Scratchbuilt, 4-wheeled On30 car on a handlaid 9" radius turnout following Geren Mortensen's (The On30 Guy) industrial trackage templates. Rail is code 70 Micro-Engineering. The car is built upon a modified heavy-duty, MDC HO passenger truck frame. See Jack Hess' articles in Light Iron Digest Volume 4 Issues #3 & #4 for construction suggestions.
The truck would not pass through the diverging route unimpeded without the addition of a guard rail adjacent to the curved stock rail. The point rails are curved through the frog to make this tight turnout possible. Definitely the place for slow speeds and reasonably weighted cars.