Ian Jackson wrote:
In message , MikeS writes

Yes but trolley buses needed overhead wires. I remember the excitement
in my schoolboy days when the bus came off the wires. I think it could
move on its battery - about 10 yards on the flat.

Indeed. I think the battery was just intended to prevent the bus finding
itself stranded in situations when the arms could not reach (or did not
have access to) any wires. I've only once seen a trolley bus on battery
power, and I think it was when it had to leave its normal path for a
short distance because of some roadworks.

Batteries in the latter years were not always in the best condition and
they were not charged at line voltage and depended on a motor generator to
charge them and it wasn’t unknown for a driver to forget to turn this on

Though the speed was only about 5 mph the range would have been a lot
further than 10 yards when in good order, wasn’t there a garage somewhere
that had an exit where trolleys had to run along an unwired street till
they reached the wires on a route.
Another probably apocryphal tale is that one on a driver training run was
taken from the system on the South
of the river and onto the Northern network and back again being driven on
and off the woolwich ferry on its batteries.
One moving on its batteries always looked a bit strange to my six year old
eyes ,usually at Hammersmith.

GH