Frank writes:

“I’m a novice HO model railroader. I usually set up a simple oval under the Christmas tree annually. I’m bored with that. Furniture confines me to 5′ x 7′ area. I want to add a couple turnouts, a 2nd oval, and sidings for some wild west buildings. What is the minimum HO turn radius for 4-4-0 and a 4-6-0 1870-80’s steam locos and that era freight cars?”