tdmidgetSince there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
You are misreading what he wrote. The "#" sign is a symbol for "pound".
What he said was:
If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7 pound oil and 8 pound oil. If oil weight varies, is every tank car weighed after it's filled?
Dave H. Painted side goes up. My website : wnbranch.com
ruderunnerTake those out of the equation and I'd expect you track defects will account for a much higher percentage of derailments. Again I have one simple question, how does that 59% compare to other unit trains?
To that point, the most direct comparison would be Ethanol trains.
Unit trains, flammable liquid, type DOT 111 tank cars, similar railroads, similar part of the country.
ruderunnerAgain I have one simple question, how does that 59% compare to other unit trains?
Yes, that is the essential question that the LA Times article needs to address in order for their conclusion about the 59% to be validated.
The TSB comment too needs to be clarified. Others have suggested contacting them to get clarification. My experience is that personally communicating with the TSB, FRA, or USDOT is all but impossible. Probably the best bet is a formal written letter sent by postal mail.
dehusman I read it perfectly. # means number to those not addled by cellular phones. https://en.wikipedia.org/wiki/Number_sign tdmidget Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke. You are misreading what he wrote. The "#" sign is a symbol for "pound". What he said was: If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7 pound oil and 8 pound oil. If oil weight varies, is every tank car weighed after it's filled?
I read it perfectly. # means number to those not addled by cellular phones.
https://en.wikipedia.org/wiki/Number_sign
tdmidget Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
EuclidruderunnerAgain I have one simple question, how does that 59% compare to other unit trains? Yes, that is the essential question that the LA Times article needs to address in order for their conclusion about the 59% to be validated.
On the FRA web site they provide the ability to search incidents reported to them, its available to the public. The data is pretty nasty to go through unless you have an account and can build a query (I don't have an account).
I looked at two things, the causes of main track derailments involving hazmat unit trains in the US in 2014 and the causes of non-hazmat unit trains in the US in 2014. Collisions and yard, industry or switching derailments were excluded, as were passenger trains and work trains..
For the hazmat unit trains I searched for trains that had hazmat and selected only those trains where the number of cars of hazmat was close to the total number of cars in the train (every train had one to three cars cover). These would have been both oil and ethanol trains. The FRA data doesn't show loads or empties or differentiate the type or commodity of the train.
In 2014 in the US there were 9 derailments on the main track, 2 mechanical causes, 2 human causes and 5 track related causes. That makes 55% track related causes. Pretty close to the 59% number quoted by the TSB.
For the regular unit trains I excluded any trains with hazmat and trains with less than 90 cars. I think looked at the train symbol or comments to see if the symbol, car types or accident description indicated it was some sort of unit train. In most cases it was pretty easy, there were about 5 trains that were unclear (minimal information) and were not counted as unit trains.
In 2014 in the US, there were 72 derailments involving unit trains on the main track, 35 track related causes, 23 mechanical related causes and 14 human, other, structure and weather causes. That makes 49% track related causes. While not as large a percentage as the TSB number it was still the largest group by far and is very close to the distribution of the hazmat unit train derailment causes.
Based on my analysis, I don't see a real strong indication that the number of track related caused derailments differs significantly between hazmat (55%) and non-hazmat unit trains (49%).
Nice research. However, the Times looked at oil unit trains while you looked at hazmat ones, which overlaps. And 59% is a rate 20.4% higher than that of other, non-hazmat unit trains (49%), which is significant. But the message is that unit trains, especially those containing liquids (oil and other hazmat) have a higher accident rate than non-unit trains. Tank cars containing oil or other haz-mats are obviously of more concern than cargoes that are not dangerous. Perhaps the problem is tank cars, whatever they carry?
C&NW, CA&E, MILW, CGW and IC fan
Paul of Covington I would think that the useful comparisons would be the number of derailments due to track failures per car-mile or ton-mile for oil trains compared to that for other unit trains and for manifest trains.
I'm quoting myself from page 6 of this thread, back in the middle of all the sloshing analysis. Are these statistics available?
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
schlimm But the message is that unit trains, especially those containing liquids (oil and other hazmat) have a higher accident rate than non-unit trains. Tank cars containing oil or other haz-mats are obviously of more concern than cargoes that are not dangerous. Perhaps the problem is tank cars, whatever they carry?
