After a string of noise complaints from passengers and people who live near BART stations and raised tracks, the regional transit system is beefing up its stock of vehicles to reduce noise levels on the railways.
BART is planning to purchase a $4.4 million rail-grinding train with local and federal funds to smooth out wrinkles in the system’s rails that cause passenger trains to make high-pitched howling and rumbling sounds.
In a 2006 rider survey, noise level was one of the top four areas of customer concern. Riders also cited dirty trains, parking and uncomfortable seats. Passenger satisfaction with BART noise levels dropped 5 percent from 2004 to 2006, according to the survey.
The noise — which also sounds like screeching — is caused by corrugation on the tracks that could be a result of wheel slippage, rail experts say. Using special trains to grind down and smooth out the rails is one of the most common ways to reduce the deafening sound, make passenger trains run more efficiently and preserve the lifespan of the tracks.
“Once you start hearing the sound of the wheels hitting harder, it’s a good time to repair the corrugation,” said Gary Kohnert, a representative from Minnesota-based Loram Maintenance of Way Inc., which builds rail-grinding trains. “It’s kind of like a car going over a pothole.”
Bob Franklin, a member of BART’s board of directors, said the loudest noises occur on aerial railways, as there is no ground to absorb the sound, and in the Transbay Tube when the trains are operating around 70 mph to 80 mph.
BART bought its first rail-grinding train in the late 1980s for about $1.1 million, but it has since become unreliable, expensive to repair and slow — it can only grind about one mile of rail each night, Franklin said. With 104 miles of track in each direction, it could take more than six months to grind the whole system. The agency ordered a second train last year that arrived this summer after being specially built.
While rail grinding is often considered the fastest way to reduce noise levels, its efficiency is also constrained by the transit agency’s operating hours. Rail-grinding trains also cause sparks on the tracks and should not be used during fire season.
“In a time like this, we’re not going to do it along the [state Route] 24 corridor because it could start a fire. Sometimes we do it in the rain,” Franklin said.
The transit agency’s Board of Directors will vote on purchasing the new rail-grinding train at a meeting at 9 a.m. today at 344 20th St. in Oakland.