So my dream locomotive model is said to "run on R3 curves", which is a wonderful thing I suppose. Now, I know it takes 12 pieces of 30 deg track sectors to make a full circle, but none of this information tells me what the actual radius of the track sector IS...unless I know the length of the sector (which is not provided by the sites who sell the track). So, for gauge 1, what do R2 and R3 curves translate into, in terms of radius? I find it hard to believe the railroad modeling industry has any engineers in it--could they make this any harder?

Thanks Tyson. I didn't want to buy the track only to find out it's the wrong size. Doesn't really matter now, since I just discovered flex is available in stainless. Very nice site you folks have built here, by the way.

Hello, Bongo Boy. Which is the manufacturer of your track? If I'm not wrong, the R2, R3, ... classification are a bit «manufacturer-dependant», so different brands may have slightly different radius for a same «Rx». For example, two european manufacturers (Roco and Fleischmann) have these R-measures in H0 track: Roco: - R2 -> 358mm radius (12pc., 30º each) - R3 -> 419,6mm " " " - R4 -> 481,2mm " " " - R5 -> 542,8mm " " " - R6 -> 604,4mm " " " - R9 -> 826,4mm " (24pc., 15º each) Fleischmann: - R1 -> 356,5mm radius (10pc., 36º each) - R2 -> 420mm " " " - R3 -> 483,5mm " (20pc., 18º each) - R4 -> 547mm " " " Notice that the Fleischmann R1 have roughly the measures of the Roco R2; same for the Fleischmann R2 and the Roco R3, and so on... This is a bit confusing, but I hope that it can be of help for you.

Seeing as you're talking gauge 1, I'll assume you mean LGB. Quoted this from MyLargeScale.com forum. DIAMETER MEASURED CENTER OF TRACK-TO-CENTER OF TRACK R1 = 1200 mm = 47.24 inches = 3' 11" R2 = 1560 mm = 61.42 inches = 5' 1.4"" R3 = 2390 mm = 94.09 inches = 7' 10" R5 = 4640 mm = 182.68 inches = 15' 2.7" I hope that's what you're asking.

Yup...that's it, and thanks. So...just when I thought things were bad, they got worse (vendor-dependent radius designations). I was actually looking at the specs for an MTH locomotive. What's weird here is that, at least for 1 guage, R2 corresponds to a 22.5 deg sector, R3 to a 30 deg sector. So...it looked like the 'R2' and 'R3' designations at least had some relevance to reality (Rx where x is approx degrees/10). But, now that you've thrown in other gauges, it looks like there's no meaning at all (and no purpose, I might add ). That's okay..I'm going to make a real effort to learn something about the craft before I start bitching too much about the goofy 'standards'! Gonna be hard though!!!

For a bit more confusion, Peco OO/HO settrack: R1 371mm, 14 5/8" R2 438mm, 17 1/4" R3 505mm, 19 7/8" I think all the British makes correspond.