By Guy Span
Published: May, 2004
Last September, Bay Crossings did an analysis of how loud was the “swift, virtually noiseless and vibration-free electric train” (as BART was billed when built). At that time, we analyzed wheel/gauge profiles, rail grinding, and other causes of wheel–rail noise propagation. And while our engineers still believe that BART fails to open the gauge enough on curves (BART standard is 1/16” and real railroads are closer to 1/4” at a minimum), we did find one significant repair that BART has quietly made.
According to spokesman Mike Healy, BART has recently run the rail grinding machine through the Transbay Tube. And that has really helped. We found the following improvements: ballasted straight track dropped two dB (decibels) to 68 dB, elevated curves dropped 8dBs to 72 dB, tunnel curves dropped 4 dB to 78, and the biggest improvement was in the Transbay Tube, where previously there had been three locations with shrill screaming that topped 95 dB (ouch!) now reduced to 79–81 dB with a few spots briefly hitting 86 dB.
The Occupational Safety and Health Administration (OSHA) has determined that the maximum sustainable level of noise in the workplace should not exceed 85 dB for a maximum of eight hours. So while your BART exposure won’t hurt you, it still remains uncomfortably loud and not what Brian Stokes, the first General Manager of BART, promised us when he offered, “the swift, virtually noiseless and vibration-free electric train.” Stokes also promised every rider would have a seat and that BART would eventually go to the airport. After spending $1.5 billion, which promise do you think was fulfilled? (Hint: Don’t look for a seat on directional commute runs.)
