The M915 is a tractor unit used for line-haul missions by the United States Army. Designed for use on improved roads, it does not have a driven front axle.

M915
A M915A5
Type6x4 semi-tractor
Place of originUnited States
Production history
DesignerCrane Carrier Co. (M915)
Freightliner (M915A2)
ManufacturerAM General (M915, M915A1)
Freightliner (M915A2 and later)
Specifications (M915A2[1])
Mass18,680 lb (8,470 kg) (empty)
Length22 ft 11 in (6.99 m)
Width8 ft 2 in (2.49 m)
Height9 ft 11 in (3.02 m)

EngineDetroit Diesel DDEC II
400 hp (300 kW)
Transmission4-speed automatic
SuspensionBeam axles on leaf springs
Operational
range
300 miles (480 km)
Maximum speed 55 mph (89 km/h)

History

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The M915 is the namesake and basis of a tactical truck series, although it is not tactical itself. It is a commercial type conventional 6x4 rear wheel drive 14-ton semi-tractor designed for use on improved roads. A powered front axle and other tactical equipment are not needed for this role, allowing a lighter and simpler truck. It shares the engine, transmission, cab, and some components of the other trucks in the series.[2]

The more specialized trucks in the series are the M916 6x6 all wheel drive 14-Ton Light Equipment Transporter (LET) tractor with rear winch; M917 8x6 20-ton, 12 cubic yard Dump Truck; M918 6x6 22.5-ton, 1,500 gallon Bituminous Distributor; M919 8x6 22.5-ton, 8 cubic yard Concrete Mixer; and M920 8x6 20-ton Medium Equipment Transporter (MET) tractor with rear winch, all of which are employed in Engineer Combat Support and Construction units.

The M915 and follow on M915A1 were a Crane Carrier Company design based on CCC's Centaur commercial tractor, built under contract by AM General between 1978 and 1982. The 1990 -A2 upgrade was a completely different truck: a Freightliner Trucks design with a different engine and transmission, hood and cab. Older models were upgraded to -A4 standard with a new cab and frame that used the original truck's components. Starting in 2009 M915A3s were upgraded to the armored -A5 standard.

Engine and driveline

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The M915 has a 855 cu in (14.0 L) Cummins NTC 400 developing 400 hp (300 kW) at 2100rpm and 1,150 lbf⋅ft (1,559 N⋅m) of torque at 1500rpm. The M915A2 had a 775 cu in (12.7 L) Detroit Diesel Series 60 DDEC II developing 400 hp (300 kW) at 2100rpm and 1,400 lbf⋅ft (1,898 N⋅m) of torque at 1200rpm. Both are turbocharged inline 6 cylinder 4-stroke diesel engine, both engines are intercooled. The Cummins uses a water to air after-cooler while the Series 60 uses an air to air after-cooler.[3][4]

The M915 has a Caterpillar 16 speed semi-automatic transmission, the M915A2 Allison HT-470 4-speed automatic.[4][5]

Chassis

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A conventional ladder frame has a front steering axle with a 12,000 lb (5,400 kg) weight rating and tandem rear axles with a 40,000 lb (18,000 kg) weight rating. The truck can have a maximum weight of 52,000 lb (24,000 kg), including a 30,000 lb (14,000 kg) load. The total weight rating of the truck and trailer is 105,000 lb (48,000 kg).[6][7]

A Holland commercial type sliding fifth wheel could carry 30,000 lb (14,000 kg).[8] It towed the M871 22+12-ton (20,400 kg) 2 axle flatbed, the M872 34-ton (30,800 kg) 3 axle flatbed, and the M1067.[9]

Operators

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References

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  1. ^ TM 9-2320-363-10 Operator's Manual for Truck, Trator, Line Haul: 52,000 GVWR, 6x4, M915A2 (NSN 2320-01-272-502) (and others). US Dept. of the Army. 1997. pp. 1–5, 1-16 to 1-19, 2–28.
  2. ^ TM 9-2320-363-10 (1997), p. 1-15.
  3. ^ TM 9-2320-273-10 Operators Manual Truck Tractor, Line Haul, 50,000 GVWR, 6x4, M915 (and others). US Dept of the Army. 1980. pp. 1-16 and 1-17.
  4. ^ a b TM 9-2320-363-10 (1997), pp. 1–17, 1–18.
  5. ^ TM 9-2320-273-10 (1980), p. 1-19.
  6. ^ TM 9-2320-363-10 (1997), p. 1-16.
  7. ^ TM 9-2320-363-20-1 Unit Maintenance Manual for Truck, Trator, Line Haul: 52,000 GVWR, 6x4, M915A2 (NSN 2320-01-272-5029) (and others), US Dept. of the Army, 1992, p. 1–13
  8. ^ TM 9-2320-363-10 (1997), p. 1-22, 2-58 to 2-99.
  9. ^ TM 43-0001-31 Equipment Data Sheets for TACOM Combat and Tactical Equipment. US Dept. of the Army. 1985. pp. 6–76, 6–80.
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