I have seen then before. I am sure they are not what triggers the gates because they are way to close. it seems that after a train passes them I hear on the scanner something like this.“NORFOLK SOUTHERN TRACK CLEAR, NO DEFECTS, TRACK 1” What exactly fo these things do? Do they have something to do with what comes over the scanner?
Hot box detectors. If a hot box is detected, it will tell the crew to stop the train and should tell them which axle.
[#ditto]
OK, but what do they do?
If it detects a hot bearing, it will tell the crew to stop the train and should tell them which axle it was/is. You can run at restricted speed with a hot box, but the car with the hot box will have to be set out as soon as possible.
They detect hot/overheated axle bearings.
Also has a dragging equipment detector that determines if anything has broken loose from the train and is dragging along the tracks. Dave H.
I totally missed that.
BTW, where did you take those pictures? That looks an awful lot like the ex-PRR now NS main (the signal bridge in the distance is the giveaway) in central PA. Is that the old brickyard crossing between Altoona and Horeshoe?
Man you got a good eye, thats exactly were it is. I live 5 minutes from there. I took them this morning. It the COBURN CROSSING.
Maybe this will help…
A “hot box” is shorthand for a “hot axlebox”. Most of the time the axle bearings (or journals) of rail vehicles are on the outside ends of the axles and we are familiar with them sticking out of the sides of car trucks at the ends of the axles.
When roller bearings were being intruduced the manufacturers gave the old style bearings the name “friction bearings” which is really a piece of marketing nonsenes… but it worked.
A hot bearing is simply one that has a fault or lacks lubricant and, like your car engine without oil, is heating up as metal turns against metal with nothing to lubricate it or disperse the heat.
When they get hot enough they can be detected by on track detectors. In the early stages they can be identified by a plume of blue smoke if the light conditions are right. Later they glow red for a bit. If they’re doing really well they can glow white hot… usually not long before something breaks and stock ends up in the dirt.
It may come as a surprise to know that it is possible to observe a hot box on the far side of a train from where you are standing. This is because the main, human, way of detecting them is by smell. A hot box gives off a very distinctive pong. So long as it isn’t blown away on a strong wind you can pick this up even from a train doing 70… if (unlike me) you have a sense of smell.
Try hot “journal” box with a journal being a bearing. Dave H.
Various defect detectors, hot box, dangling equipment, etc.
Take a look at http://www.twistedtrains.com They have a good technical description of these and sell a working unit for model trains.
If you model the modern era (or whenever these detectors were introduced), Details West makes a good set to use: http://www.walthers.com/exec/productinfo/235-900
Edit: Here is a more direct link to what Engineer6004 gave: http://www.advice1.com/twistedtrains/hotboxdetails.html
Can anyone tell us when these things were brought into use please? Please?
The “Speaking Boxes” we added in the early 1980’s.
Here’s a recording of a conrail: http://www.trainweb.org/wnyrhs/Cp5555.wav
The devices outside the rail are “hot box” detectors and detect overheated wheel bearing. Most also will detect the heat from a stuck brake (both air and hand).
The paddles detect dragging equipment.
Defect detectors have been around since the 1960s (IIRC). The first detectors had a panel of lights that would flash a code for conductor in the caboose to read.
Talking detectors came into wide spread use in the early to mid 1980s, about the time cabooses began to be eliminated. Talking detectors typically give the milepost, total axle count, and in multiple track territory the track number. If there’s a defect, the detector will give the axle number, and nature of the defect. If nothings wrong the detector normally says “NO DEFECTS” or something similar.
There are also high car, wide car, and wheel impact detectors.
Nick
Got a story to go with this thread. A few years back, when Ross Rowland was still in the good graces of NJ Transit and was running the trips with 614 from North Jersey to Port Jervis, NY. We’re rolling along and making good time. Then comes over the scanner: hot box axle 7 and 8. Guess what - the detector tripped because of the heat coming off the firebox over the trailing axles. The axles themselves were fine. But we still had to stop and answer the defect. Kind of makes you wonder what the steam crews out West do with the excursions they run? How often do they trip hot box detectors?