Rail code & sizes

[DonB]

As it implies in the title, I'm wondering where the definitive listing for model rail sizes / codes is to be found, and who devised it.

For instance, I have a quantity of N/S F/B rail sold as part of the Peco TT (3mm scale) Individulay system in the early 60's, does this fit into the coding scheme, or is now an obsolete item?

[PhilEakins]

As it implies in the title, I'm wondering where the definitive listing for model rail sizes / codes is to be found, and who devised it.

For instance, I have a quantity of N/S F/B rail sold as part of the Peco TT (3mm scale) Individulay system in the early 60's, does this fit into the coding scheme, or is now an obsolete item?

 

I don't know about definitive codes - but my understanding is that the 'code' quoted is the height of the rail in thousands of an inch.

 

Phil

[asmay2002]

As it implies in the title, I'm wondering where the definitive listing for model rail sizes / codes is to be found, and who devised it.

For instance, I have a quantity of N/S F/B rail sold as part of the Peco TT (3mm scale) Individulay system in the early 60's, does this fit into the coding scheme, or is now an obsolete item?

 

The code is the height of the rail in Thou. It's a dimension.

[melmerby]

The code is the height of the rail in Thou. It's a dimension.

 

Apart from Peco Code 55 N gauge which is code 80 rail with 25 thou sunk in the base so only 55 thou is above the sleepers.

 

Keith

[DonB]

Mickey......Thanks for the NMRA reference.

I do remember seeing that (or a similar table) in the distant past, but could not remember where! The additional 2nd and 3rd tables I found confusing at a quick look, I need to go back to understand what they are saying.

 

What about Bull-head rail? Is there a similar table anywhere?

 

Do UK and Continental model rail manufacturers adhere to the NMRA standards, or just stick at rail height for identification?.

[craigwelsh]

Mickey......Thanks for the NMRA reference.

I do remember seeing that (or a similar table) in the distant past, but could not remember where! The additional 2nd and 3rd tables I found confusing at a quick look, I need to go back to understand what they are saying.

 

What about Bull-head rail? Is there a similar table anywhere?

 

Do UK and Continental model rail manufacturers adhere to the NMRA standards, or just stick at rail height for identification?.

Tbh unless you go P4/P87 etc the shape of your railhead isn't going to make much difference with the large 00 flanges doing a lot of aligning work.

 

Code 82/83 FB is used in the UK to match up with code 75 BH which is chosen to be close to BS 95LB standard rail section. I think the FB at .82 would equate to something like 105lb rail reading the 2nd table backwards.

[FNM600]

As it implies in the title, I'm wondering where the definitive listing for model rail sizes / codes is to be found, and who devised it.

For instance, I have a quantity of N/S F/B rail sold as part of the Peco TT (3mm scale) Individulay system in the early 60's, does this fit into the coding scheme, or is now an obsolete item?

 As already mentioned the Code is the height of the rail spefified in 1/1000th of inch.

So for example code 100 is 100 1/1000th  and in mm it is about 2.5mm or .1".

The NEM and NMRA as well as the BRMSB norms mention various standard heights in mm (NEM) and thous of inch (NMRA).

 

Normes Européennes des Modellisme and National Model Railroad Association and British Railway Modelling Standards Bureau all recomend certain codes of rails for a given scale in tables.

For NEM Norm 120  http://www.morop.org/de/normes/nem120_d.pdf   in German or  http://www.morop.org/fr/normes/nem120_f.pdf  in French. For the English version translators are wanted by  http://www.morop.org/en/normes/index.html .

For NMRA http://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-15.1.pdf Recomended Practice 15.1

 

BRMSB is the only standard that has listed codes for bullhead as bullhead rail is rare in Americal and Continental Europe.

 

In any case for HO  BRMSB 1950 (yes they contemplated British HO even in those days!) and various OO and EM etc. code is 98 for bullhead and 89 for flat bottom.

 

For example a given height of rail such as code 75 could represent light rail of secondary routes in one scale(HO)  and heavy mainline rail in a smaller scale (TT). 

 

 To find out what your stock of rails is just measure it with a caliper or micrometre! 

[Junctionmad]

I don't believe there is any track standards in 00 that state rail height , the current DOGA fine and intermediate ( BRMSB never really had any teeth or success in standards ) specify code 75 BH for the intermediate track standard as a " minimum ". Standards generally refer to wheel /flange and crossing specs not rail height. DOGA fine track does not seem to specify rail height or weight ( which is entirely correct in my view )

 

Model track height is a function of real prototype height and depending on prototype and era anything from code 55-to code 92 could be appropriate

 

Code 75 bullhead being common as its closest in scale to the prototype common BH size

I don't believe there is any track standards in 00 that state rail height , the current DOGA fine and intermediate ( BRMSB never really had any teeth or success in standards ) specify code 75 BH for the intermediate track standard as a " minimum ". Standards generally refer to wheel /flange and crossing specs not rail height. DOGA fine track does not seem to specify rail height or weight ( which is entirely correct in my view )

 

Model track height is a function of real prototype height and depending on prototype and era anything from code 55-to code 92 could be appropriate

 

Code 75 bullhead being common as its closest in scale to the prototype common BH size

Hence your TT track profile might be useful in several gauges depending on what is trying to be represented

[BR60103]

Way back when, I learned that NMRA Code 100 rail would produce the standard HO flangeway when 2 rails were put side by side with the bases touching.  I don't know if it works for other sizes/scales.

[Junctionmad]

Way back when, I learned that NMRA Code 100 rail would produce the standard HO flangeway when 2 rails were put side by side with the bases touching. I don't know if it works for other sizes/scales.

In general , no. But there are some " flukey " combinations that happen to work, but only of course in FB rail.

 

Given the amount of " slop " , i.e. 15 thou in the Nmra standard flangeway, I suspect the code 100 FB rail to nmra standards providing a HO flangeway was perhaps a " lucky break )

 

Nmra 100 Rails butted together actually resulted in flangeway 45 thou , but I'm not sure this was deliberate