Edit post

Edit your reply below.

Post Body
Enter your post below.
[quote user="Paul Milenkovic"] I guess I am answering my own question with this link: <A href="http://www.tsb.gc.ca/en/reports/rail/1997/r97h0008/r97h0008.asp">http://www.tsb.gc.ca/en/reports/rail/1997/r97h0008/r97h0008.asp</A> Apparently, a truck trailer got loose from the hitch mooring on an Iron Highway trainset in service in Canada, and that trailer then smashed into a highway overpass, damaging it.  The accident report gives photos, diagrams, and text explanations of the Iron Highway trainset by way of background of how this rather exotic piece of train equipment contributed to the wreck.  They ascribe the accident to misuse of the hitch owing to its unorthodox design and lack of training of crews, but they also point to the Iron Highway trainset being operated with many broken or inoperative hardware appliances. It seems that no one properly knew either how to operate or how to maintain this piece of equipment.  A number of shock absorbers (dampers) for vertical motion of the single-axle trucks were disconnected -- perhaps when these dampers failed, it was easier to unhook them then find replacements. I sure wish I could learn how the guided-axle mechanism works as I am a Talgo/TurboTrain enthusiast.  But the accident report and related photos gives a flavor for what Iron Highway is or was and perhaps why it failed in the marketplace. It seems that Iron Highway was Yet Another Piece of TOFC Rolling Stock of which there are many others of various advantages and disadvantages to chose from.  One idea was that there would be those short platforms supported by guided axles and with frequent spacing of hitches -- the notion is that instead of discrete trailer parking spaces, there would be the effect of a continuous platform, and you could mix and match 28', 40' and 53' trailers as desired without wasting a lot of space.  The other idea was to revert to circus loading.  Each trainset could separate in the middle into two parts, each part fed by a ramp.  I guess the idea was that if the load points were interspersed throughout a train made up of multiple train sets, circus loading would be OK.  The other part to this is that you only had ramps at this trainset midsections -- there were no Clejan car bridgeplates between articulated sections, only small gaps in the platform where the platforms articulated over a guided-axle wheelset. How the mid-section ramps worked is not clear from the report -- did the trainset uncouple and separate to let down the ramps, or did the train stay coupled but the ramps swung to the sides? Inasmuch as Iron Highway is TOFC, and there are many competing designs for low-profile light-weight TOFC trainsets, Iron Highway does not seem like that big of a deal.  The sense that Iron Highway was an improvement was that it was supposed to do away with expensive hoist equipment -- a terminal could be simply a grade crossing where you parked the ramp car in the middle of a trainset.  Also, reverting to circus loading meant that the trailers didn't have to be beefed up to take hoisting, and a long train had multiple load points, one in the middle of each trainset, supposedly making circus loading go faster.  Also, you did not have to lower and raise between-car ramps because the guided axle arrangement made the trainset appear as one continous surface. As to why Iron Highway went away, the accident report hints that it was too mechanically complex for freight service, given the money the railroad wanted to spend on maintenance and crew training on some specialty equipment.  The Iron Highway trainset didn't need to be left in such a state of disrepair, but it ended up that way.  I am wondering of Talgo has similar problems, say in Cascade Service, but the Talgo Company may have their own people in Washington State to play nursemaid to this equipment until such time that Talgo becomes more commonplace. [/quote] I'll present this as I presented the question to Tom - if the independent wheelsets were too much of a maintenance hassle for inexperienced crews, why not just go with standard single axle bogies?  I don't believe that the short wheelbase of 28' and the opposite end articulation would have required any further modification for curve negotiability, e.g. no need for radial steering arms, etc.  And I can't see where using standard single axle bogies would detract from the low profile or any other advantageous aspect of the concept. There were other railcar innovations that utilized single axle bogies - the Southern 100 four bay hopper, and the Trough Train.  The Southern 100 was basically four 25' single hoppers with single axle bogies on both ends of the hopper units, and were connected by a primitive link pin connection.  Had probably the best load factor of any coal hopper or gondola, better than most current equipment.  The basic problem that caused the cessation of the idea wasn't the single axle bogies (although they could have used beefier suspension), but with the link pin connections between the individual units. The Trough Train used single axle bogies at the coupler ends, and standard two axle articulated bogies between units.  Again, no problem with the single axle bogies was reported, rather the problems lay in the relative inflexibility of the total unit when it came to replacing a bad wheelset, etc.  You had to take out the entire unit, or about 13 hopper bays. Both these examples show that single axle bogies (and the inherent tare savings of using single axle bogies over regular two axle bogies) are useful evolutions of rail equipment, but have been relegated to the dust bin of history because of a lack of patience in working out the usual kinks of new equipment.  Whether the 36' wheelbase of the TTOX/Four Runner cars was just too long, even with radial steering, has not been answered or documented by the detractors.  Given the relative success of the single axle type with the Southern 100 and the Trough Train, it could be that keeping the wheelbase to about 25' or using standard two axle articulated trucks on the opposite end of the single axles would have been the simpler solution.  All the Southern 100 probably needed was a better method of interconnecting the units and more modern suspension of the single axles, and it might still be around in some form. All the Trough Train needed was to be broken down into smaller unit numbers per car, and it would probably still be running the rails today. And all the Four Runner needed was to employ a hybrid of single axles with standard two axle articulation, and it would still be running out there today. And the Iron Highway probaby could have been saved by using standard single axle bogies rather than indepedent wheelsets, and it would be out there working for us. And all four examples would have provided the prime benefits of saving fuel, et al, as all four provided improved load factor and simplified modal transfer options over currently used equipment.
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag