[PRCo] Re: Re :Fineview PCCs

[Boris Cefer]

Yes, an obstruction in the path of the sliding track brake shoe might 
contribute to what you described before but under normal situations, the 
tangent forces resulting from a track brake application are bigger than 
would be a tangential force resulting from a car either stopped or moving 
down a grade.

B

----- Original Message ----- 
From: "Fred Schneider" <fwschneider at comcast.net>
To: <pittsburgh-railways at dementix.org>
Sent: Friday, February 17, 2012 10:45 PM
Subject: [PRCo] Re: Re :Fineview PCCs


Leverage of car moving backward.   For some reason, while you and I would 
expect the frame on which they are mounted to lift straight up with the 
shoes remaining tangent to the rail, they didn't.

The downhill (rear end of the car) end of the shoe simply behaved, Boris, 
like it was dug into the rail and the front lifted off the rail.   Perhaps, 
and you know we don't always look for what the obscure cause is when we are 
18 years old, but perhaps the rear of the shoe or the the frame was locked 
against a raised rail joint or wedged against a paving block so that as the 
car rolled backward, the shoe dug into the adjacent rail or block, and front 
lifted because the magnetic attraction was insufficient to overcome the 
rolling force of the car.

I only remember what I saw in 1958.   I didn't test it with an engineering 
mind then because it didn't make perfect sense.   When you are 18 and right 
out of high school there are a lot of things you see to which you fail to 
test with reason.  I didn't have the wisdom then to realize it didn't make 
perfect sense.   If I had, I would have probably looked to see what the shoe 
was butting up against.

Make sense Boris?

fws


On Feb 17, 2012, at 3:14 PM, Boris Cefer wrote:

> Please, tell me, what lifted the track brake shoes off the rail!
>
> B
>
> ----- Original Message ----- 
> From: "Fred Schneider" <fwschneider at comcast.net>
> To: <pittsburgh-railways at dementix.org>
> Sent: Friday, February 17, 2012 4:39 PM
> Subject: [PRCo] Re: Re :Fineview PCCs
>
>
> The company did not seem to worry about what they put on FINEVIEW on
> fantrips.   I personally scheduled a fantrip using 1707.   Believe me, it
> was not suited.   The drum brakes would not hold it on Henderson Street 
> and
> the grade was so steep that the track brake shoes lifted off the rail at 
> at
> angle of several degrees.   But we got over the line.   The also ran 1700s
> over Arlington Avenue as the tunnel bypass and that was a little crazy but
> that may have only been in the PAT days.
>
> Point is, PRC had a rational plan.   Yes it was not perfectly consistent
> over time because it could not be.  When you close barns and move cars
> because you are contracting operations, there is no way the plan can be
> preserved.
>
>
>