Pittsburgh Division 1953 ETT No. 4
Rule 1157-C25 "Cars carrying major calibre gun barrels shall be placed on the front end of train and the movement of such cars restricted to not exceed the following speeds:"
Main line Slope - Pittsburgh breech forward 40 mph breech trailing 20 mph
New Portage Branch Wye - SF breech forward 20 mph breech trailing 15 mph
Port Perry Branch perry - PG breech forward 20 mph breech trailing 15 mph
Monongahela Branch Division post (PH Division) - West Brownsville breech forward 30 mph breech trailing 20 mph
"When conditions require, speed restrictions of less than those specified above shall be made effective by local instructions.
When handling such cars, conductors must know that the enginemen have been so advised."
It would appear the routing from Altoona was New Portage Branch to SF thus by-passing Horseshoe curve using Muleshoe instead. SF - R (Perry) west of Pitcairn. Port Perry Branch from Perry to PG. Monongahela Branch from PG to Pan Handle Division post.
I don't have the corresponding Pan Handle Division ETT or the Eastern Division ETT to determine the routing further west.