People have mentioned siding length and while that is a consideration, its not the only problem with long trains. Since the problems occur with operations (i.e. car forwarding and various switching operations) a lot of the “big” train folks just like to watch them go by.
The problems occur when you get them in a yard. The yard has to have the room to receive the train, then it has to have the room to classify it and finally to assemble the cars on whatever outbound connection there is.
I run about four through freights out of my classification yard. 2 in, 2 out. Trains run in the 8-14 car range. So I have to have room to yard a train and then process it. Then those cars go to industries or interchanges. It is entirely possible to process one inbound train before the next train arrives. So my yard can easily process 28 inbound cars from through freights.
If I were to jack the train length up to 40 cars that means I would have to process 40 cars before I could receive the next train My yard would have to process3 times the number of cars from through freights, I would have to have 3x the spots at industry or room on interchanges.
Granted these considerations only apply if the operation calls for terminating trains. If you don’t terminate trains then the through trains can just make pick ups and set outs, but the operation has to be able to support the through trains dwelling to do work and has to be picked where there will be through (non-terminating) trains.
My ‘standard’ through train is 20 4-wheel wagons (maximum - may be fewer.) When it arrives at the one and only yard it drops six (maximum) and picks up six (maximum.) Up trains swap cars at the head end, Down trains swap cars at the marker end - and all trains get turned end-for-end before resurfacing from the netherworld. There’s an 8-car cut that NEVER gets switched - in fact, those cars are coupled with ancient Kadee K couplers.
My ‘standard’ local is 12 cars, and either originates or terminates at said yard. Most of the cars are switched into trains continuing in the same direction, either through or originating local. Well over 90 percent of the cars are, “Just passing through.” Except for the TTT interchange at Tomikawa and the log yard at Haruyama there aren’t any local industries to receive or ship carloads. LCL is handled at the freight houses, and moved in box-brakes.
Of course, most of the traffic is pasenger trains, and, like the freights, most of them are just passing through.
Chuck (Modeling Central Japan in September, 1964 - to the prototype’s timetable, 24/30)
Coal trains do not stop at any rail yard. The entire train is loaded at the mine, the entire train is empties at the utility.
Oil trains do not stop at any rail yard. The entire train is loaded at the Oil Terminal, the entire train is unloaded at the refinery or shipping pier.
Grain trains mostly do not stop in rail yards. Most of them are dispatched from the local elevator in 50 or 100 car “Shuttle Trains” and travel directly to the mill or to the point of shipment overseas.
There are two such large grain elevators within 25 miles of where I am sitting (Not counting the corn elevators right here in Richardton for the Ethanol Plant). The trains from Gladstone usually travel to Minneapolis to the Pillsbury mill there. The new elevator in Hebron was built with Asian money, and all of that grain goes west for shipment to Japan and China, with no middle hands in the way.
The Ethanol plant does require switching, both at the plant and in the yards all along the way. Corn comes in by rail and by truck. Gasoline used for denaturing the alcohol comes in by rail (in smaller tank cars) . Ethanol goes out in larger tank cars owned by a cooperative of ethanol plants. Brewers Yeast goes out by truck and by train. By train they ship “dried brewers yeast” and it can go in the same cars that brought in the corn. By truck, they ship “wet brewers yeast” and this requires special trucks, so the ones that bring corn in cannot take yeast out. The train also brings in coal. The plant is fired by coal, the original plan specified that the coal would be trucked in from the mines about 40 miles north of us, but they did not do their sums quite right, and that lower quality coal could not be used, so they now receive Wyoming coal by rail, but had to jury-rig a coal receiving facility which is not as efficient as what they had hoped for.
The ethanol plant has four miles of track all parallel to the BNSF mane lion here in Richardton, and they have two leased locomotiv
Just to be contrary, I once operated on a layout where coal was gathered from small mines and brought to a yard where cars were sorted according to grade. From there longer trains were made up to take them to their final destinations.
Eastern Layouts. Out here it is all a mine to plant contract. Mostly the power plants even own the hopper cars. Those trains can morph to 300 + cars, and they will not stop for any classification.
No matter what, you can expect the service to mold its self to the most profitable mode possible.
In the past, along the WM or the B&O for example, branch lines in Appalachia served many small mines, cars were gathered from small mines, and brought down the mountain to yards along the mainline, just as Chip describes.
Cool but what difference does that make. If you have a classification yard then by definition you will have trains or cuts to be classified so they will stop at the yard.
Yes, you can certainly run 100 car trains and only set out or pick up 5 cars. But that limits your operations or your location or your eras. For example, for my layout that wouldn’t work (and the same holds true for half the people I know). I model a branch. Every train on my layout terminates at Wilmington. Every through trains terminates there (and before somebody says then its not a through train, every train has an origin and a destination and every general freight train is switched up on either end of its run). Yes you can do the set out thing, but that limits your layout to someplace on the intermediate portion of a railroad.
I know through freights don’t normally work industries. When they enter a terminal, there are only four options for the cars: they go to industry, they go to interchange, then are held/stored or they go out on another train. Once again, location, location. location. For example, on my layout, in my era, there are no run throughs, so every car that enters my yard on a through freight either goes to industry or goes to interchange.
I could design a layout that only dealt in set outs, but it wouldn’t be the prototype I pi
Just South of Vancouver is the Roberts Bank Superport. Container and coal trains are both handled there. The Federal Government is spending close to a billion dollars about twenty miles east of Roberts Bank putting in overpasses on all the “nothing more than” farm roads that cross the line that goes to the port. The reason being the RR has put in new sidings in the last six months that go for miles and miles. You could not have all these roads block for long periods of time with parked trains.
The fact all this money is being spent means these “Mega Trains” are past the trial stage and here to stay.