dakotafred I wouldn't be afraid to raise the POSSIBILITY of sabotage at the first shred of evidence. After all, the kind of people who "spike" lumbering timber are CERTAIN that oil trains contribute to irreversible climate damage. I await the evidence. But let's not be innocents, either.
I wouldn't be afraid to raise the POSSIBILITY of sabotage at the first shred of evidence. After all, the kind of people who "spike" lumbering timber are CERTAIN that oil trains contribute to irreversible climate damage.
I await the evidence. But let's not be innocents, either.
tree68 samfp1943 I would hate to pull the " Conspiracy Alarm" at this point. Not knowing the statistics, or being able to understand their implications. I would leave that up to the 'Professionals' to make that call. One must also consider that had these wrecks involved unremarkable merchadise trains, they wouldn't have been newsworthy, except locally.
samfp1943 I would hate to pull the " Conspiracy Alarm" at this point. Not knowing the statistics, or being able to understand their implications. I would leave that up to the 'Professionals' to make that call.
One must also consider that had these wrecks involved unremarkable merchadise trains, they wouldn't have been newsworthy, except locally.
Do tank cars have a higher rate of derailment than other freight cars, i.e. box, stack, hopper, etc.?
As noted in the "What Causes a Derailment" thread, KP Harrier reports a derailment just occurred that didn't involve an oil train (although some tank cars are in evidence).
Most notable is that until KP posted it here on the forum, none (or very few) of us knew about it. John Q. Public, local resident of that area, probably didn't know about unless it affected his travels or he saw an item about it in the local media.
By the looks of it, this was no minor "dropped a wheel on the ballast" incident.
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...
Tank truck on fire -
http://www.usatoday.com/story/news/nation/2015/03/11/tanker-fire-shuts-down-i-94-michigan/70149392/
Never too old to have a happy childhood!
The Transportation Safety Board of Canada (www.tsb.gc.ca) released its initial report on the second Gogama accident.
Some things the report said are:
accident at mile 88.7 Ruel Sub.
train going 43 mph (old tt I have says zone speed 50 mph mile 74.3-98.1, permanent slow order 45 mph 89.1 - 93.4 within it)
94 cars, 6089 feet, 14,355 tons.
The report says there is a" section of broken rail within a plug rail joint that was installed two days before - the plug rail was put in place as a repair for an in-service thermite weld failure"
It also says ".... oil unit trains transporting heavily-loaded tank cars will tend to impact higher than usual forces to the track infrastructure during their operation. These higher forces expose any weaknesses that may be present in the track structure, making the track more suseptable to failure."
This is class 4 track - speed up 60 mph frt 80 mph pass.
Temperature was -10. The previous accident reportedly had a windchill of -45
I believe such extremes cause broken rails and flat spots on cars make it worse in such temps.
CN has put a slow order of 35 mph from Winnipeg to Capreol for trains with 20 or more cars of oil.
The bridge is replaced and the track is open.
Tank cars are typically loaded to full capacity, so are at the maximum end of their weight. If you look at the stats presented above, there were 94 cars in a train that weighed 14,000+ tons. That works out to over 150 tons per car or over 300,000 lbs. per car (since the length was given in feet, I assume the weight is in 2000 lb tons). That would imply the cars are heavy axle, 315k capy cars.
Tank cars are a very rigid car, the steel tube that forms the tank is a naturally rigid structure that has very little flex in it.
The opposite end of the spectrum is the long bulkhead flatcar (not a centerbeam) that has so much flex in it that empty cars may be speed restricted by certain railroads.
Dave H. Painted side goes up. My website : wnbranch.com
dehusman Tank cars are typically loaded to full capacity, so are at the maximum end of their weight. Tank cars are a very rigid car, the steel tube that forms the tank is a naturally rigid structure that has very little flex in it. The opposite end of the spectrum is the long bulkhead flatcar (not a centerbeam) that has so much flex in it that empty cars may be speed restricted by certain railroads.
Tank cars are typically loaded to full capacity, so are at the maximum end of their weight.
The speed restrictions on empty bulkhead flats have more to do with their "hunting" behavior (weight at the ends like dumbbells) than carbody flexibility.
