Curves are not an issue because there are relatively few and those mostly at station approaches where the train would not be at speed. The Milwaukee Road ran Hiawathas very fast with conventional coaches.
Curves and centrifugal force are a matter for any train…tilting mechanism or not. I believe how they sell the Talgo is it can go through curves 10 mph faster with the same comfort level as a conventional train moving 10 mph slower. Heard that figure years and years ago and I am not sure if it is still true
If it is, 10 mph is hardly worth the cost of maintenence unless your mainline looks like a spaghetti noodle. I think I spelled that right but if not I am sure someone will tell me.[:D]
Would VIA use them for the Toronto - Montreal corridor?
No need for tilt. VIA’s LRC cars have tilt, but it is disabled due to the train speeds being low enough not to need it anymore.
I think Amtrak should have them run from LA to Vegas. Have the line upgraded for 110 - 125mph and have high speed service between LA and Vegas.
One of the first US production TALGO trainsets (don’t remember which mountain it is) was delivered in an altered paint scheme for a planned Las Vegas service that was cancelled. It matched the Amtrak California F59PHIs. Really, though, there isn’t enough funding for this idea to be practical.
Who would pay for the upgrading? Amtrak?–it does not have the resources. The UP?–it would not consider such.
The Talgos were purchased because the plan was – and still is – to use the existing route along the Mississippi River. That section contains some curves, and the Talgos would take them at a higher speed than the Empire Builder does at present.
There was a considerable amount of confusion regarding the entire Madison Hiawatha service extension, to the point where even other rail enthusiasts thought it was to bew a separate train. In reality, it was to be an extension of existing service, with the intention of extending the route all the way to Saint Paul, MN. The thinking was to purchase the train sets first, then extend the service afterwords.
The problem there was they were planning a stub end terminal in downtown Madison and they had no agreement to return on the CP North of Madison back to the Chicago to Twin Cities Main. So if it was the plan as you say, they had some more planning and spending to do.
all you ever need to know about tilt
+1
According to the article, the main advantage of tilting is passenger comfort, not being able to navigate curves at higher speeds. The author suggests the US standard is too conservative and speeds in curves could be increased up to 10% without discomfort.
Peter gets it pretty good but tilting equipment far predates the British effort of the 80s goes back to the 3 Pendulum cars of of the early 40s. Saw the Silver Pendulum on the Q many times. (I could tell you many stories about Peter but I’ll refrain).
yes the U.S. standard is conservative but IIRC the the tilting Acella and Talgo operate at far greater cant deficiency under an FRA waiver.
Just for comparison. Lots of three degree curves with 5" superelevation between Atlanta and Charlotte. Current speed limit is 60 mph which exactly matches 3" cant def. If you allow 9" cant def., you get 81 mph. Bump up the superelevation to 6", 85 mph.
So, Talgo alone between Atlanta and Charlotte would raise speed in long stretches from 60 mph to 79 mph.
For RR built around 2 degree curves and 4" superelevation (very common). 3" cant def, 70 mph.
2 deg, with 6" super, 80 mph.
4" at 9" cant, 95 mph.
They are not really needed for the route or it’s curves to achieve significant speed increase. The former Milwaukee Road route now Canadian Pacific was the last rail line built between Milwaukee and the Twin Cities and it was originally engineered for speed, shortness of route, as well as curve reduction. Your right there are curves between LaCrosse and St. Paul but how many of them are NOT so tight that thet Talgo presents a large advantage.
The problem I have is they bypassed a quality refurbisher of railcars in West Allis that has the contract for VIA Rail Canada and is refurbishing sleepers for the new Prestige Class. Made in USA and high quality craftsmanship. That manufacturer actually uses former Milwaukee Road Passenger Car shops tooling and has been in operations since at least the late 1980’s in one location or another. So it has a track record, it also did a lot of the Alaska Railroad car rebuilding. There was even a second bidder beyond them, Wisconsin and Southern railway offered to take on the Milwaukee to Madison service for a subsidy. Both were bypassed in favor of Talgo…no reason given. &nb
The Talgo “passive” suspension does not provide all that much tilt. Unlike the Pendolino or the LRC “active” tilt systems, it spares the passengers no more than half the sideways force of curves, maybe less.
3" is the amount of “cant deficiency” allowed by the FRA in the U.S. The cant deficiency is the amount you would need to crank up the outside rail for the passengers to feel zero sideways force, and the more cant deficiency allowed, the faster you can go around a curve. The FRA allows “equipment with outboard springs to avoid adverse lean”, which is simply legalize for the Budd Amfleet truck, to operate at 6" cant deficiency, which is the same Talgo is allowed.
From Don’s article and other sources, you probably don’t want more than 6" cant deficiency anyway, unless you go to Turboliner-style “power cars” with low axle loads compared to a Genesis Diesel. So if you are going with conventional locomotives, Amfleet and Talgo probably give you the same speed around curves.
Furthermore, the same kind of partial compensation for the lean on curves offered by Talgo could be built into an Amfleet truck by canting the airsprings inward.
But in addition to the passive tilt, Talgo has a lighter weight (less fuel, especially on mountain grades and on schedules requiring better acceleration to speed), and in the absence of high-level platforms, it has a lower floor requiring fewer steps to enter. A similar low-entry advantage is to be had on California Car and Superliner bilevels, but passengers need to climb steps to the upper level to get between train cars.
It would appear to most of us that the choice of Talgo for the WI route was fairly unwise.
Nobody has posted any good reason that Talgo equipment would be unwise, only that the benefits of tilt, such as they may be, are not utilized to a great degree.
If tilt isn’t a factor, it comes down to the quality of the equipment (good, from all reports I’ve heard) and the price. Did Wisconsin get a good deal? The prior Governor thought so, apparently, and a new factory in Milwaukee was part of that calculus.
Once again the Piedmont equipment is owned and provided for by NC DOT not Amtrak. Would be foolish to get expensive equipment as NC DOT"s “Heritage” equipment is doing very fine and paid for.