wasdDidn't Expressway take ages to load/unload?
Any circus-type arrangement that does not carry its own power inherently does. Dividing a train into rakes lowers this, but not always 'net' of switching and tie-down time and cost. Trailers must be precisely backed down, then parked and the tractor extracted before the kingpin hitch can be raised and adjusted; on arrival the special hydraulic-lift yard tractors have to back in and bind on sequentially.
The specialized Expressway flats have fixed side rails, which is nifty for train ferries or Braille backing-down but not great for side access or turning by yard tractors (see Flexi-Van) which would allow gang unloading easily -- the more important time constraint. Personally, I don't think any system that relies on specialized driver skill is likely to have higher take rate over one that is drop-hook with experienced 'yard' tractor crews with specialized equipment. That will likely persist into a more autonomous age, where specialized equipment to gang-access vans won't be at all what suits long-distance, and designing machines to do both well -- while certainly possible -- will be no more successful than RailRunners.
bogie_engineer It made it unattractive to develop new and better devices, rather only cheaper versions of the same old thing, which is why we are still using the 3 piece truck in spite of it's well known deficiencies. Dave
It made it unattractive to develop new and better devices, rather only cheaper versions of the same old thing, which is why we are still using the 3 piece truck in spite of it's well known deficiencies.
Dave
Speaking of bogies. Check this one out.
https://news.cision.com/skf/r/skf-collaborates-with-ats-to-develop-solutions-to-reduce-life-cycle-cost-for-rail-freight,c2774160
http://advancedtrucksystems.com/
wasd SD60MAC9500 While the LOHR system has it attributes it’s still more expensive to operate than CP’s former Expressway service. Which is the best solution to short haul IM domestically. Didn't Expressway take ages to load/unload? Technology is not as important though. Short haul TOFC is the next frontier for railroads. They need to learn lessons from Europe to make it work.
SD60MAC9500 While the LOHR system has it attributes it’s still more expensive to operate than CP’s former Expressway service. Which is the best solution to short haul IM domestically.
Didn't Expressway take ages to load/unload? Technology is not as important though. Short haul TOFC is the next frontier for railroads. They need to learn lessons from Europe to make it work.
Approx. 90 mins to load/unload Expressway trains. One thing you have to remember. The Euro operators don't own the RoW so they can be more flexible on cost. Two different operating theaters which require different solutions. So what works in Europe will not always work over here and vice versa..
Learn from Europe (or anywhere else)? Given the management, that's unlikely.
SD60MAC9500While the LOHR system has it attributes it’s still more expensive to operate than CP’s former Expressway service. Which is the best solution to short haul IM domestically.
wasd greyhounds What's needed is an intermodal system that can use lower cost terminals and that just ain't double stack. I'd suggest a psedo TOFC circus loading operation using containers on chassis for serving places such as Storm Lake. https://youtu.be/MTvSOrTXFzw There. Solved your problem. These train sets can be loaded and unloaded in half an hour and can carry any trailer without the need for craneable trailers or any other special equipment. I can already think of a few corridors. Montreal-Toronto sticks out most in my mind. This essentially solves short-haul intermodal and does what roadrailers could never do.
greyhounds What's needed is an intermodal system that can use lower cost terminals and that just ain't double stack. I'd suggest a psedo TOFC circus loading operation using containers on chassis for serving places such as Storm Lake.
https://youtu.be/MTvSOrTXFzw
There. Solved your problem. These train sets can be loaded and unloaded in half an hour and can carry any trailer without the need for craneable trailers or any other special equipment.
I can already think of a few corridors. Montreal-Toronto sticks out most in my mind. This essentially solves short-haul intermodal and does what roadrailers could never do.
While the LOHR system has it attributes it’s still more expensive to operate than CP’s former Expressway service. Which is the best solution to short haul IM domestically.
greyhoundsWhat's needed is an intermodal system that can use lower cost terminals and that just ain't double stack. I'd suggest a psedo TOFC circus loading operation using containers on chassis for serving places such as Storm Lake.
SD60MAC9500The problem with IM (Logistics in general) is trying keeping load balance. Remember why UPS started Martrac now UPS Logistics.
