The St. Louis paper today reported a freight train received a dragging equipment defect and stopped. They found a corpse tangled in the couplers between cars. They believe he was snared while trying to climb through the train when it was stopped. He was dragged for six miles.
The term "truck hunting" has appeared a couple of times.
Definition please.
ed
MP173What is next? How far is the industry from having on line sensors on the bearings. Retailers are doing something similar to this determining the distribution of product into geographic areas. Granted the technology for reading temperature and transmitting info is considerably more advanced....but is that on the drawing board, or rather the screen at this time?
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Would the purpose of stating the temperature be for operating the train due to extreme high and low temperatures? Such as below 10 degrees (due to air brake restrictions) and above 90 degrees due to possible rail integrity issues?Ed
Most of the hot box detectors across Iowa on the UP only give temperature when giving the no defects or integrity faiure. Some don't even give that. Some you can slow down or even stop on, but most if your speed drops under 10 mph you can almost expect an integrity failure. (Once the train I was on got 3 no defect messages on the same detector)
Most of the new wayside signals that were installed when the CTC was put in have dragging equipment detectors that only talk on defect. The one that hit us today gave a total axle count. (The defect was near axle one. While bucking snow drifts the air hose came lose and struck the detector and immediately gave a defect tone.)
The detectors on the Spine do give axle counts.
The detectors across Nebraska only talk on defect. Even then sometimes they don't give a tone or talk when they find a defect. They are tied into the block system and will hold a signal against the train that the dispatcher must manually clear.
The UP has what they call the Hot Bearing Desk. When they call they generally give a car's initial and number and which axle to check.
The last time I was stopped by a hot box detector, the heat generated was from a tie-down chain on a flat that had come loose and wrapped itself around the axle.
Jeff
For example - from the NS Northern Region - Pittsburgh Division Employee Timetable No. 1 In Effect August 4, 2008 - GENERAL INFORMATION - B. EXPLANATION OF CHARACTERS on page 1 [''(5 of 158)'' of the 'PDF' version at - http://blet73.org/Pittsburgh_Division_Timetable.pdf ]:
Train Inspection Detectors:
DED — Dragging Equipment Detector
HCD — High Car Detector (includes Excessive Height Detectors)
HBD — Hot Box Detector (includes TSA, SAD and HBD detectors)
WCD — Wide Car Detector
SSD — Stress State Detector
SWD — Sliding Wheel Detector
WID — Wheel Impact Detector
All train inspection detectors are listed on the station pages according to milepost location. Unless otherwise indicated, train inspection detectors are Radio Alarm and operate in both directions on single or multiple track. Detectors on Single Track — Track will not be shown.
Note that the 2 that I have 'bolded' are additional types - also, there are 2 different kinds of clearance detectors - High Car and Wide Car. There may well be others . . .
The 'SSD — Stress State Detector ' is apparently a WILD with the capability to compare the loads on each wheel as well as opposite sides of the car. There are several pages of detailed instructions regarding it at 8. DETECTOR INSTRUCTIONS, A. CONSOLIDATED INSTRUCTIONS FOR STRESS STATE DETECTOR (SSD) AT MP PT 198.0, on pages 70 - 72 of the same Timetable [(74 through 76 of 158) of the 'PDF' version]. Interestingly, those instructions speak of wheel loads as follows: [Note that 'KIP' = 'KIlo-Pound' or 1,000 lbs.; thus, 150 KIPs = 150,000 lbs., and so on. - PDN]
The (SSD) wheel impact detector at Millcreek, will generate a Non-Critical radio alarm when there is a high impact wheel reading of more than 150 KIPs.
The (SSD) wheel impact detector at Millcreek, will generate a Critical radio alarm when there is a high impact wheel reading of more than 170 KIPs.
The (SSD) wheel impact detector at Millcreek, will generate a Non-Critical radio alarm when there is an imbalanced load reading of more than 15 KIPs.
The (SSD) wheel impact detector at Millcreek, will generate a Critical radio alarm when there is an imbalanced load reading of more than 20 KIPs.
