LAND FORCES

Stronger-Than-Steel Light Combat Trucks Still a Pipedream

2/1/2012
By Sandra I. Erwin
The U.S. military’s dream truck undulates on and off roads like a Hummer, is transported via sling under a helicopter and, oh by the way, survives roadside bomb blasts.

Military truck buyers, alas, are recognizing that this is an impossible wish list. Even if it were technologically attainable, it would be financially unrealistic. Funds for new vehicles are expected to take a plunge in the coming years, and managers of the military’s new Joint Light Tactical Vehicle are under strict orders to forgo costly bells and whistles and focus on what troops need most.

“Survivability is number one. Following is mobility,” said Michael Halloran, director of science and technology at the Marine Corps’ program executive office for land systems.

The JLTV program, intended for both the Army and the Marine Corps, is becoming a test case for how far military and industry engineers can push the boundaries of armor technology as they seek a truck to replace the Humvee later this decade. Halloran, who previously served as chief engineer for the mine-resistant ambush-protected (MRAP) vehicle, said the future truck ideally has to be nearly bomb proof like the MRAP but far lighter, more mobile and capable of going off road.

In JLTV, it’s all about “tradeoffs,” he said in an interview. “Do I need to make vehicles more survivable and give up mobility?”

It used to be that vehicle designers only were concerned with payload, performance and protection. Now cost has to be factored into the equation, said Halloran.

When the Defense Department first approved the JLTV procurement, there was a tacit belief that advanced new armor materials would be available to make trucks survivable without loading them with thousands of pounds of steel. But no breakthrough has emerged to slim down a 25,000-pound MRAP by 10,000 or more pounds.

“There is no novel lightweight armor material that has allowed us to achieve our weight savings,” Halloran said.

“It comes down to physics. … Anything under 30,000 pounds or 25,000 pounds has a tough time meeting survivability requirements,” he said.

Engineers have concluded that the way to drop vehicle weight without compromising the crew’s protection is to take a comprehensive design approach that looks at how to make every piece of the vehicle more survivable.

“It’s the seats, the floor, the V-shape hull. It’s all those components and how you integrate those components to distribute the blast effects throughout the vehicle so they don’t get to the occupants,” said Halloran. “We’ve gone back and taken a very hard look at engineering, and achieved weight savings while maintaining survivability.”

Even if there were an exotic material out there that reduces weight, if it is too expensive, the military can’t afford it, said Halloran.

“A lot of the materials that are being presented by industry, quite simply, don’t meet the cost metric that we have to have in order to make our vehicles affordable,” he said.

JLTV, in its early iteration, was estimated to cost more than $500,000 a piece. The new price target is $230,000. “There were some very good designs but they were expensive,” said Halloran. “To meet the limited budget, I don’t see a lot of changes in the way we are currently armoring our vehicles, unless industry is able to bring down the cost per square foot or cost per pound of nano-composite type materials.” The desired cost would be comparable to the price of specialty metals such as high-hard steel, rolled homogeneous armor steel or alumina.

Engineers also have realized that no single lightweight material can address the complexities of making a truck that can withstand the blast from buried explosives.

“You can’t just say make a hull out of titanium. … What we have found in blast effects and ballistic effects tests is that you need a layered approach.” Layering means, hypothetically, superimposing high-hard steel, an air gap, a tier of aluminum, with a ballistic-proof fabric coating on the back to catch any spall.

“Industry is finding this out as well,” said Halloran. “They can achieve low cost with a layering approach, versus one size fits all.”

Similar techniques are being used by scientists at the Army Research Laboratory. “We’re looking at more efficient means to distribute the energy around the vehicle,” said Patrick Baker, division chief at ARL weapons and materials research directorate. “We have already pushed the limits of materials technology, so we are pushing new mechanisms,” said Baker.

Besides armor for side, top and underbody protection, ARL is investigating other non-traditional technologies such as explosive reactive armor and electromagnetic armor. These systems have been used in tanks but are unproven in tactical trucks.

Dave Reichert, an armor expert at DuPont Protection Technologies, said one way to lower vehicle weight and decrease cost is to use existing materials in new ways. Steel, for instance, could be replaced with a hybrid armor of metal and fabric composite, he said.

DuPont is marketing a new hybrid armor-Kevlar product in partnership with Honeywell, he said. The materials are layered, instead of woven, as they have been. “When you hybridize … you get a better structure,” said Reichert. He said that metal-Kevlar hybrid systems cost more than steel, but they are lighter. “In a vehicle, you have to see savings in hundreds of pounds to make it worth paying more.”

Halloran stressed that no one technology provides the desired outcome.

“There isn’t a silver bullet when it comes to blast and ballistic protection for our vehicles,” he said. “It’s not a single-point solution.”

Another school of thought is the idea that troops would be safer in trucks that have less armor but can swiftly maneuver around obstacles. Halloran, based on anecdotal evidence and comments from troops in the field, believes that more mobility would increase survivability. “Unfortunately I don’t have the data to back that up,” he said. “If I can increase speed another 20 mph and go off road, is that going to save more lives than having to drive down the same [bomb infested] road all the time?” he asked.

As long as enemies know that U.S. vehicles only stay on roadways, they are going to keep concealing bombs along these routes. “It seems to me we ought to get off the roads,” said Halloran. “I would put our money in being able to go across country, off road, with more agility, and be less predictable.”

The U.S. Special Operations Command has embraced the idea of trading off protection for greater agility and speed. SOCOM’s “ground mobility vehicle” is much lighter than a Humvee, and has little to no armor.

For JLTV, the future was very much in doubt this fall, when a Senate committee voted to terminate the program. It proved to be a wakeup call for the Army and the Marine Corps. Appropriators recently approved $134 million for Army and Marine Corps JLTV development in fiscal year 2012. Although it is far less than the $244 million that the services had sought, officials are relieved the program is being kept alive.

“We needed a new way of doing business,” said Gen. Joseph Dunford, assistant commandant of the Marine Corps. Whereas in the past military buyers would just state their desired performance and technical specifications, now they have to “understand what the requirements cost,” Dunford said at an industry conference. “Before this, it’s kind of been a crapshoot,” said Dunford. “With JLTV, I think we are starting to come together as a community and making cost-informed trades.”

Dunford said he expects JLTV to be held up as an example for how to “change the culture of acquisitions.”

During a November hearing of the House Armed Services tactical air and land forces subcommittee, William Taylor, Marine Corps program executive officer for land systems, said he estimated that JLTV development will continue for 33 months. The focus will be on cutting the cost, he said. “There’s no gold plating.”              

Topics: Land Forces

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