But the message is that unit trains, especially those containing liquids (oil and other hazmat) have a higher accident rate than non-unit trains. Tank cars containing oil or other haz-mats are obviously of more concern than cargoes that are not dangerous. Perhaps the problem is tank cars, whatever they carry?
tdmidget dehusman I read it perfectly. # means number to those not addled by cellular phones. https://en.wikipedia.org/wiki/Number_sign tdmidget Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke. You are misreading what he wrote. The "#" sign is a symbol for "pound". What he said was: If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7 pound oil and 8 pound oil. If oil weight varies, is every tank car weighed after it's filled?
Johnny
Thank you Dave for doing that research and calculations. The result being more or less as expected.
I won't ask you to redo the math and show how the reporter came up with "3 times as often as other derailments" its pretty obvious that they included all trains in all locations and all causes for their comparison group.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
dehusmanHow did you get that unit tank trains have a higher accident rate than any other train from that data?
My error. The assumed phrase was from track-related problems ince that was what was discussed, but I should have included it.
ruderunnerI won't ask you to redo the math and show how the reporter came up with "3 times as often as other derailments" its pretty obvious that they included all trains in all locations and all causes for their comparison group.
Folks like you like to attack news reporters, but you have repeately gotten it wrong yourself. You made up a fake quote. The Times reporter said, “Track problems were blamed on 59% of the crashes, more than double the overall rate for freight train accidents, according to a Times analysis of accident reports."
Not "3 times."
I was viewing a random video of some UP genset switchers switching cars in East LA. At about 4:47, two switchers and a single tank car come to a stop at a crossing. About two to three seconds later, the tank car moves back to the locomotive. Two or three seconds later it moves away. After another two or three seconds, it starts to move back toward the locomotive at which time the locomotives start moving.
Is this due to the contents sloshing back and forth? I am not suggesting this is the cause of oil train derailments - it's just that I never noticed it before.
Anthony V.
https://www.youtube.com/watch?v=imQ_On4SfHg
tdmidget Murphy Siding If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D. Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
Murphy Siding If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D.
If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D.
Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
Thanks to Chris / CopCarSS for my avatar.
Mainstream use in the United States is as follows: when it precedes a number, it is read as "number", as in "a #2 pencil" (spoken aloud as: "a number-two pencil"). When the symbol follows a number, the symbol indicates weight in pounds. (Five pounds are indicated as 5#.)[5] This traditional usage still finds handwritten use, and may be seen on some signs in markets and groceries.
In Canada the symbol is called both the "number sign"
Murphy Siding Larger numbers mean a thicker heavier oil. Early oil refining was by fractional distillation only and fuel oils were classified by when they condensed. Number 1 oil is basically kerosene, Number 2 is Diesel and the heavier fuels go number 6, also known as "Bunker C" and "Residual" oil. The heavier , higher numbered oils have more BTUs per lb because their larger molecules have more carbon bonds. The weight difference is small between grades. "Weight" in this instance has more to do with viscosity than density. Kerosene pours about like water and Number 6 oils need to be heated to flow. "Quality" is not a factor. These oils are bought to do a job at the lowest price. Number 6 was used in steam locomotives because it had high heat content and the steam to make it flow was readily available. Number 2 is used in Diesel engines bvecause it flows readily, has a high enough ignition point, and is readily available, more now than when Diesel locomotives were introduced due to "cracking" processes that break large hydrocarbon molecules to smaller ones. Number 6 oils is not common anymore due these processes breaking it into smaller molecules for Diesel and gasoline applications.. There is some overlap, Alco engines in marine service could burn number 3 or 4 oil if heated but with even more smoke. tdmidget Murphy Siding If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D. Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke. I suppose that since you didn't read my post the way it was written, your complaint is just BS. No worries. I've had times where I have read a post too quickly and jumped to the wrong conclusion. No harm done. Now you've got me curious. In wire and sheet metal, a smaller number means a thicker material. Would bigger numbers used in relation to oil mean it was thinner or thicker? For example, would #3 oil be thicker than #4 oil, or is it a quality rating- #3 oil would be of better quality than #4 oil?
Larger numbers mean a thicker heavier oil. Early oil refining was by fractional distillation only and fuel oils were classified by when they condensed. Number 1 oil is basically kerosene, Number 2 is Diesel and the heavier fuels go number 6, also known as "Bunker C" and "Residual" oil. The heavier , higher numbered oils have more BTUs per lb because their larger molecules have more carbon bonds. The weight difference is small between grades. "Weight" in this instance has more to do with viscosity than density. Kerosene pours about like water and Number 6 oils need to be heated to flow. "Quality" is not a factor. These oils are bought to do a job at the lowest price. Number 6 was used in steam locomotives because it had high heat content and the steam to make it flow was readily available. Number 2 is used in Diesel engines bvecause it flows readily, has a high enough ignition point, and is readily available, more now than when Diesel locomotives were introduced due to "cracking" processes that break large hydrocarbon molecules to smaller ones. Number 6 oils is not common anymore due these processes breaking it into smaller molecules for Diesel and gasoline applications.. There is some overlap, Alco engines in marine service could burn number 3 or 4 oil if heated but with even more smoke.
