Road Railer-Why isn't this a slam-dunk?

[rrnut282]

Even at 150 trailers, the current FRA maximum allowed, a TC train only weighs in the neighborhood of 4600 tons.  Do you really need a DPU for that?

[Modelcar]

....Seeing the Triple Crown smoothly roll thru here and thinking of how just something a bit "out of line" from "normal", it pulled off the big sweeping curve {twice}, it negotiates coming into our city shows how "touchy" it really must be.

Having a 200 ton engine on the rear or spliced into the consist somewhere sounds like it would really be risky business.  Weight transfer from a rising grade and topping that grade and starting down grade, etc.....

Seeing T C Trains roll thru here with up to 140 cars {trailers}, connected and the power being 2  6-axle engines....Why would one need DPU...?

[oltmannd]

The last trailer on a road-railer is on a regular bogie, i.e., no coupler so you can't put a locomotive on the rear.   Besides, it's not a good idea to push roadrailers.  NS has a strict 6-axle limit while switching Triple Crown trains in Fort Wayne.

No, but you can pull them backward.  TCS has some of the old Amtrak adapters that allow this. 

If you set up the DPU right, you'd have minimum pushing - each loco would be responsible for pulling it's portion of the train. 

[Champlain Division]

I work here in Atlanta for the local transit authority.  I've lived here since 1989 and have seen NS' continued success in the TC Roadrailer business.  Needless to say, I'm impressed!

We've all seen that the TOW is a slackless operation for the most part.

The DPU question could be solved by using locomotives modified with Roadrailer type couplers.  (Wah-lah  -  Janey type coupler slack eliminated!)  A probe in front and a slot in back instead of a coupler mate.  These could be added above the regular couplers, IINM.  That lead trailer always has to "bow down" to get on the coupler mate.  With an auxilary coupler above the standard one on the engine, that would eliminate that (personally) somewhat unsightly phenomenon.

I tend to be an "Imagineer" and also a lover of passenger trains.  I keep looking at this Roadrailer technology and can't help but wonder how a passenger version of it could be designed. 

I envision high speed passenger trucks for speeds above 80 mph, windows and doors on the sides and pass-through diaphragms on both ends.  Of course, the lightweight technology would have to be beefed-up for passenger operations,  but it wouldn't be impossible.

There could be baggage, diner, lounge, sleeper and coach versions.  Dare I say even a dome version?  I suspect that service and baggage/storage cars would be captive on scheduled trains.

They could be all high level platform compatible or they could have some sort of low level vestibule or boarding door at one end or dual mode.  They could also be easily tacked-on behind a standard passenger consist. (With dual couplers, of course.) 

There's plenty of room underneath for support equipment, pass-through head-end power or some other such power system either locomotive dependent or self-contained.  (Hydrogen fuel cell powered preferably for safety.)

A twelve wheel undercarriage with a beefed-up suspension would make them roadable.  Individual coaches or sleepers could be chartered and or routed to/from as far away as the average tractor fuel range from individual depots.  Heck, you could even have one pick you and/or your party up at the curb in front of your house or at the local bus/intermodal terminal.

The biggest thing that catches my imagination of this technology is the slackless coupling and flexible rigidity of the consist.  It smoothly glides like a snake and can handle just about any curvature or grades there are on most mainline (Class 1) railroads. 

Yeah, the whole thing is a little on the crazy side, but a guy can dream can't he? 

  Do you mean something like this?

 

http://faculty.washington.edu/jbs/itrans/bladerunnerupdate.htm

 It's not really meant to share trackage with conventional "heavy rail" trains but it is along the lines of your proposal. As far as distributed power for Roadrailers Canadian National experimented with using single axle genset power untis (which rode on roadrailer type bogies) and cab units to distribute the train forces such that conventional highway trailers, modified to be able to couple to the bogies, would be usable. It was called an "Ecorail convoy". See bolow:

http://www.trainnet.org/Libraries/Lib005/ECO8004.GIF

 

 

 

Nope, neither one, really.  My idea doesn't concern itself with maintaining or resurrecting branchlines.  It's more a cheaper way to expand frequency on current routes and expand onto new routes.

