Under Amtrak’s web site under news releases the revised schedule of Lincoln service for april and may the following was foound.
UP will replaace 115,000 concrete ties previously installed on this line due to some failing a labatory test. Once again seams some company trying to pass off substandard product. Shades of the NEC & MBTA ??
HERE is actual Amtrak snipppet
A stringent Quality Control/Quality Assurance program has been set up for the Illinois High-speed rail project for materials and equipment. During the 2010-11 construction seasons, certain concrete railroad ties installed in the corridor were failing a laboratory test predictive of durability. No ties have failed in service but as a precautionary measure all 115,000 of the implicated ties are scheduled for removal from service by the end of 2012 at Union Pacific’s expense.
We’ve got spots where they break about has fast as they replace them. They had a big replacement project last year. I think it was also blamed on substandard ties being used.
A couple of the perennial spots look like they are ready for some new ties already. Heard often between crewmembers is the comment, “They sure are saving money with these concrete ties.”
Roughly 50 track-miles’ worth (46 to 58 miles is a better estimate, depending on the spacing), so it’s not both tracks involved for the entire route, etc.
This ain’t rocket science - it’s a mature technology, and the tests are well-known, so what went wrong ? That said, there are occasional weird interactions from the trace elements of the local rock source, etc. that can contaminate or weaken the concrete, and that are not caught by the standard tests. It also happens with asphalt grades and paving mixtures, but that’s another problem and story . . .
It could also result from weak/ poor subgrade conditions causing excessive ‘pumping’ up and down and flexing of the concrete ties, especially in the middle portion - us track guys call that “center-bound”, and it breaks wood ties, too. If all that was done to install those concrete ties was to ‘sled’ the track to plow out the old ballast, and nothing was done to install a new and solid subgrade/ sub-ballast, then I’d be suspicious of that as well.
But the inference from the snippet is that the ties failed a lab test, not in service. Surprising that the result of the lab test wasn’t known before those ties were installed.
To be replaced by the end of 2012 at UP’s expense - initially - but look for the warranty claim back against the supplier to follow shortly thereafter. Using a guess of $100 per concrete tie for materials and labor and equipment for the replacement only (not including other items such as the value of the track time, etc.), this looks to be about an $11.5 Million [oops] Hopefully there’s enough insurance or other financial resources at the supplier to take that ‘hit’ and survive . . . [:-^]
Once again proving the value of the lab tests - “A few fleas is good for a dog - otherwise, he forgets he’s a dog.” (Bassho, Japanese poet/ philosopher from the Middle Ages, as quoted in Ian Flem
[:-^] The laws of physics connot be denied. Concrete was or is designed for static loading. There are so many variables in the design of concrete formulas such as , water- grade of sand- size of rock grade of powdered cement and water content of rock - srface dry or saturation percent of rock. All of this is moot if the subgrade is not properly compacted to static load formulas. Paul has a good point about subgrade. These facts are known in the civil engineers book on concrete and placement.
Great question, but we don’t know (yet). From the snippet above (emphasis added - PDN):
" . . . certain concrete railroad ties installed in the corridor were failing a laboratory test predictive of durability. No ties have failed in service . . . "
But it also says “installed in the corridor” - so were those ties removed later and then taken to a lab for tests ?
Instead, I suspect what was meant to be said was along the lines of “ties that are representative - or samples taken from the same batch - of those that were installed have been failing certain laboratory tests, and so there are legitimate doubts about the integrity of the other ties from that same batch and supplier”, etc.
Stay tuned for more speicific and detailed information in the coming months as to exactly which tests the ties were failing. ( [:-,] “No Tie Left Behind”, anyone ? [swg] )
PDN: Would we be correct in assuming that there are tests for all the above operating condiitions and other conditions too ? No UP ties have had service failures but didn’t the Amtrak and MBTA go several years before any of their ties started failing ??
[:-^] Paul ; even with an excellant road bed I would suspect crushing under rails. If the event occured on jointed rail , that could possibly be the cause. Concrete cannot stand a short shock wave ., such as when the wheels cross over the joint. Think of it as a 90lb jack hammer hitting a slab of concrete. On welded rail, there would be a different set of circumstances for the fail of the tie like loose clamps. Or fore mentioned Faulty road bed.[2c]
It may not be on the specific line in question, but the UP has had many concrete ties fail. The last large replacement project in my area was blamed on substandard concrete ties originally used. It’s funny though, many of the spots replaced had already been replaced a few times. And some of those newly replaced ties last summer are needing replacement. (In some spots they changed out ties that looked better than the ones they left in.)
While it may be true that they got some bad ties, I think soil/road bed conditions also play a part in my area. Most of the broken ties seem to be in wet spots. Many of these spots once fixed are OK as long as it’s dry. Once we get a few days of rain they seem to redevelop. There is also a few places where, although not really wet, they have problems with the ties breaking.
