Muni has three rail modes and two rubber tire bus modes. Cable, Historic & LRV. Cable is the oldest. A cable runs under the street at 9mph. The cable cars have a grip that hangs underneath and 'grips' the cable both uphill and down hill. When they want to stop the car the grip on the cable is released. The actual voltage for lights on the cable cars is 6vdc. Cable cars are a national historic landmark and that division is always fully funded. There are three cables on a loop that are powered at the cablehouse. Large sheaves, probably 12' in diameter are powered by electric motors, the tension of the cable on the sheave is waht drives the system. The weight of a car descending one side of a hill help pulls another car up the hill. Sections of cable need to be replaced weekly as an incorrect grip causes damage.
Muni is hiring like crazy because they are coming off a five year hiring freeze in the craft trades and the workforce is mostly babyboomers. Every diesel shop supervisor, but one is over fifty, most over 55 and will be walking out the door in the next three years. The next jobs up will be machinist and mechanics. These announcements should be out within three weeks. I will keep an eye out for parts counter positions also.
The rest of the system:
The historic cars are cars that are pre 1950. The LRVs, Light Rail Vehicle, also powered by 600vac that it picks up from the overhead wire. The historics run on the surface streets and LRV run in the subway in the downtown business district and the surface streets in the neighborhoods.
Muni also has trackless trolley buses. These operate on 600vac from a two wire overhead system. These are just regular buses but with an electric traction motor rather than an engine and transmission.
and then there is the plow horses, the backbone of the system, the ones the City turns to when all other fail. The diesels motor coaches. There are 480 diesel buses all powered by Cummins engines with Allison transmissions.
