Train Length

Alright I’m in another Delema. Since i’m just starting in N i don’t have much equipment yet(its slowly growing) I have a roughly 10x11 foot G shaped layout. I’m trying to figure out what the i want atleast 2 passing tracks and a yard that can be used for another in the visble trackage(Hidden will be double tracked) I need to know How long of a train can i run and still fit in the passing track. and How long should the passing track be?

The passing track shuld be long enough to fit the train. How long you make the train is up to you and how many engines you have to pull it and what your max grade is. Your question has a lot of variables. There is no clear cut answer.

The Passing track should be as long as most of your trains (you can do a saw-by now and then to be interesting, but too often and it will probably be annoying, from what I read). If we figure 60 foot cars (kind of modern era average, I’d guess) a twenty car train is around 8 feet long, so you would probably get a couple of passing tracks in. In Track Planning for Realistic Operation John Armstrong points out that for a small layout (and I think you are getting at the upper end of that) a double track main actually works better than single, because there isn’t enough room for the passing tracks for single track. By the way, if you are designing, you need that book.

Yes, like SpaceMouse said, it is a chicken and egg question.

in my case I have a lot more equiptment than I have room on my layout, so my train lenghts are limited by passing siding length. But you have it easy in N especially with little rolling stock. You have to decide how long you want to run your trains and build your sidings accordingly.

All right let me clear some things up here. My layout won’t have any grades on it except when the shed settles and everything cease to be level(nothing in our house is level, square or flat) My trains will be limited by the sidings. I figure every train will have 2 or 3 units on the head end. I only have 12 atlas ore cars, 1 Athearn RTR 50 Boxcar and 1 intermountain covered hopper. I don’t have the money right now to go on a major shopping spree. and i don’t want to built my layout, only to find out that i need to go back and redo the passing tracks.

Right, your trains will be limited by your sidings, which you design to accomodate your trains. Hence the chicken and the egg thing. What you have now isn’t really at all relevant, the layout isn’t even designed, let alone built.

So, the questions you need to answer for yourself, or for anyone to give a solid answer, are the “givens and druthers” questions. Again, I refer to Track Planning for Realistic Operation. What is your vision of your railroad? If it is a shorline running 5 car locals then your passing tracks only need to be long enough for those. It you think you are going to be running 30 or 40 car trains, well, that’s different. Obviously in your space there is only a certain amount of room, but some double decking could add to that, if that’s how you want to go. Or, as I said before, make it double track and the passing tracks are not an issue, or at least not as much.

This is not really a chicken and egg question since train length does not just affect passing siding size. It also determines the size of the yard since if your trains are too big for the yard then your yard is useless. In particular, the arrival and departure track(s) must be the length of your longest train and your longest classification track should also be the length of your longest train minus the engine and caboose. I think you will find that the size of the yard will be the more restrictive variable in terms of train length than passing siding since the length of your yard will have to include room for both the yard ladder and the arrival/departure and classification tracks. With all the turnouts, it’s also difficult to curve the yard to any great extent.

Anyway, what all this suggests is to start with the yard and go from there as follows:

  1. Select the longest straight section of benchwork and assume this is the yard location (personally, I think the yard should be in the center of the layout so you can run trains in both directions from it but you could also do an out-and-back yard; you may have to play around with things to figure out what works best).

  2. Begin the yard ladder at one end. Make sure to include room for the yard lead (which can be curved and which should be at the base of the ladder just off of the main so that the switcher can service all of the tracks without clogging the main).

  3. You’ll need 1 or 2 arrival/departure tracks (which should be double-ended) and then 2-4 classification tracks. For simplicity, it would be best if all of these tracks were of consistent length. Otherwise, you’ll have to plan into your operations the fact that only certain yard tracks can be used to breakdown or makeup your longest trains.

  4. As you insert turnouts, the geometry will inevitably impose a limit on how long your yard tracks can be. This will, in turn, dictate the length of your trains and the length of your passing sid

That’s is good stuff there. But he needs to decide what he wants first, I think. If his goal is to run the longest trains possible, then it makes sense to design the yard first, and see what pops out. But, it could be that he doesn’t need the largest yard (lengthwise) possible to accomplish his goals. Which brings me back to needing “Givens and Druthers” before anything else really makes sense.

The original poster has started this, he knows the room size, he wants a yard, and he wants passing tracks (which at least implies he wants a single track main). But I think there are more questions to answer.

I’d also have to say that you can’t always make the passing tracks longer. His space isn’t that big. At some point one starts where the previous one ends, and it might as well be double track.

But with a bit more info, and the people here, there is no question that there is a solution!

All good stuff… BUT… there’s no way that in a year or two you will have the layout built and NOT have more cars and locos than you can fit on at one time… unless you are one of an extremely select few.