 

Rick Shivik

[rrnut282]

The last trailer on a road-railer is on a regular bogie, i.e., no coupler so you can't put a locomotive on the rear.   Besides, it's not a good idea to push roadrailers.  NS has a strict 6-axle limit while switching Triple Crown trains in Fort Wayne.

[crpulse]

Someone asked earlier about the Fort Worth trains. They are handled by BNSF and their terminal in the Saginaw yard a few miles north of Fort Worth along business US-287. I only got to see this operation twice since they typically run at night. They also frequently use NS run-trough power. The first time is was a GP50 the second was a Dash-9 and a GP40-2 still in CR blue.

DPU and mixed consists seems easy enough just couple the locos in between the roadrailers and the conventional intermodal equipment.

[carnej1]

I work here in Atlanta for the local transit authority.  I've lived here since 1989 and have seen NS' continued success in the TC Roadrailer business.  Needless to say, I'm impressed!

We've all seen that the TOW is a slackless operation for the most part.

The DPU question could be solved by using locomotives modified with Roadrailer type couplers.  (Wah-lah  -  Janey type coupler slack eliminated!)  A probe in front and a slot in back instead of a coupler mate.  These could be added above the regular couplers, IINM.  That lead trailer always has to "bow down" to get on the coupler mate.  With an auxilary coupler above the standard one on the engine, that would eliminate that (personally) somewhat unsightly phenomenon.

I tend to be an "Imagineer" and also a lover of passenger trains.  I keep looking at this Roadrailer technology and can't help but wonder how a passenger version of it could be designed. 

I envision high speed passenger trucks for speeds above 80 mph, windows and doors on the sides and pass-through diaphragms on both ends.  Of course, the lightweight technology would have to be beefed-up for passenger operations,  but it wouldn't be impossible.

There could be baggage, diner, lounge, sleeper and coach versions.  Dare I say even a dome version?  I suspect that service and baggage/storage cars would be captive on scheduled trains.

They could be all high level platform compatible or they could have some sort of low level vestibule or boarding door at one end or dual mode.  They could also be easily tacked-on behind a standard passenger consist. (With dual couplers, of course.) 

There's plenty of room underneath for support equipment, pass-through head-end power or some other such power system either locomotive dependent or self-contained.  (Hydrogen fuel cell powered preferably for safety.)

A twelve wheel undercarriage with a beefed-up suspension would make them roadable.  Individual coaches or sleepers could be chartered and or routed to/from as far away as the average tractor fuel range from individual depots.  Heck, you could even have one pick you and/or your party up at the curb in front of your house or at the local bus/intermodal terminal.

The biggest thing that catches my imagination of this technology is the slackless coupling and flexible rigidity of the consist.  It smoothly glides like a snake and can handle just about any curvature or grades there are on most mainline (Class 1) railroads. 

Yeah, the whole thing is a little on the crazy side, but a guy can dream can't he? 

  Do you mean something like this?

 

http://faculty.washington.edu/jbs/itrans/bladerunnerupdate.htm

 It's not really meant to share trackage with conventional "heavy rail" trains but it is along the lines of your proposal. As far as distributed power for Roadrailers Canadian National experimented with using single axle genset power untis (which rode on roadrailer type bogies) and cab units to distribute the train forces such that conventional highway trailers, modified to be able to couple to the bogies, would be usable. It was called an "Ecorail convoy". See bolow:

http://www.trainnet.org/Libraries/Lib005/ECO8004.GIF

 

 

[Champlain Division]

I work here in Atlanta for the local transit authority.  I've lived here since 1989 and have seen NS' continued success in the TC Roadrailer business.  Needless to say, I'm impressed!

We've all seen that the TOW is a slackless operation for the most part.