What I'm curious about is just what these numbers are supposed to represent. A standard maximum heavy car of 315,000 lbs. gross weight on 8 wheels is only 39,500 lbs. per wheel (79,000 lbs. per axle - roughly analogous to a 'Cooper's E-79 or E-80 bridge loading') - these 'impact wheel reading' values are like 3.8 to 4.3 times as high. Is that really allowable and acceptable ? (For comparison. a heavy 6-axle road locomotive is generally no more than 420,000 lbs. = 210 tons gross weight, or 70,000 lbs. per axle = 35,000 lbs. per wheel.) Even though I have read that the instantaneous wheel impact loads can range up to 5 time the static 'at rest' load, perhaps that is per 'truck-side' instead ? And for that much of an overload, that doesn't seem to be much of a difference between 'Non-Critical' and 'Critical'. Likewise, the imbalance range of 15 to 20 KIPs seems like a lot when the basic wheel load should be exceeding 39,500 lbs. - that's like allowing a 38 to 50 per cent overload.
From the Timetable, here's the website for the manufacturer - http://www.salientsystems.com/index.html
and for this device - http://www.salientsystems.com/prod_overload.html
and for a brochure on it, though it is captioned and advertised mainly as a Weigh-In-Motion system - http://www.salientsystems.com/wim.pdf
The 'SWD — Sliding Wheel Detector' is mainly to detect a wheel that has locked-up from a heavy brake application. There are 2 - 1 each on Tracks 1 and 2, which are the predominantly downgrade/ Eastbound tracks - at MP 240.7, which is about 1-1/4 miles below Horse Shoe Curve towards the foot of the grade at SLOPE/ Altoona.
Similarly, I recall that there used to be a 'Hot Wheel Detector', which would detect a wheel whose tread had gotten excessively hot from a heavy brake application - but not enough to cause it to slide and devleop a flat spot - which might be enough to ruin the metallurgy of the wheel and crack or break it. Perhaps that is less of a problem now with the composition-type brake shoes, which may limit the heat build-up; also, the wheels have better steel now, more capable of absorbing that kind of heat and tolerating that abuse.
From the Salient Systems website, I see that there a couple of other types of detectors, as follows:
Hunting Truck Detector - http://www.salientsystems.com/prod_hunting.html
Truck Performance Detector - http://www.salientsystems.com/prod_tpd.html
Low Hose Detector - http://www.salientsystems.com/prod_lhds.html [ for those of us of a certain age for whom this might be a double entendr/e - - no improper jokes, please !]
Rail Stress Detector - http://www.salientsystems.com/prod_stressnet.html
- Paul North.
tree68 It's not a reach to tie a detector report to a lead locomotive, assuming the infrastructure is there to transmit both to some receiving entity. It might even be possible to tie such a report to a specific car in the train, which would certainly simply locating the problem.
That's the IT function I referred to earlier -- the information from the HBD associates with the OS information from the dispatching computer and the AEI information from the AEI reader. You don't have to do anything out in the field to make this happen other than put a data radio onto the HBD that transmits its output into a file that can be stored on a server at the central office - and most of them have this already. The hard part is taking all of the data flows from all the different sources in the central office and properly and accurately associating them with each other on an automatic basis, and then building history files for each car, and each truck and each wheelset on each car.
RWM
Carl
Railroader Emeritus (practiced railroading for 46 years--and in 2010 I finally got it right!)
CAACSCOCOM--I don't want to behave improperly, so I just won't behave at all. (SM)
tree68 In addition to hotboxes and dragging equipment, I seem to recall that there are some "wheel impact detectors," whose function it is to find flat wheels.
In addition to hotboxes and dragging equipment, I seem to recall that there are some "wheel impact detectors," whose function it is to find flat wheels.
Dan
HBD's have a heck of a time with steam excursions...
I was under the impression that detectors measured the defect from the last axle, not the first.
As for "bar coding" the trains - ACI died a long time ago (those red, white, blue, and black bar codes on the cars and locomotives), but I'm thinking that most power, and definitely most, if not all cars, have RFI (radio frequency identification) tags that can be read by a trackside sensor.
It's not a reach to tie a detector report to a lead locomotive, assuming the infrastructure is there to transmit both to some receiving entity. It might even be possible to tie such a report to a specific car in the train, which would certainly simply locating the problem.
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...
MP173Falcon:That is great stuff. How wide spread are these new generation of detectors? Are each trains identification coded, forgive my basic non technical discussion, but similar to bar coding to account for each train's reading as it is read by subsequent scanners? Otherwise, how would the system account for trains overtaking other trains, etc. (You gotta realize that i am pretty slow on the technical side here). This sure is quite a jump from the old days at Porter Tower, when the HBD east of town would print out on a graph the temps of the bearings and the operator would visually interprete the info. What is next? How far is the industry from having on line sensors on the bearings. Retailers are doing something similar to this determining the distribution of product into geographic areas. Granted the technology for reading temperature and transmitting info is considerably more advanced....but is that on the drawing board, or rather the screen at this time?Ed
Falcon:That is great stuff. How wide spread are these new generation of detectors?
