Hi Rail and Toy trains

Classic Toy Trains Forum
21

Dave:

As I understand it (with information from John Armstrong’s Track Planning for Realistic Operation, 2nd edition), the real railroads rate curves in degrees changed per 100 feet of run. If you do the math out for a 5 degree curve (that’s 5 degrees in each 100 feet of run), you get a radius of 1,147’ 4.6".

When you convert that to O, you get a radius of about 286.8 inches, or about 24’. So, you’d need about 48’ to make a single half-circle out of a 5 degree turn.

A 1 degree turn, which is probably closer to the type of turn for 80 MPH, has a radius in O of 1432.5 inches, or 119’ 4.5".

I think you’d need a space the size of the Boeing airplane factory to build an O gauge layout using true scale curves.

Tony

22

Of course, none of us (unless one of us is Bill Boeing) will ever have that much space for a O-1432 curve…

But then, real railroads don’t have magnatraction!!![:D]

23

The limit of the conventional method of describing the curvature of railroad track is a 180-degree curve, where the direction changes 180 degrees in 100 feet. I think that it is interesting that this is exactly the curvature of O27 track, which has a radius of 12.5 inches, or a diameter of 100 scale feet.

24

Hmmm, now that’s truly interesting!!!