I suppose that since you didn't read my post the way it was written, your complaint is just BS. No worries. I've had times where I have read a post too quickly and jumped to the wrong conclusion. No harm done. Now you've got me curious. In wire and sheet metal, a smaller number means a thicker material. Would bigger numbers used in relation to oil mean it was thinner or thicker? For example, would #3 oil be thicker than #4 oil, or is it a quality rating- #3 oil would be of better quality than #4 oil?
Please. To all concerned, when measuring wire, a higher number indicates a smaller wire. #10 wire can safely carry more current than #14 can. Go into a hardware store and compare the diameters of the two.
Murphy Siding tdmidget Now you've got me curious. In wire and sheet metal, a smaller number means a thicker material. Would bigger numbers used in relation to oil mean it was thinner or thicker? For example, would #3 oil be thicker than #4 oil, or is it a quality rating- #3 oil would be of better quality than #4 oil?
tdmidget Now you've got me curious. In wire and sheet metal, a smaller number means a thicker material. Would bigger numbers used in relation to oil mean it was thinner or thicker? For example, would #3 oil be thicker than #4 oil, or is it a quality rating- #3 oil would be of better quality than #4 oil?
The number is a rough indication of where the oil condenses out in the fractionation process. Gasoline is the lightest, followed by kerosene. Light distillates are next and are feedstocks for #2 oil, which is the basis for diesel fuel and heating oil. At the other extreme, #6 oil is considered a heavy bottom and is a feedstock for Bunker C, petcoke, etc.
dehusman schlimm But the message is that unit trains, especially those containing liquids (oil and other hazmat) have a higher accident rate than non-unit trains. Tank cars containing oil or other haz-mats are obviously of more concern than cargoes that are not dangerous. Perhaps the problem is tank cars, whatever they carry? How did you get that unit tank trains have a higher accident rate than any other train from that data? Unless somebody has some other data, that's not what I'm seeing. The 59% is the percent of accidents with a track related cause. That doesn't say anything about the rate of accidents. One also has to be careful since the number of oil train accidents is so small, "normal" variation can greatly skew the trends compared to accidents involving other trains which is a vastly larger sample size. If in 2013 I only have one oil train derailment and its track caused then 100% track caused. If I in 2014 have 2 oil train derailments and one it track caused then 50% are track caused. Since the track caused rates have been cut in half (from 100% to 50%) have I improved? No. The percentage of track related accidents went down but the accident rate doubled. That's what bothers me about this whole discussion is that the numbers and what they are and what they mean are very imprecise. Several members of my extended family have degrees in journalism. I know what math courses they took. Never trust somebody from the media to get or report statistics correctly. I only found 9 unit hazmat train accidents in 2014 in the US, and some of those will be ethanol. So we are talking about a very, very small population. A change in one or two events can cause the percentages to swing wildly. The real answer is that we don't have enough information and we don't know exactly what population the TSB is looking at or comparing it to. All I can tell you is that when I made my best effort at an apples to apples comparison using data available from US accidents, the difference was not very dramatic.
1) The question of whether oil trains are more prone to derailment because of their unique characteristics of a liquid load and relatively high center of gravity.
2) The question is whether there is direct statistical or empirical evidence that suggests that oil trains are more prone to derailment.
The science of sloshing is too deep for me. I only know the waiter in the dining car poured just enough coffee that, even with cream added, none should land in the saucer.
Excerpt from letter by Jeff Kurtz
http://www.railroadconference.org/wp-content/uploads/2015/02/Letter-to-an-Iowa-State-Senator-from-Jeff-Kurtz-RR-Engineer-re-Train-Size.pdf
Long, heavy trains present real problems to engineers and conductors, but long, heavy oil trains bring even more problems to the table. Railroads run on territories with lots of curves and hills. Their tracks are on a roadbed made up of rock ballast. Consequently, there is some give when you’re riding on a locomotive and it will start to move from side to side. We call that lateral movement. Now take the tank cars full of crude oil moving down that same track at 50 mph. By virtue of the sloshing around of the crude because of the curves and the hills, along with the normal in train forces associated with any train, you are getting the buff and draft forces, the lateral movement, and you are also getting angular movement because the sloshing won’t just occur at right angles. Now, add in the fact that all of this is happening with a string of tank cars 7-8000 feet long and weighing approximately 15,000 tons. I don’t believe the equipment, the track, or the road bed is built for this type of stress...