The DPU question could be solved by using locomotives modified with Roadrailer type couplers.  (Wah-lah  -  Janey type coupler slack eliminated!)  A probe in front and a slot in back instead of a coupler mate.  These could be added above the regular couplers, IINM.  That lead trailer always has to "bow down" to get on the coupler mate.  With an auxilary coupler above the standard one on the engine, that would eliminate that (personally) somewhat unsightly phenomenon.

I tend to be an "Imagineer" and also a lover of passenger trains.  I keep looking at this Roadrailer technology and can't help but wonder how a passenger version of it could be designed. 

I envision high speed passenger trucks for speeds above 80 mph, windows and doors on the sides and pass-through diaphragms on both ends.  Of course, the lightweight technology would have to be beefed-up for passenger operations,  but it wouldn't be impossible.

There could be baggage, diner, lounge, sleeper and coach versions.  Dare I say even a dome version?  I suspect that service and baggage/storage cars would be captive on scheduled trains.

They could be all high level platform compatible or they could have some sort of low level vestibule or boarding door at one end or dual mode.  They could also be easily tacked-on behind a standard passenger consist. (With dual couplers, of course.) 

There's plenty of room underneath for support equipment, pass-through head-end power or some other such power system either locomotive dependent or self-contained.  (Hydrogen fuel cell powered preferably for safety.)

A twelve wheel undercarriage with a beefed-up suspension would make them roadable.  Individual coaches or sleepers could be chartered and or routed to/from as far away as the average tractor fuel range from individual depots.  Heck, you could even have one pick you and/or your party up at the curb in front of your house or at the local bus/intermodal terminal.

The biggest thing that catches my imagination of this technology is the slackless coupling and flexible rigidity of the consist.  It smoothly glides like a snake and can handle just about any curvature or grades there are on most mainline (Class 1) railroads. 

Yeah, the whole thing is a little on the crazy side, but a guy can dream can't he? 

  

 

 

[VPayne]

I concur that longer Roadrailer trains is not the problem at hand. The real challenge in any short-haul intermodal is finding enough loads heading one way on any particular day. For longer hauls there is of course a larger catchment area for the truck drayage as this can be economically covered under the rate. Roadrailers seem to be used for short-haul moves as the double stack container becomes more economic if the volume is there on longer hauls. Additionally, double stack, and all containers, are hit by the chassis pool problem for short-haulsm which TOFC and Roadrailer skirt by using railbased units that are interchangable amongst carriers.

 For short-hauls there needs to be a consolidation of destinations from one terminal in one train. There then has to be a sorting operating in the middle. While Roadrailer does certainly have a lot of train sorting in the current system it seems that the process needs to be easier. If you look in the patent records there are a few proposals that came out around the time of Mark V that dealt with the need to drop/raise the sand pads during the coupling process. If the coupling process was basically automatic once backed over a bogie it sure would make the terminals flow better.

I still think having standard trailers and adopting the rail equipment makes the most sense for short-haul moves. 

[n012944]

Now we're back to my preference of running shorter faster consists on a schedule rather than trying to accumulate a whole siding's worth of cars before dispatching a train.  However, it seems unlikely the current crop of railroad management would change that line of thought.  Therefore, any chance to save on labor by maximizing train length seems to be the modus operandi for this sect.

Most trains are run on a schedule these days, in fact on CSX every train is run on a schedule, with the rare exceptions of an extra or non revenue train. 

[Anonymous]

The "cushion car" would have to be connected to the pushing unit to shut it down when the slack is completely compressed. 

Exactly.  The cushion car would send an override signal to the pusher when slack approaches critical.

Again, why is there a need for this?  A TC (or Roadrailer, if you prefer) train comprised of (150) 53' trailers is 7950 feet long without locomotives. (Actually it is longer, I'm not counting the tongue.) Going longer means you start to eliminate potential meets due to siding lengths.  This tends to greatly reduce the capacity of the mainline as trains are held in non-optimal locations.  The costs are starting to outweigh any benefit.

