M977 Heavy Expanded Mobility Tactical Truck (HEMTT)

Gary's Combat Vehicle Reference Guide

The M977 Heavy Expanded Mobility Tactical Truck (HEMTT) series of vehicles consists of a number of different models all built on similar chassis but specially equipped to perform different missions. These 8x8 diesel-powered off-road capable all-weather trucks are used by the U.S. military to perform line and local haul, unit resupply, and related missions in a tactical environment.

Capabilities:

• All models are capable of operating in temperatures from -25° to 120°F (-32° to 49°C) and to -50°F (-46°C) with arctic kit installed.
  
  
• All models can ford water up to 48 inches (1,219 mm) deep for 5 minutes without damage or without requiring maintenance before operation can continue.
  
  
• Normal operating range of all models is 300 miles (483 km), based upon 154 gallons (583 L) of fuel and 100,000 pound (45,400 kg) GCWR, traveling over mixed terrain. Varying loads, prolonged idle, use of power takeoff (PTO), offroad driving, and climatic conditions affect operating range.
  
  
• All models are provided with sufficient tiedown points located so vehicles can be restrained in all directions during air transport in C-130, C-141, and C-5A type aircraft. All models are capable of being transported by highway, rail, and sea.

Power for the vehicle is provided by a diesel engine which is coupled directly to an automatic transmission. Power from the transmission is transferred to the transfer case and on to the front and rear axles through a series of propeller shafts and universal joints.

The engine is a 2-cycle, turbocharged, 8-cylinder, v-block diesel unit.

The automatic transmission includes an electrically controlled power takeoff (PTO). The PTO provides power to a hydraulic pump, which powers the vehicle's hydraulic system. The hydraulic system operates the self-recovery winch, the material handling crane, the heavy duty recovery winch, and the pumping equipment, depending on how the vehicle is equipped.

The transfer case connects the drive train to the number 1 and number 2 axles when 8-wheel drive is needed. The transfer case has two gear ratios (high and low) and neutral. Because the gears are not synchronized, the vehicle must be stopped before the transfer case can be shifted between ranges. Engagement of the transfer case in low range will automatically engage the drive train to the front axles.

Front and rear tandem axles are single reduction, full floating axle shaft type. The front tandem provides steering. The rear tandem is nonsteering. Both front and rear tandems are equipped with wheel differentials and interaxle differentials. The interaxle differentials have driver-controlled lockouts for positive drive to all axles in low range. The rear tandem is equipped with permanently engaged controlled traction differentials. The front and rear suspensions are tandem axle type with leaf springs and equalizer beams.

The propeller shafts and universal joints transmit engine power to the axles.

The Crew Protection Kit provides the HEMTT with improved ballistic protection against mines, improvised explosive devices (IEDs), light artillery fragments, and 7.62mm ball projectiles. The kit consists of armor panels that are installed on the cab of the HEMTT:

• Driver-side, center, and passenger-side blast deflectors under the vehicle.
• Front, side, rear, and roof armor panels.
• An armored roof escape hatch.
• Door assemblies.
• Radiator grille armor.
• Ballistic glass for windshield and side door windows.

The Crew Protection Kit has two different side armor and door armor configurations. The updated side armor and door armor are referred to as Model B.

Total weight of kit: 2,883.99 lb (1,308.13 kg). Total weight increase to vehicle: 2,490.79 lb (1,129.78 kg). Total weight of Model B kit: 3,529.19 lb (1,600.78 kg). Total weight increase of Model B kit to vehicle: 3,135.99 lb (1,422.43 kg).

All models except M1142 Tactical Fire Fighting Truck:

• Arctic Engine Heater Kit
• Chemical Alarm
• Cargo Cover Kit
• Decontamination Unit
• Gas Particulate Filter Unit
• Machine Gun Ring
• Radio Installation Kit
• Rifle Mounting Kit

M1142 Tactical Fire Fighting Truck:

• Arctic Engine Heater Kit
• Gas Particulate Filter Unit
• Radio Installation Kit

Vehicle may or may not be equipped with any of these items depending on mission, climate, or other factors.

Non-A2 and A2R1 model vehicles are equipped with a turbocharged diesel engine. These models also use an automatic transmission with one reverse speed and four forward speeds.

A2 and A2R1 model vehicles are equipped with a DDEC IV electronically controlled, turbocharged diesel engine. These models also use a push button automatic transmission with one reverse speed and five forward speeds.

