We had seen these cars on our first visit there in 1970, but to be honest, I never really thought about them until we actually saw them in operation this time around.
The cables which are about 1 1/2" (31.75mm) run under the streets of the 3 lines, the Powell-Hyde, the Powell-Mason and the California lines. The cable cars are operated by a 'Gripman' and a conductor. The gripman moves the lever which 'grips' the cable which is running at a constant speed, and the car moves forward. At the next stop, he releases the cable and applies the brake to stop the car from rolling. It's quite a tricky job being a gripman. they need to be alert to release the 'grip' when they cross another line to avoid dragging that cable up.
San Francisco's streets are sometimes quite steep so the conductor at the back helps by putting on manual brakes to assist descents.
The machines that run the cables all over the town are in the cable barn (and museum). The car barn is located between Washington and Jackson streets just uphill of where Mason Street crosses them. Cars reverse into the barn off Jackson Street and run out into Washington Street, coasting downhill for both moves.
There are four separate cables: one for the California Street line, one each for the separate parts of the Powell-Hyde and Powell-Mason lines, and one for their common section.
The cable cars are not only a tourist attraction, but they are used by the locals also to get around the city. When the cars are full, people just hang on to the railings.
It is amazing how these cable cars perform on the sometimes very steep hills of the city.
There are turntables at the three terminals served by the Powell-Hyde and Powell-Mason lines, and these two lines are served by a common fleet of single-ended cable cars. Cable cars on California Street, however, have cabs at both ends, so the terminals are single-track stubs and the operator only switches ends.
As I said, I was very impressed. Well done San Francisco.
These pictures are from my Cable Car of San Francisco video