A cable car (usually known as a cable tram outside North America) is a type of cable railway used for mass transit in which rail cars are hauled by a continuously moving cable running at a constant speed. Individual cars stop and start by releasing and gripping this cable as required. Cable cars are distinct from funiculars, where the cars are permanently attached to the cable.

The first cable-operated railway to use a moving rope that could be picked up or released by a grip on the cars was the Fawdon Wagonway, a colliery railway line that opened in 1826.^[3][4]

Another began operation in 1840: the London and Blackwall Railway, which hauled passengers in east London, England.^[5] The rope available at the time proved too susceptible to wear and the system was abandoned in favour of steam locomotives after eight years.

In America, the first cable car installation in operation probably was the West Side and Yonkers Patent Railway, New York City‘s first-ever elevated railway, which ran from 1 July 1868 to 1870. The collar-equipped cables and claw-equipped cars proving cumbersome, and the line was closed and rebuilt to operate with steam locomotives.

In 1869, P. G. T. Beauregard demonstrated a cable car at New Orleans^[6][7][8] and was issued U.S. patent 97,343.

In 1873, the Clay Street Hill Railroad, which later became part of the San Francisco cable car system, was first tested. Promoted by Andrew Smith Hallidie with design work by William Eppelsheimer, the line’s grips became the model for other cable car transit systems, whose cars were often known as the Hallidie Cable Car.

In 1881, the first such system opened outside San Francisco: the Dunedin cable tramway system in Dunedin, New Zealand. For Dunedin, George Smith Duncan further developed the Hallidie model, introducing the pull curve and the slot brake; the former was a way to pull cars through a curve, since Dunedin’s curves were too sharp to allow coasting, while the latter forced a wedge down into the cable slot to stop the car. Both of these innovations were generally adopted by other cities, including San Francisco.

In Australia: the Melbourne cable tramway system operated from 1885 to 1940 and was one of the most extensive in the world with 1200 trams and trailers operating over 15 routes with 103 km (64 miles) of track; while Sydney had two cable tram routes – Milsons Point to North Sydney (1886-1905) and King Street Wharf to Edgecliff (1894-1905).^[9]

Cable cars rapidly spread to other cities, although the major attraction for most was the ability to displace horsecar (or mule-drawn) systems rather than the ability to climb hills. Many people at the time viewed horse-drawn transit as unnecessarily cruel, and the fact that a typical horse could work only four or five hours per day necessitated the maintenance of large stables of draft animals that had to be fed, housed, groomed, medicated and rested. Thus, for a period, economics worked in favour of cable cars even in relatively flat cities.

For example, the Chicago City Railway, also designed by Eppelsheimer, opened in Chicago in 1882 and went on to become the largest and most profitable cable car system. As with many cities, the problem in flat Chicago was not one of incline, but of transportation capacity. This caused a different approach to the combination of grip car and trailer. Rather than using a grip car and single trailer, as many cities did, or combining the grip and trailer into a single car, like San Francisco’s California Cars, Chicago used grip cars to pull trains of up to three trailers.

In 1883 the New York and Brooklyn Bridge Railway was opened, which had a most curious feature: though it was a cable car system, it used steam locomotives to get the cars into and out of the terminals. After 1896 the system was changed to one on which a motor car was added to each train to maneuver at the terminals, while en route, the trains were still propelled by the cable.

On 25 September 1883, a test of a cable car system was held by Liverpool Tramways Company in Kirkdale, Liverpool. This would have been the first cable car system in Europe, but the company decided against implementing it. Instead, the distinction went to the 1884 Highgate Hill Cable Tramway, a route from Archway to Highgate, north London, which used a continuous cable and grip system on the 1 in 11 (9%) climb of Highgate Hill. The installation was not reliable and was replaced by electric traction in 1909.^[10] Other cable car systems were implemented in Europe, though, among which was the Glasgow District Subway, the first underground cable car system, in 1896. (London, England’s first deep-level tube railway, the City & South London Railway, had earlier also been built for cable haulage but had been converted to electric traction before opening in 1890.) A few more cable car systems were built in the United Kingdom, Portugal, and France. European cities, having many more curves in their streets, were ultimately less suitable for cable cars than American cities.

Though some new cable car systems were still being built, by 1890 the cheaper to construct and simpler to operate electrically-powered trolley or tram started to become the norm, and eventually started to replace existing cable car systems. For a while hybrid cable/electric systems operated, for example in Chicago where electric cars had to be pulled by grip cars through the loop area, due to the lack of trolley wires there. Eventually, San Francisco became the only street-running manually operated system to survive – Dunedin, the second city with such cars, was also the second-last city to operate them, closing down in 1957.