(HEMTT) Heavy Expanded Mobility Tactical Truck
Since the 1980s, the Army has utilized Heavy Expanded Mobility Tactical Truck (HEMTTs). They are a range of eight wheel drive off-road cargo trucks that weigh just over 38,800 lbs and are manufactured by the Oshkosh Truck Corporation. The trucks are easy to deploy and are extremely versatile, able to be used on a variety of terrains and in almost any combat situation or climate. They are currently used by the United States, Israeli Defense Force, Iraq and Egypt.
Uses for the HEMTT
The Heavy Expanded Mobility Tactical Truck is primarily used to transport combat vehicles and weapons in the field. They were first used by the United States Army in 1982 as a replacement for the M-520 GOER. Over twenty years later, 13,000 HEMTTs were still in service as the main heavy tactical vehicle for the Army and Marine Corps.
Description of HEMTTs
There are five main types of HEMTT
- M977 cargo truck with Material Handling Crane (MHC),
- M978 2500 gallon fuel tanker,
- M984 wrecker
- M983 tractor
- M985 cargo truck with MHC.
A few models are also available with a self-recovery winch.
All HMTTs are powered by an energy efficient diesel-electric drive system, called ProPulse®. This system is capable of increasing fuel efficiency by over twenty percent depending on the mission. They are able to transport up to 13 tons and has heavy-duty TAK-4® independent suspension to keep the wheels on the ground on almost every type of terrain. The wheels are also run by an electronic direct-drive system that gives torque to the wheels that require it.
When necessary, an HEMTT can be used as 200 kilowatt generator. It also requires very little downtime as it incorporates a generator charging system that can be replaced in under 30 minutes.
HEMTT Repair & Return Program (R3)
Since 1991, the over 12,000 aging HMTT vehicles have made the mandatory requirement of 90 percent readiness goal only a few times. Before they were used in the harsh environment of Operation Desert Storm, HEMTTs had always surpassed the readiness goal. For that reason, HEMTT Repair & Return Program (R3) was implemented in December 2002. The army, in collaboration with Oshkosh wanted to quickly rebuild the HEMTTs. They set a turnaround time of 100 days (including the time it would take to ship them to and from bases) to deliver “like-new” vehicles.
HEMTTs were accepted into the R3 program so long as they had an engine, transmission, and transfer case, axles, frame rails, and crane. They were also upgraded with state of the art technology that would meet the requirements of future army troops. Most of this technology has assisted in improving fuel efficiency; reduce overall weight, increase carrying capacity and increase speed and motility.
Once the overhaul is complete, they suffix R1 was added to their names as an indicator of their condition.