BART Quietly Makes
Repairs
By Guy Span
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.)