San Francisco Cable Car Barn Photos
San Francisco, California
The cable car barn houses the motors and sheaves that drive the cable cars in San Francisco. The steel cables range in length from 10,000 to over 21,000 feet and are approximately 1 1/4 inches in diameter. The cables are made from six bundles of 19 steel wires wrapped around a sisal rope core. A 500 horsepower DC electric motor keeps each cable moving at 9.5 miles per hour. The motor spins a power sheave which is a large pulley approximately 8ft in diameter. To prevent slippage, the cable is wrapped around the power sheave and then travels over and under an unpowered idler sheave in a figure eight pattern.