Model Number 8087-7899 engines are 445 hp (332 kw). Model Number 8083-7493 engines are 450 hp (336 kw).

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M977 Cargo Truck

The M977 cargo vehicle is a general purpose carrier used for ammunition resupply and other resupply missions.

• "Truck, Cargo, With Winch, M977", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/LT Crane" (NSN 2320-01-097-0260)
  $212,104. Cargo vehicle with 62,000 pound (28,100 kg) GVWR and 100,000 pound (45,400 kg) GCWR. Vehicle is equipped with material handling crane with a 2,500 pound (1,135 kg) load capacity at a 19 foot (5.8 m) boom radius and has an 18 foot (5.5 m) cargo body.
  
  
• "Truck, Cargo, With Winch, M977A2", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/LT Crane" (NSN 2320-01-493-3774)
  $260,574.
  
  
• "Truck, Cargo, With Winch, M977A2R1", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/LT Crane" (NSN 2320-01-493-3782)
  $170,580.
  
  
• "Truck, Cargo, Without Winch, M977", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/LT Crane" (NSN 2320-01-099-6426)
  $185,820.
  
  
• "Truck, Cargo, Without Winch, M977A2", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/LT Crane" (NSN 2320-01-493-3779)
  $251,388.
  
  
• "Truck, Cargo, Without Winch, M977A2R1", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/LT Crane" (NSN 2320-01-493-3785)
  $165,916.
  
  
• "Power Plant: Elec Trailer Mounted (EPP III), M977" (NSN 6115-01-374-5038)
  
  $560,000.
  
  

M977
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M977 overhead view
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M977 with a convoy on a desert road.
Operation Desert Shield.
01-APR-1992
U.S. DoD Photo
1280x768, 245K, JPG

M978 Fuel Tank Truck

The M978 tanker is used to refuel wheeled and tracked vehicles in forward positions and for other fuel resupply missions.

• "Truck, Tank, Fuel, With Winch, M978", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob W/WINCH" (NSN 2320-01-097-0249)
  $270,993. Tanker vehicle with 2,500 gallon (9,463 l) tank and fuel resupply module.
  
  
• "Truck, Tank, Fuel, With Winch, M978A2", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob W/WINCH" (NSN 2320-01-492-8216)
  $278,409.
  
  
• "Truck, Tank, Fuel, With Winch, M978A2R1", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob W/WINCH" (NSN 2320-01-492-8226)
  $172,439
  
  
• "Truck, Tank, Fuel, Without Winch, M978", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob" (NSN 2320-01-100-7672)
  $260,043.
  
  
• "Truck, Tank, Fuel, Without Winch, M978A2", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob" (NSN 2320-01-492-8215)
  $268,440.
  
  
• "Truck, Tank, Fuel, Without Winch, M978A2R1", "Truck, Tank: Fuel Servicing 2500 Gallon 8X8 Heavy Exp Mob" (NSN 2320-01-492-8225)
  $190,413.
  
  

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The HEMTT Tanker Aviation Refueling System (HTARS) is used to distribute and control fuel flow from the HEMTT tanker to the aircraft being refueled. The HTARS consists of tees, elbows, adapters, lightweight hoses, and nozzles required to set up a four-station aircraft refueling system.

There are two models of the HTARS: HTARS100 and HTARS101.

Fuel required to operate the HTARS is supplied by the HEMTT tanker and distributed through the 3-inch supply hose to the network of 2-inch hoses, tees and elbows that make up the four refueling points. Fuel flow through the system is controlled by opening or closing the valves located on each hose and tee coupling. In the event of a fuel leak, the defective component can be isolated by closing the nearest upstream and downstream coupling valves. Once isolated, the defective component can be replaced without interrupting fuel flow through the remaining refueling points.

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The Tanker Armor Module (TAM) consists of armor panels mounted to the existing M978 tanker pump module to protect the components within the module:

• Wheel well armor panel assemblies under the vehicle.
• Front armor panel assemblies.
• Rear armor panel assemblies - incorporate two swing out doors that replace the pump module rear (swing up) doors.
• Upper and lower side armor panel assemblies.
• Top armor panel assembly - includes two hinged access doors.
• Replacement lights, ladder, and rail assembly.

