Fore control notes from the September 1944 issue of C.I.C. (Combat Information Center) published by the U.S. Office of the Chief of Naval Operations.
fire control notes and comments...
Excerpts from ship reports with comments by the Bureau of Ordnance.
ON THE RADAR MARK 12
There is no comparison between the Mark 12 and the Mark 4 equipment in the ability to pick up targets at long range. Destroyers of the MAHAN and BUCHANAN types have been picked up consistently and easily in the 25,000 to 30,000 yard range band, in complete darkness, on CIC designation. “The maximum range on a DD recorded to date is 30,000 yards. Larger targets have not been tracked to extreme ranges.
A series 60 sled with radar screen was tracked easily to 20,000 yards. Aircraft are easily tracked to 55,000 yards. A drone was picked up at 36,000 yards over land. Approaching aircraft of combat types are easily detected at 40,000 yards.
The improved performance of the Mark 12 radar over the Mark 4 radar is due to the difference in transmitted peak power, the Mark 12 power being four times that of the Mark 4. This factor alone should increase range performance on targets above the horizon by about 40 per cent. The higher frequency also improves antenna gain.
ON TARGET WITH SEARCH RADAR HELP
A considerable amount of drill at picking up planes from search radar designation has been carried out, with extremely encouraging results. The average time to get the director on a low-flying plane at a range of 10 miles is about 25 seconds. That time includes training the director at least 90 degrees.
During a very recent drone firing one director picked up the drone over land at 35,000 yards. The plane had immediately faded on the SK radar, but the Mark 12 got the target, and a good Baker run was eventually fired.
The Mark to true bearing indicator now installed in Mark 37 directors is very helpful in picking up targets from CIC designation.
The pip-matching indication, superimposed oil the long range sweep on the train and elevation scopes was particularly designed to improve target acquisition. This presentation gives the pointer and trainer a complete view of all targets in the radar beam, and enables them to start getting on target before the target pip is notched. When notched, a change to “spot” or “meter” indication for more accurate tracking can be made.
DIRECTORS ON SEARCH RADAR PHONE CIRCUITS
During the night of 21 February 1944, while under plane attack off Saipan, the forward Mark 34 director, equipped with a Mark 8 radar, was able to pick up and track low-flying planes at will. Contacts were made as far out as 14,000 yards, generally between 6,000-8,000 yards, tracked as close as 1,900 yards, and then as far out as 25,000 yards (opening). Naturally, getting “on” was the most difficult problem due to the delay in surface and air search ranges and bearings reaching the directors from the radars through CIC. This lag was greatly reduced by the directors cutting in on the search radar phone circuits.
The ease with which the director crew tracked these low-flying planes offers serious possibilities worth investigating, of using the generated ranges resulting from such tracking in assisting the 40mm and 20mm gun batteries in opening fire.
NURSING MACHINE GUN BATTERIES ON LOW-FLYING AIRCRAFT
Single low-flying planes of both twin and single engine type, can be tracked from 15,000 yards on into the ship. The relative bearing and range obtained from the main battery directors is used to get the machine gun battery “on” low-flying night torpedo planes. The Mark 8 radar in some measure fills the need for information on enemy planes when they close within 6,000 to 8,000 yards, data not obtainable from the SK.
In one instance fire was opened at 1,900 yards using this information when it is believed the target would not normally have been seen until the range closed to 1,000 yards.
The bombardier’s kit is a cloth case containing computers, tables, and pertinent working materials for use in maintaining bombing records and calculations. It is provided for every student and graduate bombardier through regular supply channels.
It includes: C-2, G-1, J-1, and E-6B computers; set of dropping angle charts for use with E-6B computer; stop watch and wrist watch; pen-type flashlight; bombing flight record holder, tools; drafting pencils; eraser, dividers; Weems plotter; parallel rule; transparent triangles; bombing tables.
REFERENCE: Technical Order 00-30-38-2.
Source: Bombardiers’ Information File, U.S. War Department, March 1945.
Instructions for making a jeep lift bar from the 881st Ordnance HAM Company, from Army Motors, July 1945.
