turn-table and roundhouse

[ctclibby]

Hi All and Merry Christmas!

I am playing with my track plan including the .subject.  I am going to run *big* steam; 4-8-8-4's and such which should require about a 130ft table bridge.  I am stuck in deciding the distance of the roundhouse to the table pit and have figured out that the roundhouse door-to-door distance is the governing factor.  I have been looking at the E.Suydam 3 stall as a basis and also have found a few 'extra stalls' to make the building bigger but I don't know the door-to-door distance.  Anybody buiild one of these and have the paper plan that came with it and let me know?

I guess that this probably doesn't matter until build time, but I am trying to get stuff on the layout plan close to where it could be when built.

Ideas?

 

Thanks!

ctclibby

[gmcrail]

The governing factor for the door-to-pit length is the stall angle, not the distance between the doors.  The stall angle pretty much controls almost all of the other dimensions of the turntable-roundhouse area.  The narrower the angle, the longer is the door-to-pit distance.  If the angle is too narrow, you wind up having to put frogs in  the stall tracks, which gets to be really hairy to do, IMHO.  Most kit roundhouses have anywhere from a 7-degree to 15-degree angle.  With a 130-foot table, you'll be better off getting the matching roundhouse (Walthers makes both).  With the Suydam kit (hope you're handy with a soldering iron!), you'd have the edge of the table almost under the front of the roundhouse, since it's made for a much shorter table size. 

The larger the table, the smaller the stall angle has to be to give a decent lead in front of the doors.  I have a 14.375" table (about 104.3 feet) and a stall angle on the Heljan roundhouse of 10 degrees, which gives me about 8" (58 feet) in front of the doors.  A 130' table would leave me with about 20 feet (scale) in front of the doors.

You might even want to try scratch-building the roundhouse; once the math is done (trig and plane geometry), the only problem is the windows, which are available...

Good luck, and let us know how it goes...

[tomikawaTT]

By choosing an appropriate stall angle you can have a roundhouse apron as long as a N&W Class A, or an apron so narrow that the roundhouse roof overhangs the pit.  If the former, the radial tracks will probably overlap and need frogs.  In either case, the roundhouse will probably have to be either heavily kitbashed of built from scratch.

OTOH, there have been places where the turntable and the engine shop were NOT co-located.  Not to mention that there were many places where turntables served radial tracks open to the sky.  Then, too, many roundhouses were modified by extending a stall or two to service longer locomotives.  Or there might even be two separate roundhouses of different stall lengths served by a single turntable.  All in all, a fine bucket of worms...

Chuck (Modeling Central Japan in September, 1964 - servicing steam in rectangular engine shops)

[don7]

Hi, I have the roundhouse kit that you intend building. I took a look at the instructions to see what was mentioned about the turntable recommended for it.

On the full size layout for the floor plan it is mentioned

4. Turntable pivot is 10 9/32 in front of front edge of building.

That information is obviously meant to match the center lines of the three bays to the turntable. You could still adjust the track if the distance was not to your liking. Any adjustment would of course be longer than what is the recommended distance.

Just a point, if you did not want to solder the kit you can use a number of new glues that are on the market now that did not exist when these metal kits were brought out.

I have a number of these kits to add to my railroad layout. Besides the roundhouse there are a couple of mining kits that I intend to build.  Not sure if I will solder or glue the kits when it is time to build.