Turbotrain 1968

[Paul Milenkovic]

Jason:

I guess my obsession is the "wishbone" and "drag link" arms that make up the TurboTrain guided-axle suspension.  I have been working for the last two years on a theoretical understanding of that mechanism.  It is hard to say if Alan Cripe had any theoretical insights on this or worked from geometric intuition, but the only prior publication I have seen is in his patents.  What got me started on this is that Talgo was/is considered for the Midwest Regional Rail Initiative if it ever gets funding, and either Alan Cripe or his associates had been promoting the Fastracker DMT derivative of the TurboTrain design to advocacy groups in the mid 1990s shortly before his passing.

A paper relating the TurboTrain suspension to the theory of constant-velocity couplings -- Paul Milenkovic, Triangle Pseudo-Congruence in Constraint Singularity of Constant-Velocity Couplings, submitted to ASME Journal of Mechanisms and Robotics -- has been accepted pending a review of a revised manuscript.  A constant-velocity coupling, or CV joint, is something you have four of in a front-wheel drive car, and what a CV joint does is maintain a constant roll angle for a pair of shafts so your steering doesn't shake when you go around a curve, and the theory states that it has to maintain a symmetric relationship between the two shafts and the part in the middle.  The TurboTrain maintains a constant bank angle of the pendulum tilt for the neighboring train cars, and the guided axle is that bit in the middle maintaining a symmetric relationship between the train cars.

Not only does the TurboTrain suspension "split the difference" of the yaw angle between train cars to maintain "radial steering", it also splits the difference in the pitch angle, or any combination of the pitch and yaw angle experienced by the train cars as they roll in response to the pendulum effect around curves.  The TurboTrain system maintains the required geometric symmetries about the single-axle truck for this to happen.  The Talgo guided-axle system does a similar thing, but it only approximates the action of a constant-velocity coupling, and it can introduce small steering errors.  Also, the Talgo has a lateral degree of freedom for motion between the train cars not present in the TurboTrain, and as such, Talgo requires a system of between-car dampers on multiple axes that apparently the TurboTrain never required. 

The part about "constraint singularity" is that I am trying to rule out conditions where the TurboTrain suspension or mechanisms like it could collapse.  The last few years have seen research publications on a class of robot mechanisms that share attributes of constant velocity couplings and in turn the TurboTrain suspension, and there has been work by several engineers on determining deflection angles where such mechanisms could collapse to insure that the mechanism stays within stable boundaries.

Which brings me to a point I had raised before.  The Rapido TurboTrain model shows non-functioning "details" on the single-axle truck depicting a four-bar linkage connecting the "drag link" arms from the axle journal to the two neighboring train cars.  The Talgo uses a variation of that mechanism for its axle steering.  If you put that detail on the model, you must have seen a photo somewhere of that rigid linkage, which substituted for the spring drag-link arrangement in the TurboTrain patent.  I have also seen the spring drag link, or at least whatever system prior to the linkage drag link, in a photo in a railroad trade publication circa 1968.

I am working on a manuscript for publication in an ASME journal on the specifics of the TurboTrain linkages.  There are photos of the TurboTrain on railroad trade publications, in Trains, and in collections of railfan photographers, but photos showing any mechanical detail of the guided axle are rare.  If you have such a photo and could post it, and better yet, if you have any "provenance" -- who took the photo and when, along with any back story as to why and when the change was made to the guided axle along with any reference or attribution to who was providing that information, any of that would help me out immensely.

[Rapido]

Apparently the TurboTrain model is not just another product from Rapido Trains, although I am told based on MR reviews that they make fine products.  The Turbo is not only a "labor of love" on the part of Jason Shron but perhaps something bordering on an obsession. 

"bordering on an obsession" doesn't do it justice. "beyond an obsession" would probably be better. Even after spending years working on the model and writing the book, I still love that train.

Anyway, the realism of the prototype TurboTrain in the HO model is taken to such an extent that the HO model will be well over a year late.  Representing a prototype promised in 67, delivered in 68, and finally operating in 69, the model was promised in 07, delivered in 08, and mine (cross fingers) will be finally "put into service" at a passenger train advocacy exhibit as a "train of tomorrow" at the February 2009 Mad City Model Railroad Show. 

You will be in luck. Unless the factory burns down or is abducted by aliens, all of the TurboTrains will be in stores well before then. The Late Amtrak TurboTrains are just about to leave the factory. Here is a picture of a production sample. I added exhaust and a dust trail in Photoshop. The image without photo effects will appear in the September MR.

