South Dakota is now melting its way out of a hard, 3 months of winter. As a result of all the snow and cold, out streets are falling apart. As is usually the case, and moreso, when we have a rough winter like this one, the street department can’t keep up with the potholes.
What is the railroad equivilent of potholes? Is there some seasonal maintenance bug-a-boo problem that cause the railroads as much heartburn as the potholes do to the street deapartment?
I’ll defer to mudchicken on this one as I am 20 years removed from the scene.
You can tell when the frost comes out of the ground. Go from 2 or 3 slow orders to 2 or 3 pages of slow orders.
One year when I was working the west pool I went on vacation this time of year. My first trip back it seemed like the west end was nothing but 40 and 25 mph slows. Just close enough together that about the time the rear end cleared one restriction, the head end was going by the yellow board for the next one.
Jeff
Does the ground thawing effect track conditions?
Are these all from seasonal things, that starighten themselves out after the frost goes out, or are they things that need to be fixed by MOW crews before lifting the speed restrictions?
Who puts on the slow orders?
What happens is that when the ground freezes deep, it sometimes ‘heaves up’, depending on the nature of the soil/ rock subgrade and how much water is in it - becasue water expands a little when it freezes, and soil that’s saturated with water expands even more. But that heaving doesn’t always occur, and is not uniform - and therein lies the rub, as the saying goes. The result is excessive deviations from acceptable cross-level and/ or posted superelevation in curves, and dips and humps in the track surface. An effective but labor-intensive old-time remedy was to shim the rail with thin wood shims under the tieplates - in the middle of the ice and snow, of course.
Then the same occurs when the frost melts and the subgrade subsides. Again, it’s not uniform - the darn stuff doesn’t even go back to where it was before. So the MOW guys have to go out and fix it - usually with a tamper and ballast regulator - sometimes more stone or other equipment is needed. That’s the railroad’s equivalent of potholes.
Road crossings can be more susceptible and more troublesome because the paving heaves too, and can foul or cause the locomotives’ plow pilots to scrape or ‘hang-up’ on the high spots, as well as snagging and disconnecting air hoses causing undesired emergency brake applications, etc.
Related issues are field-welding the temporary bolted joints at ‘pull-aparts’ that occurred over the winter from the cold shrinking the rails.
Also, the freeze-thaw mechanism may be the last straw for old ties, esp. if the water can get down into the rotted carcass - which leads to wide gauge problems. That can also occur in areas where the track is filled with fine-grained materials, such as dirt or soil.
All the runoff from the melting snow can lead to washouts, ponding in the tracks, overnight freezing in switch
(1) Slow orders are generally placed and removed by the track department (roadmaster, track supervisor, foreman, etc)
(2) Low joints folllowed by warps, twists, surface defects in curves and switches/turnouts caused by uneven deflections in the ballast and subgrade that has not thawed out evenly Occasionally, deflects work themselves out, but hand tamping usually fixes most. (there are never enough surfacing machines available in the spring)
Frost heaves, low spots, wash outs, kinks in rail, kinks in rails, unstable roadbed, soft spots, water over the rails, bridges and culverts blocked or washed away, water under the rails, electrical short circuits in any and all track circuits (signals, crossings, warning devices) and communications wires and some things that happen for the first time!
One further wrinkle: When the subgrade is wet and spongy, the track surface and cross-level may not look to bad to the track inspector in his hi-rail truck or even when on foot, because the track structure is unloaded. But, then just run a heavy train on a track that looks good but is on a soft subgrade - esp. at low speeds - and the locomotives and heavy cars will find all the soft spots and wallow in them and ‘rock ‘n’ roll’, as I’m sure Jeff and others can confirm. The train crews may well wonder why the inspector hasn’t issued a slow order on that rough track - that may be the reason, because that isn’t happening when the inspector is there. Often there are subtle clues - such as mud puddles and spaces around the tie ends, mud splashes up on the rails, and sometimes broken ties, surface-bent rails, etc. The true condition of the track under load is of course what should be used to determine if a slow order is needed. When a train crew has something like that happen, they should notify the inspector to either watch the track as a train passes over it, or have him ride along with them, to see/ feel for himself. [This presumes that there isn’t a ‘dynamic-loading’ type track test car available to run over the track, which would kind of extraordinary.]
Here in the yard, switch problems increase when the ground softens. Two days ago we had a switch that was giving us problems up in Tower A (it was one of the top switches–a disaster there could have put us out of business for a while). The signal maintainers attempted to adjust the points to compensate, but the problem would reappear after a train or two. They finally had to get the section men up to tamp the area, and replace the switch machine (the old one had gotten water inside, I was told). They were still making adjustments when I left Saturday, but yesterday the switch behaved very well.
I think the thaw was the straw that broke the camel’s back for that one–I had noticed a bit of a dip when cars would go over the switch for some time now (years, in fact!). I couldn’t see anything when examining it closely, and there was no pumping in wet weather, but it just wasn’t normal–and apparently the signal and track departments hadn’t been too disturbed by it after I’d turned it in. I got used to it–and I really should have been more observant yesterday to see if that problem has been eliminated. See, I wasn’t wrong–just years ahead of my time (that’s always been a problem!).
