FM-
How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ?
nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ?
Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars?
One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations.
futuremodal wrote: Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers.
Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers.
Traffic does indeed change. I remember when we loaded almost exclusively 5 packs and 89' flats. We also used to actually switch out the cars to get them in proper order. Currently, traffic runs in sets of 6 and 12. Why? I don't know. Will it change again, undoubtedly. When I started, we loaded both trailers and containers. Now my terminal loads containers only. (A big mistake in my opinion) And because we double stack, I only handle well cars.
Due to our traffic patterns and the flexiblity of loading 3 packs, that's what my people prefer. We load out for 6 destinations. The big advantage of 3 packs is that they don't need to be shifted around to get the proper number of platforms in the proper order.
The UPS traffic is through traffic. I'm just responsible for inspecting the trailer's as they pass.
Nick
Take a Ride on the Reading with the: Reading Company Technical & Historical Society http://www.readingrailroad.org/
futuremodal wrote: nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ? Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars? One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations.
Why on Earth wold anyone want an adustable length railcar? Aside from being totally uneccessary in terms of use and expense - it would be very difficult to build. When I was at RoadRailer, we couldn't built an workable adustable length bimodal chassis because it was impossible to make it strong enough to stand the draft and buff forces in a train. The problem would be multiplied many times over in railcars.
I suppose, with unlimited expsense you could built and adjustable length railcar - but again, why would you want to?
As to dragging empty boggies behind a train - they're too light by temselves. They were at about 11,000 poiunds when I was with RoadRailer. That won't hold them on the rails. One good bounce and you've got a wreck.
nanaimo73 wrote:I was thinking more along the lines of 5 platforms on 6 trucks, that could be increased to 6 platforms on 7 trucks, or decreased to 4 platforms on 5 trucks.
Now I get it. So what you'd have is, say, a normal 3 pack spine car which is 3 platforms on 4 trucks. The two trucks on the coupler end would be a hybrid of articulation and a normal drawbar shaft. When in 3 pack mode, you just stick a coupler into the drawbar shaft, but when you want to add platforms you plug the additions into the articulation parts?
I'll just think as I go here. What if instead we have a 3-pack spine car, but with single axle bogies on the end units, thus a 1+2+2+1 set of trucks (with the 2's as normal articulated two axle trucks.) The additional units are all 1+1, but when you add the additions to the 3-pack (let's say we want a 5 pack), you make it so the two facing single axle trucks become a double articulated two axle truck. To do this, you need a way to lock the single axle truck inline with the car's spine body when in stand alone mode, but allow the two single axle trucks facing each other to become a functional two axle articulated truck when connected together. You'd do this by releasing the locking mechanism which holds the truck inline (there would be a centerplate directly over the truck to allow the truck to swing free when connected to the facing truck), and then directly lock the drawbars of the two facing trucks together so they'll act as a single two axle truck, albeit with a truck wheelbase that is longer than the normal two axle truck wheelbase. The corresponding car bodies would each pivot on the centerplate of the home axle set.
Or were you thinking more in the line of using bi-modal technology as a way of adding the extra platforms? Then you'd have a normal 3 pack in 2+2+2+2 configuration, but have extra Mark V type trucks and bi-modal platforms that are added as de facto car additions to make whatever type of slack free multiple unit car configurations as you like. Something like that?
nbrodar wrote: futuremodal wrote: Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers. Traffic does indeed change. I remember when we loaded almost exclusively 5 packs and 89' flats. We also used to actually switch out the cars to get them in proper order. Currently, traffic runs in sets of 6 and 12. Why? I don't know. Will it change again, undoubtedly. When I started, we loaded both trailers and containers. Now my terminal loads containers only. (A big mistake in my opinion) And because we double stack, I only handle well cars. Due to our traffic patterns and the flexiblity of loading 3 packs, that's what my people prefer. We load out for 6 destinations. The big advantage of 3 packs is that they don't need to be shifted around to get the proper number of platforms in the proper order. The UPS traffic is through traffic. I'm just responsible for inspecting the trailer's as they pass. Nick
The well car with the trailer hitches built in is probably the most versatile of the intermodal cars. I guess some railroads are operating under the "better to have it and not need it, rather than need it and not have it" axiom. What you lose in added tare weight for hauling a single trailer in a well car you make up for in ultimate flexibility. You can haul two UPS trailers in a single said well car, but aren't those well cars strictly stand alone or 3 pack drawbar connected, not in articulated 3 packs? I suppose the extra fuel use may not be as big a factor as one would suppose, but again that might change if fuel prices continue to increase.
I never made mention of All-Purpose well cars. Although, I do see them in the UPS trains on occation. I never really noticed if they were stand-alone or articulated.
We are a container only facility. We don't handle trailers. As such, we only use well cars. Occationally, we'll get an All-Purpose spine car, or flatcar with Interbox Connectors for containers.
You also may be interested to know, that some of the cars we use is trash service, are little more then frames on trucks, with IBCs to secure the trash containers.
greyhounds wrote: futuremodal wrote: nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ? Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars? One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations. Why on Earth wold anyone want an adustable length railcar? Aside from being totally uneccessary in terms of use and expense - it would be very difficult to build. When I was at RoadRailer, we couldn't built an workable adustable length bimodal chassis because it was impossible to make it strong enough to stand the draft and buff forces in a train. The problem would be multiplied many times over in railcars. I suppose, with unlimited expsense you could built and adjustable length railcar - but again, why would you want to? As to dragging empty boggies behind a train - they're too light by temselves. They were at about 11,000 poiunds when I was with RoadRailer. That won't hold them on the rails. One good bounce and you've got a wreck.