Interesting on the weight I wasn't aware there were any 315K tank cars. Thanks for the analysis. Have a question into the AAR on the question of 315 tank cars.
Euclid williamsb, Thanks for posting the report. I sure would like to see a detailed explanation of why this is. From the report: “Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation.” What is meant by “heavily-loaded”?
Yes this seems like a "knee jerk" statement. The fact is that all car types are required to meet AAR Chapter 11 limits on wheel/rail forces. The tests are conducted with simulation models (generally NUCARS) but if the numbers are close, physical tests with instrumented wheelsets are required. These tests include a variety of track pertabations. There is no special category for loaded tank cars, they are subject to the same limits as any 286K car.
But Dehusman's analysis seems to indicate these were 315K cars, perhaps that is what they mean by "heavily loaded".
dehusman Tank cars are typically loaded to full capacity, so are at the maximum end of their weight. If you look at the stats presented above, there were 94 cars in a train that weighed 14,000+ tons. That works out to over 150 tons per car or over 300,000 lbs. per car (since the length was given in feet, I assume the weight is in 2000 lb tons). That would imply the cars are heavy axle, 315k capy cars.
The statement in the report that tank cars are harder on track than other types of cars comes as a big surprise to me. There has been a lot of speculation that there may be something unique about oil trains that would explain the “rash of derailments,” and yet no explanation has been forthcoming. It has led to questions about such possible explanations as “sloshing” causing relatively more derailments of tank cars. And yet the answer is right under our nose if oil trains are extra heavy and thus harder on track. I am very surprised that this has not been mentioned before.
Looks like it all boils down to track maintenance again. Temporary plug failed.
Shouldn't a slow order have been in place for this defect? 25mph?
EuclidI understand your points, although I do not know how this all shakes out relative to all other fully loaded types of rolling stock. Why wouldn’t all rolling stock be designed to carry the maximum possible weight? Why just tank cars?
Of course all cars are designed to carry the maximum weight possible (or at least the maximum weight possible at the time they were built).
But not all cars are loaded to their designed gross weight. Some are empty. Some "cube out" before they "tare out," which is to say they are full before reaching their rated weight capacity. That's why auto parts box cars are so long and tall. The parts take up a lot of space, but loaded in a standard box car, they would be well under the max weight the car could carry.
If you look at the mix of many trains, you'll find that it is a mix. Particularly with intermodal and manifest trains.
Unit trains are consistently loaded from car to car. This might suggest that a potential trouble spot in the track will get hammered consistently by some 400 axles (more or less). And this might be where the problem lies in terms of stress on the track. A mixed consist will still hammer at the spot, but not as rythmically.
I'm sure coal trains (the other unit train that runs consistently over large stretches of track) may have a similar effect. I don't know if they are usually loaded to 315K, though - someone else will have to address that.
Caseys Brakeman Looks like it all boils down to track maintenance again. Temporary plug failed. Shouldn't a slow order have been in place for this defect? 25mph?
A 'plug rail' is the proper full repair for a broken rail that has happend in welded rail territory. If 'emergency' repairs are made, (joint bars applied, or a jointed 'plug rail' is installed to replace the broken section) a slow order will be issued and remain in effect until the final reapir 'plug rail' can be welded into place. While 'mudchicken' is the expert, I believe the 'plug rail' is a section of rail that is at least 30 feet long - it isn't a 'shorty' piece of rail.
The likely problem in this instance was that the 'plug rail' that was installed had a internal rail defect that was not visible at it's time of installation. No one can predict the existance of internal rail defects until a rail test vehicle has had the opportunity test the rail.
The "plug" rail is usually just a surplus or spare piece of rail of the same weight and section, like one(s) left over from/ cut off from a CWR installation/ rail replacement.
Possibly this was a defective rail that was removed some time before, and got mixed up into the spare pile by mistake ?
- Paul North.
williamsb 94 cars, 6089 feet, 14,355 tons.
I am surprised Balt didn't catch this. Train lengths include the locomotives, so the dispatcher knows which sidings will fit them. That will bump up the average weight per car. The tank cars were probably just the normal 286,000 lbs. car.
