Curve radia

it will work, although the running may be a little choppy. if it is lionel track, it comes in many diameters.

A guy I know bought an older layout (complete) and had it trucked to a new facility.  It has very wide curves, all O-31.  Each curve is followed by at least one (or more) straights.  I have never seen anything run on it, but it seemed to be a way to achieve larger curves without buying the actual track.  

You're correct about the Korean War track only being 31". Yes, you can alternate with the 1/2 straight sections. The curves will still be smooth. You will need to reconfigure your radius.

 

God Bless,

"Pappy"

It would be neat if 3- rail track would use radius as the defining number.  However, smarter people than I have chosen diameter as the defining quantity.  O-31 is 15 1/2" radius, and is actually quite tight for anything even approaching an O Scale model train.  O-72 will probably work for most 3- rail trains.  

Thanks guys, I have forwarded your answers to the customer. If anyone has one of those super sized engines and is really bored one day, it would be cool if he/she could perhaps try that out.

TinMan,

 

I think you are being mislead by some of these answers.

 

It is true, of course, that you can fill a wider area by inserting straight track between the O31 curves.

 

But, that is not increasing the diameter when it comes to running engines that require wider curves than O31. If an engine is rated at and requires O54 curves, for example, it needs O54 cvurves all the way around the curve.

 

A single section of O31 will not work with that engine. It is sort of the same principle as "a chain is only as strong as its weakest link".

 

It is true that some engines may negotiate curves slightly tighter than its rated diameter, but you'll never get a big engine through even a single section of O31 no matter how many straight sections are between the curved sections.

 

Jim

Ah Jim, the cold hard logic still wins out. I have not had any personal experience with these issues, but your approach absolutely makes the most sense to me. It's like if it smells bad, looks bad, and tastes bad, guess what it probably is bad! Thanks

Jim,

It was not my intention to mislead the OP. If you or he think so, my apologies.

"Pappy"

 

Pappy and others,

 

It was just a matter of interpretation. You guys were correctly explaining to the original poster how you could expand an O31 curve layout with straights to fill a larger area.

 

He mistook your answers to mean that a larger engine would be able to negotiate this arrangement. Just a misunderstanding.

 

Jim

It's even worse that that - center rail radius of regular "O"(O-31)is actually 14.14" computed from 10" straights in the Lionel universe.

I have a Rail King 2-8-8-2 that runs just fine on O-31 track and 022 switches.  I have a Williams Challenger that requires 072 track.  All the other post war and prewar locos that I have run just fine on O-31.  There is no hard and fast rule for track.

Another consideration is the pickup rollers.  On bigger locos, the pickups can bridge the center and outer rails if the radius is too tight, even though everything else may roll.