Well, it's "A" problem but not "The" problem. Balance is desired and often much needed, but it's one of many considerations.
We handled Martrac reefer TRAILERS over our Sioux City TOFC terminal. UPS has a major facility in Sioux Falls. We'd move UPS parcel loads west from Chicago to Sioux City, then they'd truck 'em on up to Sioux Falls for sorting. Much, but not all, of this UPS westbound parcel traffic was in their Martrac reefers. (Reefer unit not running westbound.) Then they'd use those reefer trailers to haul red meat east. It worked like a charm.
Overmod What then is needed is effective infrastructure and methods to load bulk goods like grain into well cars, and double-stack if the operating model permits it; this can be done for example with collapsible grain containers with enough structural integrity to be stacked loaded, and carried modularly in twistlocked-together multiples when deadheading back. Even a simple portal gantry at an elevator gives you the ability to fill and stage these for consolidated movement and, probably, effective block building for PSR moves 'down the line' with no additional issue than for any other stack equipment. Yes, one of the arguments for stack buildout in quantity was that it would be suited for bulk 'bridge' moves of offshore boxes to inland ports, to relieve congestion ... and wipe the eye of longshoremen's unions somewhat. There is a potential reverse use of the idea, which is to use low wells with either COFC or TOFC-with-gang-unloading as a bridge from staging points into congested areas for last-mile truck delivery, and then facilitate removal from arterial roads.
What then is needed is effective infrastructure and methods to load bulk goods like grain into well cars, and double-stack if the operating model permits it; this can be done for example with collapsible grain containers with enough structural integrity to be stacked loaded, and carried modularly in twistlocked-together multiples when deadheading back. Even a simple portal gantry at an elevator gives you the ability to fill and stage these for consolidated movement and, probably, effective block building for PSR moves 'down the line' with no additional issue than for any other stack equipment.
Yes, one of the arguments for stack buildout in quantity was that it would be suited for bulk 'bridge' moves of offshore boxes to inland ports, to relieve congestion ... and wipe the eye of longshoremen's unions somewhat. There is a potential reverse use of the idea, which is to use low wells with either COFC or TOFC-with-gang-unloading as a bridge from staging points into congested areas for last-mile truck delivery, and then facilitate removal from arterial roads.
CN, CP, BNSF, and UP backhaul grain in sea boxes already, and have been doing so for years. CN is the leader in this category. No need for specialized boxes. Santa Fe A-Stack fuel foiler contianers were designed for this and didn't catch on for this very reason. Diningcar can fill us in on the former. The problem with IM (Logistics in general) is trying too keep load balance. Remember why UPS started Martrac now UPS Logistics.
Convicted One Here is a study done for the State of Nevada just a few years ago, where they were considering an attempt to duplicate that success, which I believe is very informative, even in it's analysis of the expanded Panama Canal, and the burden placed upon east coast ports if they are to accomodate the Panamax ships https://rcg1.com/wp-content/uploads/2013/05/Final-Nevada-Inland-Port-Report2.pdf
Here is a study done for the State of Nevada just a few years ago, where they were considering an attempt to duplicate that success, which I believe is very informative, even in it's analysis of the expanded Panama Canal, and the burden placed upon east coast ports if they are to accomodate the Panamax ships
https://rcg1.com/wp-content/uploads/2013/05/Final-Nevada-Inland-Port-Report2.pdf
There were a few people in key places such as Jorge Illueca down in Panama that opposed the widening of the canal. Who instead championed using our rail network for land bridge service instead. To answer you're earlier question about single stacks. That's due to weight. Example a Maxi-Stack 1 has 5-40' wells with a GRL of 802K. A Load Limit of 619K. If you have ten 20' ISO boxes that together weigh 619K. You're only going to be able to load those ten 20's.
OvermodI am tempted to disagree slightly with greyhounds about areas with more 'distributed' loading not benefiting from stacks. Once the equipment has been built, its opportunity-use cost effectively becomes lower than 'if the equipment were bespoke for that purpose (or, as greyhounds said, needs to carry some "fair share" of the whole of the overhead costs. As older generations of stack equipment are replaced in intermodal, they remain useful for other traffic; the situation is comparable imho to the current use of early-generation TGV to provide cheap service.
