What does intermodal trains mean exactly?

[MMLDelete]

XRR, if you missed this in a different thread, check out the mother of all intermodal trains! 

https://www.youtube.com/watch?v=jdIzRFOaTCY

[charlie hebdo]

AAR definition: Rail intermodal is the long-haul movement of shipping containers and truck trailers by rail, combined with a truck or water movement at one or both ends.

[cv_acr]

Short answer, containers and trailers.

The same shipping unit (the container) is travelling by truck, ship, rail, etc. (transportation modes) to get from shipper to destination without actually trans-loading the cargo in the unit.

A bulk load of grain would be intermodal if its loaded bulk in a container and the container is transferred from truck to rail to truck.

A bulk load of grain would NOT be intermodal if it's unloaded from a truck to a hopper car, and then unloaded again into a truck or trucks.

 

tree68

Perhaps one way to consider it is that the cargo can be moved from one mode to another without handling the cargo as such.

Coal moving from rail to barges may be changing modes, but you have to physically handle the coal to do so.  The same for the cargo in a boxcar.

Cargo in a container or trailer can be moved from one mode to another without regard to what those containers contain.  A container can be unloaded from a ship, placed on a train, then trucked to the final desination. 

+1

[tree68]

Lithonia Operator

...don't let some of our brethren here confuse you by over-complicating this.

Aww, what fun is that?  Does this mean we have to tell him about the super secret handshake, too?

But LO is right - sometimes we do get carried away with our explanations.  

[MMLDelete]

To our Newbie, xploringrailroads:

It's not complicated. If a container or semi trailer is on the train, that shipment is "intermodal." If the entire train is trailers and containers, it's an "intermodal train."

If a yardmaster decides to couple some auto racks onto the train, then it's primarily an intermodal train, but includes some auto racks. A mongrel of sorts.

XRR, don't let some of our brethren here confuse you by over-complicating this. If you see a whole train of containers and/or trailers, it's an intermodal train.

[MMLDelete]

daveklepper

But arent'n (weren't?) roadrailers (NS Triple-Crown) also "intermodal?"

 

Yes. It's just a variation of TOFC. Except in this case it's "TOFB" (trailer on bogie).

[daveklepper]

But arent'n (weren't?) roadrailers (NS Triple-Crown) also "intermodal?"

[tree68]

In today's parlance, I go along with the concept of containers or trailers.  

Perhaps one way to consider it is that the cargo can be moved from one mode to another without handling the cargo as such.

Coal moving from rail to barges may be changing modes, but you have to physically handle the coal to do so.  The same for the cargo in a boxcar.

Cargo in a container or trailer can be moved from one mode to another without regard to what those containers contain.  A container can be unloaded from a ship, placed on a train, then trucked to the final desination.

As Balt notes, autoracks are not intermodal, and were it not for PSR, would not be found on container trains.    

[Overmod]

To me, 'intermodal' involves the rapid or facilitated transfer of freight between modes as much as it does the added 'convenience' of providing a single-load ride from 'door to door'.

The early containerization projects at PRR and other roads in the '20s involved a very specific service: truckload LCL using a variant of swap-body for trucks.  That accounts among other things for the relatively small footprint and shape of the 'containers' involved.

Earlier, the service provided by the LIRR allowed farmers to load their wagons, bring them to a loading point, and then 'have them' at train destination to go the rest of the way to market ... usually renting a team to do so, which tells you something about contemporary intermodal draying, too.

Using marine containers to simplify unit or block swapping, and not much later to allow doublestacking, are capacity optimization in transit and lower costs or better handling speed at either end.  Many of the "innovations" in TOFC (some of which decidedly didn't work as well as expected!) involved reducing wind resistance, easier loading and unloading to close nose-to-tail spacing or precise placement over hinge/tiedown points, reducing overall tare weight, or trying to lift rather than drive the trailers to load and unload.

Usually but not necessarily, these operations hinge on easier or cheaper net loading and unloading, sometimes using very expensive equipment that can be 'amortized' over a large number of lifts or that allow quicker throughput or train turnaround.  In most cases one of the criteria for comparison is expense of stripping and stuffing pure rail vehicles, and this is still a bit different for boxcars or reefers than it is for 'automatic load or dump' for bulk cargoes like coal, grain, or taconite which might go from rail to ship 'expediently' as part of least-cost transportation.

An interesting intermediate comes in if you consider expedited storage as part of the intermodal operation, either for asynchronous dwell or for use as 'warehouse space' during a per diem period.  A great deal of somewhat misguided ingenuity has been used in making things like extensible jacking or landing legs for containers, or cockamamie mechanical systems for self-unloading ISO containers (sometimes as if they were Dumpsters) for the same sort of "demand" that those little one- and two-track circus ramps in places like Minden, Louisiana were supposed to fill.  That stuff might be competitive with setting out boxcars on team tracks ... but not necessarily with setting out covered hoppers and letting trucks come and go with air-transfer equipment.   