The underlying point of going longer with the TOW consist would be to take advantage of an implementation of longer sidings as the norm.  Say contemporary siding length is 12,000' in five or ten years, how will the bean counters want to maximize the load factor of TOWs?

The other concern for using a mid-train unit in a TOW would be in areas of grade and curvature where stringlining a 150 unit TOW is a possibility.

Go low-tech and run a second section like the good old days.  No cushion car to deadhead back and forth as needed and the conductor doesn't have to walk 4 miles every time the ET needs reset.

Now we're back to my preference of running shorter faster consists on a schedule rather than trying to accumulate a whole siding's worth of cars before dispatching a train.  However, it seems unlikely the current crop of railroad management would change that line of thought.  Therefore, any chance to save on labor by maximizing train length seems to be the modus operandi for this sect.

The other possibility for overlong TOWs might be in combining several TOW consists from disparate locales into one at a logical junction for the long haul to distant points. 

[yippinyahoo]

Why would a Roadrailer train need Distributed Power Units?  They have ample H.P/Tonnage ratios. 

It has nothing to do with horsepower to tonnage ratios.  Rather, if one wishes for a bi-modal consist to exceed 150 units (the max allowed under FRA rules), one would need to employ a radio-controlled locomotive to be in charge of the extra units.  It wouldn't be distributed power in the context of shared power, but rather it would be a second section that is physically connected to the lead consist, and the second locomotive would be radio-controlled by the lead locomotive's engineer.

The physical connection between the tail end of the lead segment and the second locomotive would have to be arranged in such a way so that there is no chance of the second locomotive pushing on the lead consist (in violation of the prohibition of using pushers on TOW's), only pulling the trailing consist.  Thus, the emergence of the "cushion car".

This strikes me as a rather Rube-Goldbergian way of lengthening a RoadRailer train beyond 150 trailers, at the very least it would tax the skills of the engineer since he would have to watch the second locomotive very closely to avoid pushing on the RoadRailers ahead of it.  A "cushion" car would make little real difference in avoiding potential pushing problems unless the cushioning devices on the frame were more sensitive to shock than what's currently on the market, and what would happen when the cushioning devices were pushed in to their maximum travel? 

 

Perhaps the potential economics of 150+ unit RoadRailer trains is simply overcome by degradation of service / handling at origin & destination

[rrnut282]

The "cushion car" would have to be connected to the pushing unit to shut it down when the slack is completely compressed. 

Again, why is there a need for this?  A TC (or Roadrailer, if you prefer) train comprised of (150) 53' trailers is 7950 feet long without locomotives. (Actually it is longer, I'm not counting the tongue.) Going longer means you start to eliminate potential meets due to siding lengths.  This tends to greatly reduce the capacity of the mainline as trains are held in non-optimal locations.  The costs are starting to outweigh any benefit.

Go low-tech and run a second section like the good old days.  No cushion car to deadhead back and forth as needed and the conductor doesn't have to walk 4 miles every time the ET needs reset.

[CSSHEGEWISCH]

Why would a Roadrailer train need Distributed Power Units?  They have ample H.P/Tonnage ratios. 

It has nothing to do with horsepower to tonnage ratios.  Rather, if one wishes for a bi-modal consist to exceed 150 units (the max allowed under FRA rules), one would need to employ a radio-controlled locomotive to be in charge of the extra units.  It wouldn't be distributed power in the context of shared power, but rather it would be a second section that is physically connected to the lead consist, and the second locomotive would be radio-controlled by the lead locomotive's engineer.

The physical connection between the tail end of the lead segment and the second locomotive would have to be arranged in such a way so that there is no chance of the second locomotive pushing on the lead consist (in violation of the prohibition of using pushers on TOW's), only pulling the trailing consist.  Thus, the emergence of the "cushion car".

This strikes me as a rather Rube-Goldbergian way of lengthening a RoadRailer train beyond 150 trailers, at the very least it would tax the skills of the engineer since he would have to watch the second locomotive very closely to avoid pushing on the RoadRailers ahead of it.  A "cushion" car would make little real difference in avoiding potential pushing problems unless the cushioning devices on the frame were more sensitive to shock than what's currently on the market, and what would happen when the cushioning devices were pushed in to their maximum travel? 