No way. There is no such thing as a "fair share" of overhead. "Fair" is a clearly defined concept in the game of baseball. A "Fair Ball" is between two brightly marked lines on a defined playing field. Anywhere else "Fair" beomes a subjective term.
It's the marginal revenue vs. the marginal cost relationship that counts. Allocating in a "Fair Share" of otherwise unavoidable fixed and/or joint cost will produce the wrong answer every time. It's been said that railroads cannot follow the desired profit maximization, and society benefit maximization, method of pricing at the margin (where marginal cost = marginal revenue) because their marginal costs are always lower than their average costs. They'll go broke doing that. But, I've not said price at marginal costs. The rails have to be priced above that. But (another one), if you start throwing in unrelated and unaffected costs to arbitrarily cover a required "Fair Share" of such costs you'll get the wrong answer every time.
I'll agree that cascading older equipment in to less demanding service will reduce the marginal costs. But, it's not the equipment cost that's the issue. It's the terminals. Building a double stack facility in Storm Lake, IA is going to be expensive. But the Storm Lake area does generate a whole lot of long haul business consisting of pork, turkey, and eggs. This moves by truck to coastal population centers.
What's needed is an intermodal system that can use lower cost terminals and that just ain't double stack. I'd suggest a psedo TOFC circus loading operation using containers on chassis for serving places such as Storm Lake. In Chicago the containers can be delivered to various eastern and southern double stack services by rubber tire interchange. Fast and efficient. The empty containers on chassis return to Storm Lake. When taking a risk, go cheap.
But we've got to look at the marginal costs vs. marginal revenue relationship to judge this. Throwing in a "Fair Share" amount of unaffected costs will always, always, always produce the wrong answer. And it will leave the traffic to the truckers.
And I'm still waiting for Charlie Hebdo to specifically say just what about my accounting knowledge is lacking. He can't. He just made that up. As is his wont. How much time has he spent dealing with bogus cost accounting? How many graduate level accounting courses has he taken? But he says my knowledge is lacking. He's just trying to smear me.
I am tempted to disagree slightly with greyhounds about areas with more 'distributed' loading not benefiting from stacks. Once the equipment has been built, its opportunity-use cost effectively becomes lower than 'if the equipment were bespoke for that purpose (or, as greyhounds said, needs to carry some "fair share" of the whole of the overhead costs. As older generations of stack equipment are replaced in intermodal, they remain useful for other traffic; the situation is comparable imho to the current use of early-generation TGV to provide cheap service.
As far as the "mystery" as to why some well cars are only loaded one container high, I was always under the impression that extremly high value contents were sometimes loaded this way because it is impossible to open the doors of the car in the well?
Personally, I believe that as a driving force, it was seen as cheaper to raise the clearances of a few tunnels than to build longer passing sidings all across the country.
Additionally, rail has the capacity to carry more weight per unit of length than truck, and double stacking was a means to exploit this inherent advantage.
30 years ago I worked with a guy who had been in Southern Pacific's real estate wing, and to listen to him tell the story, double stack was created because Southern Pacific owned a substantial amount of land in Nevada that it wanted to sell to companies who were weary of California's high real estate costs, (inland ports) and to make that program work, double stack was a necessary part of the equation. Raising tunnel clearances, thus allowing double stack, made the rest of the pieces come together. This guy pretty much had the outlook that the main reason the earth spun was to give him a better view of the night sky....so his thoughts have to be taken with a grain of salt, but nonetheless, there are probably a few grains of wisdom one can distill out of that.
charlie hebdoInteresting views but I think jbs1 might enlighten us better on cost accounting. Several of your comments suggest your knowledge of proper accounting is not very thorough.
OK, just what comments are you talking about? Or are you following your ususal path of just making stuff up to slam other people.
What a 'pure accountant' might consider proper and what those operating the business might consider proper are two separate things.
Never confuse one with the other.
Never too old to have a happy childhood!
