I have been trying to run long trains on my flat HO scale layout, I have over 60 ft of main line. So there is plenty of distance to make it work. I seem to have found the max limit, and it doesn’t seem to matter how many engines I put on the train. Autoracks and intermodal cars seem to have more drag and limit the train length, while iron ore or coal trains can be a mile long.
Does putting on more engines help, or is there a max wieght/length a model train can be before it is just to much?
I model everything from F-7s and GP-7s to SD70MACs. While it maynot be realistic to run them together, I would like to have a realistic axle or HP to train ratio. I know the real train use complicated formulas to determine how many engines are needed. How can this be applied to model trains?
Eight autoracks is not a lot of cars, but it is an over nine foot train. I use two engines, but obviously a real railroad would only need one.
In addition to improving the rolling quality of the wheels, consider this: there is an inherent “drag” in going through curves, and if those long cars are being tested to their limits in going through curves that itself would create the situation you mention, while an even longer train – with even more wheels to create friction – of short ore cars would have no such problem.
Regardless of train length, many railroads always run at least 2 engines together. Typically, they are run back-to-back so that they’ve always got a cab in front without having to turn an engine.
The tip about upgrading your wheelsets is a very good one. I’ve almost got all my rolling stock converted to metal Intermountain wheelsets, and I use the MicroMark truck tuner as part of that process. My string of hoppers, which used to take 2 Proto GP-9s to haul around, can now be handled by a single lightweight Bachmann steamer.
Another train-length limit we face is called “stringlining.” As a train rounds a curve, too much weight behind the curve will cause the cars on the curve to roll off to the inside and derail.
Long trains are possible. Here is a youtube link to a 121 car, 7 diesel, HO scale train running on a ceiling layout across light fixtures: http://www.youtube.com/watch?v=2zgcKXrNE44
Ye Olde Saying - “A chain is only as strong as its weakest link.”
Substitute ‘coupler’ for ‘link’, and you have a critcal non-motive power factor in the upper limit to the length of a train, and that applies in both the scale and prototype.
Yes, adding more power, or distributed power, will help a very long consist along. Add hills and you may need both motive and braking power in addition to what you already have. If you want to keep those weakest links from letting go, go distributive.
On my old layout,I used to run long(15 to 20 cars)passenger trains.Let me tell you,that is a lot of weight to move.I cad to make sure all trucks were up to par and keep close tabs on couplers pulling that much weight.I also added a little extra weight to the head end cars.
The longest train I ever ran on my last layout before starting on rebuilding it was thirty-three cars. These ranged in size from forty footers to sixty-five footers. My 18" radius curves put a cap on how many cars I drag around them. Usually had three to four locos pulling, more for looks than actual effect. They were either GP’s or F units. Two F units could do the job but three or four looked better to me. If GP’s were pulling it took three to pull it wiyhout slipping and four just looked better. Free rolling wheels and good couplers are critical. If you have wheels dragging you’re wasting power that could be used to pull more cars.