@gunny posted:I doubt many engines will handle 12.4"
Good luck
Gunny
I agree. Let's remember that the "typical nominal" track radius in HO scale is 18".
FWIW, my Flyer Pacifics and even the Enhorning F unit I have are just fine on the sectional 42" (21"R) Gargraves that I'm currently using. Obviously I would prefer a larger radius, but like most of us, my space is limited.
Mark in Oregon