Could someone please take the time to explain this to me. Yes I am new to hobby. What the difference in all the turn outs? I am curious about the numbers. What would be used in what circumstance? I have a little bit of an idea, but need a little fine tuning.

Hi Rob: The numbers indicate the length of the turnout and the radius of the curved track. I don't think there is anything scientific to the numbering system. For a more complete answer I will suggest going to the NMRA website. Just type in NMRA in your browser and find the beginners information. Click on track in the righthand column and there is a whole bunch of information. Welcome to The Gauge by the way.

A # 4 turnout diverges one unit in four units of run. A # 6 turnout diverges one unit in 6 units of run , so a # 4 frog angle is bigger than a # 6 frog angle. Jacques

Hi Rob, As noted above the number refers to the the degree to which the turnout track diverges from the straight track. The higher the number the more gentle the angle. Turnouts with larger numbers help accommodate higher speeds so #6 and higher are great for the main line. #4 turnouts are pretty sharp by comparison and are often used for sidings or spurs for low speed switching of cars. Larger locomotives can sometimes have derailment problems on smaller numbered model turnouts. Ralph

So will scale length passenger cars, and long freight cars like auto racks, 89 foot boxcars, etc. Generally, if a 30 inch minimum radius is recommended for a piece of rolling stock, it also needs a #6 or bigger switch. If it works with 18 inch radius, #4 will work.

Also, numbered switches don't have a radius. There is a radius btween the points and the frog, but they straighten up at the frog; there may be curved track beyond this. Switches with a radius can't have numbers; the geometry doesn't work. Even our switches are pretty sharp compared to a real railroad. Count the ties from point to frog on a real switch, then compare it to a #6 or #8.

My CNR Maintenance of Way Handbook has diagrams showing how #10 (sharpest) to #20 turnouts are constructed. Andrew