Turbo,Talgo,LRV,Acela, "Leaning Trains" never seem to work in North America

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Turbo,Talgo,LRV,Acela, "Leaning Trains" never seem to work in North America
Posted by CandOforprogress2 on Wednesday, December 20, 2017 1:10 PM

Everytime a train set is designed to lean into curves in North America something goes wrong...Europe no problem..but here in the US equipment maintance shops can never get this right

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Posted by BaltACD on Wednesday, December 20, 2017 4:34 PM

Don't know if this was a 'tilt-train', but it doesn't look like the Spainards got it right.

         

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Posted by VOLKER LANDWEHR on Wednesday, December 20, 2017 5:03 PM

BaltACD
Don't know if this was a 'tilt-train', but it doesn't look like the Spainards got it right.

It was a class 730 Talgo (tilt) train: https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/RENFE_Class_730.html

But as already said in the other train the tilt mechanism doesn't avoid a derailment at twice the allowed speed. In both cases it wasn't a fault of the tilt passenger cars.
Regards, Volker

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Posted by BaltACD on Wednesday, December 20, 2017 6:12 PM

This video confirms the contention from the AMTK 501 thread that the heavier locomotive will track better in a overspeed situation through a curve - as the train can be seen derailing prior to the locomotive and pulling the locomotive off the track.

         

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Posted by CMStPnP on Wednesday, December 20, 2017 6:16 PM

My two cents...........fix the damn track, don't look for shortcuts via jerry rigging the equipment with all sorts of doo dads, shock absorbers and the like.      Just fix and maintain the track to the proper levels for a smooth and safe ride.    Nothing more simple than that.

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Posted by BaltACD on Wednesday, December 20, 2017 6:20 PM

CMStPnP
My two cents...........fix the damn track, don't look for shortcuts via jerry rigging the equipment with all sorts of doo dads, shock absorbers and the like.  Just fix and maintain the track to the proper levels for a smooth and safe ride.  Nothing more simple than that.

Damn, those funny things like rivers, mountains and cities keep poping up just where you want to put down some railroad tracks and for some reason it tends to cost untold millions if not billions to surmont those things that God and man have put in the way of a straight line.

         

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Posted by CSSHEGEWISCH on Thursday, December 21, 2017 6:52 AM

Talgo has always included a maintenance contract with the sale of its equipment.  It may cost more but it means that people with specialized training who know Talgo inside out will maintain it.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by VOLKER LANDWEHR on Thursday, December 21, 2017 9:17 AM

CMStPnP
My two cents...........fix the damn track, don't look for shortcuts via jerry rigging the equipment with all sorts of doo dads, shock absorbers and the like.

The Talgo system was developed in Europe to have faster trains on existing routes. What Balt describes in his post is especially true in densly populated Europe.

In the Amtrak 501 derailment the curve had the same speed limit for Talgo and conventional passenger equipment as the non-tilting locomotive is the limiting factor in this case. The tilting technique provides a more comfortable ride because of less lateral acceleration and force.
Regards, Volker

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Posted by CMStPnP on Thursday, December 21, 2017 7:23 PM

VOLKER LANDWEHR
The Talgo system was developed in Europe to have faster trains on existing routes. What Balt describes in his post is especially true in densly populated Europe. In the Amtrak 501 derailment the curve had the same speed limit for Talgo and conventional passenger equipment as the non-tilting locomotive is the limiting factor in this case. The tilting technique provides a more comfortable ride because of less lateral acceleration and force. Regards, Volker

I am aware of the Talgo design and I think it is crap.    Prefer the Accela design better as well as the replacement they are buying.     I was stationed in Northern Germany (Garlstedt) for 18 months when I was younger and have been back twice as a tourist since.   Garlstedt is just outside of Osterholz-Sharmbeck on the Bremen to Bremerhaven rail line.....about halfway up it.    Been to Denmark, Italy, Austria, Switzerland, East Germany (which is always fun to call Middle Germany to alarm the Russians), and a sliver of France.

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Posted by VOLKER LANDWEHR on Friday, December 22, 2017 2:03 PM

CMStPnP
I am aware of the Talgo design and I think it is crap. Prefer the Accela design better as well as the replacement they are buying.

Everybody is entitled to his own opinion. I just decribed why it was developed, I'm not judging it.