I've never posted a photo here before so hopefully that works. I think the "Totally Wired" Telephone Poles really make the photo. The first shipment of those is also about to leave the factory.

I saw some postings on Google Groups suggesting that one of the Train-X Baldin Diesels was used as a power car in initial tests of the TurboTrain.  Anybody confirm this, or this railroad apocrypha? 

I have not seen any evidence of this. It was running under its own power quite early on (the date is somewhere at the office). For testing the towing capability they would have used whatever locomotive was handy. If the Baldwin was handy, they would have used it. But I find it unlikely as it would have made more sense to take a unit that was currently in service. It would not have made any sense to get a mothballed unit fixed up just to do a tow test.

Best regards,

Jason

[Paul Milenkovic]

Alright already, the first person to tell me to post this in the Model Railroader section gets slapped about the face with a wet fish in the manner of that Monty Python sketch.

Some may know that Rapido Trains is coming out with an HO model of the TurboTrain. 

Rapido Train's Jason Shron is a self-admitted TurboTrain fan, starting with his childhood experiences of riding it in Canada.  One of his stories was that as children, he and his brother would stand in the passageway between train cars at the articulated connection, allowing themselves to be bounced against the sides during the time the train would negotiate crossovers and slip switches in the terminal areas, a time when the official announcement was that you were supposed to stay seated.

Apparently the TurboTrain model is not just another product from Rapido Trains, although I am told based on MR reviews that they make fine products.  The Turbo is not only a "labor of love" on the part of Jason Shron but perhaps something bordering on an obsession. 

Anyway, the realism of the prototype TurboTrain in the HO model is taken to such an extent that the HO model will be well over a year late.  Representing a prototype promised in 67, delivered in 68, and finally operating in 69, the model was promised in 07, delivered in 08, and mine (cross fingers) will be finally "put into service" at a passenger train advocacy exhibit as a "train of tomorrow" at the February 2009 Mad City Model Railroad Show.  Don't laugh about the "train of tomorrow" aspect to the thing -- see the Midwest High Speed Rail Association Web site for one advocacy group's take on the TurboTrain.

Jason Shron apparently has his TurboTrain book out already.  I am supposed to get a copy of my "TurboTrain, a Journey" upon delivery of my TurboTrain model in US DOT colors, probably sometime in October.  Many of these questions could be already answered in that book.

My personal obsession is working guided-axle and tilt linkages.  I have an operating prototype of an HO representation of the kinematic principles of the TurboTrain articulation mechanism -- it is between a pair of HO Electrotren Talgo cars and was exhibited in that form at the last Mad City Model Railroad Show because Rapido was not forthcoming with a TurboTrain model.  But I was willing to do "plastic surgery" on an Electrotren Talgo because they were discontinued and sold for cheap by Walthers, and I don't know if my wife will let me do this to a $500 Rapido TurboTrain model.  Jason went with springs for the guided axle, just like the Electrotren Talgo: I tried to "sell" him on the idea of prototypical linkage-based axle guiding, but I guess he had enough on his plate trying to get the HO model into production.

The other thing I corresponded with Jason Shron about is the Train-X antecedent to the TurboTrain.  When you think of it, Train-X was only about 10 years earlier than TurboTrain, and 10 year is as nothing these days at the rate at things are happening at Amtrak, but 10 years prior back in the day was as ancient history, and Train-X was nigh forgotten by the time TurboTrain was rolled out in 1968.  I saw some postings on Google Groups suggesting that one of the Train-X Baldin Diesels was used as a power car in initial tests of the TurboTrain.  Anybody confirm this, or this railroad apocrypha? 

[DMUinCT]

   Completed in the Summer of 1968, they were taken to severial cities for display and then used in  "Press Runs" until October. The two United Technologies (then known as United Aircraft) "Turbo Trains", UAC-1 and UAC-2 were then accepted by the U.S. Dept of Transportation on October 21, 1968 and renamed DOT-1 and DOT-2.

   As the "Penn Central" was taking over the "New Haven", they did not enter Boston to New York service until April 8, 1969.

[081552]

In the summer of 1968 my father took me to Grand Central Station to see the Turbotrain. "That's the future of rail service" pointing to the train. Sorry dad!

Can anyone tell me if the Turbotrain was running in regular service then? 

Thanks!