I’m in the beginning stages of designing my layout. One of the things I know I’m most interested in is having the ability to reverse directions of mainline travel. I believe this is commonly referred to as out and back operations? What are some the things I should consider in this design element electrically and operationally? The initial space for the layout will be in about a 11’ x 11’ area, and I’m thinking of doing a U shaped layout with flared areas around the ends of the U for additional space for large enough curves to turn back around on.
The proper term for what you want to do is a dogbone not an out and back. Your limiting factor will be the loops. A 24" radius will need a little over 4’ on each side leaving an entrance of 3’. 26 to 28" is as large as you could possibly go.
Thanks for asking a question, so that there is no doubt that you want some straight-forward help in designing a layout for OPERATION, not just a toy train to play with. I’ll try to provide some input, in reverse order of your requests. First of all, the way you chose to operate your MRR will determine the electrical wiring requirements. I will assume that you really meant an “out-and-back” layout, and are NOT committed to a single loop of track. Next decision: single or double track on most of the mainline?? If you are OK with an apparent double, and a reak “out-and-back”, then you need only one loop on one side of your “U” to reverse the East-bound train’s direction, allowing it to return to the starting point on the West-bound main. No need to wire a reversing loop at this point, but you will need one before you re-enter the originating yard on the other side of the “U”. If you decide to go with only a single main, then a reversing loop is required, with separate wiring and reversing control for it. (Lots of good help on these in current literature.) Also, a single main will require passing sidings (at least one) if you plan to run more than one train at a time. That’s even if you go with DCC or DC systems. You will need some cross-overs between the mains if ;you go with double track. be sure to place them wisely, using as large a turnout as you can, to avoid the dreaded “S-curve” especially if you run passenger or long freight cars. If you choose to have a dogbone, as described earlier, no reversing loop is needed, but you will loose quite a bit of yard space unless you plan ahead to place the yard inside one of the loops. Well, guess I’ve said enough for now…If I’ve created more questions than answers, well that’s what this forum is for: Ask them. Best wishes for a successful MR. JWHl
Out and Back is something like what the LION does. It is a two (and four) track main line that leaves a terminal on a 16" wide shelf layout and runs the room on a three level shelf with loops and a helix on two middle tables.
As far as the track diagram, here it is simplified:
It is a nine mile round trip from 242nd Street (VCP) and the South Ferry Loop and back.
ROAR
RetGM
Thanks, yes I believe out-and-back layout is what I am asking about. It has been about 20 years since I last participated in model railroading (I did save everything in boxes), so there has been a lot lost to memory and there have been many technological changes in hardware available for use now. What you pointed out so far has me thinking about this in some more detail now.
I’m a little confused on the electrical differences your refer to about single or double main lining??? In operation what I would like t accomplish is the ability to run a train in opposing directions coming and going (be able to reverses directions); I guess as you say west and east bound directions without physically picking up and turning it around. I believe continuous loop operation in one direction only would eventually get boring, so might as well plan to do it the way I want from the get go.
What are the differences between DC and DCC systems? In regards to double or single main lines, why does one require “wiring for reverse loop”, but the other doesn’t? What is an apparent double and a reak out? Are cross-overs for double tracks simply X crossing sections?
Thank you,
Nelson
How do you post an image or drawing to this sight?
First you must HOST the image on some server somewhere that allows you to share the image. There are many of these, some free, some that you pay for. The LION hosts his photos on his own servers, but not everybody has a room full of servers in their basement.
The place where you host images (perhaps Imageshack or Photbucket) will give you the URL code which you copy and on this forum you click on the “Insert Image” Icon in the forum posting window and paste the code there.
Like This: 
Now as to wiring an out and back loop such as I built, I apply the power to the loop, and the terminal gets its power from whichever route it is aligned with. My layout has two continuous loops: the Northbound Express and the southbound express. The layout is so big and convoluted that viewers cannot see that their is a loop. And with four to six trains running on the Local (main) tracks, nobody can keep track of what is going on. I cannot keep track of what is happening. I just listen for the sound of a derailment or a collision and kill the power and correct the issue.
ROAR
My loop layout pictured below could represent an out and back in two directions (not including the upper level coal branch) if you start from the yard at Brunswick, as I do. Then when I feel like testing or just letting the trains run, I can do that also.
The interchange tracks represent both ends of the layout and are connected together on the actual layout to make the loop. One track is the B&O interchange at one end, and the other track is the PRR interchange at the other end (not WM as note 1 on the drawing indicates.). There is one more track used as a runaround track for switching either interchange track.
Elmer
Nice web site.
Nelson
Nelson,
Track Planning For Realistic Operation by the late John Armstrong will give you the proper information.
I added a drawing to make sure we are talking about the same configuration. A drawback of the out and back schematic is having to do terminal work for two lines; which will surely become the mainstay of your operations. The third plan could better be called: a “double point-to-loop schematic, though with a shared terminal”.
BTW do not overestimate the possibilities of your space; assuming you are modeling in HO. An out and back is popular in the UK for layouts with merely passenger train operations. This means probably running long 85 ft coaches; requiring however the use of large radii and long turnouts.
Or are thinking about the following schematic?
Smile
Paul
What is the minimum radius I could use on the main line if I want to be able run passenger cars/later generation steam engines/modern diesels? From what I have read so far (and sort of remember from last time a did this some years ago) is that I can operate these types of equipment on a 22” radius. The bench work I’m planning on now could accommodate up top 30” radius curves at the ends and the bottom of the U and allow continuous operation in a loop.
