Jones1945
The book value of the S1 just before scrapping was $500,000. Scrap value was $14,291.
But look at the numbers for the aggregate amount PRR paid on the S1 project from inception through the great number of apparent 'change orders' Baldwin came up with. I think the total is well north of $3 million (!!!) which was amplified in both effect and opportunity cost substantially by the Depression.
If that money had to be 'kept on the books' while the asset was intact, it wouldn't be surprising to see the now-inevitable taking its course...
I think it's documented that Symes disliked the S1 because of its impact on regular operations, and that includes its tendency to go on the ground at the least provocation when hostling. That perception may be a Chris Baer artifact, but I suspect he's looked at the issue more than anyone else.
Note that much of the "HSR optimization" that would have been done from the 1920s through the 1940s would still be useful today if extant... and explicitly designed for speed or 'snapping' rather than decreasing freight grade or the need for 'helping'. That would likely be particularly true for Amtrak service from New York to 'the west' as, even by way of the Philadelphia area, there was no practical alternative other than the NYC, much longer. Combination of the Sam Rea line with electrification would only enhance this, even given the necessity of substantially and perhaps completely rebuilding that electrification for constant-tension to be of maximum worth.
The cutoff around the Philadelphia issues is likely as significant in improving timing as a great many miles of curve reduction via tunnelling. And for PRR this would become important with the rise of TrucTrain business even in the early Fifties...
Note the stylistic 'bullets we dodged' in not adopting the more highly 'styled' versions of the PRR duplex 4-4-4-4. We'd see that ribbed stainless nose love patch again on the Olympian Hi's Erie-builts ... but it worked there. (I do have to wonder whether Old Man Thunder was thinking of that other one when designing the nose of the first-generation Shin Kansen trainsets...)
Inspect that 'near' driver pair carefully, as it's an education in itself. The absolute minimum of stroke reduction on an engine this size, even considering the reduction of main-pin thrust from the duplex principle; the carrying of side rods as close to the locomotive centerline as possible; the provision of large-diameter very thin roller bearings for lightweight rods; the use of controlled lateral motion; and, of course, Baldwin Disc: both the double-disc and folded-plate aspects of the design are clearly visible here...