We did have a number of switch problems on the lower switches a week or so ago, and ponding water is often a problem in the bowl (can I hear a “Duh” here?). I think that drainage problems (and their solutions) have been neglected for a long time, and they’re coming up as fast or faster than they can be addressed.
Paul has hit the nail on the head. Near my house on CSX’s A&WP sub (which has speed limit of 50 due to poor subgrade) there is a sag that does not show under no load but dips, rocks, and rolls quite a bit un
I seen a train this morning on the CN main going through a crossing and everything was a’rockin’ and a’rollin’. The track was moving vertically about 6"-10" at least----and I saw a couple of spikes almost fall out of their holes. There are a lot of potholes in that area too----
Are they out on the track inspecting for these types of problems, or reacting to info passed on to them from train crews?
Both. Track inspectors hi-rail there territory looking for defects. Train crews will report rough track. The difference is, the track riders know what speed a certain defect is allowed. When a train crew reports rough track, other trains are instructed (on the UP, others are probably similiar in nature) to proceed at restricted speed, not exceeding 10mph until rear of train clears the limits. That’s given until someone from mtce of way can take a look at it. They will then put the appropriate speed restriction on it, if any. (I’ve reported rought track after the engines bounced over it, the air flow on the brake pipe went up considerably while pressure on the EOT dropped 10lbs. At the same spot the day before an auto rack train came apart [just uncoupled] in the same area. The track inspector came out and said it was OK for normal speed.)
Heard a lot of slow orders given, with some just lowering the speed of existing slows today. For a while, both mains were out of service near Boone for track defects. One may have been due to a sink hole that developed near the tracks.
Jeff
Why would the pressure drop that much ==> increase in air flow, without an air hose ‘gladhand’ coupling having come apart and causing an emergency brake application ? Maybe they just flexed an awful lot with the bouncing and came close to parting - but not quite - and that caused much greater leakage for a moment ?
Jeff’s auto-rack scenario above is maybe the ‘next frontier’ in evaluating this kind of thing.&nb
They know this just from experience, based on what the track feels like from the hi-rail? Or, do they get out with a level and transit?
If you’re a trackman for a railroad, you know your job, you are doing your job because you know your job. You have ditch by ditch, tie by tie experience, youy’ve worked it and learned it. You are a professional, you are dedicated, you are expert in your field (Right Of Way). You inspect, you find faults or not, you make your judgement and pass it on to the brass. If you’re right your a hero and work again tomorrow; if you’re wrong you now used to be a trackman.
Why do you think they have such jobs? If a railroad didn’t know that having a trackman inspecting the track wasn’t the cautious and cheapest way to know what’s under wheel, they wouldn’t hire somebody to do the expert job.
Henry, I think he meant the train crews in his question.
You expect and get used to a certain amount of sway and bounce. Some engines ride rougher than others. It’s a judgement call on what’s bad enough to report and what isn’t. Sometimes there’s no question a spot needs to be reported.
It’s also not unusual that a spot is reported, checked and said to be OK for normal speed. In my previous example, about a week or so later a 40 mph slow appeared at that spot. One of our fellow engrs told me about when he had the business train with the engineering dept top brass aboard making their tour. There was a spot where it had been reported a few times as becoming rough, but each time it was checked, it was reported OK. He said when he came up to that spot, he notched down on the throttle, let the slack come in a bit and they bounced over it. The business car with the brass must have bounced pretty good because immediately a 25 mph restriction was put on that spot.
That’s not to say the track inspectors where completely at fault for not putting a slow on it earlier. They only can look at a spot, maybe go over it in a hi-rail. If it appears OK, that’s how they have to report it.
Jeff
Yes to the first - plus a large amount of ‘by eye’, which is also based on experience - how ‘rough’ the track is or appears to be when under a train, and the magnitude of what the largest surface and cross-level deviations visually appear or ‘feel’ by the seat-of-the-pants method to be in a given segment. That judgment, plus the ‘guidance’ and restrictions from the FRA’s chart in Section 213.63 - Track Surface - see: http://www.fra.dot.gov/downloads/safety/tss_compliance_manual_chapter_5_final_040107.pdf
[on Page 5.38, 38 of 155 pages, approx. 2.51 MB in size for this ‘PDF’ format version] - as well as their own railroad’s standards, and especially experience with that particular section tells them what the maximum allowed speed should be. For example, from the cited FRA regs -
The deviation from uniform profile on either rail at the mid-ordinate of a 62-foot chord may not be more than
3" - Class 1 track
2¾" - Class 2 track
2¼" - Class 3 track
2" - Class&
The PRR was infamous for its track inspection by running ‘sloppers’ - the business car with a full glass of water sitting on a saucer on a table in front of the highest official. The quality of your track was rated by how much water was spilled.
Jeff, you’re being quite magnaminous, gracious, and fair with your comments on the track inspectors, and the limitations under which they labor to balance the needs for safety and speed. Thank you for that.