Do you think an HO scale train up to 15 ft. long could handle this 22" radius curve without string lining if the cars at the rear weren't too heavy? Keep in mind that there's a 9" straight in the center of the S curve.
I would add to Greg's reply that Intermountain wheelsets on the trucks to reduce rolling friction at the axles would not hurt. If the cars are 50' and greater, the Intermountain wheelsets would be necessary in addition to equal weighting.
Brandon, I'd overlooked this before, but I have a similar configuration at the "staging" end of our layout. I have 24-26" radii on two tracks; while they do not form a "continuous" dogbone - I simply want a muzzle-loading configuration to allow SLSF to run in/out of Olathe, and the same for AT&SF - I've found that with careful track laying, even a heavyweight passenger car will handle the curves at lower speeds. I'm not concerned about appearances or speed, since loop is off-stage. Probably doesn't really answer the question, but I think it can be done if space and operational objectives dictate a turn-back like this. Best Regards,