All armor panels are attached to the pump module with brackets and hardware provided in the TAM kit.

Available in tan (NSN 2540-01-542-0885) or green (NSN 2540-01-542-0889).

Total weight of kit: 1,807 lb (819.6 kg). Total weight increase to vehicle: 1,633 lb (740.7 kg).

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M978
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M978
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M978 being prepared for loading aboard ship.
After Operation Desert Shield.
11-NOV-1991
U.S. DoD Photo
1280x768, 241K, JPG

M983 Tractor Truck

The M983 tractor can pull most Army semi-trailers.

• "Truck, Tractor, With Winch, Without Crane, M983", "Truck, Tractor: Tactical 8X8 Heavy Expanded Mobility W/WN" (NSN 2320-01-097-0247)
  $159,183. Tractor vehicle with 100,000 pound (45,400 kg) GCWR. Vehicle is equipped with fifth wheel and 3 1/2 inch kingpin. Used with the Patriot missile system.
  
• "Truck, Tractor, With Heavy Duty Winch, M983A1"
  $159,183.
  
  
• "Truck, Tractor, With Winch, Without Crane, M983A2", "Truck, Tractor: Tactical 8X8 Heavy Expanded Mobility W/WN" (NSN 2320-01-492-8223)
  $201,258.
  
  
• "Truck, Tractor, With Winch, Without Crane, M983A2R1", "Truck, Tractor: Tactical 8X8 Heavy Expanded Mobility W/WN" (NSN 2320-01-492-8231)
  $143,203.
  
  
• "Truck, Tractor, With Winch, With Crane, M983", "Truck, Tractor: Tactical 8X8 Heavy Expanded Mobility W/WN W/CRANE" (NSN 2320-01-099-6421)
  $181,793. No longer in use. Was used with the Pershing II missile system and with semi-trailers with 2-inch kingpins.

M983 without crane
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M983 with crane
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M983 with Patriot launching station

M983 with Patriot radar system.

M984 Wrecker-Recovery Truck

The M984 recovery truck can tow most Army tactical trucks.

• "Truck, Wrecker-Recovery, M984", "Truck, Wrecker: Tactical 8X8 Heavy Ecpanded Mobility W/Winch" (NSN 2320-01-097-0248)
  $155,000. Wrecker vehicle with 82,000 pound (37,200 kg) GVWR and 100,000 pound (45,400 kg) GCWR. Vehicle is equipped with material handling crane with 10,000 pound (4,540 kg) load capacity at 12 feet (3.7 m) or 24,000 pounds (10,886 kg) with boom extension retracted and resting on boom support tubes, 60,000 pound (27,240 kg) recovery winch, and a 10 foot (3 m) cargo body.
  
  
• "Truck, Wrecker-Recovery, M984A1", "Truck, Wrecker: Tactical 8X8 Heavy Expanded Mobility W/Winch", "Truck, Wrecker-Recovery, M984E1" (NSN 2320-01-195-7641)
  $276,866. Wrecker vehicle with 95,000 pound (43,000 kg) GVWR and 114,000 pound (51,700 kg) GCWR that can be increased to 155,000 pound (70,300 kg) GCWR under certain conditions. Vehicle is equipped with material handling crane with 6,000 pound (2,722 kg) load capacity at 18.2 foot (5.5 m) boom radius, 60,000 pound (27,215 kg) recovery winch, and equipment body with 10 stowage compartments.
  
  The M984A1 vehicle is used as a multi-purpose vehicle capable of recovering and towing a full spectrum of loaded, wheeled vehicles. This vehicle has lift and reach capability to perform maintenance assistance associated with removing and replacing power packs and heavy components from a wide range of wheeled and tracked vehicles.
  
  
• "Truck, Wrecker-Recovery, M984A2", "Truck, Wrecker: Tactical 8X8 Heavy Expanded Mobility W/Winch" (NSN 2320-01-492-8224)
  $379,000.
  
  
• "Truck, Wrecker-Recovery, M984A2R1", "Truck, Wrecker: Tactical 8X8 Heavy Expanded Mobility W/Winch" (NSN 2320-01-492-8233)
  $199,160.
  
  

M984
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M984A1/M984E1
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M985 Cargo Truck

The M985 cargo vehicle is used to resupply the Multiple Launch Rocket System (MLRS).

