Defect Detectors

[Anonymous]

Since purchasing my new scanner, I have heard for the first time the local defect detector near my home. As far as I can tell, it gives the railroad name (NS), the milepost number and the track number, and then says, “no defects.” I was just wondering what the purpose of a defect detector is, and what “no defects” means. Thanks for your assistance.

[Anonymous]

the most common purpose for detectors is to detect "hot boxes", which are overheated wheel bearings, and dragging equipment. there are other types as well, such as high-wide load detectors generally before structures like bridges and tunnels. there's also a new detector called an impact detector for locating flat spots on wheels. no defects means the detector didn't "notice" any problems that it is set up to detect.

[Anonymous]

Which brings about a question. On UP's Sharron Springs Sub, about 6 miles west of Salina-MP 193 or there abouts, UP has recently added to the hot box-dragging equipment detector a, what I assume is, high-wide load detector. It's two telephone poles on each side of the track supporting a wire that runs up both sides & across the top of the right of way. If my decription makes any sense, is that what that is? There's no tunnels around here(or the whole state for that matter) so it must be for the bridges. Only thing is, that pretty much all that travels that line is grain & coal, not much use for a shifted load detector.
Matt

[wabash1]

on the ns the detectors are placed about every 10 miles. if you get a no defects the train has no problems and continues on. if the detector thinks it sees a problem it sends alarm out a series of 3 beeps.after train clears detector it then it gives out message what is wrong hotbox,dragging equipment,hotwheel. most hotbox alarms are false. the reson for detectors is to help prevent derailments from things that was cought by the guy in the caboose.

[Anonymous]

I tok a rail trip in 1999. On the Texas Eagle. in Missouri late at night I listened on the scanner and heard the detector announce a "hot box, east rail, axel 15 from head of train". The train immediately stopped and I could hear the radio traffic between conductor and engineer as they checked it out. Ultimately, there was nothing wrong and we were on our way, but it is good they took it seriously. The detector cannot tell which way the train is heading so it has to identify which side of the train by east or west rail.

Nearby to me is the Wisconsin Central. The detectors here also announce the axel count. I like to play a little game. All of the ore trains run power totaling 12 axels. I subtract twelve from the total axel count and divide by four to calculate the number of cars in the train. Most times it divides evenly but sometimes not. I have even heard the axel count as an odd number. Apparently, detectors are not infallible. Good luck.

[Anonymous]

yep, you guessed it right, that is a high/wide detector. More than likely there is a truss
bridge(s) somewhere around there not too far from the detector and even though it's mostly coal and grain, there is some general stuff on that line and all it takes to do some real damage to a bridge is one time, so it's a useful item to have, especially if the bridge doesn't have an awful lot of clearance where it wouldn't take much of a shift to smack it. that detector works by if something hits those wires hard enough to rip 'em off, it triggers, then a signal maintainer has to come out and put in new wires. this is the less expensive version (probably due to a lack of a lot of shiftable traffic as you noted) the other version uses an optical or laser sensor which doesn't require reseting after tripping, so i figure they're (UP) not expecting anything to trip it very often. later
derek