Just got my March edition of Trains Magazine. Lots of good stories.
In the question and answer section, though, flat spots were a topic. The answer provided was quite informative, but should have included the other method for determining the severity of flat spots: a ruler.
Condensed from NORAC 11th Edition:
A train may proceed at normal speed if the flat spot is less that 2.5" in length. If there are two adjoining spots, they have to be less than 2" each.
A train may proceed at not more than 10 MPH if a flat spot larger than the above is/are found, but less than 4", and no other defect is observed. The dispatcher must be notified promptly.
A flat spot of 4" or greater means the train stays put until it is determined safe to move. The car is to be set out at the next available location (siding, terminal).
These parameters square nicely with those in the answer in the magazine, but might give a reader a better idea of exactly what such defects actually look like, rather than the WILD indication of impact.
On the other hand, I've heard it said that a flat spot than can be heard from seven or more cars away needs attention. It may not be scientific, but if you're trackside, it's still something of a measure to judge by.
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...
tree68... On the other hand, I've heard it said that a flat spot than can be heard from seven or more cars away needs attention. It may not be scientific, but if you're trackside, it's still something of a measure to judge by.
Of course - in the real world of railroading is that 7 40 foot cars, 7 89 foot cars or 7 300 foot (5 well) intermodal cars?
Never too old to have a happy childhood!
BaltACDOf course - in the real world of railroading is that 7 40 foot cars, 7 89 foot cars or 7 300 foot (5 well) intermodal cars?
I'd use the individual wells. And it's just kind of a rule of thumb. For that matter, if it's 7 auto racks, it definitely needs attention...
50 to 60 feet is probably what most assume to be the length used for car counts. Giving car counts is part of everyday railroading.
I had to shove back a mile and a half long train to make a rear end pick up. I was told "back 3 to a joint." I moved about 2 cars, where I really should've been stopped when the conductor said, "all moving." Talk about slack.
Jeff
Incidentally you can learn to gauge train speed to within a couple of mph by getting used to the timing of flat spots. Even when there are several, you can distinguish them by tone or intensity. The rate differs notably from 38" to 36" to 33" to 28", too...
What I was hoping for was an explanation of precisely what happens as the wheel comes down on a flat spot and then cams its way back off again. The intensity goes up dramatically with the length (and hence 'depth') of the spot, for good physical reasons that are not immediately evident.
I have been a proponent for many years of the idea of 'rounding the corners' of identified flat spots in the field, rather than remachining them entirely on a wheel-lathe arrangement or changing out wheelsets with the car out of a consist. Then the loading changes as it does in dynamic augment with steam locomotives, smoothly and continuously, and not as hammer blow...
OvermodI have been a proponent for many years of the idea of 'rounding the corners' of identified flat spots in the field, rather than remachining them entirely on a wheel-lathe arrangement or changing out wheelsets with the car out of a consist. Then the loading changes as it does in dynamic augment with steam locomotives, smoothly and continuously, and not as hammer blow...
Things that are defective, do not repair themselves in futher use - rounded edges are not a fix.
Overmod Incidentally you can learn to gauge train speed to within a couple of mph by getting used to the timing of flat spots. Even when there are several, you can distinguish them by tone or intensity. The rate differs notably from 38" to 36" to 33" to 28", too... What I was hoping for was an explanation of precisely what happens as the wheel comes down on a flat spot and then cams its way back off again. The intensity goes up dramatically with the length (and hence 'depth') of the spot, for good physical reasons that are not immediately evident. I have been a proponent for many years of the idea of 'rounding the corners' of identified flat spots in the field, rather than remachining them entirely on a wheel-lathe arrangement or changing out wheelsets with the car out of a consist. Then the loading changes as it does in dynamic augment with steam locomotives, smoothly and continuously, and not as hammer blow...
On locomotives we sometimes weld the deepest spot and round the corners hopefully making one big flat spot into several small flats. I have seen a wheel that came out of the centers on the wheel lathe makeing the wheel out of round, it sounded and acted like a flatspot.
BaltACDThings that are defective, do not repair themselves in futher use - rounded edges are not a fix.
The 'major flatting damage' version is more to allow the car to move on its wheels to a convenient place to re-truck it (or change the wheelset out). It is much easier to jack the truck end up to get the wheelset clear, then rotate it and use precise machining on the 'corners' than to take the old wheelset out laterally, bring in a whole new wheelset, slide it in laterally without damage, etc. Perhaps more so if you have a whole train full of such damage.
However, for Randy to say that a wheel machined out of round (presumably more on one side) acts like it has a flat spot is troubling for the general idea, even if it's related to some kind of skidding.
Overmod BaltACD Things that are defective, do not repair themselves in futher use - rounded edges are not a fix. Not a 'fix', but a means of getting the deflicted wheelset, and the car it's under, to a place where the wheelset can be effectively changed out without holding up the train or damaging the rail as it goes. The 'major flatting damage' version is more to allow the car to move on its wheels to a convenient place to re-truck it (or change the wheelset out). It is much easier to jack the truck end up to get the wheelset clear, then rotate it and use precise machining on the 'corners' than to take the old wheelset out laterally, bring in a whole new wheelset, slide it in laterally without damage, etc. Perhaps more so if you have a whole train full of such damage. However, for Randy to say that a wheel machined out of round (presumably more on one side) acts like it has a flat spot is troubling for the general idea, even if it's related to some kind of skidding.
BaltACD Things that are defective, do not repair themselves in futher use - rounded edges are not a fix.
