As I am moving along… Slowly, but moving all the same. As you all know switches are killer on the wallet, so track buying is the only thing slowing me down right now.
I have finally got the main loop around the layout and starting my new lists for yard construction. I was just wondering if the Walthers 90’ or even the 130’ turntable and the 3 stall roundhouse will comfortably fit inside a 22" radius loop? I am pretty sure I can get the turntables to work, but not sure about the roundhouse.
I did figure and construct my benchwork to use the 90 or the 130 turntables with plenty of room for adjustments. But the roundhouse is huge and expensive and I really don’t want to get one if it isn’t going to work.
My math isn’t the best so I just need a second opinion.
It would be a lot less iffy with the 90’ turntable than with the 130’ turntable.
The 130’ turntable is 18" in diameter. Measuring from the far tip of the turntable to the back of the stall on the roundhouse is approximately 42" on the extended stall, 40" on the regular stall. Inside of a 22" radius loop, you are talking about 44" of available real estate. That is really a tight fit.
I have the 90’ turntable with the older smaller roundhouse. With the roundhouse set back from the turntable the correct distance, it measures 26.25" from the turntable center point to the back of the roundhouse. From the far side of the turntable to the back of the round house is 32.5".
Going by the numbers given, a good way to fit the elements would be to put the roundhouse (sector house?) at the track clearance point (which, for 22 inch radius, is at the 20.5 inch mark on the radius line) and bring the turntable down as close to the tangent as clearance and overhang will allow. A couple of footprint templates would do wonders for planning!
Taking Brother Johnson’s dimension, the smallest curve which would allow a half-circle or more roundhouse with a 90 foot TT at the curve center would be 28" radius.
OTOH, if you design your own roundhouse (or kitbash the Walthers house beyond recognizability) you can put the TT (90 foot) at the center of the turnback curve, build a roundhouse inward from the curve clearance line with wider-than-standard stalls and end up with a `full circle with a slot in it’ house like the one at Steamtown. It will look cramped, the tracks will not line up with the pre-calibrated indexing and it won’t be worth squat as a locomotive display facility* - but it will fit.
*With locomotives inside a roundhouse, all you see is the south ends of a bunch of northbound tenders. Put the same locos on radial tracks in the open air and you (and your visitors) can enjoy your roster. The roundhouse was a maintenance facility, not a parking garage, so shouldn’t be very large unless you turn a LOT of locomotives. Turn, in this case, involves maintenance actions, not merely spinning the loco end-for-end on the TT.
Chuck (Modeling Central Japan in September, 1964 - 2 turntables, one rectangular engine house)
![http://cs.trains.com/TRCCS/themes/trc/utility/[IMGhttp://i94.photobucket.com/albums/l109/Duane151/BDSouthLoop.png[/IMG]:550:0](http://cs.trains.com/TRCCS/themes/trc/utility/%5BIMGhttp://i94.photobucket.com/albums/l109/Duane151/BDSouthLoop.png%5B/IMG%5D:550:0){kind=link}