M1917: General | |||
Date of first acceptance | October 1918 | Total acceptances | 950 |
Manufacturers |
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Crew |
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M1917: Dimensions | |||
Combat weight | 14,500lbs 6,580kg |
Height | 91" 230cm |
Length with tailpiece | 197" 500cm |
Gun overhang forward | 0" |
Width over tracks | 70" 180cm |
Tread | 57" 145cm |
Ground clearance | 16.2" 41.1cm |
Fire height | 70" 180cm |
Turret ring diameter | 36" 91cm |
Ground pressure, zero penetration | 6.9psi .48kg/cm² |
M1917: Armament | ||||
Type | Mount | Ammunition | Traverse | Elevation |
37mm Gun M1916 --OR-- .30cal M1919 MG |
Ball mount in turret | 238 rounds 37mm (25 ready) --OR-- 4,200 rounds .30cal |
360°; 30° in mount (manual) |
56° in 37mm mount (manual) 38° in .30cal mount (manual) |
Aiming equipment | ||||
Telescopic sight M1918 (tank) for gunner |
M1917: Armor | ||
Assembly | ||
Bolting and riveting | ||
Hull | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Driver's cupola | .60" 1.5cm |
17° |
Driver's doors | .31" .79cm |
70° |
Front | .60" 1.5cm |
30° |
Sides | .60" 1.5cm |
0° |
Rear | .60" 1.5cm |
0° |
Front top | .31" .79cm |
90° |
Rear top | .31" .79cm |
65° to 90° |
Floor | .25" .64cm |
90° |
Turret | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Gun shield | .60" 1.5cm |
0° |
Front | .60" 1.5cm |
12° |
Sides | .60" 1.5cm |
12° |
Rear | .60" 1.5cm |
12° |
Top | .31" .79cm |
73° to 90° |
M1917: Automotive | |||
Engine | Buda HU modified; 4 cylinder, 4 cycle, vertical L-head gasoline | ||
Horsepower | Gross: 42@1,460rpm | Fuel capacity | 30gal 113L |
Transmission | Selective sliding gear, 4 speeds forward, 1 reverse | ||
Steering | Clutch-brake, steering levers | ||
Brakes | Mechanical, external contracting |
M1917: Suspension | ||
Type | Road wheels | Track return rollers |
Coil and leaf spring | 2 bogies/track; 5 track rollers/front bogie, 4 track rollers/rear bogie |
6/track |
Drive sprockets | Idlers | Shock absorbers | 15-tooth rear drive | Adjustable at front of track | None |
M1917: Track | |||||||
Single pin, cast steel with integral grouser | |||||||
Width | 13.375" 33.973cm |
Pitch | 9.842" 25.00cm |
Shoes/track | 32 | Ground contact length | 79" 200cm |
M1917: Performance | |||
Max level road speed | 5.5mph 8.9kph |
Max trench | 84" 210cm |
Max grade | 70% | Max vertical obstacle | 36" 91cm |
Min turning diameter with tailpiece | 20' 6.1m |
Max fording depth | 24" 61cm |
Cruising range | ~30mi, roads ~48km, roads |
The six-ton tank M1917 was originally known as the six-ton special tractor model 1917, and was the American version of the French Renault FT. The measurements for the tank were switched from metric to English for the American conversion. Some other differences present in the Americanized model were replacement of the steel-rimmed wooden idler wheels with all steel wheels, American weapons, a different engine that featured the exhaust muffler on the left side of the hull, and a bulkhead separating the crew from the engine. The idler adjustment mechanism was changed to utilize a screw on each side instead of the single fork used on the French machine. Hooks were used as tow points, and an extra outward-facing hook was added to each side of the upper hull just behind the turret to aid in shipping. The American tanks also had an additional plate featuring a vision slot on either side of the driver necessitated by allowances from the change in measurement systems. The top of the tailpiece was secured by a threaded rod with handles screwed onto each end. All M1917s were fitted with a riveted octagonal turret, as opposed to some French tanks which were fitted with a round cast turret. The machine gun M1917s were originally armed with the .30cal Marlin tank machine gun, but this was switched to the Browning M1919 starting in 1919. Browning tank machine gun tanks had a vertical seven-compartment ammunition belt rack hooked to a bracket on each side of the gunner's compartment. Each compartment could hold six 50-round ammunition belts on a hinged hook. 37mm ammunition was stowed in a 100-round rack on each side of the gunner's compartment, each having four horizontal rows that could accommodate 25 rounds; a 13-round rack suspended from the bottom of the front of the left 100-round rack, though it could be moved to the opposite 100-round rack; and a 25-round rack attached to the right side of the turret.
