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Proving ground tests show the JLTV's mountain-goat climbing capabilities. Note size of spare tire; not a one-man job to change, but the vehicle has a Dana-supplied CTIS.

Oshkosh’s $30B Humvee replacement makes soldier protection a top priority

First there was the Jeep. Then came the Humvee. Now, the Joint Light Tactical Vehicle (JLTV) will soon enter production as the 21st century mobility machine for the U.S. Army and Marine Corps. The services plan to purchase nearly 55,000 JLTVs (all but 5500 going to the Army) in a contract estimated to be worth $30 billion through 2040. The impressively engineered and robust vehicle will initially replace about one-third of the aging HMMWVs (Humvees) in service. Defense-industry analysts say it could ultimately replace the entire fleet of more than 140,000 Humvees by 2040, depending on how many of those older trucks will be “recapped” (completely refurbished) as part of a long-term plan.

JLTV low-rate production begins 1Q16 at Oshkosh Defense, which beat out arch-rivals Lockheed Martin (teamed with BAE Systems) and AM General, maker of the Humvee, for the first run of 16,901 units worth $6.7 billion over three years. Full-scale production is slated to begin in 2018. The program involves more than 300 suppliers across 31 states.

“In terms of ground vehicles this is by far the largest program for the U.S. military. Basically this is the Humvee replacement,” observed Nelson Fisk, IHS’s principal U.S.-based military vehicles analyst. Fisk described Oshkosh’s initial JLTV production contract as “a very big deal” for the company—“the most new vehicles in terms of both numbers and money,” he noted.

Oshkosh was selected for the Engineering, Manufacturing and Development (EMD) phase of the JLTV program in August 2012. The company delivered 22 prototypes, called L-ATVs, as required for government evaluations ahead of schedule in summer 2013. L-ATV testing included completion of the Baja 1000, making it the first-ever military vehicle to enter and finish the grueling off-road race. Ten days after Oshkosh’s design was declared the winner, Lockheed Martin officially protested the U.S. Department of Defense’s selection.

As this article went to press, the Government Accountability Office (GAO) was reviewing the program and will issue a decision on the protest. Related contract work at Oshkosh is not permitted to continue during the 100-day review period. Oshkosh, which also builds the larger M-ATV—a mine-resistant ambush protected truck popularly known as an MRAP—will build the JLTV at its Oshkosh, WI, plant.

Humvee + MRAP = JLTV

JLTV is in reality a robust medium-duty truck family based on a common, 21,000-lb (9525-kg) GVW platform. Features include full time four-wheel drive with Meritor wheel-end reduction drive axles, and fully independent suspension. There are two primary variants: a two-seat Combat Support Vehicle (CSV) and a four-seat Combat Tactical Vehicle (CTV), plus a companion trailer. The CSV, for utility roles, has a 5100-lb (2313-kg) payload capacity. The CTV version, offered as both a General Purpose (GP) and a Close Combat Weapons Carrier (CCWC), can carry up to 3500-lb (1587-kg).

Pentagon officials have cited a per-unit cost of about $250,000 for the base CSV. It may distress American taxpayers to learn that some analysts expect the unit cost will rise to over $500,000, as equipment packages are added in. Average unit cost is expected to fall to $400,000 as production rates increase. (For historical comparison, the original Humvee M998 base model cost the government about $70,000 each in 1985; AM General has built over 300,000 units. And the first Jeep contract in 1941 for Willys-Overland was $648.74 per vehicle; over 600,000 examples were built by Willys and Ford.)

Work on the JLTV began in 2005, as experience in Iraq and Afghanistan proved the Humvee was being asked to perform combat missions for which it wasn’t designed. The increasing threat from mines and IEDs (improvised explosive devices) brought armor protection for the crew, but with the penalty of up to 4000 lb (1814 kg) in additional weight and diminished performance. Pentagon vehicle planners came up with the MRAP, which turned out to be ill-suited for rugged terrain and high altitude operations, and is too large to be transported by CH-47 or CH-53E/K helicopters. Soldiers meanwhile asked for a vehicle offering nimble performance like the original Humvees but with much improved blast protection.

The resulting JLTV is claimed to combine the off-road capability of an unarmored Humvee with the occupant protection of the much heavier and 30% larger MRAP truck. Oshkosh Defense President John Urias described it as having “the blast protection of a light tank, the mine resistance of an MRAP, and the off-road speed and mobility of a Baja racer.” Hyperbole aside, this is a vehicle that can confidently venture far off road where there are fewer IED threats.

JLTV is capable of fording water obstacles up to 60 in (1524 mm) deep without a fording kit. That’s twice the standard fording depth of the Humvee. The Oshkosh-patented TAK-4i adjustable independent suspension (coil springs and unequal-length control arms) provides 20-in (508-mm) of wheel travel—double that of a Land Rover Range Rover. Its 25-ft (7.62-m) turning circle is 10-ft shorter than a short-wheelbase Jeep Wrangler’s.

JLTV’s 15,639 lb (7076 kg) maximum curb weight enables it to be transported by the big helicopters, C-130 and C-17 cargo aircraft, and the Navy’s amphibious assault ships.

More go-power, survivability

The vehicle’s multi-material “capsule” body structure, while boasting an energy-absorbing floor, is sufficient for non-combat humanitarian operations. For high-threat operations it will be supplemented by bolt-on modular armor for enhanced protection. The so-called “B-kit” armor panels are made of Plasan advanced composite materials to minimize weight. The body design is an integral component of Oshkosh's “Core 1080” survivability package that includes an advanced electronic sensors and communications suite.

Standard JLTV features include onboard fire suppression and central tire-inflation systems (the latter supplied by Dana); self-sealing fuel tanks; blast-restraint seats; wheel zone blast deflectors; a rear camera providing a wide-angle 25-ft view behind the vehicle, and a new “polyfibroblast” self-healing paint developed by the Office of Naval Research and The Johns Hopkins University Applied Physics Laboratory.

The vehicle uses an open electronics architecture that facilitates integration of future sensor, communications, and navigation systems as they become available. As a result, the JLTV’s crew will have significantly improved battlefield situational awareness compared with vehicles today, Oshkosh Defense officials claim.

And it’s capable of 70 mph, courtesy of a mil-spec version of GM’s 6.6-L Duramax V8 diesel, calibrated for the military’s standard JP-8 fuel and paired with an Allison six-speed automatic transmission and Oshkosh transfer case. While official output figures have yet to be released—and the military is infamous for de-rating civilian engines—the Duramax as used in Silverado 2500 pickups delivers SAE-rated 397 hp (296 kW) and 765 lb·ft (1037 N·m).

If the JLTV’s actual power is close to that of the civilian engine, it will offer a promising weight-to-power ratio of about 39 lb/hp. That’s equal to the original 150-hp, 5850-lb (2653-kg) M998 Humvee and surpasses the unarmored M1165 version, which at 6550 lb (2971 kg) is still comparatively light and nimble. But Iraq and Afghanistan combat threats added armor and a lot more mass, hampering performance. The M1165A1 Humvee version with B3 mine/ballistics kit weighs 9870 lb (4477-kg), but is propelled by just 190 hp (119 kW) and 380 lb·ft (515 N·m).

The Army anticipates having its first unit equipped in FY2018. Initial Marine Corps operating capability is expected in FY2018 with fielding to be complete in FY2022. By then some soldier hopefully will have invented a catchier name than JLTV.

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