One wye switch or three?

Lee,

I do not have realtrax software. I tried this with Atlas track to give you an idea.

Right diagram has 072 wyes with 054 curves and 1/2 curves with a special cut straight.

Left diagram uses 072 wye at top; and 2; 072 switches on the bottom w/054 curves.

Each wye takes up about 3'x4' area. These are the smallest possible that I could think of. If you went bigger they would be smoother. List of Atlas track:

Atlas Item list for 072 wye with 054 curves.rrt

NUMBER  DESCRIPTION         
(4)     Atlas 6074 O72 Wye turnout         
(8)     Atlas 6060 O54 22.5° curve         
(4)     Atlas 6061 O54 11.25° curve         
(2)     Atlas 6056X cut-to-length straight         
(1)     Atlas 6073 6073 O72 right-hand turnout         
(1)     Atlas 6072 6072 O72 left-hand turnout 

Do you currently have Realtrax Y's.  I used to have realtrax and tried the O-72 Y.  I hated it.  It gave me fits with geometry and with derailing.

Seacoast, thank you for your workup, that gives me a good target to work with.

Ron045 you have found a smaller issue where I am looking over some of the Fast Track Wyes versus the Realtrax. I have not purchased either one just yet. I do use the 072 switches with no issue on RT.

Can you explain how you had issues on your Wyes?

A wye made from three MTH O-72 wyes, six 1/2 O-72 curves and three 15 degree O-54 curves fits in a roughly 4'x4' space. You may be able to squeak larger equipment through this configuration since the O-54 section is so short. Here's the image.

Matt, great idea. Take it on step further and make it all 072 curves, space wise it would not take up that mich more space.

Thanks, but the angles don't work out with the O-72 half-curve as it's 11.25 degrees while the O-54 half-curve is 15 degrees.

Interestingly enough, you can do a radially symetical wye like the above using Atlas track. You use three O-72 wyes, six O-81 1/3 pieces (7.5 degrees each) and three O-81 full curves to accomplish the same style for larger equipment. Of course it consumes more space.

If you have the space and want to use flex track, you can build a 3x60 degree wye using #5 or larger turnouts. I've designed some during my Free-Mo/O experiments. The catch is they're huge. The first one is a 45-degree wye junction with a 48" minimum curve radius (O-96). The second is a +/- 45-degree wye module that would be used with a 45-degree left and a 45-degree right to form a T-style wye (also 48" radius). The third is a 70-inch radius (O-140) +/- 30-degree wye that would form a symetrical wye when combined with two other identical modules. I doubt any of these will ever get built but the design was an interesting mental challenge.

Matt, not to highjack this thread. I did a quick 072 "Atlas" wye with all 072 curves it works. As you noted it might not work with the angles of realtrax.

For my preference though I can see some of my larger engines having issues with the small size of this wye roughly 4'x4'. I like what you accomplished with the #5 switches.

I stand corrected, but it requires a cut section of track (17.25") using RealTrax.

No big deal, The Atlas requires a cut piece of straight track too. All this talk of wyes has me rethinking my layout plans. I have to think of an area to use one,umm, a junction or engine facility or maybe a yard, I guess the options are limitless, well limited by my space as I would want the wye abit larger in size to handle larger engines. I know the 2 rail crowd favors wyes verses reverse loops. 

Don't overlook folded wyes with crossovers inside a curve.

The big problem with reverse loops is they take a ridiculous amount of space, even in a sharp-curve 3-rail context.

I agree Matt, looking at my 072 above its huge 9'x 6'. Lee, I never considered a folded wye, to be honest I'm not that familiar with it.

A "crossover wye" is also referred to as a scissors wye, where the turnouts on two of the legs are closer together with a crossing in the middle. Though they're not as wide, sometimes they're taller. A lot of experimenting is required. You also have to watch out for the reverse-curve situation. The scissors is a little narrower, but is taller, depending on the crossing used. In this case, I used a 45-degree crossing.

Matt, thanks for the explanation. I would think a simple wye would be faster for turning around.

My layout has 2 Wye's across the middle of the figure 8.

I used a left O-72, a right O-72, and an O-72 Wye in each with O-54 curves (and half curves).

They do eat up some space but all my rolling stock and my Imperial Railking Big Boys roll thru them with no issues.

I will be upgrading everything to ScaleTrax soon tho. That track needs more switches in the lineup. I Subbed in a pair of Ross O-72 Wye's. Skip the roadbed under them and they line up pretty close.

Remember folks, Keep the track Flat to the switch for more distance than your longest engine length and life will be better. For a Big Boy that means 30" for Railking and 35" for Scale.

Russell, good idea.

Argh, I've some thinking to do.

I am really tempted to simply dump the wye, tunnel through drywall into a adjoining room and throw down a turn back loop or something. Or stick a wye leg through there and call it good. It is beginning to look like a good scissors design.

If Scaletrack was used with midwest cork or similar, will it match up with Real trax? I know I should purchase a section of scale track, take it home and see for myself... the hobby shop is a challenge to get to.

As far as the necessary for a straight section prior to a switch, I usually take the most rigid frame or longest rolling stock and plan with that.

If 072 is a "bridge too far" in angles, what about two or three 054 switches as a compromise?

I was thinking about this again and had a thought (that didn't die from loneliness.) Make a wye using three left-hand O-54 turnouts and three O-54 curves. Since they're all 30 degrees, it generates a perfect "pinwheel" three-sided wye.

Note that it only takes up four square feet for the wye itself.

Huh. Such a thought too.

Can you cheat the same way with three 072 switches?

If not, I believe we have a winnah here.

Nope. The geometry of the curve sections and turnouts doesn't work out using all O-72. You pretty much have to do a "T" style wye with the O-72 turnouts and curve sections. Plus it takes up a lot of real estate.

However, if you use O-72 turnouts, three O-72 curves, and three O-54 1/2 curves, you can replicate the geometry. If a large engine can make it through the 15-degree O-54's you'd be good to go.

Thank you Matt for your hard work.

The Power will not have issues with 054 half curves.

I'll call it Matt's Wye until I can come up with a better name... if ever.

I'm sure you can find a lot of better names. Glad I could help.