For those who are not familiar with tilting trains:
The Talgo System is a passive tilting system where the carbody is suspended above the center of gravity. The natural centrifugal force let the center of gravity move outside tilting the body to the inside. For those interested: https://www.talgo.com/en/rolling-stock/technological-principles/

The Acela Express has an active tilting system where acceleration sensors control hydraulic rams to tilt the carbody.

The active system is wider spread. Early systems sometimes led to motion sickness. With the advent of computer controlled system this problem got solved.
Regards, Volker

 

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Posted by Shock Control on Saturday, December 23, 2017 9:47 AM

BaltACD
Damn, those funny things like rivers, mountains and cities keep poping up just where you want to put down some railroad tracks and for some reason it tends to cost untold millions if not billions to surmont those things that God and man have put in the way of a straight line.

Maybe God is simply striving for realism on her train layout?

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Posted by ROBERT WILLISON on Saturday, December 23, 2017 10:03 AM

Can you really blame the equipment when the engineer runs the train off the tracks.  Perhaps we need to thank talgo for building a pretty strong train, when the train is derailed going close to 60 miles an hour over the speed limit and only ( an i mean this with the up most respect to those who were lost ) three were lost.

Very very tragic accident.

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Posted by YoHo1975 on Saturday, December 23, 2017 10:38 AM
This thread makes little sense to me. Amtrak started using Talgo Pendulars on the Seattle to Portland Run in 1994 for heaven's sake 23 years ago. And while there's been issues as the cars age, I've never heard of a major incident related to them. Since 501 was so overspeed that the car design was irrelevant. The statement: "They always fail" makes no sense to me. Can the OP provide some ACTUAL EXAMPLES?
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Posted by erikem on Saturday, December 23, 2017 11:40 AM

VOLKER LANDWEHR

For those who are not familiar with tilting trains:
The Talgo System is a passive tilting system where the carbody is suspended above the center of gravity. The natural centrifugal force let the center of gravity move outside tilting the body to the inside.

One consequence is that the center of gravity is moving outwards thereby reducing the margin of safety against tipping. I don't see this as a major safety defect as running anywhere near the tipping speed will be putting a lot of L/V on the outside rail and thus putting a lot of faith in the outside rail staying put. What it does mean is that the operating crew needs to be a bit more vigilant about not getting into extreme overspeed through curves in the first place.

Don't the Leader/Trip Optimizer devices present a moving map with grade and curve information? If so, these may provide a useful back-up to remind engineers about upcoming speed restrictions.

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Posted by VOLKER LANDWEHR on Saturday, December 23, 2017 2:50 PM

erikem
One consequence is that the center of gravity is moving outwards thereby reducing the margin of safety against tipping. I don't see this as a major safety defect as running anywhere near the tipping speed will be putting a lot of L/V on the outside rail and thus putting a lot of faith in the outside rail staying put.

While the center of gravity moves to the outsite it is lower on Talgo trains than on conventional trains: http://trn.trains.com/railroads/ask-trains/2011/07/talgo-speed-comparison

Thus the negative effect is more than compensated.
Regards, Volker

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Posted by CandOforprogress2 on Saturday, December 23, 2017 3:53 PM

So what went wrong with the VIA rail LRV? After a while they just shut it off. I thought they were state of the art for North American Passenger rail

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Posted by Overmod on Sunday, December 24, 2017 6:03 PM

erikem
One consequence is that the center of gravity is moving outwards thereby reducing the margin of safety against tipping.

Part of the 'sophistication' of some modern tilt designs, as opposed to the early Train X/TurboTrain or 'pendulum suspension' designs (including Talgo), is that the tilt mechanism is arranged so it rolls the carbody to the appropriate cant while moving the whole carbody laterally inward, to keep the dynamic roll center of the vehicle correctly aligned.  You can see the action in some of the simulation videos available.  There is still careful attention to keep all parts of the carbody within the loading gage.

If I recall correctly (and I might not) the somewhat weird suspension of the original 'commercial' Pendulum Car design accomplished tilt close to the roll center of the car, keeping the actual outward mass displacement minimized.  I believe there is a discussion in the patent material about that point, and the importance of minimizing swingout on curves.

Don't the Leader/Trip Optimizer devices present a moving map with grade and curve information? If so, these may provide a useful back-up to remind engineers about upcoming speed restrictions.

