As far as I know they were never used on passenger trains as they were not equipped with a steam line to heat passenger cars. On many railroads the Steam line also controlled the air conditioning as well.
The UP used their Challengers in passenger service and during the war trhey were used on the heavy troop mains. The Challengers in some cases pulled lightweight consists but generally were at the head of heavyweight trains.
I personally have never seen a photo of a Big Boy heading a poassenger train but that doesn’t mean it did not happen.
I’m pretty sure the answer to number 1 is a simple no, leaving the rest of the questions moot. There were only 25 ever made, and they were a rather specialized engine. They had too much power to waste on passenger service. They were also limited on where they could operate, I believe the limits were Omaha and Salt Lake City. Those terminals plus Cheyenne were the turning locations. Passenger service had it’s own specialized power.
I’m not always right, but I feel pretty confident on this one. Now that I’ve said all this, someone will find photo.[;)]
Actually, the Big Boys were cleared to Los Angeles after 1943 , but never called upon to operate there during their service life and such a reassignment would have been a major undertaking to accomplish. IE: lack of coaling facalities for example. Except for the occasional troop trains, Big Boys were restricted to freight, although all were delivered with steam heat capability for passenger service, this was later removed from most as the piping was prone to dammage during switching. UP generally relied upon Northerns and Challengers for heavy passenger work with Pacific’s, Mountain’s and even Consolidations drawing assignment for lessor demands
Were the Big Boys ever used as helpers on passenger trains?
Did Union Pacific ever run a fantrip behind a Big Boy?
Inquiring railfans want to know[:D]!
Yes the 4000s did have steam lines and were used on passengers trains when in a bing and nothing else was out there. They were used on troop trains if the train exceded 20 cars. There are photos of this. They were too powerful for a regular train and would not be able to keep the 80 mph gait of a nothern so not used often in passenger service, but they were used.
I’d suspect that the steam and signal lines were originally intended for M&E with riders, and then for both actual and anticipated troop moves, especially for the prospective Operation Downfall as it developed.
To my knowledge UP never intended to run very long passenger consists (like the proposed Chessie). Possibly the Wahsatches might have been useful on something like the common section of the ‘City of Everywhere’, but that was years after diesels offered a better and cheaper alternative.
I know nothing about the UP and how it used their steam power.
The B&O’s EM-1’s with 64 inch drivers were fast enough to be considered useful for ‘some’ passenger service on mountainous subdivisions - right up to the time that one was being used on one of the mail & express trains on the Mountain Sub between Grafton and Cumberland. https://planeandtrainwrecks.com/Document?db=DOT-RAILROAD&query=(select+97+(byhits+(range+DATE+`1946%2F01%2F01+`1949%2F12%2F31))) After that derailment EM-1’s were rarely used in passenger/express service. Instead double headed Pacific’s or Mountain’s would be the normal power.