TO GIVE 1/4-TONS A LIFT WITHOUT ALSO GIVING ‘EM A PAIN IN THE REAR END
Ordinarily, when you evacuate a helpless jeep and have to lift it on or off a cargo truck with your wrecker, the victim is hoisted by wrapping a chain around it. This gets it where it’s going. But often the jeep is in even worse shape when you’re through because the chain damages the body. To prevent a lot of unnecessary repair work, the 881st Ord. HAM Co. got busy and devised a simple sling that holds the jeep firmly but never leaves a mark.
The sling is made of a reinforced 6″ I-beam, a chain with a hook at one end, two chains with hooks on the other end, and two heavy metal rings near the center of the beam. You reinforce the I-beam on both sides, preferably with U-channel iron if you’ve got it; otherwise use plate. It’s better not to extend these reinforcements along the beam’s full length or it’ll increase the sling’s weight considerably. Instead, you can place one at each end and overlap them in the center for added strength under the ring holes.
In case you can’t find an I-beam, two pieces of frame side-rail bolted or welded together will do just as well and you won’t have to bother to reinforce it. You’ll find the exact dimensions for building the sling in Fig. 1.
To put this sling to work, first lower the top and windshield of the 1/4-ton and see that the rear seat is level with the back edge of the body. Then place the I-beam lengthwise over the jeep with the single-chain end to the rear (Fig. 2). Hook the single chain in the pintle, or if there isn’t any, under the rear edge of the frame. Then hook the other two chains under the two frame-ends supporting the front bumper. After you place the wrecker hook through the center rings, you can gently lift the jeep to where you want it with nary a slip.
Answers: 1. 2, 2. 3, 3. 4, 4. 4, 5. 2, 6. 3 (Naval Aviation News, August 1, 1944.)
Note to Pilots: This could be YOU!
Identify when Approaching Allied Ships!
GO AHEAD! Fly over one of our ships without identifying. Test the crew’s quickness on recognition… if you want that plane you’re flying punctured like a hunk of swiss cheese! Then, should you live to add up the count–you undoubtably won’t!–you can flatter the AA crews on how accurate their lead is!
But it’s saner and safer, to identify. Remember, AA crews are plenty yough and trained to shoot. If you approach Allied ships and leave them doubtful as to whether you’re friend or foe, they won’t ask too many questions, wait too long…
Don’t expect crews to take chances. They’ve had ships blown from under them, seen shipmates machine-gunned to death because they were slow to act. And most of the unfortunate cases where friendly planes were shot out of the sky were the fault of pilots who failed to identify their planes as friendly.
So don’t you take chances. Ships will challenge, but don’t wait. It’s the pilot’s responsibility to identify first.
Ships will recognize, but don’t stake your social security on it. They may not be sure, there may be clouds, enemy planes…
In the final analysis, it’s that ship and its big complement against your plane and lonely little you. You’re valuable, but you know which counts more with the Fleet!
RECOMMENDED READING: (1) Recognition and Identification Sense, (2) Identify… or Else! reprint from Naval Aviation News.
Source: Naval Aviation News, August 1, 1944.
Allied Army, Navy, and Air Force Uniforms: Newsmap, U.S. War Department, March 1943.
Reminders about the flak suit and flak helmet, from Bombardiers’ Information File, U.S. War Department, March 1945:
Flak suits consist of armored vest and apron assemblies. They are not personal issue, but they should be delivered to the plane before the flight and picked up afterward for inspection. You couldn’t carry one anyway, with everything else you’re lugging. Report to the pilot if you don’t find a flak suit in the plane for you.
Wear the suit when you approach the target area. It’s heavy but it’s guaranteed that you won’t notice the weight when the fight begins to get hot.
Note: Ask your Personal Equipment Officer to have a tab sewed on your flak suit for your oxygen mask hose clip.
The flak helmet is personal issue. If you have worn both your flak suit and flak helmet on the mission, you have a good chance of returning the helmet to the supply room personally after the flight.
TBM-3 Avenger: Movement of Personnel. (Source: Pilot’s Handbook of Flight Operating Instructions, Navy Model TBM-3 Airplane, November 1945.)
Emergency Exits and Movement of Flight Personnel for the B-25 Mitchell.
Source: B-25 Mitchell Pilot’s Manual.