A New Mission for Military Trucks: Power Generation

By Sandra I. Erwin
When troops in war zones first received the heavily armored MRAP trucks three years ago, they were relieved to have a vehicle that could withstand roadside bomb blasts.

But truck crews soon found a vexing flaw in the hulking piece of machinery: It did not provide enough electricity to power a hodgepodge of devices that needed to be plugged in.

“When we got the vehicle, there was not enough power to actually start the vehicle once you connected all the radios,” said Chris Miller, who oversees the installation of equipment aboard MRAP (mine-resistant ambush protected) trucks in Charleston, S.C.

That discovery was a wake-up call for vehicle manufacturers and for the government’s program managers. Engineers immediately went to work designing new alternators and add-on power units that would meet troops’ rampant energy demands as more high-tech gear is added to already cramped truck cabs.

The new MRAP models come with double the power — a 400-amp alternator, compared to 200 amps previously. Most of the older trucks have been upgraded to the larger alternator.

The mine-resistant truck power problem illustrates a trend seen in military vehicles over the past decade: They must be able to charge a greater array of electronic gadgets, some of which are million-dollar systems. In many of the newer MRAPs, the computers, sensors and radios cost more than the vehicle, said Miller at a recent industry conference. “I’ve had a number of flag and senior executives, and general officials come back to me to ask, ‘What’s so hard about putting a radio on a vehicle?’ and then we show them the amount of radios, the amount of displays, the jamming devices, and they all are blown away.”

The power shortfall, however, is not limited to the MRAP. Most military trucks these days, including the ubiquitous Humvees — function as makeshift command centers, weapon launchers, ambulances, electronic jammers, and perform other roles, all of which require loads of electricity to run a smorgasbord of hardware.

As more equipment requires recharging, auxiliary diesel-fueled generators often are towed into combat zones. Marine Corps commanders in Afghanistan in recent years have asked their suppliers stateside for help. They see their dependence on towable generators as an Achilles’ heel that only adds to their logistics burden and runs up fuel consumption. They would like to have trucks that can function, on their own, as self-sufficient sources of energy.

The rising demand for onboard power has set off several projects at the Marine Corps Systems Command in Quantico, Va.

John Rooney, technical director for the MRAP program, said that trying to keep up with the energy demands is a constant challenge.

“To be quite frank, we don’t always know what other gadgets are being attached in theater,” he said in an interview. “We’re always trying to monitor what else is out there.”

The 400-amp alternators that are now standard for all MRAPs should satisfy the immediate needs, Rooney said. Many trucks are being equipped with a “black box” that monitors power management. “From theater data, we are not seeing a requirement above 400-amp alternators,” he said.

But as the military continues to pile on gizmos, chances are that the electricity needs will remain on a steady climb. Rooney’s office earlier this year launched a “market survey” to learn what industry might have to offer in the realm of 1,000-amp alternators. This is not an “urgent need,” but something that is being considered for the long term, to “stay ahead of the game,” Rooney said.

Any attempt to jack up power production aboard MRAPs, or any other tactical vehicle, is likely to pose some tough choices for engineers, logisticians and bean counters.

Marine officials currently are reviewing vendor proposals for a 1,000-amp alternator for the MRAP. Some options may require reengineering the vehicle to create extra space for the new system, said Rooney. It has yet to be determined whether the trouble and cost would be worthwhile.

The lack of sufficient power can severely hamper soldiers’ and marines’ ability to accomplish their mission, Rooney said. A common complaint is the difficulty in conducting “silent watch” operations, when troops are trying to remain covert, and turn off the vehicle engine while still having to operate their computers, sensors and radios. “With a 400-amp alternator, as long as you keep the vehicle charged, it does a very good job,” Rooney said. “The challenge is when you go into silent watch mode, and the engine is not running.” To avoid draining the battery, the driver has to carefully manage power consumption, he said.

Energy creators such as 1,000-amp alternators would more than just power a vehicle’s onboard devices. They would also deliver the holy grail of battlefield energy — a vehicle with “exportable power” that eliminates the need for towable generators.

Several companies already are jockeying for future MRAP power enhancement contracts. ITT Defense is proposing a high-power alternator that was designed for commercial buses but would fit in the MRAP, said Doug Ramsey, business area lead for integrated power at ITT. According to the company’s research, MRAP users are still woefully short of the power they need, despite the recent upgrades.

“They’re making real-time tradeoffs on the electronic suite … turning off certain systems to make sure they can maintain critical systems,” Ramsey said. “The solution we have provides 1,000 amps at engine idle. … As long as the engine is on, or idling, we’re generating new organic power.”

Similar energy woes are being experienced in the Humvee fleet, which is the largest in the U.S. truck inventory.

In the Humvee fleet, “power became an issue about a decade ago,” said Jonathan Carpenter, lead engineer for expeditionary power systems at Marine Corps Systems Command.

Troops began to install additional equipment on tactical vehicles. Trucks gradually morphed from a simple means of transportation to become communications hubs and command centers. “That is when we started running out of power,” Carpenter said. Early Humvees had a 60-amp alternator, whereas the latest models have been upped to 400 amps.

The expectation is that military leaders increasingly will be seeking vehicles with exportable power so they can draw electricity from the truck engine instead of having to lug huge generators.

Carpenter’s office last year awarded a contract to DRS Technologies Inc. to build 15 prototypes of a Humvee onboard-power generator that pumps out three times more electricity than an MRAP.

