I'm having some problems with points.

ModelRailroadForums.com is a free Model Railroad Discussion Forum and photo gallery. We cover all scales and sizes of model railroads. Whether you're a master model railroader or just getting started, you'll find something of interest here.


Heartland Trains

New Member
For my layout, its going to be a 4x10 with 22 inch radius curves. The thing is, one of the switches for a passing siding is going to be on a curve. I am trying to figure out what style of switch I should use. The numbers for switches, like #4 and up, confuse me. Anything would help. Thanks

-Heartland Trains
 

Selector

Well-Known Member
Think of the distance you move through a turnout, but in feet, or some other unit. For every foot you run along the main axis of the turnout, your diverging route deviates at a certain rate if the train takes the diverging route. For a #4 turnout, the diverging route moves one foot to the left or right for every 4 feet of travel down the main axis. A #8 turnout runs 8 feet down the major axis for every foot of diversion. If you can picture it, a #8 turnout takes twice as long to diverge a single foot, so the frog angle is about half of the frog angle of a #4 turnout. The sharper the diverging angle, the smaller the frog number. In the prototype, except for street cars and some industrial track, it is unusual to see anything much smaller than about a #8. Out on the high speed rails, turnouts that make crossovers run about #25 and on up. Very shallow angle at the frog, and a very loooooonnnng turnout, probably 50-80 feet and even more for speeds in excess of 60 mph.

If you are on a curve and need to diverge, you get a 'curved' turnout. The trick is to get the right one. A Walthers #6 or a Peco #6 (I think Peco calls theirs middle radius or something like that, you'll have to look) CURVED turnout, left or right, is probably what you need. But investigate the twin radii for curved turnouts and see if you can't modify the curve enough to make such a turnout fit.
 

dave1905

Well-Known Member
One way to plan things is to go to the PECO website, they have templates for all their switches, you can print one out and see how they fit.

As mentioned the switch number is the angle of the rails at the frog (the place where the rails cross in the middle of the switch). Generally that is also how the tracks diverge past the frog, but some switches have curves in the rails beyond the frog, making them diverge faster. Because of that, not all switches of the same number are direct replacements.
 

Iron Horseman

Well-Known Member
For my layout, its going to be a 4x10 with 22 inch radius curves. The thing is, one of the switches for a passing siding is going to be on a curve. I am trying to figure out what style of switch I should use. The numbers for switches, like #4 and up, confuse me. Anything would help.
If you have a 4" space and are using 22" radius, there isn't much space (aka none) to put a passing siding on the curve unless it is on the inside of the curve with a radius of less than 22". Like 18" radius. Is that what you are doing? If so Altas used to make a curved turnout with a 22" outside 18" inside radius. Only on the used market now. their new curved is 22" inside 30" outside.

Or is this passing siding curving along the 10" side of the space somehow.
 




Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)


ModelRailroadForums.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com

RailroadBookstore.com - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section.

ModelRailroadBookstore.com - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.

Top