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After reading the news item about the Acela Express train sets brake problems I wonder what the people who ren the TVG and other high speed trains are thinking. Why are we having so many problems with the Acela system. I know this is far and away from what we have had before but why must our govermnent always try and reinvent the weel with every project. To me it would have been good economics to purchase the manufacturing rightes to a proven system and go from there. Just thought I would throw some more C*** in to the fire.
The Acela – considered as the complete system – is an extension of well-proven technology, specifically the French TGV. However, it is an extension of that technology, not a duplicate of it. Given track and operating conditions in the United States, it couldn’t be simply an off-the-shelf purchase.
In fact, the Acela, considering that it is a significant extension of technology in a number of ways, has performed astonishingly well. Of course, it would have been nice to have it perform ‘perfectly’; I’m sure the folks at Amtrak would have liked that, and I imagine the folks at Bombardier would have, too. The problems which have come up to date have been in my opinion, primarily in areas where US usage is significantly more severe than European usage.
Could they have been anticipated? Possibly. Possibly not.
To say that the wheel has been reinvented isn’t true, however. To say that inadequate funds (and time) for testing weren’t provided may be true, or it may not be – I’m not in a position to say.
However the Talgo trains operating in the Pacific northwest have been operating without these snafus…
From what I have read, the problem can be fixed easily… The brake rotors have worn out faster than anticipated… The problem is a lack of enough parts in the inventory to fix all of them… that’s why its taking so long…
When Amtrak leased the new Acela equipment it was promised that the refurbishment of the railway would also be done… That’s another problem, it wasn’t done… So Amtrak is operating this new equipment on a railway not really up to snuff…
They didn’t wear out. They cracked - at roughly half their anticipated life.
…Are Acela brake rotors manufactured in 2 pieces…In other words, split to allow them to be installed at their location inside {or back of the wheel}…?
Since the TGV right of way was built, with modern construction technology, speciificaly for the high speeds of the TGV, I would expect that the TGV’s rarely use their brakes except for making station stops or slowing for temporary slow orders.
Acela in constast, is operating on a right of way that was laid out in the middle of the 19th Century by surveyors on horseback using imigrant laborers, mules and horses and black powder for earthmoving and all the other actions of laying and maintaining track. Track alignments that were perfectly acceptable for the 1880’s became onerous to the operation of the Metroliners of the 1970’s and now even more so for Acela. While Acela may have a top crusing speed in excess of 150 MPH, there is very little opportunity to use that speed as the trains are constantly accellerating and decelerating to accomidate the permanant slow orders to safely traverse the many curves that exist on the Amtrak NEC right of way. Acela brakes probably get used 10 times more per 100 miles of operation than do TGV brakes.
If Bombardier was using TGV standards in formulating their 1,000,000 mile expected brake disk life, they did not look at the true operating enviornments of each operation and as a consequence are made ot look the fool as there are not sufficient spare parts available.
The TGV does not have an engine at each end as does Acela does it. Part of the problem with the brakes is due to two power units one pulling and one pushing. I guess we outsmarted ourselves maybe just one power unit would have been sufficient for a seven car train. Just a thought.
I think that the U.S. need to stay with cars pulled by a loco. Like the AEM7’s. Buy new cars. Open a factory here in the U.S.A .
Yes, TGVs do have a power car at each end
You are right but they also have more than seven cars between power units.
Yes, but only 8 cars.
Check out the TGV Web for all the info on them
http://www.trainweb.org/tgvpages/tgvindex.html
As an aside I’m not quite sure why this thread is going on about TGVs anyway, it’s like comparing Mustangs and Chargers i.e. Ford vs Chrysler. TGVs are an Alstom product and Acela is Bomb-a-deer. They are quite different.
Personally I think Amtrak would have been better off buying stock TGVs instead of being sucked in by the smooth talking high speed train salespersons of the Ski-Doo company.
