Cable Car Day

What the day is

Cable Car Day is observed on January 17, marking the 1871 patent granted to Andrew Smith Hallidie for the system that still runs in San Francisco.

Origin and background

The problem it solved was specific and grim. San Francisco's hills were worked by horses dragging loaded carriages up gradients that injured and killed them, particularly on wet cobbles where a slipping team could be dragged back down by its own load. Hallidie, whose family business made wire rope for mining, proposed removing the horses entirely.

The mechanism is the elegant part, and it surprises most passengers. The cars have no engine. A steel cable runs continuously in a slot beneath the street, pulled at a constant speed by a stationary engine in a powerhouse. Each car carries a grip that reaches through the slot, and the operator closes it onto the moving cable to go and releases it to stop, using a separate brake. Everything moves at the cable's single speed or not at all, which is why the ride has no acceleration to speak of, and why the operator's job is physically demanding rather than a matter of steering.

The design spread quickly to hilly cities worldwide and was then almost entirely killed by the electric streetcar, which was cheaper and did not require digging a slot along every route. San Francisco's survives largely because the grades there defeated the alternatives, and because residents fought to keep it when the city proposed removing it in the 1940s. It is now a designated landmark, and the only moving one in the country.

How to take part

• Ride one, and listen for the cable humming in the slot before the car arrives.
• Watch the grip operator work. The effort involved is not obvious from inside.
• Visit the powerhouse, where the winding machinery is open to view.
• Note the difference from a funicular or an aerial tramway, which work on entirely different principles.
• Look up what the hills did to the horses, which is the reason any of this exists.