Attacks spur research on rescue, fire-fighting technology

ROLLA, Mo. -- Anyone who doubts the power of water need look only at the devastation of a flood to become a believer.

Now researchers are harnessing that power in an inch-wide stream strong enough to cut through concrete and steel yet so controlled and precise it does not disturb anything nearby.

Had the technology been fine-tuned a year ago, it could have been used to bore through the rubble of the World Trade Center, directing water to smoldering fires deep in the heap.

As it was, the ruins of the World Trade Center burned for three months, partly because water poured on the top of the pile never reached some of the hot spots beneath.

"If you had been able to drill right into the fire, you could have probably had it out in a few days," said David Summers, a professor of mining engineering at the University of Missouri-Rolla and director of the school's High Pressure Waterjet Laboratory.

After the Sept. 11 attacks, Summers' staff began looking for ways to help speed up the firefighting and recovery efforts for future disasters. They took technology on which they already were working and modified it for a new use.

Water jet technology has been around since the 1950s, used first to clean sewers or the exteriors of homes. By the 1970s, it was being used for industrial cutting. And by the 1980s, researchers had learned that mixing fine sand with the water made it more abrasive, allowing it to cut through tough substances like steel, Summers said.

But the equipment required was still sort of bulky.

Because the water was sprayed through a tiny nozzle, a hydraulic system was needed to rotate the nozzle like a drill bit in order for the water to blast a wide enough opening to be useful.

"If you've got a structure that's collapsed, you can't be carrying really big, heavy stuff around, because you're likely to get yourself hurt," Summers said. "So we wanted to build something that's small and light, and if you take away the nozzle rotation, it makes it so much simpler. And that's what we've done."

University researchers have developed a water jet nozzle with an opening just 0.05 inches in diameter that nonetheless results in a high-powered stream about 1 1/2 inch wide.

There is no need for a drilling rotation system. The whole apparatus can fit on the back of a pickup truck, making it practicable enough to take to a disaster scene.

For a demonstration, university staff created a pile of rubble -- concrete blocks with a steel plate and thick foam in between to simulate insulation. The water jet drilled through the foot-thick stack in less than three minutes, leaving an inch-wide hole without even shaking the rubble.

Videotaping the demonstration were two visiting scientists from the Pacific Northwest National Laboratory in Richland, Wash., which is operated for the U.S. Department of Energy.

The federal government is hoping to use water jet technology to drill out the bottom of dozens of stainless steel wells used to monitor radioactive and other hazardous wastes at the Hanford nuclear site.

Water levels have dropped below the bottom of many wells. To drill new wells could cost $200,000 each. But by disintegrating the existing well bottoms with the water jet drill, the current wells could be deepened at less than $50,000 each, said Ron Schalla, a senior research scientist at the Pacific Northwest National Laboratory.

"We needed to be convinced that it would work," said Jonathan Lindberg, another senior research scientist. After watching the university demonstrations, "we were pretty convinced."

The Naval Surface Warfare Center in Crane, Ind., also is using a water jet technique developed by the University of Missouri-Rolla to cut through old munitions, allowing the explosives to be removed and the shells to be recycled.

The university's water jet technology also has been used to excavate a theater under the Gateway Arch in St. Louis. For fun, Summers uses the water jet to carve small human-shaped people out of foam -- specially cut to hold his business cards.

But Summers says he has no interest in making a business profit out of building water jet drills to be used in firefighting or rescue efforts.

"When we prove it works and is effective, then our interest in it really sort of tends to go away," he said. "We solved the problem. There are enough other problems, and that's what we do for fun."