What is a good clearance for the edge of a layout on a 22" radius loop back ?

[dmiller]

What would you recommend as a good out edge of the layout distance where the track loops back? The outer track is 22" radius. So when I cut the road bed ( cook cutter technique ) the outer edge would be at WHAT radius? I was thinking 25" or 3" from the 22'' track center to allow space to put a fasha and safety fence to keep locomotives from taking the plunge off the layout .. ( space at the loop back ends of the layout is at a premium like 48-50" thanks . The idea is allow space just for a guardrail outside the 22" outer track when I cut the wood and no landscaping scenery.
Thank you all! -dm

 

[santafewillie]

25" would definitely work. If space is at a premium, 24" would also work, but there won't be any room for scenery. Remember that you can always make it smaller more easily than you can make it larger.

Willie

 

[dmiller]

Thanks no scenery need just aisle space and a guard rail to keep the engines from plunging into the depths of H---
actually the 24" would utilize a 4' peice of plywood to cut the whole half of a circle