When I was a youngster a long freight train passed me & there was a hot journal box with smoke coming out of it about five cars or so from the caboose. The conductor was on the back steps looking at the hot box
and the engineer was apparently unaware of the situation.
Today we have roller bearings on the journal boxes, Hot box detectors,
radios, end of train units, etc.
Years ago would the engineers and firemen on such a train I mentioned be required to look backward periodically to check for such a thing.
Railroad rulebooks might have had only a general requirement, such as: “Members of the crew must watch their train closely, especially on curves and approaching switches, looking out for hot jurnals, brakes sticking …” [This from Rule 713 (C) of the Consolidated Code of Operating Rules, 1967 ed.]
It was always considered good practice for the head-end crew to make frequent checks to the rear of the train. The engineer would look over the right-hand side (especially on right-hand curves; the fireman or head brakeman the left-hand side. If the engineer was preoccupied when an inspection was in order, it was expected that the fireman or brakeman would cross over to the right-hand side of the cab to inspect for him.
crews are still required to look back from the head end and look from time to time at as much of the train as they can see… even with roller bearing cars…you still can get hot boxes…they arent as common as with friction bearing cars…but they still happen…but alot of times in todays railroading… a hot box detector will get you…and most of the time its a stuck brake…or a hand brake that wasnt taken off…
but today…should you get a hot box…you have to stop the train…and the conductor has to walk back and check the axel that was flagged by the DD…and has to check 20 axles on each side of it also…should their be nothing found…meaning the tempel stick donst melt on any of the checked axles… the train is alowed to proseed…but should a second DD get the car agin…it has to be set out regardless if nothing is found agin…and if on the first DD hit finds a hot bearing… the conductor is to use his best jugment in determining if the car is safe to move… and if so…it must go at walking speed to the place where it can be set out… ( a spear…siding…yard…what ever is the closest place it can be set out of the train at…)
csx engineer
Additionally, both conductor and engineer could have known of the hot box and been ‘limping’ the car to a spur to set it off. Also if both T&E knew of the hot box, the engineer would endeavour not to use the automatic (or train) brake as applying braking force to the hot axle could be suffiicient to ‘wring’ the axle and thus prevent further movement of the car until it was re-wheeled or cause and actual derailment. Freight car brakes apply the brake shoe to the wheel from one point on the truck and thus the braking force works against the axle from one point…if the axle is near the melting point from the hot box, the braking force is sufficient to displace the axle from center.
I saw a hotbox on a train once, in Santa Barbara.The journal had already caught fire. The crew already knew about it, and the car was set out on a siding.
In the early 90s I was on the Empire Builder, when our lead F40PH set off two consecutive detectors.The unit was set out at the next spur, and we continued with the rear unit running in reverse. At the next station we picked up a BN SD40-2 which stayed on the train to Seattle.
I’ll have to look up in some of my old CN & CP rulebooks
The train I mentioned was going at quite a clip so obviously
the head end were unaware of the situation
I noticed in the GCOR item 1.32 Overheated Wheels
"when overheated wheels are found on a train, the train must be stopped and held a minimum of 10 minutes to allow the heat to equalize through the wheels.
When traveling thru the Rockies in the dome car of the Canadian, quite a few years ago
we passed a hot box detector The lights were flashing like crazy. I didn’t have a scanner at that time
, but the conductor told me the engineer had inadvertendly applied the brakes at a
unapproate time
Pretty good, Mark but there is no bottom part on a friction bearing. There is only a top half and the weight of the car keeps it set in the journal box of the truck side frame and the top of the axle. Babbit has one very important function. The antimony shrinks rather than expands when heated. As the bearing and axle get hot within the normal range of operation on a friction bearing the shrinking Babbit allows for the expansion of the bearing brass and the steel axle to keep the relative diameters of these parts better matched.
The back of the journal box in the truck side frame is a piece of wood that acts as a seal for the oil. When it gets impregnated with the oil it swells and makes a reasonable seal unless it cracks of splits. If the car has sat in an industry track the oil will move to the bottom of the journal, the wood will dry out and the seal will leak lots of journal oil. If you have a hotbox that wood seal can catch fire so you have to check to see that fire is all out before you can deal with the problem.
Cabooses used to have spare brass bearings. All it takes to do a field repair of a journal that is not too badly damaged is to use a track jack to lift the offending journal, pull out the old brass and install a fresh one, replace the waste and oil and watch closely to see that it stays cool. The waste was replaced with wicks that were manufactured and looked like a dish washing pad that was held against the axle by springs for better lubrication. There were also waxy sticks that could be wedged against an axle to limp it to the next point the car could be set out.
An undetected hot box frequently had the fire spread to the wooden parts of a freight car. I watched a roller bearing 89’ flatcar with a load of treated power poles that burned so hot the wheels ended up welded to the rails the car was set out on. A roller bearing that is desintigrating can throw off a lot of white hot metal.