Are each trains identification coded, forgive my basic non technical discussion, but similar to bar coding to account for each train's reading as it is read by subsequent scanners? Otherwise, how would the system account for trains overtaking other trains, etc. (You gotta realize that i am pretty slow on the technical side here).
This sure is quite a jump from the old days at Porter Tower, when the HBD east of town would print out on a graph the temps of the bearings and the operator would visually interprete the info.
What is next? How far is the industry from having on line sensors on the bearings. Retailers are doing something similar to this determining the distribution of product into geographic areas. Granted the technology for reading temperature and transmitting info is considerably more advanced....but is that on the drawing board, or rather the screen at this time?Ed
Ed, the "change" is 99% about organizational methods and IT support, rather than field-based. It's all in how the railroad deals with information flowing from the field into a central location. You can let the information flow by you without collecting it or organizing it and just look for the outliers, or you can do something with it and use it to discern more subtle trends and relationships.
RWM:Got it. Never took into consideration the pickup/setout aspect of the industry. The CSX line in question doesnt seem to do any block swapping or industrial set outs on this line, so that never entered my mind.
Ed
MP173 How important is it for the crew to have length of train info, when their wheel report should also state that info. Is it just another precaution? Ed
How important is it for the crew to have length of train info, when their wheel report should also state that info. Is it just another precaution?
As far as hotbox and dragging equipment detectors are concerned, knowing train length may not be much of an issue. The hotbox and dragging equipment detectors with which I am familiar identify the location of each problem they find by stating how many axles it is from the head end.
Some installations require that the train pass with a minimum speed in order for the hotbox detection to be effective. Other, more sophisticated ones do not have this requirement and will even allow a train to stop on the detector without reporting an integrity failure.
Sometimes a detector will broadcast a false reading possibly due to a heavy brake application that the system misinterprets as either a hot axle or a hot wheel. After the train is stopped and the conductor inspects the problem(s), if no exceptions are taken, rules require that a further inspection must be made of the 5-cars (or 20-axles) either side of the alleged defect on both sides of the train.
On some railroads if two consecutive scanners detect the same problem with the same mechanical reefer, the railroad requires it to be setout - no matter what!
Not hard to engineer, at least after someone else has already done it and you can pull the sheets out of the drawer and see how they did it. Just a lot of extra work to engineer, and a lot of details to get right in the circuit drawings, checks, instrument house wiring, field work, construction, cut-over, and maintenance.
Railway Man The HBD can be set up with two island circuits, one to either side, and by designating toggles you can assign a direction to the report. For example, for a detector on an east-west track, you would choose "left first, right second" to define an eastward train (note that in signal language west is always to your left and south is always to your left -- except on some railways and some particular line segments that were backward, for example some SP lines). So if you place the HBD on the north side of your east-west main track and you are setting the toggles, better make sure that "left" is actually to your right as you face the track. I haven't talked with any of the HBD manufacturers in a few years but I would not be suprised by now if the HBDs now put out a signal that is directionally biased so it can tell which way the train is moving without having to have two island circuits.
The HBD can be set up with two island circuits, one to either side, and by designating toggles you can assign a direction to the report. For example, for a detector on an east-west track, you would choose "left first, right second" to define an eastward train (note that in signal language west is always to your left and south is always to your left -- except on some railways and some particular line segments that were backward, for example some SP lines). So if you place the HBD on the north side of your east-west main track and you are setting the toggles, better make sure that "left" is actually to your right as you face the track. I haven't talked with any of the HBD manufacturers in a few years but I would not be suprised by now if the HBDs now put out a signal that is directionally biased so it can tell which way the train is moving without having to have two island circuits.
RWM: Around here we have a HBD that is located inside the island circuit but not the actual crossing of the track over a street (HBD 200ft north of the crossing gate).(Crossing is a constant time circuit) Also the signal and switch for a TCS controlled siding is 400 ft south of the same crossing. Is this hard to engineer or not?
MP173Thanks for the explanation RWM. How important is it for the crew to have length of train info, when their wheel report should also state that info. Is it just another precaution? The train length, while critical for importance of operations, is something of a head scratcher for me. Train speed - sure, not bad to check vs internal instrumentation.Ed
Thanks for the explanation RWM.
