Passenger Trains > Kind of a train question.

Today in San Francisco I saw a municipal electric Trolley bus going down Townsend st under its own power with the trolley poles down. How is this possible. Do the new generation of trolley buses have batteries that enable them to move about without being connected to the overhead electrical wires?

Posted from Android

Some of them do -- dunno if all the newest ones do.

          Obviously they do........ or it was a runaway.
 

Yes - they have APUs - Auxiliary Power Units.  In the trolley coaches bought in the 1990s they had a small gas engine, in the newer ones it's a battery that charges when they are on-wire. 

When Stockton Street near Market was closed for many months due to the Muni Central Subway construction, southbound 30 and 45 routes (as I recall) were diverted off of Stockton and ran under battery power on their detour for quite a few blocks, until they were south of Market.  I believe the trolley poles can be lowered from the driver's seat, but of course must be raised by the driver.

Don't follow muni, or buses in don't live in the city so this all new information to me. Thanks

Posted from Android

Here in Seattle, the trolley busses built by New Flyer can run with the trolley poles down.  I've seen it on Third Ave which is buses only and has both trolley bus routes and non trolley bus routes.  The driver lowers the trolley poles to go around other busses stacked up at various bus stops. King County Metro bought several Breda dual powered busses between 1988 and 1991 to run on several of the routes rerouted into the tunnel. Upon entering the tunnel, the driver would shut off the diesel engine and raise the trolley poles.  The reverse procedure would take place upon leaving the tunnel.  They were never terribly reliable and the diesel engines were removed between 2004 and 2007.  The last Breda was retired in 2016.