This was a unique situation. I purchases a conventional standard gauge #6 engine and coaches. Engine has no traction tires or no grooves for traction tires. Engine has trouble pulling the tender. Bullfrog Snot seemed like an easy fix.
Talked to Mike Wolf at York and he set me up with traction tire wheels. Installed the wheels. That was a first class pain. Engine now work as it should.
Pictures of the #6 engine, Proto 3, now shows traction tires. You should be good to go from now on.
George