... minimum radius? And turnout numbers? There s need to have scale swingnose frogs, or longer numbers sufice? The results multiplied by 1,19 would be valid for S scale also or there other specific consideration? The layout will be this plan, that I ll put in the background in templot and scale up until the minimum radius (the lower portion of photo near triangle?) of mainline be the desirable to this requirement. There s two photos attached showing the plan. Any comments and opinions are very welcome. 1871_011836_180000000.png 1871_011902_400000000.jpg posted: 2 Mar 2012 09:36 from: Alan Turner It all depends what you mean by "scale 333kph". If you mean the naive calculation that is often banded about of 330/76.2 km in 1 hour then you could probably get away with sharp curves. If however you mean a true scale speed to correctly represent the dynamics, then your model will need to travel at an actual real speed of 330 x square root of 76.2= (appx) 2880 kph. I think at that speed ...