BART -- how to quiet noisy rail

[lpetrich]

BART hushes screechy rails | bart.gov

BART is installing custom made rail dampers to help cut the noise level at what has been one of our loudest stretches of track- between Balboa Park and Daly City. These dampers, made of steel and rubber, physically clamp onto the rail every 30 inches and help lessen the vibration that causes the well-known screeching noise when trains travel over the track.

This video explains more: Weekend Closures and Damper Installation - YouTube

As the wheels of the trains travel over the tracks, they cause vibrations, and these vibrations make uneven wear and make the tops of the rails corrugated. This is what makes the horrible noise. This is especially bad for slab track, something that BART has a lot of. BART's usual way of dealing with this corrugation is to grind down the rail.

But in tests so far, these dampers make this corrugation develop much slower, making the rails last much longer. This also means that maintenance crews can attend to other business.

[lpetrich]

Not just the tracks, but also the train wheels.

New wheel tech quiets screeching rails | bart.gov

There’s news about noise: using what is literally cutting edge technology, BART is slightly changing the surface of the train wheels to make for a quieter ride. The new “wheel profile” is already being used on the Fleet of the Future pilot car on the test track and the early reviews are glowing. “According to the train operators, the ride quality, compared to our existing cars, is like night and day ” says Chief Vehicle Engineer Henry Kolesar.

BART’s wheel surfaces are shaped to precise specifications using computerized cutters. Even miniscule changes to the specifications can have a big effect.