jonnyspeed posted:Mike CT posted:Two rail curves, in most cases, have to be twice as large. While O72 works well for 3 rail. Two rail would start, for small locomotives, at O100 or larger. You would need more space for two rail curves, though some have done two rail switching layouts, on smaller spaces. IMO. Mike CT.
I disagree and I think this kind of advice is what keeps a lot of people from trying 2R.
I have done the following actual min. radius testing over the years:
36"r - OMI Heavy Mikado, MTH H-10 2-8-0, Joe F. Converted K-Line 4-6-4 (24"r with blind center drivers), All Diesels (Atlas, MTH, 3rd Rail) up to modern 6 axles (not tested DD40 etc...), Golden Gate Depot 80' passenger cars
27"r - Atlas, 3rd Rail, and MTH F units, Geeps
24"r - Atlas SW switchers, MTH 19th century 2-8-0, MTH USRA 0-6-0, MTH K4 4-6-2, MTH 64' passenger cars
18"r - MTH 0-4-0
Obviously models look better on broader curves, but I can verify they will negotiate these curves depending on what length couplers you use.
Quick note: Two rail uses radius measurements, 3rail, for some reason, uses diameters.
36"r equates to O72 etc. Good description, of what works on curves above.