Not a 'fix', but a means of getting the deflicted wheelset, and the car it's under, to a place where the wheelset can be effectively changed out without holding up the train or damaging the rail as it goes.
The time expended to get your temporary repair equipment to the scene, is the same amount of time that is required to get equipment with a replacement wheel set on the scene to make a permanent fix.
In todays world most flat wheels in the field are found by WILD detectors and procedures are set up to handle those reports.
I would expect that wheel diameter would be a consideration on how big a flat spot could be before restrictions would be placed on a wheel with flat spots. OTOH, the WILD detectors would give a more direct indication of the severity of the flat spot.
I worked in Sorrento Valley in the early 1990's, and part of that time my primary work area was about 50 feet from the Surf Line. It was very easy to tell the difference between a Coaster and an Amtrak train - the Coasters didn't have any flat wheels while all of the converted Metroliner cab cars did have flat spots.
I remember once during a rules class, the instructor (a local operating manager) was reviewing rules that might be on the test. One rule was not moving cars with their hand brakes applied. If the brake was too tight, the wheels might slide.
Next rule. When spotting cars on a spur track, stop the movement 150 feet from the end of the track and apply the hand brake to help control the final movement. Someone pointed out the conflict between the two rules.
jeffhergertNext rule. When spotting cars on a spur track, stop the movement 150 feet from the end of the track and apply the hand brake to help control the final movement.
I have never heard of such rule. Why would it be necessary to stop short to set a handbrake on the car to be set out when the movement is being controlled by the independent brake?
Euclid jeffhergert Next rule. When spotting cars on a spur track, stop the movement 150 feet from the end of the track and apply the hand brake to help control the final movement. I have never heard of such rule. Why would it be necessary to stop short to set a handbrake on the car to be set out when the movement is being controlled by the independent brake?
jeffhergert Next rule. When spotting cars on a spur track, stop the movement 150 feet from the end of the track and apply the hand brake to help control the final movement.
What Jeff was stating went clear over your head.
The 'thought' behind it is to test that that hand brake on the car actually has the power to secure it BEFORE the car is cut away from known good brakes of the engine. Finding out that the hand brakes won't secure the car AFTER the car has been set free from working brakes is a bad time to find out.
Had a crew at Locust Point spotting a heavy duty flat loaded with a high value tranformer spotting the car on the scale for weighing. They did not ascertain that the hand brakes were defective before they cut away from the car .... it started rolling away from them, ran over a road crossing adjacent to the yard office and finally stopped when it impacted a parked locomotive outside the Crew Room - breaking the cast steel pilot on the engine. Transformer had to be returned overseas for repair/replacement. Big $$$$$$$.
BaltACD Euclid jeffhergert Next rule. When spotting cars on a spur track, stop the movement 150 feet from the end of the track and apply the hand brake to help control the final movement. I have never heard of such rule. Why would it be necessary to stop short to set a handbrake on the car to be set out when the movement is being controlled by the independent brake? What Jeff was stating went clear over your head. The 'thought' behind it is to test that that hand brake on the car actually has the power to secure it BEFORE the car is cut away from known good brakes of the engine. Finding out that the hand brakes won't secure the car AFTER the car has been set free from working brakes is a bad time to find out. Had a crew at Locust Point spotting a heavy duty flat loaded with a high value tranformer spotting the car on the scale for weighing. They did not ascertain that the hand brakes were defective before they cut away from the car .... it started rolling away from them, ran over a road crossing adjacent to the yard office and finally stopped when it impacted a parked locomotive outside the Crew Room - breaking the cast steel pilot on the engine. Transformer had to be returned overseas for repair/replacement. Big $$$$$$$.
Jeff said the purpose of the rule of stopping to set a handbrake before reaching the final point of movement was to “help control the final movement.” The point was to stop and set the handbrake 150 feet short of the point where the set out car was to be left, and then continue shoving the car to its cutoff destination with the handbrake set. This was said to be a cause of flat spots from shoving the car 150 ft. with the handbrake set.
He said the point was to control the final movement to the point of spotting. He did not say the point was to test the handbrake.
If you want to test the handbrake, why not shove the car to its destination, and then test it before cutting it off of the engine?
The point of the stub track rule is to avoid shoving the car off the end of the track. Which sometimes is in a building.
I think the reasoning between the two rules is this. In the first rule, you're moving a car that already has the handbrake applied by a previous crew. You don't know just by looking if the brake is so tight that it won't let the wheel turn. So you release it first before moving the car.
In the second rule it assumes applying a handbrake just enough to provide rolling resistance, but not enough to slide the wheels.
Just casually reading the two rules, they appear to contradict one another. If you think more indepth about them, both make sense.
Our instructions do allow moving cars with handbrakes applied under some circumstances. We are not to move them over a switch with the handbrake applied. This is usually done in yards when the brakes need to be/or are applied on the far end of the track.
(And a lot of $2600 Track Bumpers [Nolan or Hayes] live to see another day... and the unit of property test isn't threatened with being exceeded.)
$2600? That's it!? Way cheaper than I expected.
Euclid is not accounting for the effects of slack and the fact that many customers require cars to be spotted in an EXACT location with a margin of error of only one or two feet. Sometimes that also requires cars to be spotted within a foot or two of the stop block.
If you are switching bled off cars in the winter it is a good idea to apply a light-moderate handbrake and shove it for some distance, in order to condition the braking surfaces before the car is left (brakes don't work so good when they are coated in snow and ice).
If you are switching on air the engineer or beltpak operator can do the same thing by shoving an air brake application around the yard.
Greetings from Alberta
-an Articulate Malcontent
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