How much space -really.

See this thread:

https://ogrforum.com/t...p-turntable-planning

It depends upon several factors but a reasonable starting place is 18 - 22" between the edge of the turntable and the front of the roundhouse. This assumes the tracks are straight and centered within their stalls. As you move closer the tracks move toward the outside walls. Because of space limitations, some modelers will bend the tracks slightly after entering the roundhouse. This is really a generalization since it depends upon turntable and the particular roundhouse combination.

From the Korber Models guide, it appears 7'l x 4'w for a three stall house. That will let you park the engines outside of the shed. Wider for a larger shed. Thanks for the link, Bob.

5' X 7'   Korber 304 (4) stall house and a Diamond Scale 27" TT.

Great looking turntable / roundhouse area Mike.

Paul

Dennis stated this very well. It depends on many factors like the number of stalls, length of stalls (if you want to accommodate articulated engines like a Big Boy) and size of the turntable. I used a lot of real estate.

Depends on the size of the turntable and the degree of the turntable steps between tracks. A small-degree step like 7.5 degrees on a larger turntable requires longer tracks between the roundhouse and the turntable (16" for a 33" Ross). If you go to a larger arc, the tracks separate more quickly and you can have the roundhouse closer to the turntable. We changed out to the pulley so that ours steps at 10 degrees instead of 7.5 so we could locate the roundhouse closer.

On a smaller turntable, you'll need a larger step anyway because at 7.5 degrees, the tracks running rails would need to cross (there's prototype precedent for this). For example, the 24" Atlas turntable steps at 15 degrees which is fine for its size. You'll note that the track spacing at the table edge is very close, so anything smaller would be problematic.

Mathematically, you can figure out what's where with the following:

1. Theta = the arc the table moves at each step. This governs everything.
2. R = the distance from the center of the turntable to the point you're checking. So if you have a 30" turntable with 10" to the roundhouse from the turntable edge, your "R" value is 25 (15" radius of the turntable plus the 10").
3. The separation from the next track would be 2 x R x sin(Theta/2). So with our 30" turntable with a 15-degree step it would be 2 x 25 x sin(7.5) = 6.5 (roughly). This means that you can drop the step to a smaller size or put the roundhouse closer to the table.

The above gets you to the front of your roundhouse. Now you add the length of the roundhouse stalls to the mix, plus your lead-in track(s), you exterior tracks, etc. and you have your real estate requirements.

On our setup, the real estate occupied is about 5' x 10'.

Hope this helps.

Not out of your league at all. Just takes some space and some planning. Our roundhouse and machine shop were scratch builds, but the Korber roundhouse is one of the better looking kits I've seen.

Plan even if you don't have the space right now. The expensive part will be a good turntable, but even that can be worked around as I know a couple of people who have scratch-built their turntables. I even thought about doing it (trust me, if I could even think about doing it you can probably actually do it).

Peter, it really isn't that daunting to put in a nice turntable and roundhouse. A few things to consider is that a turntable/roundhouse area of a layout usually is a focal point of a layout and if you get a great operational turntable is makes it fun to use and offers a lot of operation on the layout. It is also a great way to store many engines in a relatively small area. You will find the longer you are in the hobby and acquire more engines, especially steam that it really becomes a pain to store engines off the layout and having to place them onto the track all the time and if you don't have a TT/RH that sidings to park engines not in use tend to fill up quickly. The cost of turntables tend to be around the cost of one of our scale steam engines which is a one time purchase but yet we have 5,10 or dozens of engines on our layouts.  Just a little perspective.  

Originally Posted by AGHRMatt:

Depends on the size of the turntable and the degree of the turntable steps between tracks. 

 

Matt, one of the benefits to out turntable is that you can place your tracks to fit your layout as our turntable can index to whatever angle you want to space your tracks around the TT pit. So you don't need to be concerned about having to conform to set track spacing.   This is definitely a plus on fitting a turntable into a layout plan.

I hope this helps Peter.

The base Korber 304 house is 3 stalls, then each additional stall is an add kit. The kits add to the inside, so total house planning is important, it is not easy to add a stall later. There is also an extender kit for longer locomotives. 304 with an additional stall and the extender.  Roof panels were custom fabricated with luan board.

Interior detail.

The extension for longer locomotives.



The house is a 4ft X 4ft module. The Turntable module pictured is also 4 ft X 4 Ft. The transition module to the Fort Pitt High Railer layout is 5 ft X 6 ft, one of the largest modules.  Total pictured is 13 ft X 6ft. House and TT modules together 4 ft X 8 ft.

The bike is a Trek 6500 hybrid.
A few more pictures of the modular TT and house.

That is very nice, Mike, and really shows how much space is needed. I really like that wye and 4-track switch setup. I think I would actually enjoy switching if I had the space for a setup like that. Unfortunately I don't, so I plan to limit myself to just running trains when I get my layout designed and live vicariously though photos like these.

That is very nice, Mike, and really shows how much space is needed. I really like that wye and 4-track switch setup. I think I would actually enjoy switching if I had the space for a setup like that. Unfortunately I don't, so I plan to limit myself to just running trains when I get my layout designed and live vicariously though photos like these.   We did an extensive re-model on the  6 ft X 5 ft transition module a few years ago adding Ross 204 3 way switches.  It allowed for all (5) tracks to access TT and RH modules. 
Here's a video that kind-of shows how it all works.

Thank you   Mike CT

Mike,

Great job of planning and showing how to fit in a turntable and round house without eating up a lot of area. The short siding into the turntable is the way to go for space constrained folks.

A video of my Diamond Scale TT operating. Click to access.

Nice videos Mike. I saw that first one before, but didn't realize it was the same layout. Right now I have a hidden yard planned through the wall into the next bedroom. There is also a 1' shelf leading to that yard. Since I have a closet in the bedroom where the main layout will be located, I might be able to use it for my storage yard instead. I could then maybe add a TT through the wall and put a mini-yard on the shelf, maybe expand it to 18". I'll have to play with this idea a little more.

This is how I intend to put a round house into my layout. I found it by accident, I was looking up a business location, and the google map thumbnail caught my eye.