Bruce
So shovel the coal, let this rattler roll.
"A Train is a Place Going Somewhere" CP Rail Public Timetable
"O. S. Irricana"
. . . __ . ______
AgentKid williamsb 94 cars, 6089 feet, 14,355 tons. I am surprised Balt didn't catch this. Train lengths include the locomotives, so the dispatcher knows which sidings will fit them. That will bump up the average weight per car. The tank cars were probably just the normal 286,000 lbs. car. Bruce
Nothing unusual about the train size or tonnge, although the division equals approximately 152 tons per car - While 286K is the normal max load - the carriers are working toward 315K max loads, at 152 tons per car this would be within the 315K max load. Many carriers also allow a 10% overload - an allowed 10% overload on a 143 ton car would permit a max weight of 157 tons.
BaltACD Nothing unusual about the train size or tonnge, although the division equals approximately 152 tons per car
Nothing unusual about the train size or tonnge, although the division equals approximately 152 tons per car
I've got to admit I have never given this question this much thought before. Train length includes the engines. The "A" rating is the tonnage the engines are capable of handling.
Does the tonnage listed on a train sheet or in this case a TSB report include the locomotives?
AgentKid BaltACD Nothing unusual about the train size or tonnge, although the division equals approximately 152 tons per car I've got to admit I have never given this question this much thought before. Train length includes the engines. The "A" rating is the tonnage the engines are capable of handling. Does the tonnage listed on a train sheet or in this case a TSB report include the locomotives? Bruce
Engines are not tonnage - only what the engines haul is tonnage, or at least that is the way it is accounted in the US on trainsheets.
Euclid So the oil trains are relatively higher wheel loading than most other trains? This is starting to give some unusual perspective to the comment in the report saying this: “Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation.” I guess what surprised me is that the comment seems to be in the context of explaining why the oil train derailed. The report is right to explain that it is these higher weights that will expose any weakness in the track structure. But if this can be expected to cause train wrecks, something is wrong with the plan to allow these heavier trains while allowing weaknesses in the track structure that will derail them. I am not sure that the person who approved this comment in the official report totally grasped what it would mean.
Oil train weights per car are similar to current bulk commodity trains (coal, ore, grain etc).
BaltACD AgentKid Train length includes the engines. Engines are not tonnage - only what the engines haul is tonnage,
AgentKid Train length includes the engines. Engines are not tonnage - only what the engines haul is tonnage,
Thank you. I had never actually confirmed that before.
AgentKid BaltACD AgentKid Train length includes the engines. Engines are not tonnage - only what the engines haul is tonnage, Thank you. I had never actually confirmed that before. Bruce
Which can get touchy when engines are being hauled Dead In Tow, in the engine consist as required. If a train is built for max tonnage of the working power, then 2 or 3 dead engines are added - the tonnage the working power is actually the consisted tonnage plus the dead tonnage of the DIT engines.
Thanks to deusman for doing the math on the cars. Going back to the timetable again (from 2005 but I doubt anything has changed). The heaviest car permitted: 286,000 lbs (143 tons)
CN uses ( or at least used to) a car factor for each sub. The more level the line the higher the car factor. The highest car factor was on some prairie lines of 15 each way. The CN mainline is pretty good at not having a lot of grades. For the Ruel sub the car factor westbound was 10 and eastbound (this train) was 12. SO assuming all cars were 286 thousand lbs it would be 143+12x94=14,570 tons or pretty close to the report.
Each unit is given a tonnage rating for each line. A Dash 8 (2400's) and SD60's eastbound on the Ruel sub was rated at 8920 tons.
Thought.