Interesting views but I think jbs1 might enlighten us better on cost accounting. Several of your comments suggest your knowledge of proper accounting is not very thorough.
This is one of those "Where do I start and where do I go threads." It deals with the very real cost savings of double stack and, simultaneously, with the cost savings as shown by cost accounting. They are in no way the same thing. It seems most people think cost accounting is a very cut and dried procedure that produces an accurate number that you can put in the bank. It ain't no such thing.
In reality there are fixed and joint cost that tend to get allocated as in: "There are seven switch engines in Louisville and somebody's got to pay for them." The cost accounting was allocating costs to intermodal that intermodal didn't use. But, hey, somebody's got to "Pay for them." By allocating cost to a service that didn't actually incur the cost the accounting was running the railroad out of business.
We were price takers, not price setters. What we could charge was determined by truck competition. If the allocated cost was above what we could charge we lost the business. The allocated cost had nothing to do with the actual cost, but such accounting would show a loss on business that actually sent money to the railroad's bottom line. If we backed out of such business, due to "loosing money" the allocation would go to other rail business and increase their accounting cost. Then that business would also be lost due to price and the cycle would repeat. That's a formula for going out of business.
Cost accounting is a can of worms in a lot of businesses. It's particularly wormy in railroading due to the large fixed and joint costs which cannot be accurately assigned. I never saw any railroad cost accounting that included "wind resistance." It all related back to tonnage. As in, just relate the line haul cost back to the tonnage moved by dividing total costs by tons moved. Tis garbage.
Remember that double stack was conceived and designed as a method of moving large volumes of import containers from one location, the port, to another inland location. It works very well for this and it does reduce the costs of such movements. It reduces the tare weight to be moved in relation to the payload moved. This saves money in terms of fuel, locomotives required, wear on track, etc. It also allows trains to carry more containers per given train length. This produces significant labor savings.
Double stack also works to produce real savings in the terminals. A given terminal track can hold more revenue loads. Urban land is expensive and being able to take a terminal up instead of out is a cost benefit. The railroad can also stack the containers in the terminal making better use of limited space. They don't have to fight, and these days it is a fight, to buy additional land for terminal space.
Double stack also works well for domestic freight on lanes that also serve the port traffic. i.e., Los Angeles-Chicago and Los Angeles-Dallas/Houston. It can also work in some few other lanes, but it does not work well for serving important producing areas such as western Iowa. These areas produce a lot of freight but it's not in the huge volumes generated by ports. The railroads cannot aggregate the freight from these areas in to the huge double stack trains. They could put money on the bottom line serving these areas, but not with traditional double stack service. So, they give up and simply do not try.
After all, their cost accounting will make the business from those origins pay for things the traffic does not use. As in the case of the Louisville switch engines.
There's a fairly hard limit on reducing tare weight in spine cars that don't operate in dedicated relatively short trains, for reasons demonstrated or worked out by the time of the Portager experiments. You can't get much lighter than the FuelFoiler 10packs with load'bearing either on the trailer axles (an iffy thing for a variety of reasons) or on the kangaroo pockets, and you're into the tare-weight range of the lighter well cars (which can use bridge-type and hollow-box construction in the well sidefames and are aggressively lightened almost to the point of fragility in well-bottom material, walkway and platform structure, and equipment mounting).
Part of the revolution comes with twistlock corner-casting economies, too. Van trailers in typical TOFC have to be reinforced to be lifted by these, and it is just as much mandatory to lift a van off an 'advanced' spine car as to lift it out of an articulated well suitable for other traffic. Once you have the specialized handling equipment for ISO containers sufficiently built out with, say, sea-land bridge operations, and suitable third-party and aftermarket support assured, a great deal of what can only be achieved 'cheaply' in more proprietary or operationally-limited approaches ... including my beloved lateral sideloading means for containers ... become financially less preferable.