Going for Givens or druthers…
The one you have really expressed so far that stands out is that you want 2 or 3 locos on the head end. that means LONG (25 upwards… more like 50 upwards) car freigh trains if it’s to look sensible.

RR do run cab hops with 5 locos and a caboose (or two) but power costs money.

Your layout space would tend to confine you to 1 or 2 locos on the point. You have the advantage that US practice seems to prefer to have 2 on the point over most of the country except in the NE corridor and in /around cities. I figure that this is because a loco breaking down on its own way out in the middle of nowhere is a real problem but a two loco lash-up the 2nd loco can (hopefully) keep things moving… if slowly.

You will find a lot of answers in the book recomended… and do lots of other reading and looking at pics.

have fun!

I model in HO. My siding is long enough for a 12 unit train. So that’s how long my longest train is.

Iain Rice’s layout book “Midsized and Managable” has a discussion about train length that is quite helpful and should give you answers to most of your questions. It’s available from Kalmbach.

Generally speaking, make your sidings as long as possible. I’ve never heard a modeler complain their sidings were too long!!

[#ditto] enough to support at least 10 to 12 cars.

The siding doesn’t need to be as long as your longest train, it needs to be as long as the second longest concurrently running train. So it is possible to have a siding which will hold 12 cars but run a 40 car train along with a 12 car train. You just can’t stuff the 40 car train into the siding. It must take priority over the 12 car train. The point about yards is a good point but you can cut a train before sending it into the yard but I don’t know how prototypical that is and you’d have to plan the yard entrance in such a way to handle this.

NS:

Here’s some layout design formulas that I put together to help answer questions like train length, how many cars can the layout hold, how many cars can I move in an op session, how long should the passing tracks be to allow for optimum operation, and so on.

See:
http://siskiyou-railfan.net/e107_plugins/content/content.php?content.32

If you take these formulas, get yourself a ruler, and study a few published layout plans you will learn a ton about layout design.

[#ditto] This works. I used it to help refine my design.

There have been some great tips here. Train length does impact a lot of different aspects of the layout plan. Not just passing siding and yard length, but train length also impacts staging track length, distance between towns, and indirectly affects permissable grades.

What do you do when you don’t have space to run the desired train length?

  • set a new shorter train length. Just make sure to adjust all 4 items - passing sidings, yard tracks, distance between towns, and staging track lengths - to get the maximum benefit from reducing train length.

  • use double track. You may still have problems with yard and staging track lengths.

  • set view blocks so that both ends of the train cannot be seen at once. While this helps with the visual aspect and avoids seeing the train as being in 2 towns at once, it doesn’t reduce the requirement for the length of various track segments.

If a train exceeds your entire normal viewing angle (about 115 degrees unobstructed), it will appear to be a “long” train regardless of actual length. This is true regardless of scale, and works out to be about 13ft in most cases. If you have to view the trains from a closer vantage point, then the 115 degrees encompasses less train length, and a shorter train will appear to be “long”. The view blocks work by reducing the 115 degrees of view.

My thoughts, your choices
Fred Wright

Joe:

It would be interesting to see these formulas/methods reversed. In other words, instead of starting with a track plan and assessing its operating capacity, can you start with a set of operating goals (incorporating train length, # of trains, etc.) and use those metrics to compute the number of passing sidings you need, etc. I think many people start with a set of operating goals but then struggle with how to design a track plan that meets them. Anyway, I’m sure you’re a busy man but it would be an interesting intellectual exercise to try and do this analysis the other way around.

Brad

All these tips are great. I have learned alot from here. I guess maybe i should Rephrase my question. How many feet does a N scale train, not counting the power or caboose. With 20 cars, 30 cars, 40 cars, 50 cars and so on. The yard Arrival Depature tracks are not a problem as they can extend into the Hidden trackage or around the curve. I should have also posted that i’m going to be running Modern Day NS in West Virgina, I’m thinking about 40-50 car trains. I won’t double track it becuase i find it harder to do industrial switching in N scale so the single track is going to make up for the lack of large industries. And becuase the N scale club I’m is modular and the only time we’re set up is when we are displaying, none of the members have a space large enough to set up the layout. its roughly 70x40 or something like that. And all of my friends that i am in regular contact with do HO. I really don’t want to do a double decked layout becuase my last layout was double decked(it never got finished before i decided it was too much layout for me to try to build on my own.) Joe you have some excellent points as do all of you. I’m pretty good at track laying so Once i’m out of the yard track will progress pretty quickly. As I do not have a job and i’m a student i can make pretty good progress becuase i don’t have anything to do. I look forward to showing you all Pictures sometime in the near future.