Operations Question

Model Railroader General Discussion (Model Railroader)
1

Now that I have a complete layout and can run trains of reasonable length, the one question that has come to mind is how long of a train can I expect to safely be able to back up without derailments and such ? I know this is a very subjective question but I am just looking for some experience. Ultimately my yard design will dictate how long of a train I can put in the yard but there may come a time when I need to backup on the mainline or similar. I’ve been testing freight trains of mixed rolling stock around 25 car lengths or so and no problems. I am going to bump it up to around 35 to 40, which is the longest I’d ever run on the layout and mainly for demonstration purposes. I’ll see how that works.

2

Your point of your question is incredibly subjective…

Some of the general factors that will apply…

  • The quality of your baseboard
  • the quality of your trackwork
  • The layout - this varies at different locations depending on the combination of curves, switches and grades.
  • The quality of your stock in general
  • The quality of your couplers and how they are installed.
  • The quality of your wheelsets. Good current metal wheels are probably better and less likely to cause issues than older plastic ones.
  • The order of cars in your train. An 89’ car psuhing a shorty tank is likely to be an issue… then agains so is the reverse order.
  • One thing that will make a huge psoitive difference is good quality control
  • Live frogs will probably help
  • Good locos with clean wheels will help
  • Clean track to give reliable power (and control with DCC) will help.
  • .
  • One thing to do is to make notes to see if any issues with push-backs regularly occur with specific cars and/or at specific locations. This will show up where you need to make adjustments… which is far more logical/easier than working on general impressions.
  • You might find that some cars shove back better one way round than the other. If you can find out why - like a tight trauck or coupler at one end - and let us know what you find please.

Hope this helps even though it’s extremely general.

[8D]

3

At the risk of sending everyone to sleep with another long answer…

Some things that might help…

  • When identifying where cars fall off there are two possible categories… 1. where on the track and 2. where in the train. 1. is obvious. 2… it may occur between the 9th and 10th cars everytime regardless of which cars they are. Don’t know why this would be - just something to look for.
  • When cars fall off which way do they go? left right or either way? Again this applies to bith the track and the consist
  • Again, which way is the track going, left or right as a horizontal curve - up or down as a vertical curve… the perspective being from the engineer’s seat as he watches the shove back move.
  • in notation you could use an anti clockwise circle arrow for falling off to the left and the opposite. For the track curving left a straight arrow pointing left, straight on an arrow upwards (away from the loco). If the grade is rising a wedge getting thicker to the right. If it’s at a turnout the letters SW plus ST or CT (straight track or curved track) also P or CC (points or common crossing) - 'spose you could use F (frog).
  • If the derail is in an S curve or a ladder draw a line for the curve/ladder and mark where the derail occured.
  • Noting a car you want the car number and whether it is the brake end leading or not… “CNW 56000 B” - you might add L or E for loaded or empty if this makes a significant difference to the car weight.
  • What length is a car? How many axles? Same applies to locos. Could it be a top heavy car?
  • I don’t think that I mentioned car weight last time. This may have the same sort of effects as car length.
  • It would be worthwhile noting the adjacent cars. Particular things to note is whether they are the same, longer or shorter - and the car number and which way round.
  • Another thing to note about
4

Ideally you should be able to back up any train that reasonably runs on your layout. This would be prototypically - but remember, the prototype does have derailments. Minor derailments are common enough that there rerail frogs ( http://www.walthers.com/exec/productinfo/229-7103 ) kept on the locomotive.

5

Hmmmm! We have called out all the CSIs on this one and haven’t even addressed the question, which as I recall what experience have we had backing long trains, and how many cars. I suspect that we need some moe experimentation and experience on your layout before we diagnose the source of the “problem”. I would think that you may want to put together some longer consists representative of the type of trains you will actually be operating and get a better feelfor what problems occur, and then look for the patterns, short cars, light cars, talgo couplers, a particular section of track, switches or crossovers, etc. before we finger print, collect samples, check the DNA, etc…

I have a feeling that any problems that you encounter will be applicable to your layout and rolling stock. The answers above show some experience with “problems” and how they went about solving them.

Perhaps we should look at the results we get with longer trains on our layout before we go “Houston we have a problem”. You just never know when the “Train Gods” have watched over our previous efforts and we got them right the first time.

So try the longer consists and report back if you in fact have a problem and then refer to the excellent advice above to address them.

Good luck, hoping that everything backs up perfectly for you!

Will

6

For a simple straight forward answer you should be able to back any amount of cars with smooth track work and a steady hand on the throttle at slow switching speeds.

I have back a 50 car cut through a crossover from the classification tracks to the outbound track at the club…

7

Thanks. This is what I was looking for. I figured I should be able to back up a train of reasonable length, given straight track (or reasonable amount of curves and turnouts) and good trackwork (as well as properly weighted cars, metal wheels, etc…) but there are limits. What I didn’t want to do is waste my time attempting to fix a problem for something which is generally unreasonable to attain. So far I have been able to run 25 car trains at medium throttle continuously around the double loop mainline with no derailments. I’ve also backed them up, including through a 1.5% grade with no problems. I would expect the same for 40 but at 200, I wouldn’t have that high of expectations. The longer the train the more force that is exerted on the cars closer to the locomotive. At some point the

8

You have to keep in mind that the dynamics of backing through a #6 crossover are quite different than, say, a #8,9, or 10. Also a lot depends on the cars. A lot of difference between 40’ or 50’ cars and modern 85’ auto rack or doublestacks, eh? I made the mistake once of backing a 14 car steamliner through a #6 crossover. It was someplace I didn’t ever belong and I paid for it with cars all over the landscape! Empirical data is the best, so log everything and keep trying until it doesn’t work, then you will know what does! jc5729

9

It doesn’t matter on the length of the car…Its all in the track work and a slow steady speed.I have even back 50 car pig/stack trains through those same number 6 crossovers.I have backed 12 car passenger trains into our stub end station tracks.

Why complicate a simple answer?

Of course at warp speed you are going to dump cars all over the place.

10

I have a hump yard and typically hump a train in 2 25 to 30 car cuts. My hump starts just behind 3 facing point switches and (as per Brakie’s advice) I (generally) have no problem shoving the cuts up the 2 1/2% curving grade

11

Backing a train is how I test my track when I build it, as backing is more prone to derails. Also tested my Helix in the same manner as I built each of the five layers. Just my 2 cents on getting good track…john

12

I agree entirely with Brakie ![:D]!

So long as we’re dealing with full sized trains and models that run on tracks with full sized/scaled curves and car weights. [;)]

Those of us that can afford to “Go Big” should have no problems. For the rest of us things depend on experience… otherwise known as “empirical evidence”.

Slow movement comes with the items I listed as good control, clean track and good locos.

I’ve given up watching CSI… they always win within the hour… nowhere near as good as Hill Street Blues used to be. My notes/suggestions on problem locating might be helpful in general though I hope.

Yes, hopefully the original poster will be able to push 50 mixed cars but there is no way the rest of us can know either his trackplan or the quality of things… hence the very long and very general answers. Ask me if a loco can push a car and the answer is “Yes”.

Have fun

[:P]

13

Brakie is right and this is a simple answer, as long as you take it slow and easy and have decent trackwork you can back as many as you want/need, just like the real thing. I personally do not back more than 50-60…it just depends on what i’m switching for.