• "Truck, Cargo, With Winch, M985", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/MED Crane" (NSN 2320-01-097-0261)
  $202,560. Cargo vehicle with 68,000 pound (30,800 kg) GVWR and 100,000 pound (45,400 kg) GCWR. Vehicle is equipped with material handling crane with 5,400 pound (2,450 kg) load capacity at 16.5 foot (5 m) boom radius and has an 18 foot (5.5 m) cargo body.
  
  
• "Truck, Cargo, With Winch, M985A2", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/MED Crane" (NSN 2320-01-492-8214)
  $282,002.
  
  
• "Truck, Cargo, With Winch, M985A2R1", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/W W/MED Crane" (NSN 2320-01-493-3787)
  $168,277.
  
  
• "Truck, Cargo, Without Winch, M985", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/MED Crane" (NSN 2320-01-100-7673)
  $194,853.
  
  
• "Truck, Cargo, Without Winch, M985A2", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/MED Crane" (NSN 2320-01-492-8201)
  $272,033
  
  
• "Truck, Cargo, Without Winch, M985A2R1", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mobility W/MED Crane" (NSN 2320-01-493-3789)
  $163,613.
  
  
• "Truck, Cargo, Without Winch, M985E1" (NSN 2320-01-094-7031)
  No longer in use.
  
  
• "Truck, Cargo, With Winch, M985E1", "Truck, Cargo: 8X8 57000 GVW High Mobility" (NSN 2320-01-194-7032)
  $173,779. The M985E1 is the same as the M985 except that the bed is lengthened to 420.5 inches to carry Patriot missile rounds. Cargo vehicle with 58,000 pound (26,307 kg) GVWR and 100,000 pound (45,358 kg) GCWR. Vehicle is equipped with material handling crane with 5,400 pound (2,450 kg) load capacity at 16.5 feet (5.03 m) or 4,500 pounds (2,041 kg) at 20.5 feet (6.25 m). Maximum reach in knuckle position (inner boom 10° - 15° above horizontal and outer boom horizontal) is 20.5 feet (6.25 m)
  
  
• "Truck, Cargo, With Winch, M985E1A2", "Truck, Cargo: 8X8 57000 GVW High Mobility" (NSN 2320-01-493-3790)
  $307,359.
  
  
• "Truck, Cargo, With Winch, M985E1A2R1", "Truck, Cargo: 8X8 57000 GVW High Mobility" (NSN 2320-01-493-3792)
  $215,151.
  
  

M985
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M985E1
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M1120 Cargo Truck With Load Handling System

The M1120 HEMTT with LHS is a tactical wheeled truck with integral self-load/unload capability. LHS enables a single operator to load a flatrack to a truck and/or a trailer. The M1120 can be fitted with a Container Handling Unit (CHU) capable of lifting ISO containers and shelters onto truck.

• "Load Handling System, Heavy Expanded Mobility Tactical Truck (HEMTT), M1120", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mob W/LHS" (NSN 2320-01-471-1326)
  $125,000.
  
  
• "Load Handling System, Heavy Expanded Mobility Tactical Truck (HEMTT), M1120A2", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mob W/LHS" (NSN 2320-01-492-8221)
  $226,800.
  
  
• "Load Handling System, Heavy Expanded Mobility Tactical Truck (HEMTT), M1120A2R1", "Truck, Cargo: Tactical 8X8 Heavy Expanded Mob W/LHS" (NSN 2320-01-492-8230)
  $152,975.
  
  
• "Mobile Integrated Remains Collection System, M1120"
  $250,000.
  
  

M1120
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M1120 with Container Handling Unit (CHU)
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M1120 with CHU and container
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M1120 overhead view
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Unloading ammunition at a supply point.
Operation Iraqi Freedom.
Near Tall Afar, Iraq.
09-SEP-2004
U.S. DoD Photo
1280x768, 298K, JPG

M1142 Tactical Fire Fighting Truck

"Truck, Tactical Fire Fighting, M1142", "Truck: Tactical Firefighting 8X8 Hvy Exp Mob" (NSN 4210-01-486-1035)
$640,131. The M1142 TFFT is equipped to extinguish aircraft, petroleum, brush, wildland, and structural fires at isolated military installations. The TFFT is built on a modified M977 chassis:

• The location of the HEMTT air compressor and hydraulic pump have been reversed, in order to accept the new transmission.
• Fuel tank and chassis batteries have been lowered slightly to allow room for the crew cab.
• A mounting bracket has been added on front of cab for bumper turret.
• The personnel cab roof has been modified to accept lightbars and a turret.
• Springs have been updated for 66,000 lbs (29,937 kg) GVWR.