What if somehow a unit train of oil sets up some kind of harmonic vibration that may only occurr at certain speeds ?. This vibration may cause leading or trailing trucks to impart excessive forces. That has happened on some airplanes in test that were corrected by changing some dimension(s). Now as to why other unit trains do not do this. Maybe the wheel base of oil tank cars are different than coal or grain. Someone in the know.
blue streak 1 Thought. What if somehow a unit train of oil sets up some kind of harmonic vibration that may only occurr at certain speeds ?. This vibration may cause leading or trailing trucks to impart excessive forces. That has happened on some airplanes in test that were corrected by changing some dimension(s). Now as to why other unit trains do not do this. Maybe the wheel base of oil tank cars are different than coal or grain. Someone in the know.
harmonic rock and roll is excited on 50' cars on jointed/ staggered rail between 15 and 20 MPH. Bounce resonence occurs on square low rail joints or dipped welds at 55 to 60 MPH.
blue streak 1 Now as to why other unit trains do not do this.
I believe grain trains are very susceptible to harmonic rocking, to the extent that some have rocked themselves right off the rails...
Of course, they don't explode...
In the late 60's to the early 80's - when jointed rail in 39 foot lengths was predominately what was installed in the railroads in general and my carrier inparticular and Hi-Cube covered hoppers (4500+ CuFt) were new on the railroad scene, which happend to have a 39 foot truck center. The Hi-Cube Covered hoppers had a harmonic rock off potential and my carrier had restrictions on their use. The restriction was on 6 degree or greater curves, trains handling the cars must either maintain a speed greater than 25 MPH or if they could not do that, not exceed 10 MPH during while proceeding through the restricted territory that was identified in the Employee TimeTable.
In my experience, no other car types have been so restricted. In the late 80's and early 90's, Trailer Train came out the the TTOX 2 axle intermodal cars, which had their own set of restrictions based on train handling features that were not connected to harmonic rock off.
lenzfamilyI'm no track expert but I do wonder about the ground conditions in the area and its effect on the track, grade and subgrade. Having travelled by canoe in the area myself, granted years ago, there are times I'd best describe it as soup. It could be that bad here too. I'll look back though the TSB archives to see what I can find, if anything, about this 2011 failure. (See above) I'll be interested to see the TSB investigation reports forthcoming.
The CN Ruel Subdivision consists of single main track which extends westward from Capreol, Ontario (Mile 0.00) to Hornepayne, Ontario (Mile 296.20). It is primarily composed of continuous welded rail (CWR) and is rated as Class 4 track under the TC-approved Track Safety Rules. Class 4 track permits track speeds of up to 60 mph for freight trains and 80 mph for passenger trains. However, there were permanent slow orders on much of the subdivision to protect against various infrastructure and track maintenance issues.
Preliminary indications are that track infrastructure failures may have played a role in each of the Gogama accidents and a 3rd accident that involved a mixed manifest train on the Ruel Subdivision near Minnipuka, Ontario on 5 March 2015. Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation. These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure. Given the potential damage of a train derailment, particularly when petroleum crude oil unit trains are involved, the TSB has issued a Safety Advisory Letter hyperlink to letter calling on TC to review the risk assessments conducted for the Ruel Subdivision, assess the track infrastructure condition and determine whether additional risk control measures are required when operating a ”Key Train” on this “Key Route.”
Hi All
I'm getting the idea from the TSB preliminary report on the three CN Ruel Sub derailments that track infrastructure issues really are going to be critical and perhaps causitive.
If as others (more qualified than I) have said, loaded tank cars are really hard on track, it follows that 'key routes' had really better be up to scratch. A 'key route' through a 'bog' (which is a large part of the Ruel Sub goes through) won't cut it. It appears to have been an accident waiting to happen. Significantly, to me at least, is also the fact that the TSB lead investigator in this last derailment is a civil engineer.
I can imagine a whole lot more discussion (and regulation resulting) regarding every aspect of 'key routes' and 'key trains' operation going forward.
It may be too that tank car redesigns are going to have to be rethought given other comments made about damage and loss of product in the same report.
IMHO This type of traffic may well get too 'hot to handle' if railways are going to face this kind of trouble and resulting considerable expense. Perhaps that's part of why Mr Harrison and CP are talking about wanting to have discretion and the right to refuse the haulage of certain dangerous goods. It may not be worth it to them.
I can also see the possibility of a cascading effect of expensive track infrastructure upgrades and upgraded/new tank cars looming...
It's becoming a Pandora's box of dangerous gifts that just keeps on giving.
Charlie
Chilliwack, BC
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