Don the diameter of the U-Turn is 12"
Plarnold is right about the X-Crossing. That is probably the tightest curve. In fact I actually modified one for a tricky part of the old layout but found that because I followed it up with another curve that long trains would be pulled off the short radius rail sometimes.
Plarnold is right about the X-Crossing. That is probably the tightest curve. In fact I actually modified one for a tricky part of the old layout but found that because I followed it up with another curve that long trains would be pulled off the short radius rail sometimes.