On Thu, 22 Dec 2005 14:47:15 -0800, Chippy wrote:

Richard J. wrote:

But at least they could divert, which trams and trolley buses would not
be able to do.

The trolleybus faction usually advocate hybrids, with auxilliary diesel
engines, both for diversionary and route extension purposes.

Or battery. I've seen both - in regular use, running on their traction
batteries or diesel auxillary engines.
Often now the poles no longer have ropes, if the bus de-wires, they drive
on auxillary power still they get to the next re-wire point.
I would be extremely surprised to find a modern ETB that didn't have
some capability to run independently of the wires.

The traction battery option is not new. I was told at Carlton Colville
museum last year that the old London ETB's had traction batteries and
could run quite a few miles with out the wires. Was told 'this was quite
handy in the war as they could work past damaged sections of overhead'.

In the end what a ETB buys you is the pollution is made some where else -
at the power station. They are also quiet to operate.