Tank Recovery Vehicle M311-7

M31: General
Date of first acceptance December 1942 Total acceptances 509
(109 converted to full-track prime mover M33)
Manufacturer Baldwin Locomotive Works Crew 6 men
M31: Dimensions
Combat weight 60,000lbs
27,200kg		 Height with boom stowed 117"
297cm
Length with boom stowed 317"
805cm		 Width over side doors 107"
272cm
Tread 83"
211cm		 Ground clearance 17.125"
43.498cm
Turret ring diameter 54.5"
138cm		 Ground pressure, zero penetration 12.5psi
.878kg/cm²
M31: Armament
Type Mount Ammunition Traverse Elevation
.30cal M1919 MG AA mount on turret 2,000 rounds 360°
(manual)		 Manual
.30cal M1919 MG Fixed in hull left front 0° 0°
M31: Armor
Assembly
Riveting
Hull
Rolled homogeneous steel
Location Thickness Angle from vertical
Upper front 2.0"
5.1cm		 30°
Middle front 1.5"
3.8cm		 53°
Lower front 2.0"
5.1cm		 0° to 45°
Sides 1.5"
3.8cm		 0°
Rear 1.5"
3.8cm		 0° to 10°
Top .50"
1.3cm		 83° to 90°
Front floor 1.0"
2.5cm		 90°
Rear floor .50"
1.3cm		 90°
Turret
Cast homogeneous steel
Location Thickness Angle from vertical
Front 2.0"
5.1cm		 47°
Sides 2.0"
5.1cm		 5°
Rear 2.0"
5.1cm		 5°
Top .875"
2.22cm		 90°
M31: Automotive
Engine Continental R975 C1; 9 cylinder, 4 cycle, static radial, supercharged gasoline
Horsepower Net: 350@2,400rpm
Gross: 400@2,400rpm		 Torque Net: 800 ft-lb@1,800rpm
Gross: 890 ft-lb@1,800rpm		 Fuel capacity 185gal
700L
Transmission Synchromesh, 5 speeds forward, 1 reverse
Steering Controlled differential, steering levers
Brakes Mechanical, external contracting
M31: Suspension
Type Road wheels Track return rollers
Vertical volute spring 3 bogies/track;
2 wheels/bogie		 1 on top of each bogie
Drive sprockets Idlers Shock absorbers
13-tooth front drive Adjustable at rear of track None
M31: Track
T41
Outside guide, double pin, smooth, rubber
Width 16.0"
40.6cm		 Pitch 6"
15cm		 Shoes/track 79 Ground contact length 147"
373cm
T48
Outside guide, double pin, chevron, rubber
Width 16.56"
42.06cm		 Pitch 6"
15cm		 Shoes/track 79 Ground contact length 147"
373cm
T49
Outside guide, double pin, parallel bar, steel
Width 16.56"
42.06cm		 Pitch 6"
15cm		 Shoes/track 79 Ground contact length 147"
373cm
T51
Outside guide, double pin, smooth, rubber
Width 16.56"
42.06cm		 Pitch 6"
15cm		 Shoes/track 79 Ground contact length 147"
373cm
M31: Performance
Max level road speed 25mph
40kph		 Max trench 89"
230cm
Max grade 60% Max vertical obstacle 24"
61cm
Min turning diameter 62'
19m		 Max fording depth 42"
110cm
Cruising range ~110mi
~180km

The M31 was based on the medium tank M3. The 75mm gun rotor was replaced by a door fitted with a dummy tube, and a Gar Wood Model 10-Y 5500 crane replaced the 37mm gun in the turret. The turret was rotated to the rear when not in use, and a dummy 37mm tube was attached to the turret rear to keep the appearance of a fighting vehicle. The turret machine gun mount was the British style seen on the cruiser tank Grant I instead of the normal Lee cupola. The crane could lift 10,000lbs (4,500kg) without the supporting boom jacks extended, 12,000lbs (5,400kg) with the jacks attached to the front hull, or 30,000lbs (14,000kg) with the support legs on the ground. A 60,000lb (27,000kg) capacity winch was added in the fighting compartment, and the cable was spooled out of the turret and over the crane boom or out the rear of the TRV. Tool boxes were also added to the rear sponsons and above the dummy 75mm gun. Due to dwindling supply of M3s, 296 M31B1s and M31B2s, which were similarly based on the M3A3 and M3A5, respectively, were converted by Baldwin Locomotive works beginning in October 1942. The power takeoff on the diesel TRVs was at the front and powered by the engine, rather than being at the left rear and driven by the transmission like on the gasoline radial-engined vehicles. This difference necessitated some modifications to the winch operator's position and controls.

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References

  1. Hunnicutt, R.P. Sherman: A History of the American Medium Tank. Navato, CA: Presidio Press, 1994. Reprinted with permission from Sherman, R.P. Hunnicutt ©1994, available from Presidio Press, 505B San Martin Drive, Suite 160, Navato, CA 94945.
  2. ORD 7-8-9 SNL G-169 C2 Organizational Spare Parts and Equipment, Higher Echelon Spare Parts and Equipment (Addendum) Service Parts Catalog for Vehicle, Tank Recovery, M31 (T2) (Tank, Medium, M3, w/Crane). Washington, DC: Headquarters, Army Service Forces, 6 April 1944.
  3. Catalogue of Standard Ordnance Items, second edition 1944, volume I: Tank and Automotive. Washington, D.C.: Office of the Chief of Ordnance, Technical Division, 1 June 1945.
  4. TM 9-2800 Standard Military Motor Vehicles. Washington, DC: War Dept., 1 Sep 1943.
  5. Chamberlain, Peter, and Chris Ellis. British and American Tanks of World War Two. Frome, England: Cassell & Co., 2000.
  6. Crismon, Fred W. U.S. Military Tracked Vehicles. Osceola, WI: Motorbooks International, 1992.
  7. Siemers, Cary. "USA's M3, M3A1, M3A2, M3A3, M3A4, M3A5 Medium Tanks." World War II Tanks & Vehicles and Advanced Squad Leader. 28 Jan 2001. 20 Feb 2001 <http://www.shadowsfolly.com/WWII/USA/MediumTankM3.htm>.
Last updated 11 Apr 2023.
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© Copyright 2001-24 Chris Conners