What were they used for?
They still are. Trailers and occasionally containers.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
The idea is to minimize tare weight, the amount of structure you aren't being paid to transport. In the '60s and '70s the idea came in vogue of using cheap trailers on very lightweight cars -- there were even a few 4-wheel cars proposed, and pre-Wickens the suspensions they tried were criminally primitive. With this came the age of sideloading with power equipment, mostly done with machines like LetraPorters and PiggyPackers that were touted as being able to take any old trailer and whisk it on or off from the side, with full random access, in a few seconds. (It would turn out they would usually damage trailers, if not sooner then later, and to this day special, expensive, tare-increasing reinforcement is necessary...)
About the apogee of the spine car was the ATSF FuelFoiler, from the age when 90mph freight trains were ATSF's demonstrated distinctive competence. These were about as lightweight as practical: a 10-section rake articulated in the centers with no deck -- only lowered pockets for a trailer bogie and a hitch for the kingpin. This would lower the trailers for the lowest air resistance and reduce sway and give lower CG on curves. Of course trailers had to be lifted on and off (no circus) but that was an acceptable part of the 'weapons system'.
Before anyone gets hyped about 2 axle cars
http://cs.trains.com/trn/f/111/p/13338/152433.aspx
Never too old to have a happy childhood!
BaltACDBefore anyone gets hyped about 2 axle cars
Axle vs. coupler spacing to be determined by the Bissel formula for guiding.
As usual, I'd love to read Mr. Goding's opinion on Wickens and what might constitute a stable four-wheel container platform for use in a unit train.
Overmod BaltACD Before anyone gets hyped about 2 axle cars Yeah, but we never had a real two-axle design that made any particular sense. You need to look at the real HSFV as a starting place... and not the built-to-a-price cheapened version that came later, either. Axle vs. coupler spacing to be determined by the Bissel formula for guiding. As usual, I'd love to read Mr. Goding's opinion on Wickens and what might constitute a stable four-wheel container platform for use in a unit train.
BaltACD Before anyone gets hyped about 2 axle cars
Yeah, but we never had a real two-axle design that made any particular sense. You need to look at the real HSFV as a starting place... and not the built-to-a-price cheapened version that came later, either.
American railroads and their equipment are all 'built to price'.
BaltACDAmerican railroads and their equipment are all 'built to price'.
Overmod BaltACD American railroads and their equipment are all 'built to price'. But HSFV was not particularly 'expensive' by North American standards ... just carefully engineered and correctly proportioned. It would have been highly interesting to have tried something like that around the time we imported the 100mph Leyland railbus for the NEC... it would have needed very careful damping and compliance in the 'coupler swing' arrangements to be right, but that wasn't even rocket science in 1980.
BaltACD American railroads and their equipment are all 'built to price'.
But HSFV was not particularly 'expensive' by North American standards ... just carefully engineered and correctly proportioned. It would have been highly interesting to have tried something like that around the time we imported the 100mph Leyland railbus for the NEC... it would have needed very careful damping and compliance in the 'coupler swing' arrangements to be right, but that wasn't even rocket science in 1980.
1980 - the money was being funneled toward mergers and acquisitions - not new technologies.
Overmod As usual, I'd love to read Mr. Goding's opinion on Wickens and what might constitute a stable four-wheel container platform for use in a unit train.
TTOX cars were a nightmare, especially when empty or switching.
mudchickenTTOX cars were a nightmare, especially when empty or switching.
They were also a operating nightmare - under any conditions.
The only one's that could have liked them had to be the bean counters, and only when they looked at the costs of construction, not when looking at all the other costs associated with their use and operation.
BaltACD mudchicken TTOX cars were a nightmare, especially when empty or switching. They were also a operating nightmare - under any conditions. The only one's that could have liked them had to be the bean counters, and only when they looked at the costs of construction, not when looking at all the other costs associated with their use and operation.
mudchicken TTOX cars were a nightmare, especially when empty or switching.
They see the savings that they want to see. They don't see the costs that they don't want to see. That hasn't changed and probably never will.
Jeff
bogie_engineerAt the risk of sounding flippant, the performance and reliability of Koni yaw dampers today can really make any suspension stable at NA freight speeds
Where Wickens is notable is that he designed for primary yaw stability, a bit like what Stroudley thought he was doing on the Gladstone 0-4-4s. Then instead of accommodating natural instability with intelligent brute force and charm, as in properly valves and tuned Konis or horizontal active suspension, you make the physical running gear self-correcting. It came as a great shock to me that a solid-axle wheelset with taper was dynamically better than Talgo-style separate wheels in this context, and it was not fun having to explain to someone with an ingenious patent to separate wheel rotational speed on a 'drop-in' replacement wheelset for three-piece trucks that there would be no miracle guiding improvement...
The HTCR truck has a low yaw stiffness on the end axles and those axles will hunt at a very low speed without the primary yaw dampers and that isn't fundamentally different from a single axle steering bogie, particularly with the interaxle yaw connection now removed from the HTCR.
Progressive compliance and yaw damping in Bissel leading axles has been a fascination of mine from comparatively early on. I am still uncertain as to how well the LS&MS Prairies did this -- supposedly well, where other approaches like the Reading's were disasters -- or why Wilgus retained the approach on the S-class electrics where it seemed to work at less than 90-odd mph but certainly not there.
I cannot imagine a Bissel leading axle without good progressive yaw damping if constant axle loading is desirable. Many of the late steam designs had reasonable stability -- the arrangement on the late N&W A leading trucks or some of the AMC designs being good as far as they needed to be -- but these were not powered axles.
As others have pointed out, however, the ability to equalize wheel loads is critical and given the longer length of NA vehicles, coming up with a suspension that equalizes at empty condition while not having too much change in coupler height loaded I think is the bigger challenge.
I more or less punted on this by adopting semi-active air suspension taken from listening to Kneiling, adopting what the Budd people were doing at the time, and a bit by osmosis from Mr. Klauder and the other people I was using for mentoring in specialty railroad engineering. I needed precise alignment independent of weight or track irregularity to get the sideloading to work reliably, and since this was a high-speed proportional-release-brake consist it seemed sensible to use multiple-redundant-chamber air on either side of each bolster to do the cross-level as well as longitudinal weight accommodation to ride height fine tuning. Active suspension on a locomotive is a very different proposition, one which to my knowledge has never been demonstrated cost-effective even before conditions of reliability come into play. That impression may well be due to my own somewhat autodidactic ignorance, though.
I don't think there are good solutions for the coupler-height issue on very-low-tare long equipment outside active adjustment. At one time or another I tinkered with the idea of adjustable draft-gear height, like a controlled version of coupler swing. I can tell MC to relax his opinions of horror ... it is a nonstarting idea for ever so many reasons, as are the only less slightly crackpotted idea of 'retainer'-like manual adjustments of running ride height to be set by carmen during inspections...
For some reason I remember the dominant 'excuse' about couplers on lightweights in the stiff-primary-gospel days being that the little platforms were meant to ride lousy when loaded -- the shock being taken in the compliance and damping of the trailer tires and bogie suspension and fancy hitch design -- so that the ride height would not have to change much...
I wonder if anyone in the age of 89' low-tare TOFC flats did the Bissel calculations from stretched-draft-gear pivots to truck center net of the 'drawbar length' represented by the coupling?
I have yet to hear a hogger who enjoyed these in their train.. From being too light. Hunting at track speed. Derailing quite often when MTY. Even TTX was happy when these got scrapped. Great concept, just not the concept for North American HH.
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