There is another idea that might work for an adjustable length spine car that uses the nut and bolt concept. It's basically a center sill that is round and bolt or screw shaped - turn it one way to lengthen the car, turn it in reverse to shorten the car. The center sill thus is the "bolt" and the end platforms/truck attachments are the "nuts". The platform itself would use the slider chassis mechanism to change it's length in conjunction with the center sill. The main benefit of this design is that all the longitudinal forces are taken up by the "bolt" in equal proportion regardless of car length, and the car itself can be configured for any length desired between the minumum and maximum. We have rotary drawbars, why not rotary center sills?
As for towing free wheeling RoadRailer or RailRunner bogies, if they are attached to each other using a light weight (for easy handling) slot-on-slot drawbar, the lack of vertical play in that type of connecting device should limit bounce, as the weight of the fore and aft bogies would counter the vertical tendencies. Of course, any such device would have to be tested prior to actual use.
The "newest" CP Expressway cars added to the fleet are just old 55' flat cars from the 50's or 60's permantly coupled in groups. State of the art technoligy, same old cars in new paint.
So it went from CSX Iron Hiway to CP Iron Hiway to articulated Expressway cars back to ordinary pig flats sevice. That's the evolution.
M636C & Paul Milenkovic discussed: "I have found the original CSX Iron Highway prototype! Are you all sitting comfortably? It was purchased by an AUSTRALIAN Road Transport company CRT ..."I'm resurrecting this 13+ year old thread to give you a link a webpage about the bogies on the Iron Highway platforms that ended up in Australia. On the Motive Power (formerly MK Rail) website, "New Truck Design for Iron Highway," undated, http://www.railmotive.net/22newtruckdesignfor.html. Those are two-axle bogies, to accommodate the lower allowable axle loads on Australian tracks compared to the U.S. where one axle was sufficient.
This is an interesting solution, although I wish they had made more explicit reference to the braking arrangements.
A critical detail in this truck design is the arrangement that keeps the two sideframes aligned with the bolster, comparable to the wedges and shims in a three-piece truck. While I understand the computer-generated image may not be a 'structural' model, I note that the circumferential reinforcement of the bolster opening and springing in a three-piece truck is absent (there are no pedestal tie arrangements visible, either), and the frame opening at the top of the 'bolster pocket' has a relatively sharp radius. Since the frames are inside, it may be very difficult (as in the Allied Full Cushion) to keep the areas of potential cracking monitored in service.
One of the points of the original HPIT suspension in the Iron Highway was that any differential-loading-caused rotation of the truck frame was inherently accommodated by the bearing of the single axle. That is not true of the newer arrangement, and this will result in some rotation of the bolster relative to the sideframes. This combined with 'anti-lozenging' indicates that a very precise arrangement possible involving spherical bearing surfaces needs to be provided between sideframes and bolster, and again the installation and inspection of these may be difficult in practice.
The bearing discussion is an interesting one in principle. Presumably the inline narrow bearings have adequate grease sealing that they meet modern AP standards. It's well-recognized that AP bearings in many modern three-piece applications considerably outlast the practical wheel life of the sets they are installed on (effectively leading to 'wasted capacity' as the bearings must be removed and rebuilt any time the wheels have to be changed out). It should be possible for the wheels to be removed from these new sets without disturbing the bearings.
On the other hand, automated devices that scan for 'hot bearings' now have multiple layers of structure to attempt to 'see through', and I suspect the design would not be accepted in any context that required the ability to scan remotely for 'hotboxes'. Theoretically this might be gotten around by using heatpipes from the bearing boxes or seats 'inboard' to an IR-enhanced emitting surface at the bolster ends, visible past the "rubber" springing and endplates; that being a passive device tolerant of considerable vibration and impact damage, and in principle easily replaced if disabled.
I'm not convinced that the steering via links is comparable, though. It is required on the two-axle truck for obvious reasons; presumably those reasons are presumed to occur on a truck with narrowly-spaced axles (as here) but I have to wonder if links to the two sideframes, rather than to the bolster as the 'default' two-wheel version provides, is the best solution for truck steering in the presence of what (in Australia) may be a considerable level of line/surface defect and consequent differential sideframe pivoting accommodation (as in three-piece trucks). It would be interesting to consider the effect of leaving some of these links disconnected, as Prof. Milenkovic indicated might have been typical practice (see his post in this thread Aug 14 2006). I'd be particularly interested in what Dave Goding might have to say on this general subject, as his experience in what does and doesn't work well in guided-axle trucks is substantial. (He is also, as I recall, familiar with the stillborn attempt here in the latter '90s to accommodate some of the effect of heavier-axle-weight cars by using multiple-axle freight truck designs...)
I wonder whether a Taylor-type sideframe (with a circular 'bearing surface' in the center of each sideframe, with a bolted saddle to hold this firmly in the sideframe and act as a pedestal tie while allowing easy sideframe/wheel lift at servicing) would be a reasonable enhancement to the design.
I might also add that the redesigned sideframe arrangement appears to be relatively well suited to using disc brakes (with the calipers and mounts balanced either side of a bolster attachment, and the discs allowed to 'float' vertically with suspension accommodation between the pads). Since these wheelsets are already incompatible with 'general' wheelsets for conventional three-piece interchange trucks, adding a central 'seat' and perhaps keying arrangement for a suitable disc rotor seems relatively simple.
I need to bump this to go with Prof. Milenkovic's, for the oh-so-Canadian-appropriate hat trick of Iron Highway posts. This one contains the truck design that was supposed to adapt the original independent-wheel single-steered-'axle' underfloor bogies to work in Australia, where lighter track standards dictated 'more wheels'...
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