How important is it for the crew to have length of train info, when their wheel report should also state that info. Is it just another precaution? The train length, while critical for importance of operations, is something of a head scratcher for me. Train speed - sure, not bad to check vs internal instrumentation.
How important is length! From a dispatcher's and a conductor's point of view, a whole lot more important than speed ...
With apologies to the genius of Harry J. and Rita Fink, screenwriters:
"I know what you're thinking. "Does this train have six thousand feet or only five?" Well, to tell you the truth, in all this excitement after those last three pickups and set-outs and the lousy paperwork from customer service, I kind of lost track myself. But being as this next siding will only fit five, and we'll stab three Z trains and a business-car special if it doesn't fit, you've got to ask yourself one question: Do I feel lucky? Well, do ya, punk?"
I'm certainly no expert on detector technology. But one important development in this area which hasn't been mentioned yet in this thread is the "networking" of detectors. Historically, each detector operated as an isolated island. Today, however, detectors may be linked to a cetnral office. This allows a railroad's computers to see not only the condition of a train as a passes a single detector, but changes from detector to detector. That can be important. For example, if the temperaturet of a bearing has increased significant from one detector to the next, that can be a warning of an imminent failure even if the 2nd detector's reading, by itself, wouldn't be of concern. Another important development in this area has been the deplyment of detectors that sense things beyond the traditional hot bearing or dragging equipment conditions. For example, there are detectors that actually listen to bearings and can recognize the accoustic signature of a failing bearing. There are also detectors that measure wheel impacts. It's a fascinating, and still developing, technology.
BTW, CSX HBD activated this evening...first time I have heard it. Interestingly, the crew did not report to the dispatcher and continued moving. It was an unusual symbol W003, with only 221 feet of train (operating at 56mph).
Much like the coal power generating station thread, this is one which needs to be read a couple of times...appreciate the explanation.
MP173The local CSX hot box scanner provides considerable information, including track #, length of train, train speed, and number of axles. Great info. How do these scanners work? I can definately see how the number of axles are determined, but how does the scanner determine the train speed and the length of the train? Is the train speed based on a reading based on the average speed of the train (which can change if the train is braking or accelerating)? If the speed is used for determining the length of the train, then would the change of speed also affect the length reading? Basic physics tells me that if you know the speed of an object, and the elapsed time (during the passing), one can easily determine the length of the object. For instance, if a train is going 60 mph and it takes 70 seconds to pass, then the length would be around 6156 feet in length. So, how do these scanners determine the speed and the length of the passing trains? What about when a train stops during the passage of the scanner? Would that reading be null and void? Ed
The local CSX hot box scanner provides considerable information, including track #, length of train, train speed, and number of axles. Great info.
How do these scanners work? I can definately see how the number of axles are determined, but how does the scanner determine the train speed and the length of the train? Is the train speed based on a reading based on the average speed of the train (which can change if the train is braking or accelerating)? If the speed is used for determining the length of the train, then would the change of speed also affect the length reading?
Basic physics tells me that if you know the speed of an object, and the elapsed time (during the passing), one can easily determine the length of the object. For instance, if a train is going 60 mph and it takes 70 seconds to pass, then the length would be around 6156 feet in length.
So, how do these scanners determine the speed and the length of the passing trains? What about when a train stops during the passage of the scanner? Would that reading be null and void?
HBDs detect speed of the train using the same technology that a grade-crossing predictor (GCP), aka constant-warning time device, does for a grade-crossing approach circuit. It works like this. The GCP places a frequency onto one of the rails at the grade crossing. The frequency travels outward in both directions a measured distance (that depends upon the maximum possible speed of the approaching train. At the end of that distance a "narrow-band shunt" connects the two rails. The shunt consists of a wire that passes through a filter which allows an electrical circuit through the device only within a narrow band of frequencies that happens to correspond to the frequency that the GCP is putting out. This allows the shunt to reject the d.c. track circuit voltage, electrocode, etc., that might be present. The frequency travels back down the other rail and returns to the GCP. The GCP circuitry compares the frequency that went out to the frequency that comes back. No change, no train. Now a train enters the circuit by passing over the narrow-band shunt and approaches the grade crossing. The GCP looks at the change in the frequency. Suppose the train enters the circuit and immediately stops. The frequency from the GCP going out is still the same as the frequency coming back, so the GCP says, "whatever's out there, it must be stopped." Now suppose the train does not stop but stays moving. By doing so it changes the impedance of the signal (it causes a phase shift) which the GCP circuitry measures to determine speed of the train. As the train changes speed the impedance changes.