Note that a great deal of facile and sometimes thoroughly thought-out ingenuity has been directed at the issue of aerodynamic gaps between containers in articulated sets. One example was supports on adjacent cars that would take a sort of lightweight high-cube 20' unit, which would circulate in a kind of parallel traffic with marine-container stacks, articulated over two coupled car-ends of well equipment. In practice this was about as valuable as the expensive Ericsson (I think it might have been Sony-Ericsson doing the actual "thinking") and Lucent research into 'utilizing the silence' in digital voice by aggressively compressing the 35-odd-bit packets comprising a given call stream. And a moment's reflection on the actual sources of drag on a well train would tell you why, just as it would tell... well, really anyone actually interested in gasdynamics... why the various flavors of Arrowedge were a misguided scam. (Incidentally the reported damage was the culmination of quite a bit of wrong wishful thinking about how the streamlines ought to have gone leading to the avoidance of positive twistlocks -- a bit like what made Beauvais cathedral collapse the first time, but I digress...)
One semi-practical solution is to make inflatable shaped dunnage bags that attach to collapsible frames that go on the four casting holes on the end of a container, and then inflate them with something like tapped reservoir air. This can be adapted to singles in wells or to drop with appropriate spoiling effect down from upper contunuity in stacks to some of the irregular lower gaps, and it is not rocket science to provide RFID-style radio 'deflate' valves for intermediate handling. You will note that if I can think of this, many with a far more pressing interest in shaving tenths of a percent off operating cost -- and both the authority and means to build up the equipment, trining, etc. to put it in practice -- will also have done so, and would have tried it somewhere in the nearly 40 years of increasing stack demand.
It should not be a surprise that the main benefit of doublestacking was to cram more boxes into the same length of train.
As for tare weight, a quick look at Greenbrier's website shows that their current 89' flatcar design weights 83,000 lbs, while their single 53' well car weighs 55,000 lbs. A 3 or 5-pack's tare weight per carbody would be a few tons less, due to having fewer trucks. Ditto for 40' wells due to their shorter length.
Air resistance can be minimized by loading a train with as many doublestacked cars together as possible, or but putting a 53' container on top of a 40' container to minimize the gap. That's not always possible, but every little bit helps.
I would think that the gap under the trailer creates a significant amount of air resistance friction. Placing trailers in well cars could help eliminate this, though perhaps the higher tare weight of the well car over the spine car would outweigh this benefit. CN used to do this on intermodal trains in eastern Canada, so they would fit through the old St. Clair River tunnel.
These benefits of doublestacking were both apparent and well known in the industry before Hunter Harrison ever came to Canadian National.
Greetings from Alberta
-an Articulate Malcontent
Backshop Paul Milenkovic SD60MAC9500 Summary of APL initiating stack train service. Pay attention to the second part as it explains the imbalance of traffic flows. Also later in the summary how stack trains have reduced cost. The linked article claims reduced fuel consumption on account of reduced tare weight relative to what -- 89' COFC/TOFC cars taking a pair of 40' boxes at the time? Whether the tare weight reduction is that great over an articulated spine car needs to be considered. I argued that a double stack, because of its height and because of large gaps between containers, must have an aerodynamic penalty over single-level. I get that in most freight operations, weight, especially in overcoming grades is the dominant factor in fuel consumption. But intermodals are the fastest freight trains out there, and the aerodynamic fuel penalty of piggyback is regarded as substantial. I would be suprised if double stack is more fuel efficient than piggyback given the height and the gaps. Obviously, the "know nothing idiots" working for the railroads disagree.
Paul Milenkovic SD60MAC9500 Summary of APL initiating stack train service. Pay attention to the second part as it explains the imbalance of traffic flows. Also later in the summary how stack trains have reduced cost. The linked article claims reduced fuel consumption on account of reduced tare weight relative to what -- 89' COFC/TOFC cars taking a pair of 40' boxes at the time? Whether the tare weight reduction is that great over an articulated spine car needs to be considered. I argued that a double stack, because of its height and because of large gaps between containers, must have an aerodynamic penalty over single-level. I get that in most freight operations, weight, especially in overcoming grades is the dominant factor in fuel consumption. But intermodals are the fastest freight trains out there, and the aerodynamic fuel penalty of piggyback is regarded as substantial. I would be suprised if double stack is more fuel efficient than piggyback given the height and the gaps.