Torsional Rigidity of Tank Cars
Stub sill tank cars, similar to the tank cars that derailed in this occurrence, utilize the tank itself as a centre sill and are more rigid than traditional rail cars. A consequence of this is that, as one corner of the car travels over a track irregularity (for example, a turnout or entrance/exit spiral to a curve), the diagonally opposite corner of the car may experience some degree of wheel unloading as a result of the rigidity of the car body.
For other types of rolling stock, which can twist more readily as they negotiate varying track structure, vertical unloading at the diagonally opposite corner will not occur to the same extent. In this case, the forces at one end of the car will not necessarily affect the truck at the opposite end.
Track/Train Dynamics
The wheel/rail interface sees a combination of lateral (L) and vertical (V) forces when a car is moving. The ratio of lateral-to-vertical (L/V) forces provides an indicator of the likelihood of a derailment. The tendency toward derailment increases as the L/V ratio increases. A high lateral and low vertical force (for example, empty cars travelling on a curve) could result in the wheel flange being pushed up and over the gauge face of the rail or result in the rail being pushed outward (that is, rail cant) and possibly rolling over. The highest L/V ratios will typically occur when there is a sudden reduction in vertical load. A wheel L/V ratio of between 0.80 and 0.90 of sufficient duration is known to cause wheel climb.
Longitudinal train forces are transmitted through the train between the coupler pivot points. When a train is being pulled on tangent track, the train is typically experiencing draft forces (that is, tensile forces acting along the centre line of the track). When a train is operating on curved track, the longitudinal forces, whether compressive (that is, pushing) or tensile (that is, pulling) and related coupler angles, result in lateral forces at the vehicle centre plates and at the car wheels. These lateral forces are transmitted by the wheels to the rails. The magnitude of the lateral forces at the rail will vary based on the magnitude of the longitudinal force, the coupler angle, the grade and the degree of curvature.
Interface Journal hits the spot.
http://interfacejournal.com/archives/category/wheelrail-profile-design
TSB,quoted by wanswheelStub sill tank cars, similar to the tank cars that derailed in this occurrence, utilize the tank itself as a centre sill and are more rigid than traditional rail cars. A consequence of this is that, as one corner of the car travels over a track irregularity (for example, a turnout or entrance/exit spiral to a curve), the diagonally opposite corner of the car may experience some degree of wheel unloading as a result of the rigidity of the car body.
Someone who is an expert in railcar dynamics comment please: this statement does not seem particularly accurate to me if the car in question is riding on three-piece trucks with a typical amount of side bearing clearance or long-travel CCSBs. The actual resultant of any torsion from 'excess rigidity' of a tubular tank over a centersill car, after the side bearing compliance and the geometry of the equalizing action of the three-piece truck sideframes is included, does not seem to be of the magnitude to produce a massive propensity toward derailment by itself. That's historically been one of the major selling points about three-piece trucks in general -- why interchange cars could run 90 mph on the Super C without spilling left and right with regularity, or why the U.S. Army Corps of Engineers had so much trouble derailing their test train with explosive sabotage in WWII, for a couple of examples.
Meanwhile, look at Tuzik's article in the Interface Journal link wanswheel provided: I see evidence there that high lateral/low vertical force often tends to turn rails over, rather than causing wheels to lift -- something pointedly absent from the TSB's little graphical 'analysis' as provided.
But I'll wait for voices with more experience, for what do I know?
Wizlish wanswheel Stub sill tank cars, similar to the tank cars that derailed in this occurrence, utilize the tank itself as a centre sill and are more rigid than traditional rail cars. A consequence of this is that, as one corner of the car travels over a track irregularity (for example, a turnout or entrance/exit spiral to a curve), the diagonally opposite corner of the car may experience some degree of wheel unloading as a result of the rigidity of the car body. Someone who is an expert in railcar dynamics comment please: this statement does not seem particularly accurate to me if the car in question is riding on three-piece trucks with a typical amount of side bearing clearance. The actual resultant of any torsion from 'excess rigidity' of a tubular tank over a centersill car, after the side bearing compliance and the geometry of the equalizing action of the three-piece truck sideframes is included, does not seem to be of the magnitude to produce a massive propensity toward derailment by itself. That's historically been one of the major selling points about three-piece trucks in general -- why interchange cars could run 90 mph on the Super C without spilling left and right with regularity, or why the U.S. Army Corps of Engineers had so much trouble derailing their test train with explosive sabotage in WWII, for a couple of examples. But I'll wait for voices with more experience, for what do I know?
wanswheel Stub sill tank cars, similar to the tank cars that derailed in this occurrence, utilize the tank itself as a centre sill and are more rigid than traditional rail cars. A consequence of this is that, as one corner of the car travels over a track irregularity (for example, a turnout or entrance/exit spiral to a curve), the diagonally opposite corner of the car may experience some degree of wheel unloading as a result of the rigidity of the car body.
