Monthly Military: The FMTV

Over the decades medium tactical trucks have played a important role in the US military’s fleet, so keeping these machines technologically up to date has been crucial. In the early 1980s, the U.S. Army began looking for a successor to the M35 2.5-ton cargo truck, a design whose origins dated back to World War II. By the summer of 1984, an official program was launched to find a replacement for the current in-service 2.5 and 5-ton vehicles. A focus was placed on modularity, durability, and strategic deployment capability.

This would eventually result in the Family of Medium Tactical Vehicles, or FMTV. No less than seventeen variants of the Steyr 12M18-derived machine would be developed over the following years, fleshing out both the Army’s Light Medium Tactical Vehicle (LMTV) and Medium Tactical Vehicle (MTV) roster in the process.

Now in production for over two decades, the FMTV’s designs have evolved substantially since the first iterations entered service in 1996. Production of the FMTV has taken place under the supervision of several different companies since, with the Oshkosh Corporation currently overseeing construction operations. Today the FMTV performs more than half of the U.S. Army’s local, line haul, and unit resupply missions in combat, combat support, and combat service support units.

Development and General Design Specification

Used primarily by the Austrian Army, the Steyr 12M18 seen here served as the foundation for the FMTV’s design. The U.S. Army’s specifications required substantial revision to the design however, with a minimum of 50% U.S.-spec content. Image: Military-TodayAfter sorting through a number of proposals, in October of 1988 the U.S. Army awarded a five-year contract for FMTV construction to Stewart & Stevenson, a program which would be extended well into the 21st century as Stewart & Stevenson would be absorbed into Armor Holdings, a company which was later acquired by BAE Systems in 2007.

At its core, the FMTV provides rapid unit mobility and resupply in varied terrain and climates. The Steyr 12M18 was the basis for the FMTV’s design, a general purpose truck that had been developed for use by the Austrian military and in service since 1986. The Steyr design was substantially modified per the U.S. Army’s stipulations though, which included a requirement for a minimum of fifty percent U.S.-sourced content in the new vehicles.

Despite the numerous variants developed over the years and the obvious distinctions between the 2.5-ton 4×4 and 5-ton 6×6 iterations of the trucks, the Family of Medium Tactical Vehicles is reasonably homogeneous. There is an 80-percent part commonality across the lineup, which reduces the logistics burden, as well as operational and support costs.

Featuring extensive corrosion protection, the FMTV was the first truck to pass the U.S. Army’s 22-year accelerated corrosion test. The chassis is built around a conventional C-section design with tubular cross-members, which is constructed using high-grade 758 MPa steel.

Suspended on parabolic tapered leaf springs with telescopic shock absorbers in both 2.5 and 5-ton configuration (5-ton vehicles also have an anti-roll bar in the rear), the FMTVs are motivated by a 7.2-liter six-cylinder Caterpillar C7 diesel engine outputting 275 horsepower and 860 lb-ft of torque in 2.5-ton configuration and 330 horsepower/860 lb-ft in 5-ton configuration, hooked to an Allison 3700 SP seven-speed automatic with integral single-speed transfer case.

This yields a top speed of about 58 miles per hour. Outfitted with a 56-gallon fuel tank, it gives the vehicles roughly 300 miles of operational range, depending on configuration. Steering is power assisted and handled exclusively through the front axle.

In M1078A1P2 2.5-ton LMTV cargo configuration, these machines have a 5,000-pound payload, weigh in at roughly 11 tons, and measure 9.3 feet in height, 8 feet in width and 22.1 feet in length. The M1083A1P2 5-ton MTV cargo variant doubles that payload, expands the length to 23.9 feet, and increases the curb weight to roughly 12.5 tons. These specifications allow the vehicles to be deployed by C-5 Galaxy, C-17 Globemaster, and C-130 Hercules military transport aircraft.

Though the FMTV are typically unarmed, over the years these vehicles been increasingly used for occupant protection in combat zones. Along with the FMTV’s central tire inflation system, operations in Iraq eventually led to the development of the up-armored Low Signature Armored Cab (LSAC), which adds ballistic and mine blast protection for improvements in crew survivability.

Additionally, in order to meet the US Army’s current Long Term Armor Strategy (LTAS) for armored cabs, BAE Systems developed the LTAS cab for the FMTV. The LTAS design allows for vehicles to be armored with kits that can be adapted to specific threats, as well as new armor upgrades as they become available.

Variants

Since FMTV was put into service in 1996, a number of different configurations have been developed off of the general FMTV design, and the range of tasks that these vehicles can perform showcases the versatility of the FMTV platform.

In addition to the M1078 LMTV and M1083 MTV cargo configurations – which would spawn a number of variants of their own – the platform would eventually underpin van configurations like the M1079, an MTV tractor (M1088), a wrecker configuration  (M1089), a 5-ton dump truck (M1090), and a 1,500-gallon fuel tanker (M1091), among many others.

Versions of the FMTV have also been outfitted has launching platforms for the M142 High Mobility Artillery Rocket System (M1140) as well as the Medium Extended Air Defense System (MEADS) with the XM1160 variant.

Future Development

More than 100,000 trucks in the FMTV family have been produced to date, and they currently see use around the world. While the U.S. has procured the lion’s share of these vehicles, the military forces of Israel, Saudi Arabia, Greece, and Iraq are among the many nations that have put the Family of Medium Tactical Vehicles into their service.

In 2016, the U.S. Army solicited proposals for an FMTV A2. Rather than replacing the FMTV altogether, this would serve as a substantial update to the general platform. The Army’s specification calls for capability improvements for the suspension, wheels, and tires, integrated underbody protection; increased engine output, a higher capacity alternator, and updated safety enhancements.

In May of 2017, Oshkosh Corporation submitted a proposal for the FMTV A2 that included 16 potential variants, along with three different trailer configurations. However, official word on which company has been awarded the contract by the U.S. Army isn’t expected until the second quarter of 2018’s fiscal year.