Code whatever

'Tis the size of rail, so Code 100 was the older OO standard, now reduced to (IIRC) 80, N used to be (IIRC) 80 and is now available in 55 - IIRC it is a measure of the height of the visible rail (some, eg Peco N fine) have some of the rail set into the sleeper base as otherwise the rail would be too flimsy. For the life of me I cannot remember if this was mm or some Imperial measure.

Regards

Mike

The height of the rail in thousandths of an inch. So code 100 is a tenth of an inch.

So it is independent of scale.

Hundreds of an inch. Code 65 = 0.065"

My bad! You're correct.

Code 100 represents rail of 152lb/yard in HO, slightly lighter in OO. !52lb rail was AFAIK only used by the Pennsy, and even they did not use it extensively. Still, because of that fact, 16.5mm track for HO is to scale, sort of.

Code 80/83 represent the heaviest currently used rail for OO/HO, about

132lb/yard. Most track is built with lighter rail, hence Peco's code 75, and code 70 rail for 16.5mm track from Shinohara, etc.

Code 80 for N is simply not to scale, but it's robust enough to stand up to repeated assembly and disassembly. Code 55 is about right for 152lb rail. A better rail size for N would be code 40, but that is a fragile rail, easily kinked. I used code 40 for a 16.5 mm gauge turnout about 40 years ago, glued the rail down with Pliobond. Worked well as a demo, even with 0.035" wheel flanges, but I never installed it in a layout.

Rail height and weight and therefore scale appearance correlate fairly well, but not perfectly. Code 100 with a narrow railhead will look pretty good if the track is ballasted, painted, and weathered. Look at real track for ideas on how to do this. In this, as in so many aspects of model railways, illusion often creates as good an effect as true scale, and sometimes better. ;-)

cheers, wolf k.

The code number is the height of the rail in thousandths of an inch.

Starting at the bottom: code 55 is N gauge code 60 is Z gauge and N-6.5 code 75 is OO/HO gauge amd HOm code 80 is N gauge and something called OO-9 code 83 is HO gauge code 100 is OO/HO gauge and something called O-16.5 code 124 is O gauge code 143 is O gauge code 200 is 1 gauge and something called SM-32 code 250 is something called G-42

In the above listing "something called" indicates that Peco made up the description. The original way of describing narrow gauge track is to use the scale, followed by a lower-case n, and an indication of the full-size gauge; thus OO-9 is OOn30 or OOn2 1/2

HTH

It's much too simple to say "is". Code 55 is also used in H0 gauge, and I've used code 100 in 0 gauge. You can use whatever rail suits your prototype and scale.

Then there's code 40 which is mostly used in H0f, N, Nm/Nn3 and Z gauge.

Erik, you're right. I was just listing the stuff that is available ready-made in the UK. If you make it yourself you can use anything, although I think code 250 might be a bit big for Z scale :-)

Erik,

Not forgetting 2mm scale :-)

Jim.

...and 4mm scale narrow gauge (S4n2) :-)

Sorry, sometimes I just forget those weird British scales ;-)

Thanks for all the very informative answers.

-- Richard

That is with ready to run track, flrex-track etc,.

You can use what you like - several 7mm Colonel Stevens-ish light railway layouts use code 100.

"Mike Smith" wrote

Indeed the measure in in 1/1000ths of an inch.

John.