From Noel Reed --

Wheel trolleys were used on the Sydney to Potts Point trolley bus route.They were smaller than the standard tram trolley wheels and were particularly prone to de-wirements especially on out bound services at the corner of College and William Sts where the outbound TB wires crossed first the inbound TB wires then four successive tram wires while rounding a right hand curve.

I well remember one such dewirement at night, involving one of the two single deck trolley buses whose long trolley poles must have had considerable inertia.

Noel Reed.
----- Original Message -----
From: Tom Fairbairn
To:TramsDownUnder@...
Sent: Saturday, January 20, 2007 1:53 PM
Subject: [TramsDownUnder] Re: Skids & Round Wire (WAS: Trolley wheels)

--- InTramsDownUnder@..., Peter Groom <groomp@...> wrote:
>
> Some of SF MUNI's trolley coach lines had (still has?) some old round
> wire but the ears appear to be hammered on - they have no clamp
> screws and have tapered ends.
>
> The line that I'm thinking of, the 33, was SF's first TC line and its
> first coaches used wheels, but went to shoes before WWII(?).
>
> pete groom
>
> <snip>
*******************************
Pete, a lot of the old round wire systems had ears for the pull-offs
and hangers that were soldered in place, and that sounds like what you
are describing. Those would probably work OK with pans or skids. There
were also some that were pressed around the contact wire or used
bolted clamps, but both of those have a tendency to cause skipping and
arcing at the hangers and pull-offs when the wheels or shoes contact
them, especially at higher speeds, and they also required frequent
checks to be sure they weren't getting too thin from wear and arcing.
They are mostly used now for temporary work with round wire.

Many of the frogs were stamped metal (saved up-front money) and those
would snag some skids and tear the carbon blocks out of pantographs.
Pans will generally work past turnout frogs that are cast and have
lead-in/lead-out fingers applied, although some slight modification of
the side ears might be necessary. Crossing frogs require some special
design. TDU has a lot of photos that show these critters, as I know
you're aware.

I never heard, as you mentioned above, of using wheel trolleys on
trolley buses. I would suspect they would be giving constant problems
with dewiring, should the bus not exactly centre under the wires. All
trolleybuses I've ever seen use swiveling carbon shoes to allow the
bus to swing to the sides of the wires. However, I also suspect the
wheels were used to begin with until they proved inadequate to the job.

Regards: Tom Fairbairn

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