A while back i asked do all commercial turnouts meet NMRA recommendation? Since then I’ve realized that turnouts with the same frog number don’t have to be the same length.
The figure below shows the lead-lengths (point to frog distance) of various #6 turnouts with closure rails having smaller radii (blue) and varying length straight sections (red). (only the closure rail is shown)
Would you be interested in commercial turnouts of the same number (e.g. #6) with different lead lengths to fit different situations on our layout?
Do you choose a particular manufacture because you realize their turnouts have a particular length?
LION usually uses Atlas #6 (I presume the 14.4" inch one shown) and then cut them even shorter beyond the points and beyond the frog. Him wants to cram in as many as is posible.
This is sure, it’s better to have a closure rail whith a good lenght especialy if you use long rigid wheelbase locomotives.
I’ m not sure but I beleive it’s the choice of Peco whith is line of turnouts, the number of the frog remain the same for the small, medium an long turnouts.
In the real thing the number open the angle and of course it’s far better, but any way a long closure rail is best, so I try to use as most as possible n°8 because of longer closure rail.
We need to not forget we use compromise in our small world.
I have both Atlas and Peco #6 turnouts on my layout. The Atlas turnout is 12" long, while the Peco turnout is 9" long. When constructing a yard ladder, that 3" savings is invaluable.
The shorter radii result in longer straights through the frog and the points, but those longer straights don’t improve tracking through the turnout.
As for commercial products, I was once told (and still believe) that no mass-produced turnout has ever met the dimensions found in NMRA Recommended Practices.
My personal solution is to hand-lay all of my specialwork. If I build a, ‘Plain jane,’ turnout it will have either a #4 or #5 frog. It’s much more likely to be a #? built as a spiral easement off a superelevated curve. [The #4s are found on the Tomikawa Tani Tetsudo, which is limited to rolling stock that can handle a 350mm (<14 inch) radius and embargoed to anything that can’t run up the mountain goat trail the surveyors followed.]
Chuck (Nonconformist modeling Central Japan in September, 1964)
The longer straight is accompanied by a tighter closure rail curve - and a, ‘Snap your neck,’ lurch since there’s no easement effect. Rolling stock that would be happy with the wide radius of a longer turnout might balk at the tighter curve - especially stiff steam or non-steam with three traction motors per (prototype) truck.
I have some 2-C+C-2 catenary motors that will take a #5 with the longest possible curve in the closure rail. Most commercial #6 turnouts will put them on the ground. As for those #4.5 frog Atlas - fuhgeddaboudit.
If you did what Lion did and trimmed the straight sections before the points and after the frog, the Peco would be 3/4" shorter than the Atlas.
There’s quite a difference between these two turnouts and I wouldn’t be surprised if some locomotives had problems on the Peco but not on the Atlas even though their both #6s.
I’d appreciate measurements for any other turnouts with different frog numbers and from different manufacturers.
