In article ,
says...

On Thu, 22 Dec 2011 09:28:40 -0000, harry wrote:

On Dec 22, 8:53 am, polygonum wrote:
On Thu, 22 Dec 2011 00:14:17 -0000, Tim Watts
wrote:
harry wrote:

There are eyes on the poles and they are spring loaded upwards. The
wires are "8"section, there is a pinching device.
There was a long bamboo pole threaded under the bus for the purpose
ofhooking/unhooking wires.
Best laugh was when the bus went one way down a junction and the
poles
went the other way. (Someof the junctions had automatic "points" but
sometimes they got out of sequence.
There was a manual ring for the conductor to pull to move the
"points" on most junctions.

The old trollybusses in Riga (1997) were even simpler:

Flexible cable from each pole ran down to a sping loaded retractor
spool
on
the back of the bus (think hoover cable rewind). To move the pole,
conductor
pulled on the wire. Very simple

There was some sort of hook on the pole and the vehicle which could be
used
to latch the pole down to if required.

And the trams in Riga have properly designed track loops at route ends.

--
Rod- Hide quoted text -

- Show quoted text -

Why? The driver just walked up to the other end in our trams?
The trolley buses mostly did a loop through local housing estates at
our terminii.

I wrote "trams" not trolley buses.

At minus some large negative number of degrees and thick with snow, I
guess the driver would rather NOT walk round.


No need. Simply install an automatic trolley pole reverser.

It consists of a simple delta arrangement of the overhead with sprung
points at the three intersections. When the tram arrives at the
terminal, the trolley pole goes straight on past the delta.

When the tram leaves, the trolley pole is pushed ahead of it and forks
off onto the delta, swinging round as the tram proceeds. Once the pole
reaches 90 degrees to the direction of travel, it reverses direction and
is pulled conventionally onto the third leg of the delta and back onto
the main overhead.

A model showing the principle can be seen he

http://www.gordonstrams.net/SDTvidpage.htm

Off course, modern trams use pantographs, which are bi-directional,
anyway ...

--

Terry