8" Howitzer Motor Carriage M431-7

M43: General
Date of first acceptance June 1945 Total acceptances 24 + 24 converted from 155mm GMC M40
Manufacturer Pressed Steel Car Co. Crew 8 men
M43: Dimensions
Combat weight 80,000lbs
36,000kg		 Height over howitzer mount 130"
330cm
Length without howitzer 280.4"
712.2cm		 Howitzer overhang forward 0"
Width 124"
315cm		 Tread 101"
257cm
Ground clearance 17"
43cm		 Fire height 102"
259cm
Ground pressure, zero penetration 10.6psi
.744kg/cm²
M43: Armament
Type Mount Ammunition Traverse Elevation
8" Howitzer M1 or M2 M17 on rear of chassis 16 rounds 36°
(18° left and right;
manual)		 +45° to -5°
(manual)
Aiming equipment
Panoramic telescope M12 or M12A7C and telescope M69G for gunner; elbow telescope M16A1G for cannoneer no.1
M43: Armor
Assembly
Welding
Hull
Rolled and cast homogeneous steel
Location Thickness Angle from vertical
Upper front .5"
1.3cm		 58°
Lower front 4.25" to 2.0"
10.8cm to 5.1cm		 0° to 46°
Upper sides .5"
1.3cm		 0°
Lower sides 1.0"
2.5cm		 0°
Rear .5"
1.3cm		 0°
Top .5"
1.3cm		 85°
Front floor 1.0"
2.5cm		 90°
Rear floor .5"
1.3cm		 90°
Howitzer shield .5"
1.3cm		 ~45°
M43: Automotive
Engine Continental R975 C4; 9 cylinder, 4 cycle, static radial, supercharged gasoline
Horsepower Net: 400@2,400rpm
Gross: 460@2,400rpm		 Torque Net: 940 ft-lb@1,700rpm
Gross: 1,025 ft-lb@1,800rpm		 Fuel capacity 215gal
814L
Transmission Synchromesh, 5 speeds forward, 1 reverse
Steering Controlled differential, steering levers
Brakes Mechanical, external contracting
M43: Suspension
Type Road wheels Track return rollers
Horizontal volute spring 3 bogies/track;
2 dual wheels/bogie		 2 dual/track, 3 single/track
Drive sprockets Idlers Shock absorbers
13-tooth front drive Dual adjustable at rear of track One on each bogie
M43: Track
T66
Center guide, single pin, cast, steel
Width 23"
58cm		 Pitch 6"
15cm		 Shoes/track 86 Ground contact length 164"
417cm
T80
Center guide, double pin, rubber and steel
Width 23"
58cm		 Pitch 6"
15cm		 Shoes/track 86 Ground contact length 164"
417cm
T84
Center guide, double pin, rubber
Width 23"
58cm		 Pitch 6"
15cm		 Shoes/track 86 Ground contact length 164"
417cm
M43: Performance
Max level road speed 21mph sustained
24mph dash
34kph sustained
39kph dash		 Max trench 92"
230cm
Max grade 60% Max vertical obstacle 24"
61cm
Min turning diameter 83'
25m		 Max fording depth 40"
102cm
Cruising range ~100mi, roads
~160km, roads

The 8" HMC M43 was a 155mm GMC M40 with the weapon replaced with the 8" howitzer. The gun mounts and carriages were identical. When mounting the howitzer instead of the gun, the nitrogen pressure in the recoil mechanism was increased from 1,820 to 2,000psi (from 128 to 140kg/cm²) and the nitrogen pressure in the equilibrators was decreased from 1,510 to 1,355psi (from 106 to 95.27kg/cm²).

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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. TM 9-747 155-mm Gun Motor Carriage T83 and 8-inch Howitzer Motor Carriage T89. Washington, DC: War Department, 26 February 1945.
  3. TM 9-747 155-mm Gun Motor Carriage M40 and 8-inch Howitzer Motor Carriage M43. Washington, DC: War Department, 15 September 1947.
  4. TM 9-3054 8-inch Howitzer M2 (Mounted in Combat Vehicles). Washington, DC: Department of the Army, 30 June 1953.
  5. Doyle, David. M40 Gun Motor Carriage and M43 Howitzer Motor Carriage in WWII and Korea. Atglen, PA: Schiffer Publishing, Ltd., 2017.
  6. Chamberlain, Peter, and Chris Ellis. British and American Tanks of World War Two. Frome, England: Cassell & Co., 2000.
  7. Siemers, Cary. "USA's Self Propelled Guns." World War II Tanks & Vehicles and Advanced Squad Leader. 4 Feb 2001. 19 Feb 2001 <http://www.shadowsfolly.com/WWII/USA/SelfPropelled.htm>.
Last updated 21 Jan 2024.
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© Copyright 2001-24 Chris Conners