Turnout question-072 or #5

If you use 2 072's you will have the dreaded s-curve to negotiate. If you use the 2 5's you will have a section of straight to ease the transfer.

The numbered turnouts have a section of curve which ends in a straight., the 072's are simply a section of curved track.

Are you coming back to parallel or continuing the turn for the mainline?

I don't see a #5. There is an 11° and a #4 & and a #6.

If you are coming back to parallel the two lines, the turnout used will set the center rail to rail spacing. use an 11° or #4 or #6 with a transition piece or suitable curve.

If you are continuing the curve, I would use the 072 or larger depending on the radius of the curve.

The Ross 11-degree is very close to a #5 (The Atlas #5 is 11.25 degrees). The turnout to use depends on what you're trying to accomplish. My personal preference is for numbered turnouts which I what I specified for mainline crossovers for the club layout (way before I even thought of scale wheels and Kadees). A crossover from a straight main to a straight secondary main should be done with numbered turnouts.

The only way to cleanly do a crossover with a pair of O-72 curves without a long straight in between is to take a left O-72 going into a right O-72 (or vice versa) on a corner of one of the mains which can complicate the design.

My take on turnouts is to use a numbered one unless you absolutely need a curve replacement.

I guess a picture is worth a thousand words. The mainline trackage is through the curved portion of the switch. I realize my trackage here is not exactly the same, but I can fiddle with the number 5 curve transition and make it be the same. My question is which switch is a better choice when used in this manner.

And I really appreciate the responses I have had to this question.

Jeffrey

Here is the actual location on the layout-- the mainline goes thru the curve of the switch.

ALWAYS choose the turnout that does NOT stall your locos at slow speed when there is a choice of several turnouts. If you choose a #5 and your locos do not have adaptive roller spacing you will end up running the locos through the turnouts at warp speed. None of my Lionel or MTH locos stalled on an O-72 turnout. Beware the curved O-72 however. It will derail some locos.

Are number 6 switches ok? I was using them to make crossovers.

Here is the file with the entire layout. I have five #6, and the rest are 064, 072, and #5's--

Jeffrey

Very true, my Lionel EM-1 will derail on a O72 turnout, however it will negotiate the no. 5 switch

Jeffrey,

Using a O-72 switch fits in well with your plan to make the track line up with the crossover since your other switches are also O-72.  I would stay with it.

However, if you want to use a Regular (11 degree) switch, you will need to use a section of curve track that is 11.5 degrees to complete the 22.5 degree curve needed to line up with the crossover.  I redid this section of your layout using a Regular switch and a O-72 curve section cut to 11.5 degrees.  You can use any size curve you want as long as it is cut to 11.5 degrees of curvature.

Why use a Regular switch?  Since you stated the diverging route is the mainline, using the Regular switch and a broad curve like O-96 would look better with long passenger cars.

CAPPilot--thanks for helping me understand the transition curve measurements, also for taking the time to redo my RR track drawing. I am trying hard to create track work that will be inherently derailment free. I had read "Track Planning for Realistic Operation" by John Armstrong many years ago, and drug it back out and read through  it again. Reminded me about "S" curves, and some other things, and I have tried to incorporate his ideas into the plan. Then I see it is fairly common practice to do parallel track cross overs with number 6 switches, so I changed that. I was going to use scaletrax, and ordered a couple of 072 switches and some 072, and 054 track, but was not overly impressed with the mechanical aspects of it-- particularly in regard to not using pins to join the track, and even though I tacked it straight down on plywood, the rail ends did not line up perfectly--so I jumped ship, and am going all Ross/Gargraves. If you don't mind, please look over the rest of the track plan, and see if anything jumps out at you. I really intend on running small equipment--4 axle diesels, 40 foot box cars, and my theme is a back woodsy branchline. However,-- I wanted the option to run some fairly large steam, so the main loop is all 072- but I realize long passenger cars (which I have little interest in) look BAD on this small curvature track-- but short stuff should be fine.

Just a thought, consider designing curves and turnout usage for the largest equipment your real estate could possible handle.  One can not predict where their interest may wonder in years to come.