[Anonymous]

Why would a Roadrailer train need Distributed Power Units?  They have ample H.P/Tonnage ratios. 

It has nothing to do with horsepower to tonnage ratios.  Rather, if one wishes for a bi-modal consist to exceed 150 units (the max allowed under FRA rules), one would need to employ a radio-controlled locomotive to be in charge of the extra units.  It wouldn't be distributed power in the context of shared power, but rather it would be a second section that is physically connected to the lead consist, and the second locomotive would be radio-controlled by the lead locomotive's engineer.

The physical connection between the tail end of the lead segment and the second locomotive would have to be arranged in such a way so that there is no chance of the second locomotive pushing on the lead consist (in violation of the prohibition of using pushers on TOW's), only pulling the trailing consist.  Thus, the emergence of the "cushion car".

[rrnut282]

Why would a Roadrailer train need Distributed Power Units?  They have ample H.P/Tonnage ratios. 

For example the power evolution on NS out of Fort Wayne to Atlanta was a single GP50 (about 3600HP?) when trains were 75 and 100 trailers.  When TC trains went to 125 trailers they added a GP38 to most trains.  Now the 150 trailers are pulled by two 4000HP units as a general rule.  Just yesterday I saw 135 trailers being pulled by a single SD70-2 that seemed to have no problem making track speed.

[VPayne]

  It seems the Roadrailer Mark V (separate bogie) has a few disadvantages, a relatively high draft/buff line of around 50 some inches as opposed to 34 some inches and the need to make blocks up from tail to front (a lack of random access). I don't really see the weight penalty as an issue as the nearest competitor, the domestic 53'x102" container has a significant weight penalty due to the chassis + container combo weighing too much while a AAR semi-compatible 53'x102" trailer must sit atop a quite heavy railcar in a single stack configuration.

  The high buff/draft line is what makes the trains a little more likely to stringline but then again the relatively low Center of Gravity helps. However, with no random access the sorting that can be done in route is somewhat limited unless the train is completely taken apart. For shorthaul traffic over a route system made up of a star a lot of sorting needs to be done unless the trailers are divided into two blocks, which I think Triple Crown has started to do with the Roadrailer drawbar meant to join the ends of two trailers.

  However, the terminals still require a lot of bogie jockeying and a groundsman cranking the sandpad legs up or down and making the air connections. It seems that the ideal intermodal system needs to combine a lot of things:

Standard 53' trailers can be used - CPR's Expressway has done this,  but.

1. Random access for sorting of trailers without breaking the train, CPR's Expressway cannot do this.
2. A simplified terminal procedure which is no more difficult than backing a trailer to a loading dock and securing it, this way OTR drivers could also load trailers.
3. Low Center of Gravity to allow for a lighter car, right now the low centered mass of the railcar keeps the TOFC loads on the rails.
4. A draft/buff line at current levels or lower.

[edbenton]

FM I personally have seen a trailer heavier in construction than a roadrailer buckle from hitting a dock.  Try having a train of them with a DPU if and when one hits the ground you are talking a huge mess basically get the gons and the big end loaders to pick up the mess.  You are talking trailers that are designed to have the load supported by the walls they have no structure in the floor or sides to speak of.  I have seen plate side trailers which are what road railers are based on break from to road vibrations.  The only differance in a road-railer and a regular plate side is the nose plate with the coupler nose and the rear door plate also the air lines for the brakes on the RR wheels.

[Modelcar]

...Does any RR have such "absorber" car or do they even exist now....?   Probably not.  Would it be too risky to have a consist "connected" together and be guaranteed that too much "force" might find it's way to the roadrailer cars ahead and cause a failure of one or more....causing a massive derailment.

Braking and throttle control would have to be controlled with a fine threaded adjustment so as not to over run the first part of the train, etc....Do such fine adjusted controls exist to be able to do that....?

