Back-to-Back WYE's

Why or why would you do that? (I'm such a dork).

If you put two wye's back-to-back, wouldn't you have an 'S' shape if you the switches were aligned two out of the four combinations? It would seem to me sooner or later you would have an engine that would have trouble with that.

Maybe I'm the dummy, but it would seem that it would enable you to turn engines and cabooses around much like a turntable?  I would think that you would want enough space between the switches to allow longer engines or cars to be turned?

Art

What is the effective radius of these switches?It appears that it is quite large.

An Atlas-O 072 wye is approximately 22.5 degrees between the two legs or 11.25 degrees between one leg and the center. For the Atlas-O wye, connecting the single track end to one of the diverging tracks would bring one track back to parallel and the other to 22.5 degrees from the straight. The "S" curve would be composed of two "half" sections with a small section of straight built into the switch. It would a lot easier to navigate than two 22.5 degree 072 curves connected to form an "S".  

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SanteFeJim,

    Depending on who's track/switchews you are running you may have a problem, FasTrack because of it's design can accommodate most big engines when setting up back to back Y's with the single track end joining the Y switches. For best results make a piece of custom track between the Y switches to accommodate the scale steamers if you must.  It can be done, when designed out properly.

PCRR/Dave

Here is what a yard ladder utilizing Ross 11 degree wyes would look like.

The above four tracks maintains a 4" track spacing, which is my preferred minimum, others will state that you can go closer. 

Will a challenger / big boy / cab forward go thru it?  Don't know.  What I do know is that an MTH Great Northern R-2, 3rd Rail Z-5, Z-6, and Z-8 will not go thru a Ross "Y" ladder without derailing, nor will these reliably go through crossovers made with Ross 101 and 102 switches.  

Reverse curves are the concern, and this will also be an issue if you are going to utilize Kadee couplers on long rolling stock.  

The best way to test out what you want to do is to mock it up, and try it, or design conservatively.  Conservatively, utilizing #6 switches, in the below possible configurations is the safest way to go.

Layout from the following link.  The layout was with #4 switches, but the principle is the same with #6.  Altas #5.5 would work well too, as was done on Hot Water's railroad.

http://cs.trains.com/mrr/f/11/t/187957.aspx

GNNPNUT

I'm not sure that I would try back-to-back wye switches.  Assuming one wye switch is to allow yard entrance from two different directions or to turn trains (using three sides) and the second wye of the back-to-back is to start yard track building / entrance, why not use a Ross 3-way or 4-way to start the yard and avoid the "s" curve, no matter how mild.

Chuck

I put back to back wye's on my layout in my storage yard area.  I'm using the dreaded FasTrack and my Premier Big Boy has nor issues pulling in or backing out.  I have 90" 0f track between both wye's and enough track on the end to allow the Big Boy to do a run around.  I also added wyes on the ladder to allow more storage tracks.

jmiller320,

   What do you figure would be the minimum track length you could use between the FT Y's for running your Big Boy?

PCRR/Dave

Photo of a layout under construction 1997 with a 072 turning wye.

In photo below take a view over the red caboose and down under the bridge to the lower level and you can see two of the 072 Frank Curtis Wyes that tie into the inner mainline to make up the entire wye.

Layout was dismantled in Oct. '09 and I don't recall dimensions. But I backed and turned both a N&W "J" and a CC&O Challenger through each leg problem free. An Engine could negotiate the wye fairly quickly. However turning a freight or passenger consist was slow to avoid car derailment when backing and fouled the inner mainline which made up one leg of the overall wye.

Jim, these are 2 Ross back to back wyes.  At the time they did not offer a double slip switch. The turnout leading into them is also a wye. The one furthest to the right is a no. 6. As far as a Big Boy negotiating them I can't comment on that. I do back consists of 21" passenger cars as well as all my engines with no issues. 

Okay guys, I gonna save 1,000 words here and use a picture.  The back-to-back WYE's are at the yard throat, inside the red circle.  To the left is the 20-track yard.  To the right are the leads into the main lines.

No that you can see it, I will repeat the question.  Can I run large locomotives(Big Boys, Cab Forwards, Challengers etc.)  through back-to-back wye's w/o problems? 

