Hello everyone,
After purchasing #6 turnouts for my yard from CabooseHobbies fell through, I am forced to use #8 turnouts. This is fine, but it forces me to place a curved turnout into the yard lead. So:
A. I've heard that the radius given by Walthers is inaccurate for their curved turnouts. I am planning to buy a #8 curved turnout that is advertised as 32/36. What is it in reality? The curve that the turnout must be set into is about 30" radius.
B. Has anyone had problems with using curved turnouts in the yard ladder before? I've seen a number of them used, but I do recall a post on this board saying their club had issues backing in long cuts of cars. I am planning to run 20 car trains, so this is a significant consideration.
C. For best fit, the yard lead curve and curved turnout will have to be on a grade. This would exasperate any issues with backing long cuts. Any other issues to be considered with a curved turnout on a grade?
Thanks in advance
1. WALTHERS/SHINOHARA 'curved' turnouts I believe are made to metric measurements, therefor conversion to NMRA 'numbers' is approximate.
This also true of Peco and other foreign made products.
2. The outer curve is the defining one, the inner curve is approx. 4" less r.
3. The Geometry of a straight wheel flange pushing into any curved rail gap is problematical - not to say it can't be done - just that it's somewhat more prone to derailments - not what I want for a busy #1 yard switch.
4. Shinohara made products are among the best made. If Your hobbyshop cannot get Walthers #6s, I think I would shop for Micro-Engineering #6 - or Peco's code 83 'Insulfrog' turnouts.
#6s make a much better yard ladder.
Don, thanks for you reply. I agree on the quality of Shinohara turnouts. I never seriously considered ME turnouts, but they seem to be the same price as Shinohara and more importantly available. ME makes great flextrack so I must assume their turnouts come to the same standards, but could you or anyone else share their experiences with them?
Selector, thanks, that just about answers the first question. But it is interesting to see that both you and Art have had issues with tracking.
I've got 3 curved Peco turnouts, the 19/22 radius ones. I can't say that any of them has given me the slightest problem. In fact, I've been so satisfied with the Peco's that I've given up buying Atlas, despite the price difference.
The one warning, though, is to be careful with your installation. If you're going to connect them to flex track, be extremely careful to avoid kinks. I would solder all of the flex-track connections to the turnout on the bench before installation. Yeah, they're that fussy. It's not so much the turnout as the fact that you've got 3 curve-to-curve joints close together. If you don't watch yourself, one of them is going to be a problem.
Once you've got them installed well, though, they work great. For me, this took a great leap of faith, because 2 of the 3 are in the subway tunnels, and, as it happens, they're both directly underneath the above-ground main line, so there's no liftoff for access. So far, though, it's been close to 2 years with no problems at all.
It takes an iron man to play with a toy iron horse.
Mr. B, thanks. Peco is a bit out of my price range right now though.
Virginian, that image is less than pleasant. Was that from "first hand" experience?
http://www.trains.com/trccs/forums/1109674/ShowPost.aspx
I think this is the thread your looking for. Has the actual radius in it.
Commercial curved turnouts are generally engineered by taking a normal turnout and curving the straight leg to the desired radius. For a given frog angle, this means the curvature of the inner leg must be sharper than on a normal turnout of the same frog #. Because both paths curve the same direction, a curved turnout takes much more length to achieve the same path separation of a normal turnout. A wye, where the legs curve in opposite directions, achieves the separation in a much shorter distance.
These physical realities mean that in a curved turnout, the frog # controls the difference in the 2 radii. The higher the frog #, the closer the 2 path radii can be to each other. A #8 typically has 4" difference in radii. A #6 curved turnout has to have a greater difference between the 2 radii. So the 36/32 figure for a #8 is probably fairly accurate, but the 24/20 #6 is not.
My father placed a Shinohara #8 double slip where the yard joined his double track main line. It finally became quite reliable, both forwards and backwards, but took a lot of tuning of the double slip, the adjoining tracks, and rolling stock to get it there. So, will a curved turnout in the yard lead work? Yes, but. Everything (turnout, adjoining track, wheels) must be to a little tighter tolerance than with a standard turnout.
For turnouts on grades (and/or super elevated curves), it is critical that the turnout itself be on a flat plane. The plane can be tilted in any direction, but a straight edge across or along the turnout itself must hit all railheads equally. All transitions - vertical, horizontal, superelevation twist - must be quite gradual, and cannot occur within the turnout boundaries.
Hope this makes sense and helps
Fred W