[PRCo] Re: 1700-series PCC Interurban TrolleyCars

[Fred Schneider]

Interesting point, Boris, but prior to the PCC cars there were no  
separate track switch throwing resistors on cars.   You had one and  
only one way to flip the switch (other than a manual switch iron) and  
that was to pull power (or coast), or if the contactor was close to  
the switch point, pull power with brakes on so that you had control  
of the car.

PTM teaches motorman to thrown the track switch at Museum Road with  
Red Arrow foot-control cars by just using the power pedal; I simply  
won't do it ... too risky because if you misjudge how far behind you  
that contactor is, the car accelerates too much just ahead of a  
mandatory stop.   I always hand throw it with those cars.   I'm a  
little conservative.

In some instances it is impossible to adjusted the threshold amperage  
for all cars that might go through a contactor.   Let me give you an  
example.   If you give set the contactor in the Baltimore Streetcar  
Museum so that some of those small wooden 1896 and 1898 Brownell 2- 
motor cars can work a switch contactor, then the static load on the  
Peter Witt ... lights, heaters and air compressor in the winter will  
be enough to trip the contactor.   If you set it so that the coasting  
Witt will not trip it under any circumstance, then the small cars  
will only throw it if you stop with the trolley pole right on the  
contactor, and notch into the second point with the hand brakes tied  
down tightly .    What's the answer ... their solution is dispatch  
all the old wood cars out of the yard which allows coasting through  
the contactor.   The other answer would be to hand throw every time.

On Oct 1, 2007, at 2:02 AM, Mark McGuire wrote:

> That's quite alright, Phil. Most of the guys on this list are very  
> up on the technical aspects of trolley operations. I am not. I  
> have, however, learned to ask questions no matter how moronic they  
> may be. I am glad I asked this question.
>   Fred III sent me an off-list e-mail once when I first signed up  
> for this. In it he stated that everyone on this list puts their  
> pants on one leg at a time. I took that to heart and became less  
> ashamed to ask what I'm sure many percieved as "stupid questions".  
> In fact, I once again thought of that before I asked this latest  
> question. I thank Fred for taking the time to do that.
>   I have learned more than can be imagined just by reading the  
> posts on this list and am very thankful to be here.
>   Oh, and welcome aboard Phil. You've already taught me something  
> and I'm sure you'll teach me even more.
>
>                             Mark
>
> -- Phillip Clark Campbell <pcc_sr at yahoo.com> wrote:
> Pittsburgh was one of those companies.  Power / coast used in the  
> description because it is more !descriptive! than toggle / coast  
> isn't it.  Please accept my apologies for the confusion.
>
> Phil
>
>
>
>
> ----- Forwarded Message ----
> From: Boris Cefer <westinghouse at iol.cz>
> To: pittsburgh-railways at dementia.org
> Sent: Sunday, September 30, 2007 10:04:14 AM
> Subject: [PRCo] Re: 1700-series PCC Interurban TrolleyCars
>
> It was strictly prohibited on some properties to set the switch by  
> power
> application because it causes burning to the overhead contactor and  
> may
> cause also further damage to the track setting circuits. Pushing  
> the track
> switch button limits the setting current to +/- 70 amperes while power
> application is always higher than 220 amperes.
>
> B
>
> ----- Original Message -----
> From: "Mark McGuire" <macmarka at netzero.net>
> To: <pittsburgh-railways at dementia.org>
> Sent: Sunday, September 30, 2007 6:30 PM
> Subject: [PRCo] Re: 1700-series PCC Interurban TrolleyCars
>
>
>> Now please explain to a rookie what the track switch is for. I  
>> thought the
>> switches were controled by either coasting through or applying  
>> power. Was
>> this button mainly used in the older days?
>
>
>
>
>
>
>
>
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