I mentioned this in a post on one of these threads.  Considering that the system already is intended to 'optimize' fuel consumption by controlling throttle well in advance of grade increases, it should be trivial (if indeed necessary at all) to implement safety features in "inertial navigation" as well as GPS-based tracking that would provide proper advance warnings of most fixed hazards (and, implicitly, the effect of continuous effective train control approaching them).  I believe researchers at Carnegie-Mellon have already developed a practical version of the necessary algorithms for 'fusing' GIS and differential GPS into haptic maps for autonomous vehicles; the task for rail-guided vehicles is considerably less, as would be an effective IxD for crews.

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Posted by erikem on Monday, December 25, 2017 1:18 AM

Overmod

Part of the 'sophistication' of some modern tilt designs, as opposed to the early Train X/TurboTrain or 'pendulum suspension' designs (including Talgo), is that the tilt mechanism is arranged so it rolls the carbody to the appropriate cant while moving the whole carbody laterally inward, to keep the dynamic roll center of the vehicle correctly aligned.  You can see the action in some of the simulation videos available.  There is still careful attention to keep all parts of the carbody within the loading gage.

If I recall correctly (and I might not) the somewhat weird suspension of the original 'commercial' Pendulum Car design accomplished tilt close to the roll center of the car, keeping the actual outward mass displacement minimized.  I believe there is a discussion in the patent material about that point, and the importance of minimizing swingout on curves.

My recollection was that the UA Turbotrain used the linkages fpr the guided axle to tilt the train when rounding curves. This would seem to imply that the tilt would increase with an increase in degree of curvature and not necessarily with cant deficiency. I may be mis-undertsanding what's going on with the tilting mechanism.

Putting the rool center close to the center of gravity came to mind after reading Voelker's response as it would keep the cg close to the car center. OTOH it sounds like a great way of making the passengers seasick and produce some -um- interesting effects of all the passengers sit on one side of the car.

I'm developing the opinion that active tilting is the way to go, but teh control system needs to be designed with care.

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Posted by Overmod on Monday, December 25, 2017 8:16 AM

Active tilt is the best way to go as soon as pendulum tilt runs out of bounds (see Bessemer turret ships for the maritime version).  What I recommend in the short run is to join the Yahoo Group for the APT; many of the original engineers are there and have stories and explanations far beyond "written history" on what works, and what doesn't, in high-speed tilt.  And they had no better computers or technology than would get you to the Moon...

One important hint: when doing full negative-cant-deficiency demonstrations: (1) restrict journalist free alcohol intake; (2) make sure any violation of (1) stays seated at speed; (3) if at all possible use very small windows or block the view of what appears to be happening outside.  It is not a good thing when the tilt effect produces effective POSITIVE cant deficiency on a (buzzed or worse) standing passenger's inner ear, and he attempts to resolve the sudden feeling with reinforcing visual cues...

I recall the linkages on the Cripe train controlling the degree of actual pendulum tilt, and providing damping, and (perhaps most importantly for those who remember the interesting intercar dynamics on some NYC subway trains in the '70s!) coordinating the tilt between adjacent sections to keep the passageway/diaphragm nonalarming.  The actual mechanical pivot point is still at the top of the 'bogie' A frame on the TurboTrain if I recall the construction correctly.

Of course there is always the tilt mechanism in the Hornby model of the APT-P, which did more or less what you describe with a different mechanism: the sharper the curve, the steeper the tilt, with the 'reference angle' between the two cars relative to the 'Adams bogie' between being the control input.  This approach is, gently put, not the best if you expect to find your train standing on a superelevated curve giving minimal cant deficiency at expected road speed -- I remember the experience, if not the name, of one station on NYC south of Harmon in 1971 which still had something like 10.5 degree for Great Steel Fleet comfort but decidedly less than pleasant standing tilt ... now add locked-in tilt compensation for some calculated cant deficiency and imagine the result...

Perhaps the best way to visualize the Pendulum Car arrangement is the diagram in the Life Magazine article:

https://books.google.com/books/about/LIFE.html?id=uj8EAAAAMBAJ

I believe the arrangement in at least one of the 'production' cars carried the spring towers higher in the carbody, on either side of the aisle at bolster location, but I do not have access to my notes on it.

 

 

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