The problem with the SDP40F was that they had their water tanks inside the body (FP45s had part of the fuel tank partitioned off) and this raised the centre off gravity. On curves with poorly secured rail, the surge of water in the tanks due to the curve caused a high lateral force on the trailing truck (the tanks were behind the engine) which turned the outer rail over.
If Amtrak had fitted HEP generators, making an SDH40P (as had been orignally planned), the problem would have gone away, and they would have had more economical and more powerful units (not to mention quieter) than the F40PH, and it would have cost them less. But the real reason for the derailments wasn't known at the time. I have the NTSB official investigation report and they hadn't a clue. EMD did their own investigation, and they wanted to prove the problem was all in the track so they didn't find the problem either. Since they were building the "rebuilt" F40PH units, they were happy with the result!
But keeping an SDP40F is a good idea, particularly if the mistake made in scrapping them so early is learned!
But to reflect back to Dan's post, there is a B-24 being preserved in Australia, having been recovered from about thirty years in the New Guinea jungle. Anybody with any "Liberator" spare parts could think of donating them to the Australian project. It is the last complete (well almost) airframe that saw Australian service. These Lend Lease aircraft were important in saving Australia from invasion by Japanese forces in 1942 - 1945, and were used for long range maritime patrol.
Peter