SD60MAC9500 Summary of APL initiating stack train service. Pay attention to the second part as it explains the imbalance of traffic flows. Also later in the summary how stack trains have reduced cost.
Summary of APL initiating stack train service. Pay attention to the second part as it explains the imbalance of traffic flows. Also later in the summary how stack trains have reduced cost.
The linked article claims reduced fuel consumption on account of reduced tare weight relative to what -- 89' COFC/TOFC cars taking a pair of 40' boxes at the time? Whether the tare weight reduction is that great over an articulated spine car needs to be considered.
I argued that a double stack, because of its height and because of large gaps between containers, must have an aerodynamic penalty over single-level. I get that in most freight operations, weight, especially in overcoming grades is the dominant factor in fuel consumption. But intermodals are the fastest freight trains out there, and the aerodynamic fuel penalty of piggyback is regarded as substantial. I would be suprised if double stack is more fuel efficient than piggyback given the height and the gaps.
Obviously, the "know nothing idiots" working for the railroads disagree.
I never called anyone a name. I asked questions on whether the double-stack technology is optimum with respect to all of the variables involved.
The "guys in charge" have been known to make bad decisions. There are manifold business case studies of such a thing. Precision Scheduled Railroading is a controversial practice for which industry insiders on this forum claim as much.
I have asked questions of other Forum participants regarding the PSR question, and people have been patient in their replies.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
oltmannd The early stack trains were the brainchild of American Presidents Line. (APL). They got the SP and later the UP interested in runnind double stack trains of marine containers. Stack trains have really good load/tare ratio, conserve terminal pad track space, and allow trains to fit into more passing sidings.
The early stack trains were the brainchild of American Presidents Line. (APL). They got the SP and later the UP interested in runnind double stack trains of marine containers. Stack trains have really good load/tare ratio, conserve terminal pad track space, and allow trains to fit into more passing sidings.
That's the same story I heard when working at American Steel Foundries in 1991. ASF's development of the articulated connector was a factor in making it work and made ASF lots of money. I can't recall the name of the driving force at APL, but he was well known and respected in the industry. The AAR was incredibly slow to allow the double stack cars in interchange service so as I heard the RR's operated them by inter-line agreement as AAR dragged it's feet in approving the car design.
What I saw during my time on the freight car side of the RR industry was that the AAR would delay and delay issuing approval of new design components until a second supplier had developed a competing device, at which point the rail equipment buyers could get the suppliers bidding against each other to lower the price. It made it unattractive to develop new and better devices, rather only cheaper versions of the same old thing, which is why we are still using the 3 piece truck in spite of it's well known deficiencies.
If you can beg, borrow, or scan one, get a copy of the November 2011 TRAINS magazine!
EVERYTHING you EVER wanted to know about the history of double stack trains is in there!
In particular, an article by one of the key people in development of double stack - Dave DeBoer - wrote a significant article show the who, what, when and how it all came together in the 1970s and 1980s. The entire issue is a bonanza of intermodal must-read information!
When CSX opened its ramp at Chambersburg, PA about a decade ago - the track facilities were constructed with 13K feet of track for rail cars to service the facility. When the ramp was opened there were a number of locations, both on the Main Tracks from Cumberland to Cherry Run as well as on the Lurgan Sub to Chambersburg that caused loadings to be clearance restricted to single stacks. Plans were in progress to make the route available to double stacks. While the route was only being used with single stacks Chambersburg frequently had more than the alloted 13K feet of traffic and was routinely operating two trains in each direction, daily.
Once the clearance modifications were completed to allow double stacks - one train daily that was 9K feet or less easily handled to business.
JPS1 As I watched a double stack train with many JB Hunt containers pass through Temple, TX today, I got to wondering. Who came up with the idea? Was it the railroads or the truckers or both together?
RRs liked the operational cost savings and being able to avoid add pad track space to terminals, so they pushed all the intermodal customers to start stacking. Some of the premium customers pushed back - their operations were more flexible with TOFC equipment (UPS, LTL carriers, etc.)