Sure sounds risky, of course the weak link being the "fragile" strength of the roadrailer type cars.  Seems to be a pretty high risk envolved to "save" the cost of another crew, hence being able to separate the trains.

[Anonymous]

Well, first let's explore if there is indeed a need for DPU's in bi-modal operations.

At a max of 150 units, a typical bi-modal train is around 8,000' - just about the limit for most current sidings.  But what if siding lengths of 10,000' or 12,000' become the norm, and railroads want to have all trains max out on length to satisfy the bean counters?  At that point, bi-modal is at a (further?) disadvantage to TOFC and COFC, because those types of trains can lengthen at will without any operational limitations.

Thus, for bi-modal to continue to have the full scale of operational competitiveness with other intermodal technologies, it will need to be able to run trains of 175 or even 200 units per consist, e.g. exceeding the current operational limits by 25 to 50 additional units.  That's where distributed power would come into play, and for DPU's to be effective they have to be a certain distance from the lead units, e.g. 1/3 of the way back in the consist.

Since there is a restriction on using engines as pushers for TOW's, a DPU used in bi-modal operations would have to be implemented in such a way that it is only pulling the trailing portion of the consist, and not pushing on the lead portion of the consist, right?  So a specialized railcar placed behind the transitional bogie of the lead portion of the consist and ahead of the DPU would function solely as an "absorber" of any and all buff force from behind, yet still allow the whole consist to be physically connected together.  The car may need to have a transmitter itself that sends a signal to the trailing unit to "back off" a bit on the throttle if buff force is too constant.

I wonder if that would satisfy the regulators enough to allow bi-modal operations in excess of 150 units?

[nbrodar]

I could see why an unmanned consist out on it's own is a bad idea, but why would a trailing consist that's say 100' behind the lead consist be a danger?  Maybe the possibility of a driver at an unmarked rail crossing instinctively starting out across the crossing without looking back past the first trailing consist?

A.) The signalling system won't allow it.  Under the current signal structure, the following section would get nothing but Restricted Proceeds and have to be able to stop within one-half the range of vision.

B.) How do you maintain the spacing?   How do tell if the second section is creeping up on you or dropping away?

C.) Operating rules require Point Protection outside of an RCO Zone.  ie Someone must see the leading end, and see the track ahead is clear.

D.) What happens when the second section goes into emergency, or hits a defect detector.  Or Worse yet, someone hits the train.  How do you know? 

Nick

[spokyone]

I could see why an unmanned consist out on it's own is a bad idea, but why would a trailing consist that's say 100' behind the lead consist be a danger?  Maybe the possibility of a driver at an unmarked rail crossing instinctively starting out across the crossing without looking back past the first trailing consist?

Yep! That happened in Spokane Valley one night 10 years ago when a cut of cars started rolling back to Yardley from Kaiser plant. The crew took off in pursuit and were about 300' behind when the hotpot truck crossed after the cut went by. No one hurt and the 2 pots did not rupture. The cut crashed into a E/B waiting for a signal.

[Anonymous]

There is no technological reason why a trailing unit physically separated from the lead consist cannot still be controlled by the lead unit.  So that leaves it to either a regulatory issue or the fact that no one has thought this up yet, since bi-modal operations are still a rare occurance.  Since there doesn't seem to be any cut and dried rules regarding DPU's in TOW's, only regs against pushers, my bet is on the latter.

Once you pull that pin...the DPU and anything behind it becomes a seperate train, requiring it's own crew.  

The government bans the use of unmanned/remote leading locomotives outside of an active Remote Control Operation Zone. 

Nick

I could see why an unmanned consist out on it's own is a bad idea, but why would a trailing consist that's say 100' behind the lead consist be a danger?  Maybe the possibility of a driver at an unmarked rail crossing instinctively starting out across the crossing without looking back past the first trailing consist?

