Unlike other streetcars or trolleys that use overhead cables for power, cable cars attach to a cable running under the street that pushes the cars forward. This entirely mechanical process depends on the steady rotation of large wheels at the cable car system's powerhouse, according to the Market Street Railway website.
Andrew Hallidie created the first cable car line in 1873, based on his knowledge of ore-hauling and suspension-bridge technologies, to help passengers get up the steep slopes of San Francisco, according to the Cable Car Museum. The earliest cable car lines ran on steam power instead of electricity.
The different technologies used in electrified rail transport can cause confusion. Market Street Railway explains that the term "cable car" refers specifically to vehicles that use underground cables, while the terms "streetcar" and "trolley" describe vehicles connected to overhead electrical wires.