Of the 950 M1917s, there were 374 37mm gun tanks, 526 machine gun tanks, and 50 signal tanks which possessed no armament but carried a radio in a fixed superstructure.
M1917A1: General | |||
Date of introduction | 1930 | Total acceptances | 7 converted from M1917 |
Manufacturers |
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Crew |
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M1917A1: Dimensions | |||
Empty weight | 14,200lbs 6,440kg |
Height | 91" 230cm |
Length with tailpiece | 208" 528cm |
Gun overhang forward | 0" |
Width over tracks | 70" 180cm |
Tread | 57" 145cm |
Ground clearance | 16.2" 41.1cm |
Fire height | 70" 180cm |
Turret ring diameter | 36" 91cm |
Ground pressure, zero penetration, empty | 6.7psi .47kg/cm² |
M1917A1: Armament | ||||
Type | Mount | Ammunition | Traverse | Elevation |
37mm Gun M1916 --OR-- .30cal M1919 MG |
Ball mount in turret | 238 rounds 37mm --OR-- 4,200 rounds .30cal |
360°; 30° in mount (manual) |
56° in 37mm mount (manual) 38° in .30cal mount (manual) |
Aiming equipment | ||||
Telescopic sight M1918 (tank) for gunner |
M1917A1: Armor | ||
Assembly | ||
Bolting and riveting | ||
Hull | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Driver's cupola | .60" 1.5cm |
17° |
Driver's doors | .31" .79cm |
70° |
Front | .60" 1.5cm |
30° |
Sides | .60" 1.5cm |
0° |
Rear | .60" 1.5cm |
0° |
Front top | .31" .79cm |
90° |
Rear top | .31" .79cm |
65° to 90° |
Floor | .25" .64cm |
90° |
Turret | ||
Rolled face-hardened steel | ||
Location | Thickness | Angle from vertical |
Gun shield | .60" 1.5cm |
0° |
Front | .60" 1.5cm |
12° |
Sides | .60" 1.5cm |
12° |
Rear | .60" 1.5cm |
12° |
Top | .31" .79cm |
73° to 90° |
M1917A1: Automotive | |||
Engine | Franklin series 145; 6 cylinder, air-cooled, gasoline | ||
Horsepower | Gross: 100@3,100rpm | Fuel capacity | 30gal 113L |
Transmission | Selective sliding gear, 4 speeds forward, 1 reverse | ||
Steering | Clutch-brake, steering levers | ||
Brakes | Mechanical, external contracting |
M1917A1: Suspension | ||
Type | Road wheels | Track return rollers |
Coil and leaf spring | 2 bogies/track; 5 track rollers/front bogie, 4 track rollers/rear bogie |
6/track |
Drive sprockets | Idlers | Shock absorbers | 15-tooth rear drive | Adjustable at front of track | None |
M1917A1: Track | |||||||
Single pin, cast steel with integral grouser | |||||||
Width | 13.375" 33.973cm |
Pitch | 9.842" 25.00cm |
Shoes/track | 32 | Ground contact length | 79" 200cm |
M1917A1: Performance | |||
Max level road speed | ~9mph ~14.5kph |
Max trench | 84" 210cm |
Max grade | 70% | Max vertical obstacle | 36" 91cm |
Min turning diameter with tailpiece | 20' 6.1m |
Max fording depth | 24" 61cm |
Cruising range | ~30mi, roads ~48km, roads |
The rear hull of the M1917A1 was longer and taller to accommodate the new engine. The tanks were also equipped with a self starter, and the engine, transmission, and clutches were mounted as a single unit, which eased maintenance. The increased weight and speed necessitated strengthening the idler wheel rims. The engine was governed down to 2500rpm to prevent damage to the powertrain components.