For reversing direction of operation I’m thinking of having a crisscross or a cross over in the bottom of the U section of the layout. The two legs of the U will run down benches of 9’ foot length, and the distance between the two legs (from outside to outside) will be about 9.5’ to 10 ‘, so area between the two legs at the bottom of the U or the ends will have sufficient space for crossing over and changing directions, I think.
Paul
If you take the last schematic you show, an oval with reversing loop, but bend it in to a U shape and that is what I’m think of doing.
Nelson
Hi Nelson,
If i understand your aims well you are thinking about a plan like this:
You are talking about a 30" radius, IMHO way to large for the 11x11 space you have. Some issues are quite visible in the drawing, less obvious is the lack of long straights along the front edge. This will reduce the possibilities of stations within good reach (no further back then 30")
The ideas of the Layout Design Group about appropriate radii are quite clear. Personally i would not use a ratio under 1:2,5.
. The LDSIG (Layout Design Special Interest Group) developed a rule of thumb relating radius to length of longest cars. The rule is fairly conservative. But it does allow pretty quick evaluation of the practicality of a given curve radius in light of planned operations (the intent of the rule of thumb). All the empirical and anecdotal evidence I have seen suggests that the 3X minimum is right on for long trains and operations with a helix.
Here are some curve radius guidelines based on the lengths of your longest pieces of rolling stock.
2X - Some model equipment may be able to track reliably on 2X their length, but this is generally considered pushing it.
3X - Making your curve radius at least 3X the length of your longest cars gets reliable tracking around curves, but looks toylike.
4X - If you make your curve radius at least 4X, your longest cars will look much better on curves.
5X - If you make your curve radius at least 5X, your longest cars will couple easily with minimal manual fiddling of the couplers.
This measurement is based on the length of your longest car (coupler to coupler).
The best way to communicate would be to start with a drawing of your room or space, with all obstacles like doors included.
As the Lion suggested, you insert any digital photo or scanned diagram in a Host (ie) Photobucket. Type in Photobucket.com to get a free assignment to some designated MRR Album. I have a MRR Album with 68 images in the Library. The way mine works now is that I click the cursor on the desired image and then click on “Share” There will be a “Link” option above. Click on it, then click on the IMG option. Momentarily, a yellow background with th word “Copied”, appears. Now go to the Trains.com Thread where you want to Insert the Text and Image. You can then click on “Paste” (or "ctrlV), and the text and lengthy image code will appear. Scroll down to Post and click on it. The text and image will appear after the Original Post (OP). To make additions or changes, click on the little pencil icon (lower left on page) Delete or make your correction or addition, and then “Post” again. To get back to an established Photobucket Album you type in “Photobucket.com login” Then click on “Image Hosting free photo share and Video share at Photobucket”. It is not as complicated as the description may appear. Bob Hahn If you desire to have an “AVATAR” picture, instead of the yellow circle head, let us know and we will describe how to make the transition.
My railroad is truly and out and back type. It goes around the walls of a 12’ by 12’ room with a peninsula in the middle. The peninsula holds the key to the out and back as that is where the wye is located. Two legs of the wye are actually on the layout itself and the third leg is a 4" wide by 4’ long cassette that attaches to the end and goes behind the entrance door of the train room. I start at the yard on my workbench, work my way around the walls to the peninsula, back around the wye to reverse direction and then travel the opposite way back to the yard. Hope that helps.
Hi JBU,
Your plan seems to be a point-to-wye schematic, quite different however from an out-and-back.
Have a look at my first posting.
paul
I have to respectfully disagree with you. The train heads out from a specified place, gets to the end of the line, turns on the wye and comes back to the same place it started. That to me is an out and back. Whether it uses a wye or not is immaterial, IMHO.
John,
it has nothing to do with respect. It is not up to me or you to invent the proper meaning or notion of a word.
An out-and-back has a specific meaning in model railroading; whether you like it or not. If you are not interested in its well established meaning and so use it in a different way, it might cause a problem. Also the OP was not aware of its proper meaning. IMHO it is wise to use a notion as it is normally done.
A point-to-point. a point-to-loop or a point-to-wye do allow trains to run back and forth; or out and back if you prefer. However an out-and-back is a schematic where two roads share one terminal, at the other side they are connected, together forming a large reversing loop.
( see John Armstrong, Track Planning For Realistic Operation dating from 1963 page 65)
Smikle
Paul
My apologies to you and Mr. Armstrong. I have always referred to my layout as an out and back because in operations thats what it does. The wye track performs the same function as a reverse loop, it just looks different. Perhaps there needs to be an update to the definition of an out and back? Or a new definition to describe an arrangement such as mine. I’m sure I am not the only one that has this type of arrangement.
Paul
Yes, your diagram is close to what I had in mind for my layout. The one functional or operational difference would be another crossing track at the bottom so directions could be changed from either direction of operation. I guess you could call it a bent figure 8, maybe. Your comments and diagram do make me concerned about how restricted a radius turns (loop) I can place at the two ends of the U legs. I agree I do want some areas with decent length of straight track for a passenger terminal, and had even considered placing a turn table on the opposite leg. The suggestions based on 2X, 3X, 4X etc. car lengths seem very reasonable and helpful, darn it. As most people do I guess I’m trying to have as much real operational fun as I can in a small space. The layout will be in a room about 250 sq. ft., but I can only utilize about 100 sq. ft. for this project that is placed in a corner of the room.
Thanks,
Nelson