Fire probe puts focus on engines of buses.

Byline: Tim Christie The Register-Guard

Federal traffic safety investigators plan to examine this week's Lane Transit District bus fire as part of a larger probe into bus blazes around the country that have one common denominator: the same type of engine.

The National Highway Traffic Safety Administration opened a preliminary investigation into the bus fires last month that focuses on Series 40 and 50 turbocharged diesel engines manufactured by Detroit Diesel Corp.

The traffic safety agency has received reports of at least 20 fires involving 12 public transit fleets around the country, including LTD's, agency spokesman Rae Tyson said.

Officials in the Office of Defects Investigation are close to completing the early stages of the probe and will decide soon whether to conduct a full-blown engineering analysis, he said. That process could take as long as a year and result in a recall if engineers find a safety defect.

Detroit Diesel may choose to voluntarily recall the engines if there is a defect, Tyson said. About 20,000 of the engines are in use around the country.

Detroit Diesel spokesman Tom Freiwald said his company, a subsidiary of DaimlerChrysler, is cooperating with the transportation safety agency investigation. The company also is interested in inspecting the LTD bus in Eugene to determine whether that fire was caused by a problem in the engine, he said.

LTD bought five 60-foot articulated buses in February from New Flyer of America. The buses, built with accordionlike bends in the middle, are powered by Detroit Diesel Series 50 turbocharged engines.

One of the buses caught fire about 6 p.m. Tuesday while heading south on Interstate 5 near the Highway 58 exit. All 20 or so passengers and the driver escaped unhurt.

The fire began in the engine compartment, and Oregon State Police investigators said the fire apparently was caused by transmission fluid leaking onto the engine.

A one-page summary of the NHTSA preliminary investigation says the agency is looking at the engine-turbocharger combinations used in the vehicles, specifically whether turbocharger failure caused the fire.

A turbocharger allows an engine to burn more fuel and air - and thus boosts power - by using exhaust to drive a turbine that forces more air into the cylinders.

In the 20 bus fires under investigation, no injuries were reported, NHTSA spokesman Tyson said. He did not know which companies manufactured the buses, nor did he know over what period of time the fires occurred; all of the engines had been manufactured since 1995.

Federal investigators have concluded that a fire in Hawaii last summer involving the same model of New Flyer bus as the one that caught fire in Eugene is not related to the reported Detroit Diesel engine fires, Tyson said. The Hawaii bus was powered by a diesel engine manufactured by Cummins.

San Diego Transit experienced four fires in 1999, 2000 and 2003 involving 60-foot articulated New Flyer buses powered by Detroit Diesel Series 50 engines. An independent investigation blamed the fires on the transit district for inadequate maintenance of hoses.

As a result of the investigation, San Diego Transit began using a beefier hose on its buses and installed a more rigorous preventive maintenance program, said Claire Spielberg, interim general manager of San Diego Transit.

"I do not believe it's the engine" causing the fires, Spielberg said. "It's probably poor maintenance practices or simply hydraulic hoses that let loose and spray fluids on the exhaust manifold or some other hot part of the engine."

The bus manufacturer, not the engine maker, is responsible for determining how the engine fits in the bus and for the network of hoses and wires needed to make it run, she said.

Detroit Diesel engines are widely used in public transit buses and have a good performance history, said Greg Hull, director of safety and security for the American Public Transit Association, which conducted the San Diego investigation.

Investigators from New Flyer, the bus manufacturer, and LTD's insurance company, plan to begin their examination of the bus fire on Monday, LTD spokesman Andy Vobora said. That investigation is expected to take two to three weeks. They may call in other experts, such as someone from Detroit Diesel, if necessary, he said.

LTD has taken the remaining four 60-foot New Flyer buses out of service and replaced them with 40-foot buses. That's caused some crowded, standing-room-only trips on some routes, and longer waits for passengers on others, Vobora said. For instance, buses on the 79X route, which runs from Martin Luther King Jr. Boulevard to the University of Oregon, have been running at capacity at times, meaning some riders have to wait three to 15 minutes for the next bus, he said.

The 60-foot buses won't be returned to service until the cause of the fire is determined.