[Juniata Man]

I'll stand by my earlier post where I noted that intermodal means multiple modes are involved in the movement of a shipment. This definition - if you will - was drilled into my hard head by Colonel Robert Dudley when I was an aspiring "traffic guy" many, many years ago. 

That said, I will concur that what we now think of as an "intermodal train" is one carrying piggyback (the old TOFC) or ocean or domestic containers (COFC). In other words, the equipment in which the shipment is loaded is moving via multiple modes.

As Balt notes though, more and more "intermodal" trains are carrying autoracks and, taking it a step further, more and more manifest trains now have intermodal blocks. I know where NS is concerned, train symbols are becoming just about useless in determining what traffic is being handled in that train.

 

[chutton01]

As has been stated, intermodal as we thing of it (COFC/TOFC) has been around for quite awhile. Would you consider PRR LCL container service, moving containers from flat to truck for local delivery, from the 1920s intermodal? I would. (Yes, yes, I know the LIRR and others hauled loaded wagons to market on flat car in the late 1800s, early TOFC of a sort).

Here's kind of a hokey history of the shipping container (mostly geared toward the marine aspects and Malcolm McClean, although early railroad container shipments gets a brief mention.  What I didn't see mentioned in that history was a mention of a device that made COFC pay for the railroads (as well as the Marine lines) - the Interbox Connector (IBC), which locks containers together making rail double stack (and marine multi-stack) service possible, much like the development of the ACF Hitch made TOFC service viable (until the 2000s when it kinda fell flat on its face - I think less than 8% of intermodal rail traffic is TOFC as opposed to COFC in recent years).

While autoracks aren't intermodal, they have similar priority on the railroad, so they will often be on the same trains (at least where I am,.

But what if the autoracks are in fact trailers on a flat-car - TOFC indeed! OK, to be fair apparently shipping auto-carriers loaded with vehciles on flat-cars faded out by the mid-1960s, but still it looks kind of interesing. Now if only those Revel/Con-Cor auto-haulers (that in HO came with the Ford C-series tractors) were available in bulk...

[BaltACD]

Harrison

In addition to what others have said, intermodal trains sometimes have autoracks either before or after the "intermodal" (containers, trailers, etc). While autoracks aren't intermodal, they have similar priority on the railroad, so they will often be on the same trains (at least where I am, so CSX/NS).

Combining autoracks with intermodal trains was a result of EH Harrison's PSR implementation on CSX.  Autoracks are not considered intermodal they are considered 'automotive' as a class of traffic.  Intermodal trailers and containers cannot be handled at a terminal that is designed to handle the traffic of autoracks, conversely the traffic carried on autoracks cannot be handled at terminals designed to handle trailers and containers.

[Harrison]

In addition to what others have said, intermodal trains sometimes have autoracks either before or after the "intermodal" (containers, trailers, etc). While autoracks aren't intermodal, they have similar priority on the railroad, so they will often be on the same trains (at least where I am, so CSX/NS).

[charlie hebdo]

I agree with Lithiona. Intermodal is what the AAR or FRA or any of the major railroads define it as.

[MMLDelete]

Juniata Man

Intermodal simply means the freight shifts between multiple transport modes between origin and destination. Acccordingly, an intermodal train - by definition - is a train carrying freight than has or will use multiple modes of transportation between origin and destination.

 

 

I don't agree with that. If a unit coal (or other commodity) train gets to an unloading facility, is loaded onto a barge, and then later the coal gets to its final destination by truck, it has used three diferent modes. But the train was not an intermodal train.

 

An intermodal train has special flatcars that carry semi-trailers or containers. The containers can be pairs where one is stacked atop the other.

 

Intermodal means that the train carries its loads in equipment that is actually part of another mode (usually highway). A trailer gets attached to a cab, then moves over the highway. Similarly, a container (essentially a trailer box without wheels) is placed on a special flatbed trailer, then pulled by a cab over the highway.

 

Nowadays, "piggyback" trailers are not as common as containers. If you look closely at trucks on the highway, more and more of the trailers are actually containers.

 

Juniata, I'm virtually certain you knew that, but just didn't word it quite right. I wanted to make it clear for our newbie.

 

 

[timz]

Think boxcar freights in 1950 were intermodal, since the freight often went from the car to a truck?

You're not going to get an "exact" definition of intermodal. Fans call trains "intermodal" when they include containers or trailers, and maybe that's all the term means.

[Juniata Man]

Intermodal simply means the freight shifts between multiple transport modes between origin and destination. Acccordingly, an intermodal train - by definition - is a train carrying freight than has or will use multiple modes of transportation between origin and destination.

[mudchicken]

Any mixing of modes of transportation. Rail/Truck, Rail/Container, ship/container, train/bus, etc.

[xploringrailroads]

Hi. As a newbie, I would like to know what is an intermodal train exactly?

Thanks for your help!