This is not an installation tutorial for the Walthers HO scale turntable but it does provide information on track spacing that might come in handy. I had to go through this exercise for myself so I thought it might be useful for others. I wanted to know the optimum spacing angle for service tracks radiating from the turntable.
This turntable has a 12 3/4" pit diameter and a 13 3/4" diameter outer edge. What would be the best spacing angle for tracks coming off of this turntable? The drawing below shows the turntable and various spacing angles. Further discussion follows the drawing.
Green = Turntable and locomotives
Blue = Track
Black = Roundhouse structures
Tracks A & B show a 15 degree separation between tracks
Tracks C & D show a 10 degree separation
Tracks E & F show a 12.5 degree separation
Note that my following comments have nothing to do with prototype practices. This analysis simply trys to determine how much space is required to “cram” a turntable and service tracks into a model layout. The real world had other needs and typically had much more real estate to work with.
A 15 degree separation is a waste of space since even at the edge of the pit there would be plenty of clearance between locomotives. With this separation a lower number of service tracks can actually installed in a given space.
A 10 degree separation requires a minimum of 1 3/4" past the turntable rim for clearances between locomotives. This requires longer service tracks and more space on the layout.
A 12.5 degree separation allows the service tracks to be as close together as possible but still have clearance between locomotives almost at the turntable rim. This appears to me as being the optimum angle for modeling with this turntable.
Roundhouses