Sunday, September 9, 2007

Cable Car 101

I live really close to the Cable Car Museum and it only took me 5 months to visit. This morning I was getting some work done and downing lattes at the Gallery Cafe. As soon as my laptop battery died the museum sang it's siren song and I strolled across the street to finally take a look.

There are 4 really, really, really, ridiculously long cables that run under the streets in SF (and travel at 9.5mph). These (above pic) are the wheels (sheaves) that power the cables. The Hyde St. cable is off to the right of the picture. Each cable gets 3 sheaves to run through. The close two turn opposite each other routing the cable in a figure 8 and the 3rd sheave is about 100 feet away (top of pic). It's a pretty cool system...the figure 8 makes the cable touch 3/4 of the sheaves surface which creates the necessary friction and the 3rd sheave is mobile because the cables stretch as much as 100 feet before throughout their lifetime.

They even have a lower level (below the street) where you can see the cables entering and exiting the museum. It was really cool to see the angles of the sheaves that allows the cables to route around underneath the city streets. I tried to take a picture here too, but it was dark and the flash glared too much against the glass.

That's my cable car lesson for you. I could get into the whole gripping of the cable, but I don't want to spoil the entire museum for you. (yeah, there's not too much to it).


Katie said...

You finally made it... Kind of interesting, huh?

ADIG said...

Very cool and well worth the visit.