[PRCo] Re: Pgh Railways Street Car Operators Wanted Ad

[Schneider Fred]

I'm laughing my pants off about recommended tension.   We need a box  
of new springs at PTM.   You can put up one pole on 78 with one  
hand ... probably has all of 15 pounds tension. It needs to be  
replaced badly and springs cost mucho dollars.   Any one want to  
contribute?

And 5326 has one spring that damn near lifts me off the ground.


On Oct 25, 2009, at 2:48 PM, TEP wrote:

>
> No typo. The carbon shoes on a trolleybus require slightly more  
> than twice
> the upward spring force of a streetcar trolley pole, nominally 72  
> lb each.
> They have to stay on even when off-centre -- the maximum roam is 14  
> ft.
>
> The operator is instructed to only handle one pole at a time but  
> this is
> often breeched meaning grabbing both ropes at once -- and the 140  
> lb uplift
> requires at least that body weight according to my physics.
>
> At  the time of the ad the US was contributing to the UK war effort  
> through
> lend-lease, but was not at war, and there were strong forces in the  
> USA
> opposing entry, despite Roosevelt's views. So I might be speaking  
> German now
> if not for Pearl Harbor!
>
> Tom P.
> -----------
>
> Phillip Clark Campbell wrote: 2: Is that a typo - 70#? Ohio Brass  
> recommends
> a maximum of 30-32 pounds for wheels; 25-30 pounds for shoes at  
> wire height
> of 18-feet. I understand Prc used a modestly higher figure for  
> interurbans.
> In 1941 which we are discussing, OB was the standard to follow. Modern
> trolley poles today may use less 'tension' as mass of pole is  
> lighter. 70#
> isalmost triple the low figure for shoes; poles would snap in two  
> under such
> tension while severe damage would result to the overhead on  
> dewirements
> regardless of effectiveness of retrievers.
>
>
>
>