[PRCo] Re: Wheels__&__Shoes

[Fred Schneider]

Why did it take so long.  Wheels were reasonably suitable on a trolley wire with
a completely round cross-section that is held up by an ear that wraps around the
wire.  But those ears cause problems with anything that slides over it ... the
shoe wants to take chunks out of the ear and vice versa.

The ideal solution was a pantograph.  But it requires a firm and properly
aligned roadbed or the car will rock and ultimately the pan will catch somewhere
and tear down wires.  And it also wants a figure "8" cross section (or grooved
as Ken called it) wire which is clamped from the side ... the bottom surface is
perfectly smooth.  When trolley bus lines were installed, this type of wire was
installed initially.  But trolley lines had mostly "O" cross section wire with
ears wrapped around it, and it costs money to tear it all down and start over.
In a business that lost money over its entire life, you just didn't add to the
loss by tearing down wire just so you could hang up new wire.

So why did PAT and Red Arrow wait until the 1980s to hang new wire?  Because by
then it was done with Federal and State grant monies and not out of the
farebox.  It doesn't even show in the operating expenses.   Why didn't
Pittsburgh at least change to shoes earlier?  Probably no good reason to spend
the money.  Speeds were not high. Rolling stock wasn't heavy and power robbing.
And there was no joint operation with trolley coaches (both using the positive
wire).   Charles Shauck is dead, so is Karl Hittle, and R. Tighe so I can't ask
the question.  But we can observe two bankruptcies between in 23 years between
1917 and 1950 and that may be all we need to answer the question.  I do know
that Charlie came out of every annual budget meeting with his requests slashed
deeply.

I might add that pantographs were much more common in countries where track
maintenance is superior.  Russ Jackson was talking to one of the Kawasaki people
from Japan, a man who had observed that the PC (PRR and New Haven) strung
contact wires directly over the track instead of staggering it back and forth to
spread wear across the pantograph shoe (common in most countries).  Russ joked
back that "We stagger the tracks."
With staggered rail joints there can be a lot of sway in rolling stock, and with
undermaintained track the rocking is sufficient to allow a pantograph to tear
down the wire.  This generally isn't a problem on the other side of the ponds,
and therefore wire is staggered.  .

Pantographs were

ktjosephson at earthlink.net wrote:

> Old WEPCO documents indicate that TMER&L believed that mixing shoes and
> wheels was a problem because wheels tended to bounce and arc more often
> shoes, causing the wire to peel. (See page 436, CERA Bulletin 112.) Cars
> equipped with shoes would plane off the peelings,  supposedly weakening the
> wire. This was based on their own findings during the 1920s when rebuilt
> interurban cars were equipped with shoes and run in mixed service with
> wheel-equipped city cars on some stretches of street trackage. Greasing the
> wire seemed to help reduce wire wear.
>
> I wonder if TMER&L's conclusion was based on one individual's personal
> belief, or if a superintendent needed an excuse to slip an all-shoe fleet
> proposal past the bean counters.
>
> I am certainly not an expert, but I would think the condition and type of
> wire (round or grooved), base spring tension on the cars, speed of
> operation, road bed condition, etc. would affect the amount of bounce the
> collector would have as it rode along the wire. This is indicated in the
> book as well as blaming starting with a heavy load from a dead stop with
> such a small area of contact on the wire ("high current density") for wire
> wear.
>
> I do not know if mixing shoes with wheels really caused problems, or if
> these problems are only evident on heavily traveled sections of line.
>
> Pittsburgh had lousy track for years and  used wheels long after most other
> North American operators went to shoes.
>
> Most operators found shoes to superior for all-around operation. As I noted
> above, maybe the Milwaukee system had a large stock pile of wheels and
> wanted to justify a large scale conversion to shoes. Corporate leaders are
> more likely to let the worker bees make do with what's on hand unless
> somebody can convince them that a major investment in change would be a
> profitable benefit to the corporation.
>
> But I would like to know why Pittsburgh did stick with wheels for as long as
> it did. I know this was touched on in "Traction and Models" during the mid
> 1970s, but a definitive answer from PAT was never published in the article.
>
> K.