Dead Man's Curve! Yes..."O" scale in less space than HO! 12 radius curves....VIDEO LATER

The postwar Lionel/Marx/Hafner guys would be proud.

Back in the late 50's Atlas was making 12" radius curves they came in sets like the TYCO Mantua General. Perfect for a small bedroom layout which I had.

So you're one of those wide radius guys!!!! I was setting up my super streets to test and see if I wanted to put them on the layout. The MTH PCC worked fine.....so I tried the big ALCO diesel......It actually worked on the curves......just not a loop!! 

If I was you I would try running an engine with cars coupled behind it and not just one at a time pushing them or running just the engine.  I've had smallish stuff (7 1/2" long) that couldn't handle 27" curves because of the couplers pushing outward and derailing things, including the engine.  On some the trucks wouldn't rotate far enough

Now's the time to make sure.

- walt

Interesting! I'm a little leery about that track over the sump pump thing though

Ho is normally measured to the track gauge's center line.

O gauge that distance varies by mfg., but Lionel used the outer rails dia.

I run an 0-4-0 on hand bent 0-17.5 (o.d.)...it is IN a 1940s cabinet type T.V., behind the glass screen

Quite a few others I can run on 0-21 that is in my bedroom.

The Berk Jr couldnt manage 0-21, so six driver steam seems to be about the limit there. (and drawbar may not swing enough on some)

All my diesels the couplers hit the steps in the turns at 21"; so no dice.

I've read a Plymouth switcher could pull off 0-15. That would make a figure 8 length in O, real close to the same size as a HO R-18 circle.

Couplers over many years (and mfg.s), vary slightly in size. The smaller, tighter fitting knuckles will rear their heads in anger, binding in curves as large as 0-27, making smaller curves impossible. (I have a K-line GG-1 with a "small metal knuckle" that can manage 0-27 with the right lead car. But put another small knuckle car up to it, and it binds too much for 0-31, and barely pulls off 0-36.

It comes down to experimenting.

walt rapp posted:

If I was you I would try running an engine with cars coupled behind it and not just one at a time pushing them or running just the engine.  I've had smallish stuff (7 1/2" long) that couldn't handle 27" curves because of the couplers pushing outward and derailing things, including the engine.  On some the trucks wouldn't rotate far enough

Now's the time to make sure.

- walt

I agree!

My layout is 7 x 9 with about half O-31 curves. I have had to modify cars designed for O-31 to get around the tightest parts of the layout. I built a few Craftsman Kits. The kits come without trucks so I bought accessory truck assemblies where the couplers and trucks are one assembly. On the first one  I followed the truck placement of the instructions and the ends of the cars bumped into each other as the couplers ended up to close horizontally to the end of the car body. I salvaged it by using Cabose trucks which pushed the couplers more outside the car body profile. Later ones I built I moved the trucks closer to the end of the car. On vintage style cars with truss rods I had to again deviate from the instruction on the termination points of the truss rods in order to clear the trucks when they rotated enough to make O-31 curves.

I also bought some O-31 MTH streamliner cars and the observation car had to have surgery on its rear underbody to clear the trucks on these O-31 curves it was rated for.

If I had to do this layout again (no chance, too old!) I would not use such tight curves at all or MTH sectional track. That would be hard in such a small layout if you want more than one contiguous loop (I would want two mainlines to run two trains at once on different loops).

LDBennett

All my trains run just fine on O-27 curves. I bet most could handle O-24 just as well! Partly why O-27 is so much fun. You can get more trains in less space than HO!