I wish I could help, but all I see when I try to visualize what I think you mean is a Gordian Knot of track that will have to occupy a huge footprint in the centre of your layout space.
Can you provide a rough schematic of what a double and triple turning wye should look like?
here is a diagram of the only scissors wye i can find, there should be others but i can't visualize them
I think he means a second wye inside of the first.
The only way I can see to accomplish it would be with six "wye" turnouts and a minimum of two double slips.
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The scissors wye only really is smaller in one dimention. The top isn't as thick. It sacrifices that thickness for added length though. The other two legs are pretty much normal. It's a very specialized piece of trackwork that wasn't real common, though not unheard of. It was most often seen in mountainous areas where space was limited by some natural obstruction. I've seen it used in cities too for the same reasons.
The only double or triple wyes I know of actually occupy more space then a conventional wye because of aded trackage making them thicker in all dimentions. The ones I've seen don't use slip switches but instead use regular diamonds, so they really aren't any more useful then a regular wye. The only uses I've seen them for are multi-track wyes where each track has it's own wye, they just happen to overlap.
Maybe I'm not understanding the question though..............
There are a couple of wye designs in the following collection of "modules".
Perhaps one will give you some ideas.
http://i197.photobucket.com/albums/aa266/exPalaceDog/A0-AAAA-5-1.jpg
Have fun
I have an old Atlas book, "Atlas Custom Line Layouts For HO Scale Railroads," 2nd edition. In the back it has six different single track wyes and one double track. The double track uses 2 wyes, two left and two right #4 turnouts, 22"r track. It is 70" long, doesn't say how wide, about 36" if I measured right.
I would think that a newer Atlas book would have a similar section in it, shows many types of ladders, crossovers and track transitions as well as the wyes.
Have fun,
For the tracklaying masochists among us, the St. Louis Union Terminal had TWO triple-track wyes that overlapped each other and spread out into a huge fan of back-in platform tracks. I haven't found a plan for that - but, then, I haven't looked.
I suspect that the station and the wyes would pretty well fill a two-car garage - without any additional track to support it!
Chuck (modeling Central Japan in September, 1964 - without wyes)
Slowly building a layout since 2007!
rxanand wrote:And if you want to see something really amazing, take a look at the turning pentacle ! The text is German but the pictures make the concept clear.
Thanks for the incredible idea and link. I just may use it where I was struggling to find space for the wye tail.
Fred W
Thank you for all the good info. i am not sure what i will do but when i get the design together i will put it up for dismemberment. love this forum and check it daily, don't say much but read a lot.
again thanks for the help
while we're on the subject of wye's , what is the minimum space that an HO wye will take ? i'm wondering if i have room for one to turn small steam engines , say anything that would fit a 90' turntable .
thanks in advance
ernie
A 90ft turntable handles some medium size steam pretty handily (4-6-4, 2-8-4, etc). More important to the size of your wye is the minimum radius. The 90ft dimension sets the minimum length of tail tracks. Also, a big impact is the size and type of turnouts you are using. Wye turnouts will take the least space because they inject curvature into 2-3 sides of the wye. Constant radius turnouts will take less space than the more prototypical straight frog (numbered frog) variety. Straight track after the frog - built into most commercial turnouts - will add to space requirements. When designing a wye, you can trade off one dimension for the other by where you locate the curves.
For example, a wye where the base is straight: assuming constant radius turnouts, the base of the wye is going to be twice the curve radius long over the switch points. From the base to the points on the tail is going to be one times the curve radius. Note that to get all constant radius turnouts, you are probably going to have to hand lay them (there may be some Peco turnouts, including a wye, that have constant radius throughout).
By inserting 60 degrees of curve into the base of the wye - including the diverging angle of the turnouts, you arrive at the most compact arrangement overall. Each leg has a total of 60 degrees of curvature, including turnouts. Each side would be on the order of 90% of the curve radius, again assuming cosntant radius turnouts. You need to add space for straight frog turnouts, and any other straight track within the wye itself.
Perhaps the best way to design a wye for your stituation is to draw a few in your favorite track planning software. Assuming the correct turnout libraries, it will give you the real size with your chosen curve radius, turnouts, tail track length, and curve configuration.
my thoughts, your choices