Wars have given us the Jeep, the computer and even the microwave.
Will the war in Iraq give us the Tiger?
Military scientists at Edgewood Chemical Biological Center at Aberdeen Proving Ground hope so. The machine - its full name is the Tactical Garbage to Energy Refinery - combines a chute, an engine, chemical tanks and other components, giving it the appearance of a lunar rover. It's designed to turn food and waste into fuel. If it works, it could save scores of American and Iraqi lives.
Among the biggest threats that soldiers face in the war in Iraq are the roadside bombs that have killed or maimed thousands since the U.S.-led invasion in 2003. Because some military bases lack a landfill, transporting garbage to dumps miles away in the desert has become a potentially fatal routine for U.S. troops and military contractors.
The Tiger would attempt to solve two problems at once: It would sharply reduce those trash hauls and provide the military with an alternative source of fuel.
It is the latest in a long line of wartime innovations, from can openers to desert boots. The conflict in Iraq has produced innovations such as "warlocks," which jam electronic signals from cell phones, garage door openers and other electronic devices that insurgents use to detonate roadside bombs, according to Inventors Digest.
"In wartime, you're not worried about making a profit necessarily. You're worried about getting the latest technology on the street," said Peter Kindsvatter, a military historian at Aberdeen Proving Ground, who added that money is spent more freely for research when a nation is at war. "Basically, you find yourself in a technology race with your enemy."
The Tiger, now being tested in Baghdad, would not be the first device to turn garbage into energy - a large incinerator near Baltimore's downtown stadiums does it. But it would be among the first to attempt to do it on a small scale. Its creators say it could one day become widely used in civilian life, following the lead of other wartime innovations.
During World War II, contractors developed the Jeep to meet the military's desire for a light, all-purpose vehicle that could transport supplies.
The development of radar technology to spot Nazi planes led to the microwave, according to historians.
The World War II era also gave birth to the first electronic digital computer, the Electronic Numerical Integrator and Computer, or ENIAC. Funded by the Defense Department, the machine was built to compute ballistics tables that soldiers used to mechanically aim large guns. For years it was located at Aberdeen Proving Ground.
This decade, the Pentagon determined that garbage on military bases poses a serious logistical problem.
"When you're over in a combat area and people are shooting at you, you still have to deal with your trash," said John Spiller, project officer with the Army's Rapid Equipping Force, which is funding the Tiger project. "How would you feel if somebody was shooting at you every other time you pushed it down the curb?"
He and other Army officials said they could not recall any specific attacks against troops or contractors heading to dumpsites.For years, large incinerators have burned trash to generate power. Baltimore Refuse Energy Systems Co., the waste-to-energy plant near the stadiums, consumes up to 2,250 tons of refuse a day while producing steam and electricity.
The process is so expensive that it has only made sense to do it on a large scale, scientists say.
The military has spent almost $3 million on two Tiger prototypes, each weighing nearly 5 tons and small enough to fit into a 20- to 40-foot wide container. The project is being developed by scientists from the Edgewood, Va.-based Defense Life Sciences LLC and Indiana's Purdue University.
The biggest challenge was getting the parts to work together, said Donald Kennedy, an Edgewood spokesman. Because the Tiger is a hybrid consisting of a gasifier, bioreactor and generator, much of it is built with off-the-shelf items, including a grinder.
Another big challenge: expectations.
"When we would initially talk to people about the Tiger system, a large percentage would refuse to believe it could actually work," Kennedy wrote in an e-mail. "Alternatively, a similar percentage would be so intrigued by the idea that they would demand to know when they could buy one for their neighborhood."
The Tiger works like this: A shredder rips up waste and soaks it in water. A bioreactor metabolizes the sludge into ethanol. A pelletizer compresses undigested waste into pellets that are fed into a gasification unit, which produces composite gas.
The ethanol, composite gas and a 10-percent diesel drip are injected into a diesel generator to produce electricity, according to scientists. It takes about six hours for the Tiger to power up. When it works, the device can power a 60-kilowatt generator.
The prototypes are being tested at Camp Victory in Baghdad
Initial runs proved successful. The prototypes have been used to power an office trailer. At their peak, they could power two to three trailers.
In recent weeks, the scientists suffered a setback: The above-100 degree temperatures caused a chiller device to overheat and shut off occasionally. A new chiller from Edgewood just arrived at the site, Kennedy said.
After the 90-day testing phase that ends Aug. 10, the Army will decide whether to fund the project further.
Its developers envision the device being used to respond to crises such as Hurricane Katrina, when there is no lack of garbage but a great need for electricity.
Spiller, of the Army's Rapid Equipping Force, said he is optimistic.
"The mere fact we wrote a check means we think it's got a high chance of success," Spiller said.