The system consists of a permanent-magnet alternator that is sandwiched between the engine and the transmission. It can provide 30 kilowatts of power when the vehicle is stationary, and 10 kilowatts while on the move. By contrast, a 450-amp alternator would produce 12 kilowatts of energy.

“These technologies are a couple of years out in terms of maturity,” said Carpenter. “The Marine Corps is still firming up its requirements for export power.”

The Corps’ “expeditionary energy” strategy calls for tactical vehicles that can provide the lion’s share of power on the battlefield by 2025, Carpenter said. But there are no specific targets yet for what percentage of the Humvee fleet potentially would have these high-energy systems. Some trucks may not need it, he said. “We don’t want to spend money on vehicles that don’t take advantage of the capability.”

Anecdotal evidence indicates that commanders would welcome the new technology. In many remote areas where U.S. forces are deployed, generators are hard to come by, and even harder to refuel and repair. “But everyone has vehicles,” Carpenter said. “With current storage capacity and current alternators, they can’t capture enough energy off the vehicle to run the radios for long periods in a silent-watch operation.” If a unit is sent on a mission on short notice, the time associated with setting up a generator and the wiring required to safely operate it create enormous obstacles, he said. “Our ability to run the power directly off the vehicle that they drive could save a lot of time.”

Manufacturers of hybrid-electric vehicles have been courting military customers for years, pitching these systems as the answer to battlefield power needs. But the DRS built-in generator seems more appealing because of its relatively simple integration with the standard drive train. It would not require any additional training or maintenance, said Carpenter. In his opinion, the military will eventually acquire some hybrid-electric tactical vehicles. “But I don’t think it will be because of fuel efficiency, but because of the added energy storage capability.”

DRS received a contract in August 2010 to produce 15 prototypes of a Humvee with onboard power. Larry Platt, the company’s vice president of Marine Corps programs, said the 30-kilowatt generator sits in the space of the current transmission. It is a clean swap that does not require any modifications to the engine, he said.

This system is intended to unburden marines from heavy fuel-hogging generators, Platt said. He noted that a towable 30-kilowatt generator with a trailer weighs about 3,000 pounds. A trailer consumes 90 square feet of deck space on a ship. “In a time of diminishing dollars, this may have a greater benefit than introducing a hybrid-electric vehicle,” he said. From a logistics standpoint, he said, “We can reduce cube and weight aboard ships and aircraft.”

The 15 test vehicles are being shipped to members of three Marine Expeditionary Force organizations for evaluation. DRS officials are confident that, if the tests go well, the Marine Corps could end up buying several hundred more.

The same technology could be scaled up for other vehicles, including the MRAP and the Army’s Stryker armored personnel carrier, said Platt. DRS has teamed with Allison Transmission Inc. to build comparable power systems for larger vehicles. “We know it’s possible to take this across the medium vehicle fleet,” he said.

Besides the 15 Humvees, the Marine Corps is testing five 7-ton medium tactical trucks that are being equipped with an onboard power system designed by the vehicle manufacturer, Oshkosh Corp. There will be “limited user evaluations” over the next year, Carpenter said.

The Oshkosh power system produces, when the vehicle is stationary, 120 kilowatts of power. “This could replace 60- to 100-kilowatt generators for short periods of time,” said Carpenter. It delivers 21 kilowatts of power on the move, on top of the available DC power that the vehicle gets from the alternator.

To illustrate the amount of energy this truck would deliver, Carpenter said that 120 kilowatts would be enough to power a small hospital, or an entire city block.

The 7-ton trucks, known as MTVRs or medium tactical vehicle replacement, are used to tow big generators. But reaching far-flung areas where U.S. forces are fighting in Afghanistan has become more challenging as fuel supplies are disrupted and bomb attacks are on the rise. A 100-kilowatt generator weighs more than 6,000 pounds and requires bulky engineering equipment to move around, which creates more targets for the enemy. “If we can pull power from the vehicle, the vehicle itself can drive into austere environments and provide power,” Carpenter said.

In the MTVR, he said, “We are electrifying the whole vehicle … getting rid of the mechanical transmission and putting in a large generator.” All the power from the engine is turned into electricity, which can either turn the wheels to move the vehicle, or can be drawn as usable electrical power, he said.

The five MTVR prototypes will be delivered over the next 12 months, said Carpenter.

This month, the Marine Corps will be hosting an “experimental forward operating base” at Twentynine Palms, in the California desert, where selected contractors have been invited to demonstrate fuel-efficiency technologies and vehicle onboard-power systems.

NEST Energy Services, a small business that specializes in solar power systems, will be offering a hybrid auxiliary power source that can be mounted on the fender of a Humvee or an MTVR. The vehicle engine powers the generator, and it can also be charged with solar energy.

For the Army, which expects to dramatically increase the use of smart phones and handheld computers on the battlefield, one of the concerns is having enough power to recharge the couple of dozen, or more, devices that a company would be carrying. Commanders expect most of that power to come from their vehicles, said Col. Daniel Pinnell, commander of the Army’s 2nd Brigade Combat Team, 1st Armored Division, at Fort Bliss, Texas.

Based on anecdotal feedback from soldiers during last month’s “network integration exercise” at White Sands Missile Range, N.M., “power is a significant issue,” he told reporters at the NIE’s brigade headquarters. Solar panels are becoming more commonplace as a fallback energy source to recharge phones, “but they are not a replacement for plugging into the wall for 40 minutes,” Pinnell said. The advice he gives to soldiers is to ration their power cautiously. “Turn the radios off when you don’t need them.”                     

Grace V. Jean contributed to this report.

Topics: Land Forces, Land Forces

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