Heavy Recovery Vehicle M511-6

M51: General
Date of first acceptance August 1954 Total acceptances 187
Manufacturer Chrysler Corp. Crew
4 men:
  • Commander in cab center
  • Crane operator in cab right rear
  • Rigger in cab right front
  • Driver in cab left front
M51: Dimensions
Combat weight ~120,000lbs
Height over AAMG ~129"
Length with boom and spade in travel position 399"
Width over tracks 143.0"
Tread 115.0"
Ground clearance 18"
Ground pressure, zero penetration 11.5psi
M51: Armament
Type Mount Ammunition Traverse Elevation
.50cal M2HB MG Cal. .50 AA machine gun mount 7046650 on commander's cupola 1,500 rounds 360°
Night vision
Infrared periscope M19 for driver
M51: Armor
Rolled homogeneous steel
Location Thickness Angle from vertical
Upper front .75"
Lower front 1.5"
Upper sides .75"
Lower sides 1.0"
Upper rear .75"
Lower rear 1.5"
Top .75"
Front floor 1.5"
Rear floor 1.0"
M51: Automotive
Engine Continental AVSI-1790-6; 12 cylinder, 4 cycle, 90° vee supercharged fuel-injected gasoline
Horsepower Net: 765@2,800rpm
Gross: 980@2,800rpm
Torque Net: 1,670 ft-lb@2,100rpm
Gross: 1,870@2,400rpm
Fuel capacity 400gal
Transmission XT-1400-2A, 3 ranges forward, 1 reverse
Steering Mechanical, T-bar
Brakes Multiple disc
M51: Suspension
Type Road wheels Track return rollers
Torsion bar 7 independently sprung dual/track 4 dual/track
Drive sprockets Idlers Shock absorbers
11-tooth rear drive Dual compensating at front of track On first 2 and last 2 road wheels/track
M51: Track
Center guide, double pin, rubber chevron
Width 28"
Pitch 7.09"
Shoes/track 81 Ground contact length 186.25"
M51: Performance
Max level road speed 30mph sustained
48kph sustained
Max trench 110"
Max grade 60% Max vertical obstacle 36"
Min turning diameter Pivot Max fording depth 60"
Cruising range ~150mi

The M51 heavy recovery vehicle utilized suspension components of the 120mm gun tank M103. A 30-ton (27-metric ton) crane boom occupied the center of the vehicle, and a 45-ton (41-metric ton) Pacific Car and Foundry Co. Model J-10 main winch was located in the front of the vehicle. A 5-ton (4,500kg) Pacific Car and Foundry Model E auxiliary winch was located beside the main winch and was accessible through a hatch in the hull front. The auxiliary winch was used to handle the main winch cable, lower the spades, and for light winching operations. The main winch was provided with 300' (91m) of 1.25" (3.18cm) thick 6x37 steel cable, while the auxiliary winch had 475' (145m) of .5" (1.3cm) thick cable. The crane boom could be traversed 30° to either side by a double-acting hydraulic cylinder mounted on its base, and the inner boom could be extended so that the hook, normally 4' (1.2m) from the rear hull, would hang 8' (2.4m) from the rear hull. With the boom retracted, the crane could lift 30 tons (27 metric tons) at a distance of 6' (2m) from the rear hull plate; with the boom extended, 15 tons (14 metric tons) could be lifted 12' (4m) from the rear hull plate. The boom winch had 215' (65.5m) of .625" (1.59cm) thick cable, and the crane hook winch had 145' (44.2m) of cable of the same diameter. During recovery operations, the vehicle was stabilized by spades fitted to the bow and rear. From July 1956 to July 1958, all but ten M51s were reworked at the Lima Ordnance Depot due to engine, transmission, and winch problems. The fifty-two updates performed on each machine cost $26,000 per vehicle, compared to the production cost of about $150,000 for a new M51. The ten vehicles not included in the modification program were scrapped.




  1. Hunnicutt, R.P. Firepower: A History of the American Heavy Tank. Navato, CA: Presidio Press, 1988.
  2. TM 9-2320-204-12 Operation and Organizational Maintenance Heavy Tank Recovery Vehicle M51. Washington, DC: Headquarters, Department of the Army, 28 April 1958.
  3. TM 9-2320-204-35 Ordnance Field and Depot Maintenance Miscellaneous Components for Tank Recovery Vehicle Heavy M51. Washington, DC: Headquarters, Department of the Army, 21 May 1959.
  4. Crismon, Fred W. U.S. Military Tracked Vehicles. Osceola, WI: Motorbooks International, 1992.
  5. Standard Military Vehicle Characteristic Data Sheets. Center Line, MI: Army Tank and Automotive Command Research & Engineering Directorate, Jul 1960.
  6. Icks, COL (Ret.) Robert J. M103 Heavy Tank + M41 Light Tank (Walker Bulldog). Ed. Duncan Crow. Windsor, England: Profile Publications, Ltd., Mar 1972.
Last updated 29 Jun 2023.
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