane down Bearing 020 Range 20 miles. 10 Bearing 108 Range 16800 FR Bearing 145 Range 3000 11 Bearing 110 Range 16300 Estimate the time your DD's will reach the firing position on the target's bow. 12 Bearing 112 Range 15700 FR Bearing 145 Range 5200 13 Bearing 114 Range 15100 Lookout reports the enemy cruisers have opened fire. 14 Bearing 116 Range 14700 FR Bearing 145 Range 7200 15 Bearing 119 Range 14100 Own DD "Emerald" is hit. Own cruisers open fire the lookout reports. 16 Bearing 122 Range 13700 FR Bearing 145^ Range 9200 At time 17 your DD's will reach the firing point. Find the BTC for their 45 knot spread torpedoes. Draw in the BTC lightly. Surface plotters check the results of the assistant evaluator on the DRT. 17 Bearing 125 Range 13200 Find the retirement course the destroyers should take to reach 15000 yards in minimum time using a speed of 30 kts. Draw that line in lightly to see how it checks with the plots that will follow. 18 Bearing 128 Range 12800 TBS xmission from destroyers "Torpedoes away on BTC 064 retiring on course 203." 19 Bearing 131 Range 12500 Figure the time that the torpedoes that the destroyers fired at time 17 should hit. 20 Bearing 135 Range 12000 FR Bearing 166 Range 13800 Lookout reports that "Jack" is hit in the stern and on fire. "Emerald" is dead in the water sinking rapidly. '21 Bearing 138 Range 12000 The lookout reports shell hits on the leading enemy cruiser--that a small fire was started. 22 Bearing 142 Range 11800 FR Bearing 174 Range 16800 The enemy now breaks off the engagement and retires to the South. The remainder of your force will rendezvous at point "Zebra" which now bears 296 range 22000 from the destroyers and 249 range 19500 from the heavier units of your task force. What speed must the destroyers have to reach point "Zebra" simultaneously with the heavier units if the heavy units make 25 knots? (S 28.2) Time of rendezvous? (1745½) PROBLEM NO. 15.
Surface Plotting Exercise
Start below and to the right of the center of your sheet. Scale 2000 yds/in. Your task group is on 0280 S20. You do not know how long you
--A-42--
PROBLEM NO. 15 (cont.)
Surface Plotting Exercise (cont.)
will be on that course. Your present DR position at 0426 is L26°14'S Lo146°29"'W. Tour task group consists of your ship, a CL, steaming with another CL and 3 destroyers. Your mission is screening landing operations to the south of you. Contact with surface forces is expected.
0526 Few strangers Bearing 356 Range 18900 Looks like 6 or 8 ships 27 Strangers Bearing 357 Range 17700 Raid desig Raid "Dog" 28 Raid "Dog" Bearing 358 Range 16700 The lookout reports that raid "Dog" appears to be 2 large ships probably cruisers and 6 small ships probably destroyers. 29 Bearing 359 Range 15700 30 Bearing 000 Range 14600 The cruisers open fire on raid "Dog" 31 Bearing 001 Range 13500 32 Bearing 000 Range 13000 One enemy cruiser hit. 33 Bearing 359 Range 12300 34 Bearing 358 Range 11750 Sound contact; Left cut on, Bearing 207 Range 3600 35 Bearing 357 Range 11100.The Sound contact is desig raid "Easy," Right cut on Bearing 199 Range 3400 Raid "Dog" appears to be splitting. 36 Bearing 356 Range 11100 Bearing 357 Range 10300 appears to be 4 DD's closing Nearer raid is designated "D-1" 37 Bearing 357 Range 11100 appears to be 2 CA and 2 DD's desig "D-2" Dog-1 Bearing 358 Range 9500 Right cut on Bearing 177 Range 3000 372 D-1 Bearing 359 Range 9000 One enemy DD is hit 38 Left cut on Bearing 162 Ranee 3000 381 D-1 Bearing 359 Range 8700 (Raid D-1 designated primary Target) 382 D-2 Bearing 356 Range 11100
Another small target Bearing 359 Range 9300 is designated D-3 and reported by lookouts as one DD burning.39 D-3 Bearing 002 Range 9500 391 D-1 Renrine 395 Range 7500 392 D-2 Bearing 000 Range 12000
Lookout reports that the burning DD (D-3) has exploded and sunk.40 D-1 Bearing 359 Range 6300
D-2 Bearing 004 Range 1300041 D-1 Bearing 000 Range 5100 Lookout reports one DD burning, badly
D-2 Bearing 007 Range 1400042 D-1 Bearing 355 Range 5000 Two DD's sunk Change cus to 190 S 30
D-2 Bearing 009 Range 1500043 D-1 Bearing 354 Range 6600
D-2 Bearing 010 Range 17000
Another contact Bearing 356 Range 7000 The lookout reports that this is a single DD burning dead in the water --desie D-444 D-1 Bearing 356 Range 8600 45 D-2 Bearing 010 Range 20000 Lookout reports the CA's are retiring at high speed. All other raids have disappeared from the screen. --A-43--
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