Turnouts

Look at this picture I found of a storage yard. http://www.gmrg.org.au/images/wall-const-2009-04_01.jpg
For future reference, in HO scale, what kind of turnouts would I need to do something like this with code 100 track. Keep in mind I have a Bachmann Spectrum 4-8-2 and an SD40-2 that would need to make the turns. Thanks in advance for the input. - Brandon

 

The photo appears to have been removed. However, in general I would say that the 4-8-2 would be happier, and so would anything longer than 40' cars, if you used #6 turnouts (#4s would be a problem, though probably not for the SD40). I would use #8s if you are planning on main line crossovers.

GS

 

The yard in the other pic wasn't anywhere near this long and it wasn't snap track on plasitc road bed as this one appears to be, but turnouts on each end of the yard like this is what I had in mind. By #4, #6, & #8, are you refering to the Mark IV turnouts from Atlas? http://www.atlasrr.com/Trackmisc/hocode100.htm - Brandon

 

Greg's advice is very good, the bigger the better, for cars and engines. One thing to remember, a little fall into the bowl tracks, will help, so the cars do not roll out. The term Bowl, in railroad language of course refers to yard tracks that are high on both ends and lower in the middle, so cars do not roll out of the yard.

 

The numbers refer to are the frog angle and not any particular brand of manufacture. #4 = a 1 in 4 angle or about 14 deg 15 mins; #6= a 1 in 6 angle or about 9 degrees 32 mins, etc.

 

Thanks Karl, again right on target. In laymen terms, you would measure back on the frog tread, any number, so if the measurement say is 2 inches across the frog tread, just measure to the 3 inch mark across the frog tread. If it is about 8 inches then its a No. 8 frog, 10 inches is a No. 10 frog. Like Karl said 1 inch of spread for the number of the frog.

 

Neither am I advocating trespassing on railroad property, nor am I advocating walking on the rail, but if one were to go to the heel of the frog where one's foot is exactly the distance between rails of the frog heel. From that point, walk heel to toe until one reaches the point of frog. The number of heel to toe steps will equal the frog number.

 

Let's make this a little simpler. When you go to the hobby store, or on line, or wherever you are planning to buy your turnouts, the number (4,6,8) will be clearly identified on the package. You don't need to measure anything unless you are hand-laying turnouts.

GS

 

OK. The degree of the curve decreases as the number of the turnout increases. So, is there any one brand of turnout that is preferred over the rest and if so, why? Also, to start a yard, would I have to do anything besides simply place the turnouts end to end? With a left turnout from the main, could i simply put a bunch of right turnouts end to end, starting at the left turnout and visa versa on the other end?

 

OK, OK ... I'm just going to have to look for the numbers on the box!
For someone who was versed in vectors, chords, great circles, degrees, and minutes ... I have no idea what a frog heel or tread is?
Can you explain that a little?

 

Yes, that is true, but it is better to say that as the frog number increases the frog angle decreases. The diverging route of a turnout is not a circular curve, so the curve radius is commonly described as a curve equivalent or replacement radius. See the attached Frisco table. When looking at the prototype data it is clear to see the compression required when modeling the track structure. The Frisco used number 15's and 20's for passing tracks and cross-overs between mailines. On the KC Sub the Number 20's had curved points, and trains were allowed 50/55 mph through the diverging route. In HO scale, a number 20 is over 31 inches an length.


The track centers in your yard will dictate the spacing linear spacing of your turnouts. Use of a scale drawing or a full-sized drawing on craft paper will help with this dimension. Or even just lay the track components on the road bed before tacking them down. When designing a yard lead, the two key diemesion to know are the frog angle and the distance between the point of switch and the point of intersection. These dimensions may vary from manufacturer to manufacturer.


Lots of folks swear by Peco; I haved used Shinohara now Wathers with success, others hand lay everything. Since you are a DC guy, the Altas brand may suit your needs.

 

Sherrel, don't think too much about it, us track guys like Karl and I, just like talking about track.
Short story, like Greg said the larger the number of switch, the better the cars will go through it without trouble. As Keith said you can have a normal ladder or a reverse ladder, the track centers will differ some. Old yards had 12 to 13 foot centers and more modern centers are 15 foot. Short story, anything you want.

 

Again, to simplify: Do not worry about frog heel, frog tread, any of that. I have been in this hobby for more than 50(!) years and do not know the answer to any of those questions. Also, I use DCC and have had no problem with Atlas track. Some people have other preferences. My only caveat would be to pick a brand and stay with it, if only for compatibility's sake. As far as spacing goes, figure 2 inches center-to-center for parallel main line or yard tracks. The suggestion about reversing the ladders for a double-ended yard is a good one if you can do it. Otherwise you will end up with some short tracks on one side of the yard.

GS

 

NMRA Recommended Practice RP-11 correlates the size of the equipment that you want to run with the minimum radius of curves and turnout number:

http://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-11.pdf

Rich

 

My largest steam locomotive, a 4-8-2, has 4 axles, each 6 feet apart.
http://www.frisco.org/vb/attachment.php?attachmentid=20983&d=1352590232
I assume that's an 18' rigid wheel base... but I'm not sure if that' the way to measure the rigid wheel base of a steam locomotive.

My largest diesel locomotive, an SD40-2, has six-axle trucks and is 68 feet, 10 inches long.
http://www.thedieselshop.us/Data EMD SD40-2.HTML

According to the chart at http://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-11.pdf, I would need at least a number 6 turnout.

The chart and the specs were very helpful. Thanks. - Brandon

 

I recently discovered the existence of Mark 2 and Mark 3 turnouts through ebay. Some, if not all of their turnouts have metal frogs. Are turnouts with metal frogs old but good or should I avoid buying them? I had never heard of a metal frog until this week and my research was inconclusive. Someone enlighten me please. Thanks. - Brandon