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Siemens SC-44 Charger seen rolled out across country to replace some older locomotives for corridor work.
https://seattle.curbed.com/2017/11/20/16683002/amtrak-cascades-new-train-model
The new Siemens Charger locomotives, with 16-cylinder, 4,400-horsepower engines, are both lighter and quieter, and meet EPA emission standards. The trains will travel the same speed as before—79 miles per hour—but they'll reach the top speed faster.
http://urbanmilwaukee.com/2017/11/16/plenty-of-horne-amtrak-rolls-out-new-locomotives/
The new locomotives can also take you to from Chicago to Detroit, or Chicago to St. Louis, for example, and they can do it using one-third the fuel, emitting one-tenth the pollution, and at speeds up to 125 miles per hour. (The Chicago-St. Louis route has been cut from 5-1/2 hours to 4-1/2 hours thanks to the new engines and track improvements.
"A lot of our customers care about the earth and about pollution, and these are so much cleaner to operate, and they're better for our partners at IDOT and the customers because they're going to cost less to operate in that they get better mileage," said Marc Magliari, Amtrak spokesman.
Just saw one while I was out for a cigar and thought it was pretty cool, I figure others might find it interesting as well. I have been taking my kids to go watch them do trackwork on the north-south line in Oregon and was wondering why they were so extensive in replacing all of the old ties. Although the speed limit is 79 I wonder if this will be increased with updated track and new locomotives. Here is hoping someone models it soon so I can waste money.
https://en.wikipedia.org/wiki/Siemens_Charger
4400 horsepower, top speed of 125, and meets EPA Tier VI emission standards.
(Score: 5, Informative) by frojack on Wednesday December 06 2017, @07:21PM (1 child)
Yes prefab sections of rail are quite common, especially on existing rail lines where disruption of service is expensive. It takes a lot of cranes and backhoes to pick them up and put them down. But you can build these in any open space, all measured and trimmed to perfection, put them on bogies and roll them down the track to where you need them, and drop them in place usually with a much smaller crew and much less time than the best track laying machines.
The concrete ties are NOT more cost effective, contrary to popular guessing. They aren't even cheaper in most cases.
In places like much of central europe they are preferred. but it is principally because they have cut down all the big timber in Europe and have very few suitable trees of size (and proper wood, such as oak) to make ties out of. Its a raw material decision. Further, you don't have to treat concrete with creosote, which is garnering more attention these days as it leaches into streams over decades.
They are heavier, and tend to keep the rail line in place (especially in curves), but this is disputed by some railroads which claim it is simply inferior ballasting standards. (Gravel too fine, rock too soft, etc).
They don't last significantly longer either.
Wood ties last 35 years in wet hot condition, 50 to 100 years in dry desert conditions. Wood ties can be burned for energy recovery [rta.org] and are mostly carbon neutral when burned. They bend rather than break when loaded excessively. They handle freeze thaw cycles better than concrete.
Concrete ties tend to fail by breakage rather than rot slowly, and when they do, they often have to be replaced immediately, because one broken tie tends to zipper up the track and break the next. When they do need replacement, you have the problem of busting them up to recover the re-rod, and dispose of the crushed concrete (which is almost never used in new buildings due to uncertain provenance).
The economics have been studied [rta.org] in quite good detail. Curve radius, megatons carried per year, cost differences per tie, etc.
There is no cut and dried universal case for concrete ties or Wood ties. Its a raw material decision, and the cost benefit analysis is very location specific.
No, you are mistaken. I've always had this sig.
(Score: 2) by Grishnakh on Wednesday December 06 2017, @09:59PM
That all sounds like a good analysis, but one thing I'll point out is that concrete technology isn't static (unlike wood, where trees aren't exactly evolving to make better wood for railroad uses), and is constantly improving. Surely some research has been done into making better concrete formulations for this application. So theoretically, the case for concrete should be getting better over time versus wood as the technology improves.
As for reusing old concrete, I thought there were already ways that old concrete was recycled to be used in new concrete, not for higher-performance things like buildings, but usually for applications where quality isn't quite so important, like maybe road beds, or other "filler" applications. There should be no shortage of places where old concrete can be used as a low-cost filler.
The paper you cited is from 1993. That's almost a quarter-century old now. I wonder if the equation has changed much since then.
Note that I'm in no way an expert on concrete or railroads, and it's completely out of my field, I'm just raising a few questions, as I'm curious about the subject.