Originally posted by TheAntiGates Living nearby to MP 186 of the UPRR Austin TX Sub Reply tree68 Member sinceDecember 2001 From: Northern New York 25,011 posts Posted by tree68 on Thursday, April 7, 2005 9:52 AM The technology has been around for years. Saw it described once in Trains relative to cab signals. I'm not a signal maintainer, but the problem is either the teething that Huge alludes to, or changes in the roadbed. Salt + water increases conductivity, which can cause false trips. As I recall its a problem the signal folks fight all the time, getting the sensitivity balanced between properly sensing trains and not reacting to the conductivity of the roadbed. The frequencies aren't even RF - they are actually in the audio range (Middle C is around 260 or so). While electronics are used now, at one time all that pulsing was done by relays... Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it... Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, April 7, 2005 11:09 AM QUOTE: Originally posted by Hugh Jampton AC track circuit frequencies, possibly jointless if there's lots of crossings close together. Yeah, all the rail was welded, and since there were 2 rail lines crossing each other with near by grade crossings in 3 of the possible 4 directions, all of the switches between the lines had wire jumpers spliced in, patching around the switches Reply Edit Join our Community! Our community is FREE to join. To participate you must either login or register for an account. Login » Register » Search the Community Newsletter Sign-Up By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy More great sites from Kalmbach Media Terms Of Use | Privacy Policy | Copyright Policy
Living nearby to MP 186 of the UPRR Austin TX Sub
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
QUOTE: Originally posted by Hugh Jampton AC track circuit frequencies, possibly jointless if there's lots of crossings close together.
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