The State : Cable Car Clatter Studied

Swarms of hums, buzzes and jingles emitted by the new cables that move San Francisco’s cable cars are creating such a racket that the city has plunked down $125,000 to find out what all the noise is about. Never really quiet, the rolling mutter of old has turned into a kind of low-frequency series of whacks, described by engineers as comparable to “a hammer blow at 120 times a second.” Experts say that there has been some progress in attacking the technical problems associated with the noise but that a quick solution does not appear to be in the cards. About $60 million was spent to renovate the 111-year-old system, which reopened last June.