I came across this line on another news site (emphasis mine): “The only car that is on the tracks is the rear locomotive.” My question is, was there also a front locomotive? Perhaps not, as the Amtrak Cascades does sometimes use a cab car at the head end. That would create a push-pull configuration which in the push direction is intrinsically less stable, as determined by a British accident inquiry:
It was theorized that the use of the locomotive in the rear further added to the severity of the crash, as the locomotive continued to push forward into the train after the derailment took place. This is a common situation found in accidents where push pull consists are used, and would turn up as a factor in future accidents both in the UK and abroad.
I have no idea if this was the case here, but just a thought that crossed my mind when I saw that.
I’m not sure how accurate this is, but measuring on Google maps, the curve radius is about 800 ft (245 m).
Plugging into the formula here, and Assuming maximum track superelevation in the US at 6 inches and standard track gauge at 4 ft - 8.5 inches (1.435 m), yields a Vmax of about 35 m.p.h.
Plugging into the max speed formula on Wikipedia gives a Vmax of about 25 m.p.h.
That, plus the info Lawoot supplied suggesting a speed limit of 30 m.p.h. in that area, I’d say excessive speed in the curve was a major factor in the accident. I hope the conductor was not sleeping, or had any sort of automation turned off.
Perhaps it would help to distinguish between commuter trains and long distance passenger trains. Most of the trains (all?) in the Northwest are long distance and not commuter trains.
Except, DuPont is not part of that service. The train stops in Tacoma, then it stops in BFEast Olympia. The train should go through the population centers where it provides service and skirt the ones where it does not stop. This worked kind of pretty well for decades on that route.
Exactly, eschereal! Add to that the heavy traffic through the JBLM corridor and the back-ups this will cause because the tracks are right next to the overpasses through JBLM and you will see further problems.
Part of the Point Defiance Bypass plan was also to extend Sounder commuter rail farther south, into places like Lakewood (current end of the line), then on to Olympia. The Cascades service that Amtrak 501 is part of is more a regional rail/short haul operation, running from Vancouver, BC in the North, to Bend Oregon in the South. And while able to go ‘faster’ than a regular Amtrak long distance train, its top speed is still capped at about 80 MPH. It makes up speed by being able to go through (some) curves at a higher, as the cars use the Talgo Pendular System. “…the train tilts naturally inwards on curves, allowing it to run faster on curves without causing discomfort to passengers.”
I have read statements that the rear unit (the one that stayed on the rails) was NOT in active use. The train was being pulled by the Charger locomotive at the front of the train. Since the Chargers are new in revenue service, Amtrak had the P42 on the rear as a fail-safe in case the new locomotive had any bugs. Normal cascade Trains are Locomotive - 12 Talgo cars - Cab car (or sometimes a 'cabbage, which is a former Amtrak F40PH with the diesel removed, but with the cab controls still in place).
That answers my question, thanks. I had not been able to find any info on the locomotive configuration. BTW, you accidentally misattributed my question to Procrustus – no big deal, just for the record.
No. The entire run of track is rated for 79. If you look at google maps, the location of the crash has a bright red dot. Go to satellite view and look at the actual tracks. That is no way a 30mph curve – and anyway, Washington always under-rates curve speeds by at least 10mph, in terms of staying in control at least.
Satellite view is exactly where I looked. I can’t find anywhere that says the entire run is rated for 79. Maybe you didn’t like the Washington Post cite, so how about now the NTSB agrees (per NPR).
“NTSB: Amtrak Washington Train Traveling At 80 MPH In 30 MPH Zone”
I imported the satellite view into CAD and scaled accordingly. The curve radius is I measured is 700-900 ft radius. Granted, I am making the assumption that the superelevation is within typical maximum of 6 inches, but 30 mph seems about right for that curve unless the recent modifications were beyond what is typical in the US. Again, if you have information showning that they used non-standard track gauge and superelevation in that area, I would love to update my calculation.
Here in Las Vegas, a while back we found that we had quite a few accidents on a then-new flyover built as part of our I-15/US 95 “Spaghetti Bowl”. Engineers were called in and they faulted the design of the flyover, which caused people to have to slow down excessively due to the severe arc. The report said that was bad design because people have expectations and having to slow from 65 to 25 to make the curve was deemed to be more than people would reasonably expect to have to slow down.
This sounds like exactly the same problem now with these tracks.
If you’re driving down the road & there’s a sharp curve ahead, there are signs, either showing the curve(s) &/or reduced speed limits. They don’t have these on train tracks. The engineer is supposed to have the route memorized & know where he is at all times & know when to apply the brakes before a big curve. I’m guessing there was some training (no pun intended) for the engineer, but given this was the first day of a brand new route I’m guessing s/he didn’t know realize where they were.
I also heard that PCT was not installed on these tracks. I’m kind of surprised that a new line was allowed to go in w/o it.
.jpg){kind=link}