Someone who is an expert in railcar dynamics comment please: this statement does not seem particularly accurate to me if the car in question is riding on three-piece trucks with a typical amount of side bearing clearance. The actual resultant of any torsion from 'excess rigidity' of a tubular tank over a centersill car, after the side bearing compliance and the geometry of the equalizing action of the three-piece truck sideframes is included, does not seem to be of the magnitude to produce a massive propensity toward derailment by itself. That's historically been one of the major selling points about three-piece trucks in general -- why interchange cars could run 90 mph on the Super C without spilling left and right with regularity, or why the U.S. Army Corps of Engineers had so much trouble derailing their test train with explosive sabotage in WWII, for a couple of examples.
The statement Wanswheel pasted was from the TSB, but they aren't experts?
AnthonyV I was viewing a random video of some UP genset switchers switching cars in East LA. At about 4:47, two switchers and a single tank car come to a stop at a crossing. About two to three seconds later, the tank car moves back to the locomotive. Two or three seconds later it moves away. After another two or three seconds, it starts to move back toward the locomotive at which time the locomotives start moving. Is this due to the contents sloshing back and forth? I am not suggesting this is the cause of oil train derailments - it's just that I never noticed it before. Anthony V. https://www.youtube.com/watch?v=imQ_On4SfHg
Most likely a partially loaded car. Like I said earlier, you don't feel the sloshing on loaded cars but certainly do on partial loads.
10000 feet and no dynamics? Today is going to be a good day ...
EuclidActually, I would think that any type of freight car could rock side to side and reduce loading on the two wheels on the side of the truck where the car was rising; and add loading to the two wheels on the side where the car was dropping.
They can, and they do; this is obviously an intermediate step in the 'harmonic rocking' reported to cause derailments in covered hoppers and the like.
That is not the point being made in the TSB snippet, however. They appear to be claiming that torsional unloading can cause enough reduction of tread load to cause flange climb and derailment, when actual sources in the Interface Journal report very different effects. I would choose to trust published sources in a respected industry journal over a report from a political entity. Others may of course differ.
Wizlish Euclid Actually, I would think that any type of freight car could rock side to side and reduce loading on the two wheels on the side of the truck where the car was rising; and add loading to the two wheels on the side where the car was dropping. They can, and they do; this is obviously an intermediate step in the 'harmonic rocking' reported to cause derailments in covered hoppers and the like. That is not the point being made in the TSB snippet, however. They appear to be claiming that torsional unloading can cause enough reduction of tread load to cause flange climb and derailment, when actual sources in the Interface Journal report very different effects. I would choose to trust published sources in a respected industry journal over a report from a political entity. Others may of course differ.
Euclid Actually, I would think that any type of freight car could rock side to side and reduce loading on the two wheels on the side of the truck where the car was rising; and add loading to the two wheels on the side where the car was dropping.
Wizlish I would choose to trust published sources in a respected industry journal over a report from a political entity.
Refering to the Canadian TSB (or the NTSB) as a "political entity" is a desperate attempt at smearing a very respected independent agency. The trade journal is a good reference, but hardly the final arbiter since they do not investigate accidents.
schlimm I'm with Wislish. The transportation safety Boards are at best, investigators. They most emphatically are not experts. Their job is to ask questions, not answer them. Their ridiculous premise that track irregularity on one corner might affect the other corner would require all wheels to be rigidly affixed to the car and unsprung. What we have is people who are supposed be asking questions trying to answer them. Wizlish I would choose to trust published sources in a respected industry journal over a report from a political entity. Refering to the Canadian TSB (or the NTSB) as a "political entity" is a desperate attempt at smearing a very respected independent agency. The trade journal is a good reference, but hardly the final arbiter since they do not investigate accidents.
I'm with Wislish. The transportation safety Boards are at best, investigators. They most emphatically are not experts. Their job is to ask questions, not answer them. Their ridiculous premise that track irregularity on one corner might affect the other corner would require all wheels to be rigidly affixed to the car and unsprung. What we have is people who are supposed be asking questions trying to answer them.
He's certainly a good journalist (Medill at Northwestern) but seems to have no background in engineering or science.
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