We were running downgrade from Cresson, which is shortly thereafter almost flat and level trackage.
With a consist well over 6000' in length, having 15,000 tons of TTX piggyback trailers behind us, when we started through the New Portage bore. I put the train into the throttle 1 position, and by the time we had reached the Tunnelhill side of the bore, most of the train weight was now cresting over the summit of the -1.87% grade.
Putting the loco throttle to the zero position, and applying the 50% dynamic brake setting, I slowly put the loco throttle into the notch 6 position, which slowed the train somewhat.
The rear end helpers now also crested over the summit, and the entire train weight was bunched up, with the slack run in. The train was increasing in speed all along the sweeping Salpino Curve, and by the time we reached Bennington Curve interlocking, I had put the dynamics into the notch 8 position, and applied several notches on the service brake application. The train speed was ever increasing past 35 mph, and by the time we had passed Allegripus Curve, the train was beginning to become out of control. Trying to avoid a full emergency braking application, that could cause a run-in derailment, I further applied the service brake, until we had a full brake application.
Moving the throttle to zero, I applied the 100% dynamic braking, and put the throttle quickly back into the "Run 8" position.
The train was now at 45 mph, and approaching MG tower we informed Alto tower that we were now a full fledged run-away, and our trainline air pressure had been Psssssst away in our multiple service brake applications.
We now attempted full emergency braking, as we came within sight of the Horseshoe we were doing 55 mph. Hold on, and brace yourself I cried to my conductor, or make like the birds, and jump (NR at 55 mph).
By the time we reached MP 241.7 we were doing in excess of 65 mph, and shortly thereafter we derailed, blocking the entire 4 track main, with 28 derailed TTX Piggyback flats of US Mail. Some trailers flipped and ripped open, and US Mail was all strewn all over creation, down over the steep, rattlesnake, copperhead and stickerbush infested hillside (and each and every piece of US Mail had to be personally retrieved by a small army of leatherneck workers, using rope harness's and winches).
Within several hours only one track (the #4 track) had been hastily repaired, and opened for operation through the derailment site.
This, did in fact occur, on the prototype on several occasions through out the history of the Horseshoe, the last being @ 1993.
Just some other notable accidents were: The steamer boiler explosion at SF tower fatally injuring the tower operator (portions of the boiler were hurled 1000' into the air, coming to rest 3/4 mile distant), Bennington Wreck of the Red Arrow, Allegripus fatal wreck of a steamer (named Allegripus) that plunged down over the cliff side, and the TTX piggyback trailer US Mail train wreck at Cold Curve.
