1873
Cable Cars
Andrew Smith Hallidie (1836–1900), William Eppelsheimer (1842–unknown)
One thing that is true of all engineering endeavors is this constraint: engineers must work with the technology available at the time. Thus, an engineer working in the mid-1800s did not have access to things like lasers, microprocessors, or inexpensive aluminum.
So from 1873 through 1890, when promoter Andrew Smith Hallidie and engineer William Eppelsheimer set about to design a transportation system in San Francisco, one constraint they had to work around was the size of existing steam engines. Steam engines were big and they were heavy. They had to carry a water supply and a coal supply. That worked for a big steam locomotive pulling a long train with hundreds of passengers. It did not work at all for small streetcars running up steep hills on city streets.
The size of the era’s steam engines therefore determined the architecture of the system. The steam engines would sit stationary in a building, and their power would be distributed with moving steel cables running in channels beneath the street. If the cable car line is two miles long, it requires at least four miles of steel cable running in a loop. Rollers and pulleys along the route minimize friction on the cable.
The cable car has a lever used by the operator. The lever manipulates the mechanism that grips the cable. When the car is gripping the cable, the car moves. When it is not gripping the cable, the car can coast or brake.
At the end of the line, the cable runs through a large pulley so it can return toward the steam engine. The car either has to turn around on a turntable, if the car has only one set of controls, or, if it has controls at both ends, it has to go through a switch that puts it on another track.
With a cable speed of 9.5 mph (15 kph), cable car systems seem like quaint anachronisms. But at the time, they were state of the art. Engineers had built a working system that made getting around the city much easier. A century later, the system is still working.
SEE ALSO High-Pressure Steam Engine (1800), Erie Canal (1825), Diesel Locomotive (1897), Internal Combustion Engine (1908).
San Francisco cable cars, shown here, are still in operation today.