As unconventional as it sounds, the idea of a "cushion" car in front of a DPU may not be all that far-fetched if indeed the viability of bi-modal operations is contingent on maximizing the number of units beyond 150, or in preventing stringlining around mountain curvature.  That would allow for a physical connection of the DPU with the lead consist, yet would prevent any variations in force between the trailing DPU and the lead engine's consist from crumpling one of the lead consist's trailers/chassis.

[nbrodar]

There is no technological reason why a trailing unit physically separated from the lead consist cannot still be controlled by the lead unit.  So that leaves it to either a regulatory issue or the fact that no one has thought this up yet, since bi-modal operations are still a rare occurance.  Since there doesn't seem to be any cut and dried rules regarding DPU's in TOW's, only regs against pushers, my bet is on the latter.

Once you pull that pin...the DPU and anything behind it becomes a seperate train, requiring it's own crew.  

The government bans the use of unmanned/remote leading locomotives outside of an active Remote Control Operation Zone. 

Nick

[Anonymous]

Then again, I suppose there's some other antiquated FRA rule that requires DPU's to be physically connected to the controlling engine!  Well, then how about a "cushion car"?  This would be an intermediate unit placed behind the trailing unit of the forward portion of the consist and ahead of the trailing DPU locomotive.  It would have no real buff or draft resistance, but instead would allow for some "play" between the trailing TOW and the first DPU locomotive.

FM really needs to do his homework on this issue.  If such a rule even existed, DPU and its predecessors could not be operated in the first place since by definition there was no direct physical connection between the controlling(master) unit and the remote (slave) units because of the intermediate freight cars.

Paul, do you ever get tired of trolling?

Do you even know what you're talking about?  DPU's are radio controlled, not by physical connection with the lead units (as in a typical locomotive lash-up).  There is no technological reason why a trailing unit physically separated from the lead consist cannot still be controlled by the lead unit.  So that leaves it to either a regulatory issue or the fact that no one has thought this up yet, since bi-modal operations are still a rare occurance.  Since there doesn't seem to be any cut and dried rules regarding DPU's in TOW's, only regs against pushers, my bet is on the latter.

 

[CSSHEGEWISCH]

Then again, I suppose there's some other antiquated FRA rule that requires DPU's to be physically connected to the controlling engine!  Well, then how about a "cushion car"?  This would be an intermediate unit placed behind the trailing unit of the forward portion of the consist and ahead of the trailing DPU locomotive.  It would have no real buff or draft resistance, but instead would allow for some "play" between the trailing TOW and the first DPU locomotive.

FM really needs to do his homework on this issue.  If such a rule even existed, DPU and its predecessors could not be operated in the first place since by definition there was no direct physical connection between the controlling(master) unit and the remote (slave) units because of the intermediate freight cars.

[Anonymous]

I take it then that TOW rules were developed specifically for the RoadRailer technology, and have been subsequently applied to the superior RailRunner technology as well, even though the RailRunner system has operational advantages that would seemingly allow for reverse moves, distributed power, et al.

...

I had an old RailRunner VHS tape that showed the product being tested at Pueblo, and I seem to remember a mention of this buff/draft strength and flexibility.  I wonder if RailRunner tried to get an exemption from the current antiquated rules for TOW's and was turned down?

The TOW rules deal specifically with RoadRailer type equipement. There's actually a list of banned and allowed trailer numbers in the rule book.

Not being something we run, I haven't seen any rules dealling specifically with RailRunner. Looking at the RailRunner, I image they could fall under the rules for the old TTOX Front Runner cars.

Nick

I would think the TTOX had more buff and draft specs than the RailRunner bi-modal chassis, if for no other reason than the weight differential favors a more rugged TTOX over RailRunner (25,000 lbs vs 9,000 lbs for RailRunner sans bogey weight).

Here's an idea!  Why not allow bi-modal DPU's to run physically separated from the preceding portion of the consist?  That way, there's no chance of a crumpling push from behind unless the lead consist just plain stops dead in it's tracks.   Since DPU's are controlled by radio, is there really any need for physical connection to the other segments of the train, other than assisting with air supply and braking?

