Bomb Snuffer : Mobile Police Device Bottles Up Explosives

There are a lot of legacies from the 1984 Summer Olympics--things like the swimming stadium at USC, the bronze statue in front of the Coliseum, the thousands of team pins gathering dust on collectors’ shelves.

For Herb Williams, there is a 6,000-pound hollow ball of steel.

“I love it,” Williams said. “I love it ‘cause it works.”

Williams is a member of the Los Angeles Police Department bomb squad and the ball is a “total containment device,” a movable chamber in which the squad can safely detonate the explosives it is sent to disarm.

The ball, four feet in diameter and mounted on a heavy-duty truck, is so unusual--and so expensive--that only one other police department in the United States has one: New York City’s.

Conventional bomb trucks simply muffle and deflect a blast, usually skyward. The total containment device actually contains a blast; the only outward signs that one has taken place are a slight shudder, a metallic clang and a gentle hiss.

The biggest advantage over conventional bomb trucks is that the detonating can be done safely right where the explosive is found, eliminating the need to haul dangerous and unpredictable explosives through city streets to some remote disposal site.

Williams said total containment devices were developed for the Navy in the 1970s for use in testing explosives.

“They’re made of cold rolled steel, plate upon plate, all welded together to form a perfect sphere, three inches thick,” he said. “It’s got to be machined very carefully. You can’t have any dings.”

The device works, he said, by allowing the shock waves generated by an explosion to dissipate harmlessly inside, “spinning round and round” while the intense pressure of the blast is bled off slowly through a quarter-inch vent.

To construct and machine such devices is an expensive matter--each one costs about half a million dollars--well beyond the budgets of most police departments.

“But we have a guy who found out the Navy had one in Maryland that they didn’t need any more,” Williams said. “Knowing that Los Angeles could be a prime target for terrorists during the Olympics, the Department of Defense had no heartache about parting with it. I think we got it for nothing, or maybe we paid a dollar.”

The ball was hauled to Los Angeles on an Air National Guard plane and delivered to the bomb squad yard behind the Northeast Division station in the Atwater district. Williams and his associates scrounged up an old garbage truck, some blue paint, a few red lights--and Los Angeles’ total containment device was ready to go in time for the Summer Games.

As it turned out, the truck was not needed during the Olympics, because the only incident during the Games that involved explosives was a phony terrorist attack staged by a police officer anxious to impress his superiors.

It has been deployed a lot since, “probably six or eight times a month,” Williams said.

Williams said he cannot reveal any details about the big blue truck’s missions. He also declined to discuss how big an explosion the device can contain, other than to say it has handled nitroglycerin, blasting powder, plastic explosives and TNT, with the pressure inside reaching “well above” 50,000 pounds per square inch.

When word comes that the truck is needed, it is driven as close as possible to the explosive.

One member of the team, swathed in a protective bomb suit that leaves only his hands exposed, carries the explosive to the truck. He reaches in through a circular doorway about 18 inches in diameter to place the explosive in a sling inside the chamber. A detonating package prepared by the squad is placed next to the explosive.

The twin doors, each machined from steel three inches thick, open inward, so the force of the explosion will slam them shut. These are left open a crack for the wire leading to the detonating package.

When the squad sets off the package, there is a slight jolt, the clang of the doors slamming shut and the hiss that lasts about half an hour as the pressure inside is slowly released through the vent.

Once the hissing has stopped, a team member reopens the doors and takes a sample of the residue left in the bottom of the chamber for a laboratory analysis.

“They said we can keep using this thing until it stretches three-eighths of an inch,” Williams said. “Well, we measure it after every time we use it, and it hasn’t stretched yet.

“It’ll be around a lot longer than we will.”