Now, we have all steamship and a big chunk of truckload traffic moving in stacks with a relatively small amount of premium traffic and niche truckload stuff going TOFC.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Paul Milenkovic I never understood why the fractional improvement in containers per siding-constrained train length added up to an advantage over a number of disadvantages. For one, the number of containers is not doubled because there are gaps between container wells required for the trucks. I have also seen many a stack train where a goodly number of the cars are only loaded with a single stack of container. Two, it must have cost capital up front to insure that these excess height cars could fit under bridges on the routes involved, and there must be places these cars cannot go. Three, there must be a big boost in aerodynamic drag to have the loaded cars that tall and to have the large gaps between the containers. Four, I can understand that inbound ocean containers are served by a yard with gantry cranes, but the receiving intermodal terminals need either gantry cranes or Piggy Packers with a high reach. There are side-transfer options for single-level containers, which could reduce the cost of a terminal, allow for more local terminals and reduce the distance and hence cost of drayage (trucking) to the final distination. Five, with respect to the use of articulated well cars, the intermediate trucks are probably at weight/axle load limits -- evidence of this is the use of a larger wheel diameter that tolerates higher loading. In using articulated cars, the use of "3-packs" may have to do with the articulated trucks all being shared between one end car and one intermediate car that reduces the axles loading somewhat. Limiting the number of articulated cars as does the use of double-trucked well cars on 53-foot trailers also increases gaps and air resistance, which is a major contributor to fuel consumption of fast intermodal trains. The whole enterprise has a "feel" of optimizing one metric -- the number of loads per train -- without looking at all costs and the "big picture" of an intermodal train as part of a larger transportation system.
I never understood why the fractional improvement in containers per siding-constrained train length added up to an advantage over a number of disadvantages.
For one, the number of containers is not doubled because there are gaps between container wells required for the trucks. I have also seen many a stack train where a goodly number of the cars are only loaded with a single stack of container. Two, it must have cost capital up front to insure that these excess height cars could fit under bridges on the routes involved, and there must be places these cars cannot go. Three, there must be a big boost in aerodynamic drag to have the loaded cars that tall and to have the large gaps between the containers.
Four, I can understand that inbound ocean containers are served by a yard with gantry cranes, but the receiving intermodal terminals need either gantry cranes or Piggy Packers with a high reach. There are side-transfer options for single-level containers, which could reduce the cost of a terminal, allow for more local terminals and reduce the distance and hence cost of drayage (trucking) to the final distination.
Five, with respect to the use of articulated well cars, the intermediate trucks are probably at weight/axle load limits -- evidence of this is the use of a larger wheel diameter that tolerates higher loading. In using articulated cars, the use of "3-packs" may have to do with the articulated trucks all being shared between one end car and one intermediate car that reduces the axles loading somewhat. Limiting the number of articulated cars as does the use of double-trucked well cars on 53-foot trailers also increases gaps and air resistance, which is a major contributor to fuel consumption of fast intermodal trains.
The whole enterprise has a "feel" of optimizing one metric -- the number of loads per train -- without looking at all costs and the "big picture" of an intermodal train as part of a larger transportation system.
UP seems to operate in that manner, double stacks and singles, especially for international containers; single well and articulated cars; lots of power, front and midtrain.
diningcar In the 1970's Santa Fe's Engineering and Computer Programmers developed a train simulator program which, among other factors, analyzed wind resistence. It further determined which locations along what we now call the Southern Transcon were most vulnerable under 'normal'conditions. Thus the power could be added or reduced on certain operating districts, of course also dependent on other factors. No doubt that has all been refined through the years and helps to explain the success BNSF has along this 'transcon'.
In the 1970's Santa Fe's Engineering and Computer Programmers developed a train simulator program which, among other factors, analyzed wind resistence. It further determined which locations along what we now call the Southern Transcon were most vulnerable under 'normal'conditions. Thus the power could be added or reduced on certain operating districts, of course also dependent on other factors. No doubt that has all been refined through the years and helps to explain the success BNSF has along this 'transcon'.
Aside from the 1970's fuel crisis. Did any of this data help lead to the development of the fuel foiler concept?
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