Then again, I suppose there's some other antiquated FRA rule that requires DPU's to be physically connected to the controlling engine!  Well, then how about a "cushion car"?  This would be an intermediate unit placed behind the trailing unit of the forward portion of the consist and ahead of the trailing DPU locomotive.  It would have no real buff or draft resistance, but instead would allow for some "play" between the trailing TOW and the first DPU locomotive.

[oltmannd]

Here's an update on handling TOW equipment...

TOWs must not operate with other freight cars, except intermodal.  When handled in intermodal trains, the TOW equipment must be on the rear, and the total train tonnage may not exceed 5000 tons. 

You cannot shove against TOWs (as in helper service).  Which I take to mean you can't use DPUs.  However, we don't use DPUs so I don't have any rules governing thier use and can't be absolutely sure. 

Your not suppose to make reverse movements with TOWs at all, unless absolutely necessary.  If you must shove TOW equipment, you may only have one unit online, and make the move at no more then 10 MPH.

Nick

I take it then that TOW rules were developed specifically for the RoadRailer technology, and have been subsequently applied to the superior RailRunner technology as well, even though the RailRunner system has operational advantages that would seemingly allow for reverse moves, distributed power, et al.

If you recall, RoadRailers are assembled in "elephant-style" configuration - the front of a RoadRailer trailer is connected to the rear of the preceding trailer, which itself is resting on top of the bogie.  That in and of itself is probably why push moves might dislodge the rear of the trailer from the bogie.

RailRunners are directly connected to the bogie front and back - there is no contact with the other trailers/chassis.  This double bayonette configuration of the bogie allows for bi-directional moves.

I had an old RailRunner VHS tape that showed the product being tested at Pueblo, and I seem to remember a mention of this buff/draft strength and flexibility.  I wonder if RailRunner tried to get an exemption from the current antiquated rules for TOW's and was turned down?

They can exempt all they want to. But the bottom fact is that trailers will fail. All you got is a aluminum skeleton much like open grid benchwork, two load rails, trailer wheel and frame assembly and planks all the way to the 5th wheel king pin plate. That plate is the strongest item on the entire rig. Everything else will fail if you applied the pressures found in regular trains to it.

If you installed a DF underframe to it to make it work, the weight gain will make it so obese that it's no good for hauling cargo anymore; all you can put in there is toilet paper or pre-made popcorn in boxes.

The walls are crappy, you can gut them with a good circular saw and the roof is nothing more than a thin sheet of something plastic to keep the rain off.

maybe one of those fancy european coupler cars on 4 wheels with a 5th wheel on one end and a standard coupler on the other with a tandem well... you would have constant shortages of them similar to chassis.

You are speaking of RoadRailer vans.  I'm speaking of RailRunner chassis.  According to the RailRunner website, the 40' chassis is rated for 400,000 lbs of rail draft and buff forces, which means that one could place.....well, maybe 10 units in front of a pusher.  As for balanced power via DPU's, unless there's a risk of one engine konking out............

RoadRailers are good for 400,000# buff and draft, too.

[snagletooth]

     OK, so roadrailers sound kind of wimpily built compared to a regular freight car.  Has anybody ever crinkled any of them, through mis-handling?

Oh yes it happens all the time. Hi-way trailers just arnt suited to railroad use

P

 

OOH YES! Ive spen t many an hour looking for containers and trailers thet didn't have "holes" in the roof from bad lifter's. CR being the worst. They drop them cranes wrong and BOOOM,and four BIG hol.es in  the roof, can't haul that to the customer!
Awe well, at least I hauled for PTL, got  45's and 48" out of CR 47th  for "Bulk Mail" knowing I was hauling it down to Streator. HEHE, The DS used to work for  PTL HEHE!  I was once so tired I claimed Streato, he came back, " You mean bulk mail, Right!".

"Oh yeh, Bulk Mail! I'm with PTL, Right!"