Track Center Spacing for 30" Radius

Currently building the benchwork for my layout and was wondering if 2 1/2" centers is enough spacing for paralel tracks on a curve with a 30 radius. I will be running 85’/89’ cars (autoracks, superliners, flatcars etc.). I was looking for specific spacing and found general terms but not minimums.

Any help is appreciated.

Mike in Tulsa

John Armstrong recommended 2 1/8" when the inner track is at 30" radius. If the inner is nearer to 26", add 1/4". He also said that you should experiment with your largest articulated loco or longest rolling stock to make sure.

The inner track is 30"r, the NMRA tables list 32"r req. 2 1/2 centers, but do not list a req. for 30"r.

Sounds like 2 1/2 will work, I think my superliners are the longest and have the most overhang in the turn.

Thanks.

Mike in Tulsa

I have found that with 30" radius on the inside there are only a few occasions where cars will brush if the outside track is larger than 30" and the spacing is 2". The worst case scenario is two 85’ passenger cars. On the inside track the widest point is the end of the car and on the outside track the widest point is the middle of the car so if they pass you are home free. UNLESS you have a brakeman hanging on the car side :-).

HO,…N,…O,…?

Sorry it is HO.

Mike in Tulsa

The reason that I asked the scale is that it makes a huge difference.

These guys are on the money for HO.

2 1/2" is more then enough for 30" curves. I use 2 1/4" and have no problems. Although, with 89’ flats, and full length passenger cars, 2 1/2" will get an extra measure of security.

Nick

Update>>>>>

I just finished laying parallel tracks, inside track at 30"r and outside at 32 1/2"r making them 2 1/2 on center. I ran my longest cars (superliners, autoracks, 89’ flat cars etc.) and everything clears fine. Infact, there is quite abit of clearance.

Just wanted to thank everyone for their input.

Mike in Tulsa
BNSF Cherokee Sub

are you guys talking about center of main line to center of spur or sidings

NO, he is talking about a double track main line where there is a curve, and both tracks have different radii in order to stay close but still run in the same right of way…the same roadbed. Since tighter curves mean that longer cars and engines will have a more exaggerated overhang at EACH end, there is a real danger of sideswipe if the spacing on those double track curves isn’t sufficient to allow clearance. Of course, we are only concerned about the clearance on the outer side of the inner track and the inner side of the outer curve. This is where the trouble will lie if we don’t plan to accommodate our largest overhangs.