That progress in 1958 I traveled behing two E-8A units pulling a nine car train the Morning Twin Zephyr at 106 mph near Prairie Du Chien thats 4,500 hp pulling a train that was twice as heavy as todays Acela and the American taxpayer didn’t have to pay for it. So now we can travel 150 mph witha seven car train and two power units that develop how much horsepower and the American taxpayer has to pay for it. We sure haven’t come far in 45 years have we! Remember in 1958 the first jet airliners were entering service and we have progressed into space through aviation while rail is lagging behind. Where is the research and development in rail in comparison it certainly moves at a snails pace.
R&D? All it takes is a little cash. How big is your savings account?
Hugh-
At least the Amtrak guys insisted on steel wheels on the trains. Although tracks on the locomotives and skis on the passenger cars might have been interesting. LOL
(I think in Wisconsin it is known as Bomb-bar-deer. Bar being the place where snowmobilers go to warm up.)
Jay
One factor that might have been overlooked is the Acela Expresses are heavier than the TGV’s, and that combined with the need to apply the brakes many times, especially on the north end of the NEC, could be one of the reasons why the cracks prematurely appeared in the spokes of its rotor disks.
Don’t forget that at Praire du Chiene you had a straight track. Sure, at the same time GG-1’s were regularly expected to run 100 mph with 22 car trains in the corridor on the portions that were straight. I once rode an Advance Congressional in WWII that made it from Washington to New York in three hours and five minutes. I forget which stations stops we made, but I think it was just Baltimore, Phila-30th, and Newark. Once rode a Metroliner (original) at 136mph, and the UA Turbotrain at 110 mph.
I wonder if they are thinking of adding traction-type magnetic track brakes to Acela?
Dear not suggest it, adds weight and maintenance.
The legend of the GG1 continues to grow! The speed limit on the NEC was 80 mph and a single G could handle a sizable train at that speed, but 20 cars at 100 mph! When the Gs had the Metroliner service and were allowed 100mph, it was all they could do to get to 100 with 3 Amfleet and a gen car.
I find it had to believe that Bombarier didn’t properly allow for the train’s weight or speed - that’s pretty easy to calculate and test for. I can beleive they didn’t properly know or understand how the brakes would actually be used. They could have gotten probable brake application data from train simulations, but at design time, there was no real data to work with. Perhaps the brakes are being worked harder and more often than the simulations showed. It’s also possible that the parts that are failing are just plain defective. Maybe the castings cooled too quickly and had residual stress in them or they cooled too slowly and were too weak… Perhaps the steel was not the proper grade or not clean enough. There’s lots of possibilities - maybe there’ll be an ASME paper on it someday.
I’d guess that these brake discs press on the axles before the wheels are pressed on, so it’s a big hairy deal to replace these parts, even if there were enough
I wonder if some of the rotor problem is in the casting design and process. This [spokes breaking] was a problem in early casting and was solved with design of part and chemistry of metal.In this high tech era each time something is reinvented the history is disregaurded.
…Finally…someone contributes a bit of info how these disks are put in place…I was wondering if they were in two halves since the wheel would have to be removed to do anything of replacement…One can easily see brake disks on regular passenger cars and they do look just like one would think they would {as compared to disks on autos}, only much larger…
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QUOTE: Originally posted by oltmannd
The legend of the GG1 continues to grow! The speed limit on the NEC was 80 mph and a single G could handle a sizable train at that speed, but 20 cars at 100 mph! When the Gs had the Metroliner service and were allowed 100mph, it was all they could do to get to 100 with 3 Amfleet and a gen car.
I find it had to believe that Bombarier didn’t properly allow for the train’s weight or speed - that’s pretty easy to calculate and test for. I can beleive they didn’t properly know or understand how the brakes would actually be used. They could have gotten probable brake application data from train simulations, but at design time, there was no real data to work with. Perhaps the brakes are being worked harder and more often than the simulations showed. It’s also possible that the parts that are failing are just plain defective. Maybe the castings cooled too quickly and had residual stress in them or they cooled too slowly and were too weak… Perhaps the steel was not the proper grade or not clean enough. There’s lots of possibilities - maybe there’ll be an ASME paper on it someday.
I’d guess that these brake discs press on the axles before the wheels are pressed on, so it’s a b