Canadian Derailment and its cause.
https://www.progressiverailroading.com/federal_legislation_regulation/news/TSB-Ice-jacking-led-to-CN-train-derailment--61326
Never too old to have a happy childhood!
Isn't this the sort of thing that periodic tamping of loose spikes is intended to prevent?
Convicted OneIsn't this the sort of thing that periodic tamping of loose spikes is intended to prevent?
Not too many tie and surfacing gangs out in the middle of Winter. From the description it sounds as if the 'jacking' happened under traffic as a significant portion of the train passed over the point of derailment before the derailment happened.
Just read the report, and it seems that there are not too many defenses for this kind of situation ?
One that springs to mind would be a track inspection immediately beofore a train is scheduled(?) In areas where this condition [ice jacking] has previously caused derailments, or is a potential for a derailment; HOW do the CN or CP protocols respond?
[I would think that a low temperture range, that would be in place over a specified time range would be one way.]
Are there (or is there) any definite protocol(s); for operations when these kinds of weather conditions become problematic? Just asking.
samfp1943Just read the report, and it seems that there are not too many defenses for this kind of situation ? One that springs to mind would be a track inspection immediately beofore a train is scheduled(?) In areas where this condition [ice jacking] has previously caused derailments, or is a potential for a derailment; HOW do the CN or CP protocols respond? [I would think that a low temperture range, that would be in place over a specified time range would be one way.] Are there (or is there) any definite protocol(s); for operations when these kinds of weather conditions become problematic? Just asking.
I might remind all - when plowing snow - only the area above the top of rail gets plowed. The area in the gauge below the top of the rail remains snow covered and thus it is not possible to view the ties, tie plates or spike condition.
The issue happens in the lower 48 and is more commonly associated with sand and dirt causing reverse cant in the tieplates which eventually rolls the rail enough that you have gage problems - at 60-61" you just fall in.
Knocking down spikes on downed ties (tamping? ) only does so much. Sounds like the area is a good candidate for D-E Clips or pandrols. A lot of times, you cannot control what you can't see. If Mr. Sun can't warm up the rail enough to melt around the rail and drive the water off, then you have problems-then the mechanical action starts in very tiny increments.
I'd be curious to see how agressive they were with ballast regulators in the cribs around where this happened. You want ties sticking up 1" out of the ballast for a reason.
Ice jacking was a new term to this former Colorado roadmaster who constantly fought with loess (red blow dirt) in the Oklahoma panhandle north of Boise City (loosened up by red-wheat fields) that caused unwanted rail cant.
"Are there (or is there) any definite protocol(s); for operations when these kinds of weather conditions become problematic? " Just asking.- Quit running those shiny toy things until you can clearly see the OTM in the track structure?
mudchicken"Are there (or is there) any definite protocol(s); for operations when these kinds of weather conditions become problematic?"- Quit running those shiny toy things until you can clearly see the OTM in the track structure?
As a sort of peripheral note: I noticed years ago that the laser systems being developed for 'railhead cleaning' (like the LaserTrain setup being tried in the New York area) can be used to sense both effective cant and gauge widening when used for scanning. While this is not a sure prevention of derailment from ice jacking, it would likely pick up many instances if the usual sort of 'pilot train' is periodically being run on a line to keep it open without plowing.
One of the more common set-ups for the past 20 years has been lite-slice technology that does as mod describes. The major problem with this is heavy snow or ice, even when the heavy rain or snow stops* - the sensors get clouded over or refuse to work period. (lots of stopping to clean sensors, unreliable or no data being a constant problem) Not everybody has the means or availability to run a flanger ahead of a measurement sensor equipped unit.
* similar to problems encountered with wheel slip detection on locomotive traction motor housings.
mudchickenThe major problem with this is heavy snow or ice, even when the heavy rain or snow stops* - the sensors get clouded over or refuse to work period.
Aggressive dressing and cleaning of the sensors and emitters is one technique -- analogous to European methods of washing and wiping headlights on autobahns,but much more positive and continuous. Think the action of one of those rotating ship or plow windows, with superheated air ducted in and rotation both of blading/brushing and of the overall window disc slinging off contaminants. Some effective shuttering or lensing for the power-laser emitters (assume they would be fiber or disk lasers with good efficiency and sealed cooling). There are also products, some of them long-obsolescent things designed for the electric-railroad kind of market, that could be used in conjunction with laser and hot air to keep the railhead and gauge corner 'visible' enough on average even in heavy snow or icing that the computer will extract the 'trend' information effectively enough to advise the extent of problem (and intelligently fuse data and video to tell the right people quickly and cogently when it thinks there is an issue ... or if it is advised to check for some problem or combination and has to do a real-time quick review...
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