[USMA:22031] Re: Fwd: [A_A] "millimeter tolerance"

[kilopascal]

Title: Re: [USMA:22021] Fwd: [A_A] "millimeter tolerance"

2002-09-03   I too saw that and was somewhat confused by it.  I did not know exactly what he was referring too and what Americans should be proud of.  Was he upset that a French Railroad maintained a tolerance of 1 mm whereas American railroads are 25 times more tolerant?  Thus implying French technology superior to American.  Was it the fact the French were using metric measures and the Americans were still using obsolete units, thus contributing to the backwardness of American technology compared to the French.  It seems somebody is a little jealous here.   Actually, I did not see anything in the article that implied all French track is kept to 1 mm tolerance.  Just the TGV test track.  And maybe it had to be in order to keep the train stable at 300 km/h.  I doubt there is an American train that can go anywhere near that speed.    What I also noticed that was quite quaint was the use of dekanewtons:   Replacing the copper contact wire by a lighter cadmium alloy wire was considered, but dismissed on the grounds of time and cost. The critical speed of the test track catenary was then to be increased solely by increasing the tension in the wire. For the test runs, the usual tension of 2000 daN was increased to 2800 daN and exceptionally 3200 daN. For some of the faster runs over 500 km/h, the voltage in the catenary was increased from the usual 25 kV 50 Hz to 29.5 kV. Why not use kilonewton, as it reduces the number to two digits.   John       ----- Original Message ----- From: Louis JOURDAN To: U.S. Metric Association Sent: Tuesday, 2002-09-03 01:44 Subject: [USMA:22028] Re: Fwd: [A_A] "millimeter tolerance" A total non sense. I would hope that Americans have other reasons to be proud...   Louis