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| Re: Metro-North New Haven Line on track for new cars (219655) | |||
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Re: Metro-North New Haven Line on track for new cars |
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Posted by WillD on Wed Feb 22 17:34:57 2006, in response to Re: Metro-North New Haven Line on track for new cars, posted by SUBWAYMAN on Wed Feb 22 16:52:31 2006. Come now, don't let Brian suck you into the rolling scissors of internets arguments.I'll readily acknowledge that the FRA has had a hand in making passenger railcars heavier. It's an unfortunate side effect of a few crashes scaring Congress into yelling 'do something' at the FRA so that they cover their asses before we have an accident like Eschede. Certainly I'd imagine the freights are thrilled to see passenger trains get heavier, since they can play a bit faster and looser with them if they feel they're insulated from lawsuits by the FRA's 'superior' crashworthiness requirements. Whether these crashworthiness requirements are really better is quite up for debate. The FRA only appears to specify buff load in pounds, which currently appears to be 800,000lbs. Presumably this load is to be sustained without deformation, but in a head on accident forces are quite likely to be MUCH higher than that and no mention is given to how the deformation will eat up energy. We currently design railcars like they designed automobiles in the 1950s, to withstand moderate speed accidents without any structural deformation. However when the speeds increase to the point where deformation will occur no matter what there is no guidance. What we need is a measure of the total amount of energy in Joules that will be absorbed by a given structural area designed to fail before the body does. Just like the first automobiles to use crumple zones it seems counterintuitive to wreck a trainset. However, if you allow the trainset to deform in the areas you want it to and safeguard the passengers and crew then you now have a safer trainset than if you'd accepted no deformation to begin with. Unfortunately the FRA has turned a blind eye toward cars that use this sort of energy absorbsion. |
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