[PRCo] Re: Trolley question

[Schneider Fred]

It was my impression that both R55 and R59 had to stay on the rails  
when grinding.   I don't remember a swivel harp but I only saw it  
once at age 13.   Thirteen-year-olds do not look at the same details  
that 69 year olds observe.


On Feb 3, 2009, at 3:26 PM, Phillip Clark Campbell wrote:

>>> From: ROBERT R ROCKWELL
>
>>> Does the trolley wheel harp or slider swivel on the pole ?
>>
>> From: Phillip Clark Campbell <pcc_sr at yahoo.com>
>>
>> No for streetcars
>
> Pittsburgh did have at least one piece of equipment where the harp  
> with wheel
> did swivel didn't they.  This was their portable rail grinder.  To  
> keep the line
> running when grinding, rubber wheels were dropped and the grinder  
> operated
> under power to the side of the track;  the trolley wheel swiveled  
> to allow this
> maneuver.  The grinder operated up a ramp onto a flatbed trailer  
> when work
> was finished.  Early trolleybuses also had this swivel harp and wheel.
>
>
> Phil
>
>
>
>> 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
>
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