As speed changes over an HBD, so does the impedance. The HBD circuitry is typically set to report only the leaving speed as the last axle departs the HBD, because that is the speed the train is traveling at when the report is issued. The HBD is typically equipped with an island circuit in addition to the GCP frequency that turns the HBD on and off. In other words, the HBD doesn't even activate until a train gets within, say 50 feet, of the HBD, and the moment the last axle leaves the island circuit it is no longer shunted and the HBD turns off. That is when the report is issued. Train length can be calculated from train speed and occupancy time of the island circuit. Modern detectors with additional microprocessor capacity add up all of the speed changes and acceleration/deceleration episodes and calculate a length. It's just some algebra you could do with a pencil and paper.
The heat detection component consists of an infrared detector. Most modern detectors are arranged to detect both overheated bearings and overheated wheels.
Thanks, Paul, I did not think of braking heat. I can see the heat of braking being held because of the hot brake shoe being held against the hot wheel tread.
James
Photo of 'shelled' car wheel, from a Transportation Safety Board of Canada report on - "Railway Investigation Report - Main-Track Derailment - Canadian National Train Q-120-31-12 - Mile 114.8, Montmagny Subdivision - Lévis, Quebec - 12 November 2004 - Report Number R04Q0047 - RAIL REPORTS - 2004 - R04Q0047" at -
http://www.bst.gc.ca/ENG/rapports-reports/rail/2004/r04q0047/r04q0047.asp
"The running surface of the failed wheel exhibited shelling spots adjacent to the wheel flange, one with a diameter of 1.7 inches and the other with a diameter of 2.4 inches (see Photo 2). The 2.4-inch shelling spot was not continuous, but the 1.7-inch shelling spot exceeded the limit prescribed by the Association of American Railroads (AAR), which requires that wheels with continuous shelling spots on the running surface measuring 1 inch or more in diameter be taken out of service. There were no indications or flaws due to heating."
I believe that such shelling usually or often occurs in conjunction with flat spots from sliding during braking, but I could see where it could occur simply from overheating and melting during heavy braking, if the braking force wasn't quite enough to make the wheel slide. But I'm not an expert in this, and will defer to anyone else here who is.
There might also be a good photo of this in an AAR 'Wheel Defects' publication, too.
EDIT - Upon further thought - yes, 'shelling' can occur without a flat spot. Rails will 'shell' from just repeated cyclic high loads, without any wheels sliding on them or brakeshoe heating.
This article - Investigation of wheel tread irregularities - from the December 1989 Railway Age at - http://findarticles.com/p/articles/mi_m1215/is_n12_v190/ai_8274769/
starts off with "Recent studies have shown that freight-car wheels in revenue service develop tread irregularities in the form of slid-flats, shells and spalls, which can cause high impact loads in excess of 100,000 pounds." [emphasis added - PDN] It's a pretty interesting and readable summary of these kinds of matters.
Does this normally occur near a flat spot?
RWM will probably chime in with a better answer but here goes...
Shelling is the process by which portions of the wheel tread melt, displace on the tread and reharden. This causes a build-up on the wheel that makes it go kur-KLUNK, kur-KLUNK. kur-KLUNK, leading to rail damage, further wheel damage, damage to lading, derailment, etc.
Nick
Take a Ride on the Reading with the: Reading Company Technical & Historical Society http://www.readingrailroad.org/
The Butler What is "shelling?"
What is "shelling?"
Good question tho...(seriously).
CShaveRRIf a train stops (or even slows down too much) over one of our detectors, we get an "integrity failure" message. But our detectors don't give speed and train length, or even axle count (IIRC--it's been a while).
Carl,
I realize the detectors aren't perfect and that hopefully they'd catch whatever would be wrong before you see the car from the tower-say one isn't caught? Would the crew on the ground be looking for dragging equipment prior to humping or are they looking for reporting marks for the next 'kick'? Would the car get pulled out to a RIP track (depending on what was wrong) or something else?
While there is the possibility of radar and lasers (LIDAR), I suspect that speed is determined by measuring how long it takes for a wheel to cross two points, which really don't have to be very far apart. Trending can help deal with any variations, so once the train clears the HBD/DED, the detector can announce the speed, along with everything else.
The detectors I hear most often (CSX) generally report location, track (if more than one), defects if any, train speed, and axle count.
Every now and then I'll hear a bogus axle count - at least I'd consider an odd number to be bogus...
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