Code 83

[darthraven]

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.

[GoCanes]

Code 83 is a fine track.  Enjoy.  (May I suggest #6 turnouts?)

[darthraven]

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.

[rogertra]

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.

[ChrisS]

The #'s refer to the diversion from straight. Think rise over run

[blf]

Code is a # in thousands of a inch in height I believe. Bill

[darthraven]

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.

[Doneldon]

darth-

Exactly.

     -- D

[rogertra]

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.

[Woody Elmore]

Roger - tell that to NASA.

[JerryB]

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/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

[ebtnut]

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. 

[darthraven]

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).

[rogertra]

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. 

[poliss]

British OO models are 4mm to the foot.