[PRCo] Wheels__&__Shoes

[James B. Holland]

Pittsburgh and Philly both used wheels.     Philly converted to shoes 
about 1975--1980  --  Pgh. converted to pantographs from wheels.

More to convert with large city  --  frogs are different.     With 
wheel, only one point of wheel touches frog base whereas 3-4--inches of 
shoe touches base.     More runner // guide overlap on the frog for 
wheel which plays havoc with shoes.     They installed some wheel frogs 
here in San Francisco in the latter 1970s and on a turn like the 42-wye 
the pole would go straight thru.     Try to go straight thru at the same 
type of location and the pole would make the turn.

Am told that Philly didn't convert frogs when they changed and they 
reportedly didn't have problems  --  but probably wasn't much left of 
frogs at that time because of wear!


rogertrolley.1 at juno.com wrote:

>It alway seemed to me a real mystery as to why PRC used wheels,when idustrywide most all companys used shoes so as to not wear out the overhead and to libricate it with carbon inserts. Johnstown used shoes and Pittsburgh didn't. Back in 1958 it seemed an achronism that it was that way,whereas you would think the big city would be far more modernistic than the small burg like Johnstown would have been !!!  cheers rogertrolley
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