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

[Phillip Clark Campbell]

From: John Swindler <j_swindler at hotmail.com>
To: pittsburgh-railways at dementia.org
Sent: Mon, October 26, 2009 5:55:25 AM
Subject: [PRCo] Re: Pgh Railways Street Car Operators Wanted Ad


System component 4.65 in the PCC2 state inspection
manual requires the pole tension to be : 
"check shoe pressure against wire (25 to 30 ft. lbs.)
using a spring gauge.  

This is done by tying a short loop in the trolley rope
(Elmwood has some ex. Navy men) and using a spring gauge. 
The tension can be adjusted at the trolley base.  
There's a "U" clamp on the pole that can be moved. 
Also nut and bolt assembly with each spring.  


Cheers

John
________________________________

________________________________
Mr.Swindler;

Picking a little with the above:  Spring gauge should be looped
over the trolley shoe, not attached to the trolley rope.  While
modest, the spring which keeps the rope taut will add to the
tension needed.  I.e., if the rope exerts a 1-pound pull with the
shoe at 18-feet, then the actual pressure from the pole is
26-pounds  (assuming 25-pounds pressure desired  --  26#
minus the 1-pound pull of the rope = 25#.)

Phil



> > 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.
> >
> >
> > 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# is almost 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.