In a page A3 article this morning, the Washington Post quoted an Amtrak statement concerning the speed protections north and south at Frankfort Jct. Southbound was given automatic train stop protection because the approach from the north for this class of train (regional passenger) was 110 mph and, should the engineer overlook making the required reduction for the curve, it could not be rounded at 110 mph.
In contrast, from the south (east in the statement), the approach velocity was mentioned as being as high as 80 mph by Amtrak "while those in route to New York (from the west) are slowing from speeds of up to 80 mph." But, Amtrak continued, [automatic train stop] was not installed for trains headed from Philadelphia to New York, because [these approach] speeds "were so much lower that a train that did not slow could still round the curve without derailing."
I want to not follow the published Post report further because its gist has already departed very slightly from my own understanding. In the 70's and 80's (ie, PC and Amtrak eras in the NEC) my engineering company had contracts involving PC and later directly from Amtrak. One involved modifications at Ivy City to do light repairs on the GG-1 engines owned by Amtrak, as well as the Metroliner equipment.
It will help to go back to the PC standards in this regard. From 30th Street station north, the usual passenger speed limits were 30-> 70-> 50-> 100-> mph. I believe this was a reference to locomotive-hauled passenger equipment of the "tubular" car type. In reviewing my information, there is a certain class of equipment ("A"?), and/or possibly identified as "Metroliner," that was permitted 60 mph around the curve at the present derailment. I believe, however, that the reference was to self-propelled Metroliners, not the later trains consisting of locomotive-hauled Metroliner coaches.
In my opinion, I think the self-propelled Metroliners would have had a sufficiently low center-of-gravity to safely round the accident curve at 80 mph. However, I cannot entirely confirm that a "tubular" train locomotive-hauled by the one-year old "600"-class B-B electric engines could even round this posted 50 mph curve at 70 mph [as had been my opinion in my last post]. It may be slightly short of it, and thus with reasonable certainty 80 mph here would have been out of the question.
A comment on the GG-1 locomotive may be useful here. Based on some logical evaluation of what I know about their construction (probably a little more than is usually found published), I formed the opinion that the GG-1 electrics could very possibly have rounded the accident curve at 100 mph, given a suitable train possibly such as Metroliner coaches (I'm more certain of the engine than the coaches of its day, from memory). It's a matter of where the center-of-gravity is located (and if the high rail has enough rail braces on it).
You might conclude that PRR thought it better to build locomotives that could tranverse such curves unintentionally, rather than spend substantial sums on easing curves at such locations (there is another awkward curve on the Harrisburg line, just west of Paoli). Then, the engineering question is not why PRR did not ease this curve at Frankfort Jct, but rather why the policy of avoiding engines with a high center-of-gravity was discontinued without compensating measures.
In the matter of memory loss, we had such an experience here in the family. A case of head hitting the driver's-side door pillar, unconsciousness for a time--less than an hour (concussion obviously), and memory loss. The neurosurgeon explained this as a never-completed transfer from short-term memory to long-term memory, seen quite often in such situations. Memory of the accident never came back, as far as I know; no other permanent effects seen. In fact, the victim showed not incapacity in any other area of activity, physical or mental, except inability to recall the missing 15 minutes.
So, yes, I find the engineer's inability to remember not at all surprising, nor his seemingly unimpaired ability to apply the brakes. It is possible we see two such incidents, of different degree, overlapping. Hopefully, some here will have seen the brief TV clip of the engineer's windscreen this morning.
By the way, the rate of acceleration (increasing speed) can be shown as being constant at 5/6ths foot per second per second, from a projected point of beginning about two miles (a little less?) short of the brake application. This rate is somewhere between one-quarter and one-third the rate of acceleration the engine would be capable of, at first glance.
--Frank
IMHO 
We're hearing from psychologists, physicists, urban blight experts, lawyers, etc. And guess what?....none of us are part of the investigation, as far as I know, so it's all nothing but interesting speculation.
), but even those trains were affected when congestion was really bad.
