[PRCo] Re: Trolley question

[Phillip Clark Campbell]

> ----- Original Message ----

> From: ROBERT R ROCKWELL <w3syt1 at msn.com>
> To: pittsburgh-railways <pittsburgh-railways at dementia.org>
> Sent: Tuesday, February 3, 2009 10:49:36 AM
> Subject: [PRCo] Trolley question
> 
Mr.Rockwell:

My first answer to each question is for streetcars and the second one is for
trolleybuses but there are always exceptions aren't there.

> Does the trolley wheel harp or slider swivel on the pole ?

No for streetcars
Yes for TBs
Some streetcars retrofitted with swivel harps.

> Does the pole swivel in the base?

Pole is clamped into the base for both streetcar and bus.


> 
> Does the spring loaded base assembly swivel on the car roof ?
> 
Yes, the base moves to allow movement of the pole.  There is a shunt attached
to the base so current is routed around bearings otherwise they would arc, pit, and
eventually freeze.  This shunt will limit how far the pole can move but it is generally
arranged so it can turn 180-degrees and operate from that position if necessary.


Phil