All in all, it would seem to be quite a project.
Did any railroads leave a small turntable in place and simply add another larger turntable?
Rich
I would think that going from 90’ to 130’ with a table would involve building a whole new roundhouse facility. Much of the ‘reason’ for large turntables (instead of wyes) would likely have involved a longer duration to WWII (specifically Operation Downfall after 1945) with large engines and coast-to-coast tenders that need fast turnaround. Much of the need for that kind of capital investment evaporated around 1947… replaced by dieselization.
Preston Cook just donated a large number of his images to the Jefferson Library in St. Louis, including early EMD optimization of diesel service facilities. Comparing those with conventional ‘roundhouse’ design is interesting.