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Discussion Boards => General Discussion => Topic started by: darthraven on January 30, 2012, 05:32:55 PM

Title: Code 83
Post by: darthraven on January 30, 2012, 05:32:55 PM
After getting to go to a hobby shop that carries train stuff (130 miles away) and looking at the different types of track I settled on Atlas 83 flextrack for the main part of track.  Still need to do some research on the different turnouts before I decide on that part though.
Title: Re: Code 83
Post by: GoCanes on January 30, 2012, 09:34:04 PM
Code 83 is a fine track.  Enjoy.  (May I suggest #6 turnouts?)
Title: Re: Code 83
Post by: darthraven on January 30, 2012, 09:40:57 PM
I am as of now still unaware of what the different #'s mean.  I do plan on researching it some though before deciding which ones to get.
Title: Re: Code 83
Post by: rogertra on January 30, 2012, 09:56:59 PM
Quote from: darthraven on January 30, 2012, 09:40:57 PM
I am as of now still unaware of what the different #'s mean.  I do plan on researching it some though before deciding which ones to get.

Google is your friend. :)  Tell you everything you need to know about rail sizes but code 83 is a better choice than code 100 but depending on era, you may also think about using code 70 on sidings, yard track and industrial spurs.

Title: Re: Code 83
Post by: ChrisS on January 31, 2012, 09:25:13 PM
The #'s refer to the diversion from straight. Think rise over run

Title: Re: Code 83
Post by: blf on January 31, 2012, 09:37:30 PM
Code is a # in thousands of a inch in height I believe. Bill
Title: Re: Code 83
Post by: darthraven on January 31, 2012, 10:05:40 PM
so after some initial research it looks like the numbers on the turnouts are for how sharp the curve is the lower the number the sharper the curve.
Title: Re: Code 83
Post by: Doneldon on January 31, 2012, 11:18:39 PM
darth-

Exactly.

     -- D
Title: Re: Code 83
Post by: rogertra on January 31, 2012, 11:39:23 PM
Quote from: blf on January 31, 2012, 09:37:30 PM
Code is a metric # in thousands of a inch in height I believe. Bill

Can't be "metric" and have the measurements in "thousands of and inch".  :-)

Two completely different measurement systems.

Title: Re: Code 83
Post by: Woody Elmore on February 01, 2012, 10:21:16 AM
Roger - tell that to NASA.
Title: Re: Code 83
Post by: JerryB on February 01, 2012, 01:56:20 PM
Quote from: darthraven on January 31, 2012, 10:05:40 PM
so after some initial research it looks like the numbers on the turnouts are for how sharp the curve is the lower the number the sharper the curve.

Close, but not quite correct. On prototype turnouts, both the through rail and the diverging rail paths are straight through the frog. There is a curved rail part between the point and the frog, but the frog is not curved, and the rail (curved or straight) after the frog is technically not a part of the turnout.

Model turnouts, especially those found in sets, are frequently curved to match the curvature of the accompanying set track. That allows for direct replacement of a piece of curved track with a turnout, thus making for easier beginner layout construction. These turnouts are not models of prototype turnouts and cannot be defined by a simple number.

The curvature through the frog is not present on turnouts modeled on prototype practice. The number (#4, #6, #10, etc.) describing prototype and scale model turnouts actually describes the departure angle of the frog. For example, a #4 turnout has a departure angle (of the frog) that is 1 unit of departure on the diverging rails for each 4 units along the through rails. Likewise, #6 turnouts have 1 unit of departure for each 6 units along the through rails.

Most prototype railroad turnouts are relatively large frog numbers, meaning they are 'gentle' or 'shallow' departure angles. The frog angle is directly related to the service and speed of the turnout. As an example of prototype practice, the American Railway Engineering and Maintenance of Way Association's (AREA) specification for a #20 turnout has a diverging speed limit of 45 miles per hour! Not many model railroads that would have the space to accommodate a #20 turnout.

Here are a couple of links to the National Model Raillroad Association's (NMRA) turnout specifications and recommended model practices:

http://www.nmra.org/standards/sandrp/rp12.html (http://www.nmra.org/standards/sandrp/rp12.html)

http://www.nmra.org/standards/sandrp/rp-11.html (http://www.nmra.org/standards/sandrp/rp-11.html)

Model railroads, once they develop past the set track stage, tend to use much smaller frog angles than the prototype railroads, with #4 or #6 turnouts used for yards and #6 to #8 turnouts used on mainlines. Compare that to the AREA #20 turnout information above!

If you have managed to read this far, I hope this makes some sense. Do some research using Google if you want some more information and details.

Happy RRing,

Jerry
Title: Re: Code 83
Post by: ebtnut on February 01, 2012, 04:07:37 PM
Jerry's commentary is right on point.  As a practical matter, use No. 4 turnouts for tight spaces.  Be aware that larger equipment, especially steam locos, may not pass through them.  Most anything except maybe a stiff ten-coupled steamer will negotiate a No. 6 and I would try stick to that turnout number if space allows.  If you really have the space, use No. 8's on the main line tracks.  BTW, the Bachmann 2-10-2 will have no trouble with No. 6 turnouts. 
Title: Re: Code 83
Post by: darthraven on February 01, 2012, 10:18:20 PM
Jerry, Thank you for the detailed response.  It was considerably helpful.  This will be my first layout and will be freelanced I am not super interested in prototyping at the moment ( that may change as I learn and my skill level advances).
Title: Re: Code 83
Post by: rogertra on February 02, 2012, 08:31:02 PM
Quote from: Woody Elmore on February 01, 2012, 10:21:16 AM
Roger - tell that to NASA.

And you saw what happened there?  :)

That's because the designers designed to metric, which was how the contract was written but the NASA "engineers" read the design in Imperial, NASA goofed, not the metric engineers.

So what I wrote, "Can't be "metric" and have the measurements in "thousands of and inch"." is 100% correct.  :)

Title: Re: Code 83
Post by: poliss on February 02, 2012, 08:41:00 PM
British OO models are 4mm to the foot.
Title: Re: Code 83
Post by: rogertra on February 02, 2012, 09:31:29 PM
Quote from: poliss on February 02, 2012, 08:41:00 PM
British OO models are 4mm to the foot.

That's not the same thing.
Title: Re: Code 83
Post by: JerryB on February 03, 2012, 11:46:07 AM
Quote from: poliss on February 02, 2012, 08:41:00 PM
British OO models are 4mm to the foot.

The assertion about 4mm scale above seems to be deliberately trying to confuse the folks asking questions here. Lots of scale factors are described in various measurement units for a variety of (usually historic) factors.

That has absolutely nothing to do with crossing two measurement systems as was done above in claiming that 'code' is somehow a combination of inch and metric specifications. It isn't.

In track and rail, the code numbers simply specify the height of the rail in thousands of an inch, that being an American inch. Here are some examples:


There is no metric term associated with the specification of rail height using the code numbers.

Happy RRing,

Jerry