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| Re: Metro-North New Haven Line on track for new cars (219645) | |||
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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 17:16:39 2006, in response to Re: Metro-North New Haven Line on track for new cars, posted by SUBWAYMAN on Wed Feb 22 16:22:23 2006. If you doubt my numbers you can check here: http://www.sonic.net/~mly/Caltrain-Electrification/2000-08-Rolling-Stock-Draft/a6.pdfThe M7 is given as the second entry in that document. You can cite the weight sans toilet, which saves you all of 3,000lbs, but doesn't really fix anything. Note the second entry in the document, the Montreal MR90 EMUs which AMT uses on the Deux-Montagnes line. They were ordered in 1992 and were perfectly legal for purchase in the US at that time, indeed I believe NJT considered an up-rated version, but rejected it for more push-pulls. The MR90s are designed to work on 25 kilovolt, 60 cycle AC power and thus, like the M2s, M8s, Arrows, Silverliners and Metroliners they have to lug those heavy AC transformers around. Note the weights given for the MR90, at 126,000lbs for a powered car with cab that EMU is lighter than a bathroom equipped M7, and only 1000lbs heavier than the same car without such facilities. Also check out the difference between the trailer car with cab weight and the power car weight (126,000lbs minus 100,000lbs), at 26,000lbs it's almost right for a transformer. Now the trailer car has no propulsion equipment, so knock off 6000lbs for electronics and motors, and you're left with a 20,000lb transformer. However, as I said above these EMUs are designed to work on 60hz power, not the 25hz stuff that the NEC runs on. I'll admit that MN's territory is 12.5kv@60hz, but presumably they'd like the ability to run through to NYP someday, and I believe 11.5kv@25hz operation is specified on the M8. As frequency decreases transformers get heavier, unfortunately I don't know the exact relationship, but it doesn't seem much of a stretch to see a drop from 60hz to 25hz leading to an increase from 20,000 to 30,000lbs. Have I proved my case to you? The numbers I am providing are grounded in reality. And you're right, it's my opinion that the M7s are flawwed, but that opinion is based on this study of contemporary EMUs. What quantifiable figures are your opinions on the M7 based on? |
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