The intent of the Hot Box Detector (HBD) is to “see” an over heated journal condition before the human eye is able to. In some cases, if you can actually see an over heated bearing, that train will probably derail within a mile or 2. The Hot Box Detector, using infra-red technology (some manufacturers are even trying accoustical type detectors that can “hear” a defect), can be triggered by 3 different sets of alarming criteria: should a journal reach an absolute temperature of 161ºF, when the journals on the same axle are compared and one is reading 104ºF higher than the other, or, if the same journal received a “warm” warning at 2 consecutive HBD sites. The alarming temperature levels can be set by the railroads. Usually, the “Tempil Sticks” that are carried by the on-board crews melt at a higher temperature than what our alarming criteria is set for. So, we’ll get reports of “no cause found” for the HBD alarm. The Tempil Stick is like a wax crayon that you can buy for different temperatures. If you had a 210º Tempil Stick, it would melt when it’s applied to a surface that is 210º, or, hotter. I think the train crew has to draw an “x” on different areas of the alarmed journal box and then look to see if their “X” marks smear or melt.
Boy, am I ever getting educated on journal boxes, I appreciate the simple language you are all using, Even I can get a good grasp of the subject.
I mentioned about the hot box detectors on CPR in the rockies, with the flashing lights during the seventies. When traveling with my scanner now on Amtrak I find they are all talking detectors. Are the flashing light detectors obsolete now on CPR and other roads ???
I’m not sure about the flashing ones…
All dedectors I know of on the CP are talking ones… some will talk to the crew on the engine, some will only talk to the RTC if there is a problem and some will talk to the crew and give the RTC a print-out of the results.
I don’t know what good a flashing hotbox detector would be nowadays, because the detector wouldn’t know the results of the inspection until the train has passed the detector, and once the train is past the detector there is nobody on the tail end to see if something is flashing.
The only thing I know of that still flashes in this part of the world are “Call boxes” they are used if the RTC wants to get a hold of a line maintainer and he isn’t answering his radio, so a light will flash and hopefully the line maintainer or maintenance of way guy will see the light and call up the RTC.
To my knowledge, even those aren’t used to often anymore.
Detectors are communicating directly to the trains…Train Dispatchers have more than enough communicating to do already, to increase their communications load by having to relay the results of HBD’s which the FRA requires to be spaced no further apart than every 40 miles (I think); a result of which most Class I’s space their detectors approximately 20 miles apart, so a single malfunctioning detector can be taken out of service, without requireing the train to be stopped an inspected by the crew, which is the case if a train operates the 40 miles without passing an operative detector.
The best advice from old heads I have been told on this is when your train is caught by a TWD and nothing wrong is found, still set the car out. You are only protecting yourself from a possible problem becoming a real problem. The rr can’t nail you for taking the safe course.
There are certain detectors that only talk to the RTC.
There is a WILD (Wheel Impact Load Detector), on the CN Yale subdivision, that never says anything to the train crew.
The WILD will communicate the results to the RTC and if there is a car or cars that have big enough flat spots (AKA Thumpers) then the RTC will call the train over the radio and designate a speed not to exceed (Usually in the neighbourhood of 25 - 35 MPH). The train crew never knows what the WILD detector said, just what the RTC tells them to do.
Here on CP, if you get hit by a Hotbox detector, you go back to inspect, and if you can’t find anything wrong with the said axle, you must inspect 16 axles on either side of it. If you still can’t find anything wrong, then your train may proceed.
If you then get hit by another hotbox detector, (with the same axle) you have to go back and inspect again, this time if you STILL don’t find anything wrong, you have to set out the car no matter what.
Setting out the car the first time when you find nothing wrong may be the safe course, but it could very well be that there was just something wrong with the HBD, setting out the car unnecessarily is a big deal, and makes a lot of extra work for everyone, because now someone has to come out and inspect, give it the OK, and another train will have to pick the car up online. The car is now delayed (depending on what it is, it’s a big deal) and it creates an entire ripple effect, a big deal indeed if there was nothing wrong in the first place.
I enjoy listening to my scanner as a steam special trips a hotbox detector.It goes wild counting every axle as a defect.After about three axles the detector will say something like "Detector malfunction,stop your train"and repeat this message several times.Most of the time a railroad will shut off the detectors before a steam excursion for this reason.
The whole business of HBDs is curiously fascinating to me – the effort to figure out a sensor, or group of sensors, which will correctly sense a failing bearing (‘hot box’) virtually all the time, but not cry wolf. Interesting problem. Compounded by that ‘correctly sense’ business – this is particularly necessary in the case of roller bearings, which almost everything runs on today, as they can go from fine to a bit of distress to total and catastrophic failure in that 20 to 40 mile interval – with no visible warning.
CSX in Maryland used to have a revolving white light on a signal mast for the caboose personnel to see to let them know their train had actuated the Hot Box Detector. At one time, there was even a Message Board that would allow you to read which axle had the defect. But, we all know what happened to the caboose era. We tried “Talkers”, but, if the airwaves were busy with other radio traffic, the HBD would “wait it’s turn” to talk to the train. But, when running a train at 125mph (better than 2 miles per minute), the train could quickly be out of the range of the HBD radio! Our HBD data is now, for the last several years, transmitted to the CETEC Control Center in Phila., PA via modems. If the mainframe computer there receives an HBD alarm, that computer will send out a command to drop the home signal at the next interlocking that the train is approaching to a Stop Signal. In my earlier post, a lot of our “no cause found” for an HBD alarm is due to the Tempil Stick allowing for a higher temperature than what are alarming criteria is set for.