How Does A Cable Car, Like Those In San Francisco, Move?
A cable runs continuously in a channel between the tracks, which are located just below the street. The cable is controlled at a central station, and usually moves about 9 miles (14-5 kilometers) per hour. On the underside of each cable car is an attachment called a "grip." When the car operator pulls a lever, the grip latches onto the moving cable and is pulled along. When the operator releases the lever, the grip disconnects from the cable. The car comes to a halt when the operator applies the brakes. Also called an endless ropeway, the cable was invented by Andrew S. Hallidie (1836-1900). Hallidie first operated his system in San Francisco in 1873.
Sources: Smallwood, Charles A., et al. The Cable Car Book, pp. 6-7; World Book Encyclopedia, vol. 3, p. 7.