In general, I find that the Mallets are the best running locomotives through complex track arrangements. The locomotives you need to be concerned about operating through complex yard tracks are the rigid 8, 10 and 12 driver wheel arrangements.

Jim,

   Thanks much you answered exactly the question I had on how this would actually set up.

PCRR/Dave

I'll post a couple photos once the paint dries.

Jim,

   Sounds great, no matter how you cut it, you have to have enough room to make it work correctly, I think some time I will try to make a shorter version of what you have designed, will eventually see how the FasTrack spacing can be engineered to make it happen. I am thinking about some custom size pieces between the Y switches.  I do have to worry about the old Williams Diesel that is suppose to run on 054 & above.

Monster of an old Passenger train, I would like to be able to back in thru the Y switches and drop the cars, using the TR function from my DCS hand held remote control and operate the FT CC switches from the Legacy Cab2.

PCRR/Dave

LOS,

  Man I agree if he has the room, why do the job twice.

PCRR/Dave

I built a modular yard that uses 7 11 deg. wyes to split 3 tracks into 6 interconnected tracks. The outer 2 splits are back to back 11 degree wyes, and the inner tracks are actually 3 11 degree wyes spliced together to make all the tracks 3.5" on center. Everything runs through it without issue. I started with un-wired manual switches so I could control all the block ends for the yard tracks, just make sure you jump wire all the rails between the wyes so  you don't have dead spots. The angle is so shallow, no equipment has problems. Worst case scenario is probably a 4-12-2, and even that is fine. 

Thought I had a picture, but apparently I don't. I'll dig it out of the basement and take one after the kiddo goes to bed later. Its still a work in progress, but I used it in a show to make sure everything worked before I did the scenery.

Boilermaker1 -

Your response was the most encouraging.  I too am planning on using 3.5 inch centers on all 20 yard legs.  And, the fact that you can run a loco with a 4-12-2 wheel arrangement makes me think that a Big Boy, Cab Forward or Challenger should also make it through.  It is indeed a very shallow angle.

I am still looking forward to your pictures.  Hope you will post them when you find time.

Jim

Haven't read through the entire thread yet... But the first thought that occured to me was the possibility of using a double-slip in place of the back-to-back wyes.  You'd avoid the S-curve issue, since the double-slip switch would give you a crossing for that route.  Just a thought.  Either that or extend the distance a bit between the wyes to avoid the S-curve.

David

These are GREAT suggestions and you absolutely MUST do this! That 12" of straight track will make a huge improvement in the way this track arrangement works. It is the reverse curves that will cause derailments with the big steam locomotives. The short section of tangent track will eliminate the reverse curves.

The middle track splitter is 3 wyes that are spliced together. The left hand switch in this photo.

Just checked and the only double slipper Ross makes is a #4.  I would stay with the #11 wyes.  And again, look at his drawing.  He is talking about putting the single track end of the wyes together.

Jim,

Here are a couple of shots of my back to back Ross 11 degree Wye's. I originally had a double slip in it's place but it did not give me the switching flexibilities I wanted. I only run two axle diesels but scale length freight and passenger (80') cars. My only steam engine, a 3rd Rail Berk with a 2-8-4 wheel arraignment (blind center drive wheels) have no problems negotiating the switch arraignment. I did cut off some of the straight lead in section of each wye to get the points closer together. I did this to eliminate some of the small amount of offset of the straight thru tracks. The engines and cars due "wiggle" a bit as they go thru the switch. Looking back, I might have been able to cut more of the lead-in rail off and get the points even closer together and all but eliminate the "wiggle". Because of the roller pick-up spacing on some of my engines, I did have to power some of the insulated rails with relays to get them thru.

11 degree wyes make for a gentle turn but you'll still have an S curve.  Might want to draw it with 072s but put some straights in between to avoid the S curve. 

What William just said - stay away from O72s.

With any curved switch, no matter how wide the curvature, track will not flow nearly as smoothly as you see in Cape Cod's excellent trackwork.

Jim

Jim,

My yard is less than 1/4 the size of your plan.  I use Atlas track and have a single straight section between the wyes.  No problems with running large Pennsy steam and Centipedes. In my world the Pennsy owned the NP.  I had no problems with a Z-8 either.

Norm