Fastrack curve sizes - Classic Toy Trains Magazine

QUOTE: Originally posted by LS1Heli It has nothing to do with the roadbed. The diameter is the diameter of the curve that the engine is physically making. Outer rail to outer rail.

LS1Heli,

Unfortunately, to confuse things even more, Lionel has actually designed the Fastrack system to be measured center rail - to - center rail. The O36 section circles are precisely 36" in diameter measured center rail - to - center rail, and the roadbed is 3 11/32" wide, so a circle takes up 39 11/32", or just shy of the 40" as Houdy indicates.

One problem with the Fastrack geometry is that the "O36" straights should be 12.73" long, the 90 degree crossings should be 10.54" across, and the 45 degree crossings should be 14.91" across. If this were the case, you wouldn't need so many small "fitter" sections for standard track layout configurations.

Rob