What qualifies a passenger train car for 125 MPH operation?

Trains Magazine Passenger
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There has been a lot of discussion regarding Amtrak wanting to qualify new train car purchases for 125 MPH operation, including everything from the controversial new baggage cars to the recent multi-state pool to get a good price on bilevel coaches.

What qualifies a railroad car for 125 MPH operation? Do the manufacturers use computer software such as ADAMS (Automatic Dynamic Analysis of Machine Systems) to determine the critical speed at which truck hunting (also called nosing) sets in? Or is this largely an experimental science where someone build a railroad car, tests it, and applies damping or shims as needed to qualify?

Is a railroad car design tested at Pueblo, Colorado? Do they run such a car on their test track, or does any qualification for high-speed tracking behavior take place on their roller test stand? Do they test that car under “real world” conditions of different track quality and especially variation on the rail profiles that occur with wear?

When a car is qualified for 125 MPH operation, are specification issued for, say, the amount of wear allowed to the wheels to maintain that rating? The amount of degradation of suspension parts? Are there any specs for the condition of the track. Not just the FRA Class 1, Class 2, . . .rating, but are there specs on the allowed wear of the rail profile as it interacts with the wheel profile in regards to stable running?

For the 125 MPH qualification, is there any standard for the amount of impact, damage, or wear a particular truck, axle loading, railroad car, and especially locomotive has on the track?

Do people at Amtrak, either in management or maintenance shops know about these things? At the FRA? I have heard accounts of rough rides on Amtrak trains that people blame on “bad track”, that is, the fault of the host railroad. Could some of those cases be the result of worn wheel or trucks, that is, an Amtrak maintenance concern?

If

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Very interesting. Elsewhere in the forum people have praised the Amfleet trucks as featuring a sort of pseudo-tilt feature to enable their good performance at 125 MPH on the Northeast Corridor. Indeed, when I rode the old Metroliner II and the nearly same Northeast Direct, I only occasionally felt that my stomach was steering the train.

From what I understand about the NEC, baggage service is generally not offered because the baggage cars only qualify for 90 MPH service partly due to their excessive age and obsolete trucks that do not allow for faster service. The upcoming Amtrak order does call for 125 MPH-qualified baggage cars so we can hopefully check our baggage on the Northeast Corridor between WAS and BOS anytime soon. Other NEC-travelling trains do have baggage cars which probably don’t run at 125 MPH once they reach the electric portions of their trip.

What I don’t understand, however, is the distinctly silly total lack of checked baggage on the Acela.

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Perhaps I am out of the loop…

What is controversial about the baggage cars?

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The Acela is a premium-fare short-to-medium-haul operation oriented to business travel so checked baggage service is not needed.

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I used to get involved in exactly this sort of thing. I have conducted ride quality tests on locomotives and business cars on Conrail and witnessed some more done by Amtrak on FL9s and RoadRailers. I was also involved in some tests of EMD’s radial truck. I haven’t been involved in the past 15 years or so, so I may be behind the times a bit.

No new equipment that is going to operate outside of the range of similar equipment is going to hit the rails without some sort of actual testing. I believe that most of the time, the testing is specified by the purchaser. I believe the AAR has standards for freight car testing but I don’t know if the FRA is involved these days with some requirements of their own or not.

Generally, you are looking at measuring lateral and vertical forces. Lower is better. (duh!) It is usually sufficient to place accelerometers over the bolster centers and look for incidence of high forces. Pretty much, if the forces are always low, you are good to go. Bouncing, hunting, poor lateral suspension, etc. are all going to show up at the car body. You can also instrument the truck with displacement transducers to see what’s going on with the various moving parts (spring travel, rotation, etc.) if you need more detail or have found problems. (Much of what I learned about this work came from guys in Conrail’s test lab - some of whom worked on the NYC jet-powered Budd car) Most of the time, I did side by side comparison tests against a know “standard” locomotive and work was focused on avoiding ride quality complaints on new locomotives. Not quite the same thing as HSR…

As for wheel profile, you at least want to document what you are testing. I would think for high speed operation it

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It’s the 60’ baggage cars that are the problem. The converted 85’ ones are good for 110 mph. The shorter the car, the lower the hunting threshold speed. EMD GP40/50/60 and F40s all had issues because of their shortness. EMD recommended truck to frame dampers if they were to operate >60 mph.

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Prior to this weekend’s announcement on state agencies making a pooled purchase of bi-level coaches, the most recent passenger train purchase was an Amtrak contract to purchase single-level cars, suitable for interoperation on the Northeast Corridor (NEC). The contract specified that the train car operate at 125 MPH, even though this equipment is mainly for the Florida long-distance (Silver Service) and other trains operating into Penn Station.

The idea is that Amtrak doesn’t want slow trains on the NEC slowing down their fast trains. Sensible idea on the face of it. As a result, a large portion of the Amtrak contract was to acquire 125 MPH-capable baggage cars.

Many view this as a sensible and necessary thing for Amtrak to do – if Amtrak wants to continue the Silver Service, which are popular long-distance trains, and if Amtrak doesn’t want those trains to present a bottleneck on the NEC, high-speed baggage cars are needed.

The question, however, was that Amtrak’s first new car purchase in since forever included a large purchase of non-revenue cars (the baggage cars). The thought was offered that aging hand-me-down Amcoaches could be converted to baggage cars and meet the 125 MPH requirement at much lower cost.

There is also a philosophical component to this with respect to prioritizing use of scarce capital money. The first thing Amtrak does with its ARRA (Stimulus Bill) money is to buy baggage cars. One faction around here has the idea that Amtrak wouldn’t be doing that if it were not a necessity. Another faction holds to the idea that baggage cars meeting the requirements can be had much more cheaply than the near, what was it, about 5 million dollar per car purchase price, namely by converting aging Amfleet.

Th