What would typical power on a loaded coal train in 1948 coming into reading yard have looked like? Also the opposite direction empty string of 55 ton hoppers coming back from port richmond?

K, M, I-9 and I-10 classes could be considered the coal drag pool. Diesels, other than the FTs undergoing tests on coal and Catawissa Br. trains, did not show up until after 1948. After 1948 was also the beginning of T-1s being bumped by diesels to coal service. Camelback consolidations were all permanently removed from service by year's end in 1948 (End of camelbacks on the Reading).

Not to Challenge Evan, just for topic of conversation. I am by no means not even classified as a student of Reading Steam.... casual observer at best.

So here's my question to the question. Remembering back to an article by Bert Pennypacker in a Bee Line that was kind of dedicated the "Crossline." As I recall Bert described the evolution to the K class as pretty much engineered for that run and them being the Queens of the manifest runs from Rutherford to Allentown. Of course I haven't read that article since the last century, I'll have to look it up and re-read it.

Would that thought tend to push the I-9, I-10, M-1 and T-1 more to the mainline runs from the coal fields?

Note these are questions not answers...…. just throwin em out there.
Rob

While the Ks were built to increase the speed on the cross lines, there are numerous, dated photos of them on coal trains. Videos show them on coal trains at Tamaqua, St. Clair and Gordon. I did miss the class N-1, which ran mine runs, brought trains to the St. Nicholas breaker and down to St. Clair. The N-1 class was used for power on the cross line manifest runs before the Ks arrived. The K class doubled the N class's top end speed of 25 mph. Fair assumption that by 1948, EMD's FT diesels were displacing K class engines to lesser runs? Anyone have power assignment documents from 48?

Was it common that 2 engines would get used like a T1 and K1 or 2 I9/I10?

It would have been an unusual circumstance for double heading large engines of the T and K classes. Remember the main line had a ruling west bound grade of 0.3%, which allows a locomotive to handle as many empty hopper cars back to the mines as it could haul loaded cars to Abrams Yard. T-1 class could handled 125 loaded 55T hoppers to Abrams yard, with the train length being determined by the yard’s capabilities (Track and yard capacities, for the T-1 class, were determined by test runs.). The main line was single engine territory, except during traffic surges. The Bethlehem Br. and the mountain lines passed Pottsville were helper (double headed) and pusher territories in the steam era..