The TFFT is not designed to tow a trailer.

The TFFT is equipped with a water cooled, Deutz water pump engine and Darley pump; bumper turret; roof turret; four ground sweeps; pump house; pump operators panel; and cab instrument panels. The equipment body of the TFFT is equipped with 14 body stowage compartments

M1142
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M1142
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M1158 HEMTT-Based Water Tender (HEWATT) (NSN 2320-01-528-6294)

$400,000. The HEWATT is equipped to extinguish brush, wildland, and structural fires at isolated military installations and to support M1142 Tactical Fire Fighting Truck (TFFT) operations. The HEWATT is built on a Heavy Expanded Mobility Tactical Truck (HEMTT) M985 chassis:

• A mounting bracket has been added on the front of the cab for bumper turret.
• The personnel cab roof has been modified to accept lightbars.
• Rear springs have been updated for 66,000 lbs. (29,964 kg) GVWR.
• Air compressor and power steering unit have been swapped to allow room for PTO drive system.
• Fuel tank has been lowered for water tank mounting.
• Cab steps were increased in size to allow for safer cab access.
• Driver side air supply port has been relocated left of pump operator's panel.

The HEWATT is not designed to tow a trailer.

The HEWATT is equipped with a bumper turret, four under truck nozzles, a driver side and passenger side discharge, a one-inch diameter hose on a mechanical/electrical hose reel, a Class A foam system, a water system, a 2500 gallon portable water reservoir, a pump operator's panel, a cab instrument panel, driver side and passenger side auxiliary inlets, main inlet, and direct tank fill inlet.

M1158
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M1158
900x520, 42K, B/W, PNG

M1977 Common Bridge Transporter

The M1977 CBT is made up of a transporter, consisting of a remanufactured and modified M977 HEMTT truck chassis with a self-contained Load Handling System (LHS) and either an an M14 improved boat cradle (IBC) or an M15 bridge adapter pallet (BAP).

The CBT is used for loading, transporting, unloading, launching, and retrieving bridge erection boats (using M14 IBC) and the ribbon bridge, and improved ribbon bridge (using M15 BAP).

The CBT also provides the capability for performing cargo-hauling missions using the Palletized Load System (PLS) flatrack loaded to 10 tons (9 metric tons). The CBT is capable of towing the Palletized Load System (PLS) trailer to increase hauling capabilities.

• "Truck, Cargo, Common Bridge Transporter, Without Winch, M1977", "Transporter, Common Bridge" (NSN 2320-01-442-1940)
  $215,862.
  
  
• "Truck, Cargo, Common Bridge Transporter, Without Winch, M1977A2", "Transporter, Common Bridge" (NSN 2320-01-492-8218)
  $207,241.
  
  
• "Truck, Cargo, Common Bridge Transporter, Without Winch, M1977A2R1", "Transporter, Common Bridge" (NSN 2320-01-492-8228)
  $144,574.
  
  
• "Truck, Cargo, Common Bridge Transporter, With Winch, M1977", "Transporter, Common Bridge" (NSN 2320-01-443-8023)
  $226,150.
  
  
• "Truck, Cargo, Common Bridge Transporter, With Winch, M1977A2", "Transporter, Common Bridge" (NSN 2320-01-492-8219)
  $217,434.
  
  
• "Truck, Cargo, Common Bridge Transporter, With Winch, M1977A2R1", "Transporter, Common Bridge" (NSN 2320-01-492-8229)
  $149,912.
  
  

M1977 Model A with LHS
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M1977 Model A with BAP mounted on LHS
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M14 Improved Boat Cradle (IBC)
590x360, 17K, B/W, PNG

M15 Bridge Adapter Pallet (BAP)
650x520, 15K, B/W, PNG

Bridge bay
680x450, 8K, B/W, PNG

North Dakota Army National Guard 957th Multi-Role Bridge Company.
Bismarck, North Dakota.
11-FEB-2003
U.S. DoD Photo
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North Dakota Army National Guard 957th Multi-Role Bridge Company.
Bismarck, North Dakota.
21-FEB-2003
U.S. DoD Photo
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