We notice teh Same issues in OTR Trucking certain roads regardless of what the States do to fix them always are rough and need repair. As anyone that has driven here in IL can attest to the I-39 IL bridge called the Abrabham Lincoln Memorial or as us Locals call it the Never ending Delay. What is the cause they think Harmonics is the latest guess. Bad Design of the Bridge has led to now 3 Complete Bridge Deck replacements in less than 20 years since it opened.
Is there usually a resilient pad under the rail to protect the concrete from repeated shocks? I checked several sources listed by google and found some pictures showing some sort of pad under the rails, but many without; but there was no mention of them in the texts.
Most everyone is straying away from the intial information presented.
The removal is,apparently, being triggered by the results of a LABORATORY test, not in-service issues. As Paul noted, it is surprising this wasn’t recognized before the ties were put in.
It would be helpful to know what the test was, then speculation could run rampant.
Concrete ties, as with wood ties, have their own special issues. Amtrak’s problems on the NEC, for example, went primarily to the aggregate used being reactive with the cement of the concrete mix design causing the tie to come apart. The forward looking fix for that is to know your aggregate source and make the specs very tight.
Concrete ties are less forgiving that wood in a center bound roadbed condition, that’s why care has to be taken is properly preparing the roadbed.
Abrasion in heavy tonnage and/or curve areas is an issue for any tie but trickier in concrete because rail seat abrasion is so hard to see. The rail, when not loaded looks normal until you stand on your head an look under the base of rail and the tie dap to see the gap worn into the concrete tha is hidden by the ballast next to it. Amtrak derailed twice on the same subdividion a few months apart for the same issue. That’s why track geometry cars are used to determine the angle the rail is tilting and a gage restraint mesuring car is used to load the rail to open the gage simulating a train passing.
In wood ties you usually see the outside edge of the plate cutting into the meat of the tie.
Isn’t this a fun business? Just goes to show you. It’s always something…
“During the 2010-11 construction seasons, certain concrete railroad ties installed in the corridor were failing a laboratory test predictive of durability”
I read this as ongoing tests are revealing that the ties won’t last as long as first anticipated, and are being replaced before they fail. Since this is a newer type of railroad application, it would seem logical, that some of the original ties would have been held back for future testing.
I picture a lab somewhere doing tests that age the ties, to see how they will preform down the road. I’ve seen testing on some wood products, where freeze/thaw cycles and wind/rain/sun cycles are done a gazillion times, and then the product is re-tested to see how it effects the product.
Both Paul North and Steve14 hinted at some situation that no one seems to be including.
First is the Transportation Technology Center near Pueblo, Co. My understanding is that one of its specific tasks is to test and determine the suitability of things like concrete ties ( design/materials/lifespan) under test conditions?
Secondly, I cannot speak specifically to the situation with railroad ties, but having worked on a number of road building, and bridge{new and rehabilitation] jobs here in Kansas, under direction of KDOT materials, I know they really watch things like aggregate quality (in all phases, and tests). Specifications include aggregate from specific rock quarries, that will meet specific hardness testing and other quality tests.
Seems like that protocol would be a given for something as critical as railroad ties?
There was also a comment mentioning that part of the the problem with the ties was that they were sourced from an off-shore supplier(?). Quality issues there?
PDN also (I Think) noted that the laboratory testing phase should have been done before the ties were placed in service, and it would seem like UP, or any other end user would be conducting their own testing of their materials long before they were placed, just as a matter of course?
Ultimately, it seems that UP and other end users need to be more careful with the materials being supplied to them…Trust BUT Verify!
I have never been involve in Purchasing so what I am about to say is based purely on observation.
When purchasing wood ties, they have always been viewed as a homogeneous commodity - specify the level of creosote infusion and buy several hundred thousand. I am willing to bet, in relative terms, the same type principals are applied to the purchase of concrete ties. Concrete ties are also viewed as a commodity, select the vendor based on the vendor supplied specs and buy several hundred thousand units. The supplier is responsible for making the ties to comply with their specs. Whatever testing the carrier may do on the supplied product is totally at the carriers discretion. If the carrier has had a track record with a particular supplier the testing probably won’t be as rigorous as it would be with a new supplier or a supplier that has had a spotty track record in the past.
[quote user=“samfp1943”]
Secondly, I cannot speak specifically to the situation with railroad ties, but having worked on a number of road building, and bridge{new and rehabilitation] jobs here in Kansas, under direction of KDOT materials, I know they really watch things like aggregate quality (in all phases, and tests). Specifications include aggregate from specific rock quarries, that will meet specific hardness testing and other quality tests.
Seems like that protocol would be a given for something as critical as railroad ties?
There was also a comment mentioning that part of the the problem with the ties was that they were sourced from an off-shore supplier(?). Quality issues there?
PDN also (I Think) noted that the laboratory testing phase should have been done before the ties were placed in service, and it would seem like UP, or any other end user would be conducting their own testing of their materials long before they