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| Cable cars in San Francisco run on rails by gripping an underground cable beneath the street. They do not utilize any overhead wires like streetcars do. |
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The cable car
Cable cars (right) run on rails with a slot between the tracks where an underground cable runs at a continuous nine miles per hour. The cable runs from a central powerhouse, from huge winding wheels, as the cable cars themselves are completely mechanical and have no means of independent locomotion. In order to move forward, the underground cable is grabbed by a grip on the cable car that works like a pair of pliers. Originally, the powerhouse used steam power to run the cables beneath the streets, but as electricity became more commonplace, steam engines gave way to electric motors (hydroelectric power) which wind the huge wheels that spin the cable to this very day.
Cable cars were invented in 1873 by Andrew Hallidie to climb the hills of San Francisco. Many cities once had cable cars, but today, San Francisco’s Powell-Mason, Powell-Hyde, and California Street lines are the only ones left in the world. The Powell Street cable lines and the F-line form an 'iron triangle' of historic transit service between Downtown San Francisco and Fisherman’s Wharf.
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| Streetcars in San Francisco run on rails by connecting a trolley pole to an overhead electric wire. |
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The streetcar, trolley, or tram
Streetcars, trolleys or trams, (right) also run on rails, but with no slot between the tracks. Unlike the mechanical cable cars, streetcars are propelled by electric motors and require an overhead wire to draw power from. Far faster than any earlier form of urban transportation, the streetcar quickly eclipsed cable cars and horsecars as America’s choice for transit in the first half of the Twentieth Century. With 100,000 vehicles and 45,000 miles of track in the US by 1918, the streetcar helped trigger rapid urban growth and created the nation’s first true suburbs.
San Francisco has the world’s most diverse collection of streetcars in regular transit service, and many are quite unique and different looking. As for the cable cars, they are all very similar in appearance. But, there’s a simple test to distinguish streetcars from cable cars:
If it runs on steel rails with a wire overhead and a pole touching the wire, it’s a STREETCAR. If it runs on steel rails with an open slot between them, and no overhead wires, it’s a CABLE CAR.
(Just to confuse things, San Francisco is also one of the few American cities that operates trolley coaches, which look like regular buses, but with twin poles on the top that connect to double overhead wires. So, if it runs on wires, but has rubber tires like a bus (no rails), it’s a trolley coach. Market Street Railway has helped Muni preserve four historic trolley coaches dating from the 1940s and 1950s, though they are not currently used in service.)
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