Even if you never get larger equipment.  Large curves and  gentle turnouts will make small equipment look  more at home.

Jeffery,

I made some changes based on what I would do, and they may not be what you would do.  So take them as recommendations only.

  1.  In the upper left of your track diagram it looks like you have two tracks that run parallel to each other through 180 degrees of turn.  These tracks get farther apart around 90 degrees of turn.  I like my parallel tracks to be parallel, so I changed the tracks to remain parallel at 4” center to center.  I also changed the curve diameters to O-80/O-88 for better clearance since Ross curves are only on 4" centers.  Check the Initial curve pieces, they start larger (O-88/O-96) then get smaller to make the 180 degree fit plus act as transition curves.

  2.  Added 2nd crossover in upper left for added flexibility. I used #5 switches because this arrangement of the switches does not have an S curve issue.

  3.  The 4-track yard in the lower right used O-64 switches which I do not believe are good yard switches.  I used #4 switches for the yard.  You lose a little length, but get a 5th track.  Also, the #4s will provide more reliable operation for backing through the switches.

  4.  In the lower right I used a #5 switch and a section of O-96 curve to smooth this turn out.  It will look better with all sizes of rolling stock and be better operationally.

Just some of my thoughts.  Have fun finalizing your plan.

That is exactly the feedback I needed--particularly about #4 switches being better switches in a yard-- and the fact that backing through #4's is better than 064's. I also had not thought about using larger radius curves as transition curves. I think the parallel trackage will look much better. The three tracks inside the right most return loop are for an engine service facility. Would you say that those should be #4's as well-- instead of 072's like I have now?

I really appreciate all the help.

The $100 bucks I spent for the RR-Track program is probably the best money I have ever spent. How you would draw all this up, and keep making changes using paper would be tough.

Concerning the parallel curves on 4 inch centers-- I have seen some discussion about possibly needing as much as 6 inch separation on curves because of the severe overhang on some engines. However, with 080, an 088 curves-- maybe this is not an issue? As I have said-- I really intend to run smaller stuff-- but years down the road-- I "might" want to run an articulated. Will I be OK?

Jeffrey

Jeffrey, an issue or two back, OGR had an article on just this issue.  Using 072 parallel curves, Jim Barrett found that a LIONEL Big Boy on the inside track and a 21" long passenger car on the outside track would require a minimum 5.25" of center-to-center rail clearance. 

Using larger radius curves will reduce this some from the 072 curves used in the article, and Big Boy overhang is among the largest you'd likely encounter.  While you may not run 21" passenger cars, the 86' and 89' scale freight cars pose a similar overhang issue.  So there is no hard and fast "safe" minimum spacing because of variations in locomotives and rolling stock. 

Jeffrey,

Heed Tom's and Carl's advise about planning for future possibilities.

My layout uses all Ross switches and Ross/Gargraves track EXCEPT for the curves of my double track mainline.  My double track mainline has O-81 minimum inside curves and the two tracks are set at 4.5" center to center.  I use Atlas O track on the curves because its curve selection is based on 4.5".  My worse engine offenders for swing out are my Lionel Centipedes and my MTH Q2.  Both these engines will pass by my 21" passenger cars (cars outside track, engine inside track) but just barely.  If someone brings over a large articulate it may have to run on the mainline by itself. 

You have a different situation.  Your parallel tracks are not from a double track mainline, but are a single track main and a siding.  Looking at your plan, I would say the outer track should be the mainline track, and the inner track will be used for switching the two stub end sidings.  Because of this I THINK for the majority of your railroading the 4" spacing should be adequate.  Keep the siding for your local freights and hopefully your dispatcher will keep in mind any limitations should your CEO acquire any Big boys in the future.

#6 turnouts are fine, but may have stalling with shorter locomotives at low speeds. There's a work-around for that by using the closure rails to extend the common and hot connections depending on how the turnout is thrown using the extra contacts on a Tortoise motor.

I looked at your plan and either type of turnout will work. My concerns about O-72 turnouts is when people use them for crossovers or sidings.

Jeffrey,

I played around with your engine yard and came up with a couple of ideas.  Both these use specialty track.  The one replacing your yard uses Ross' 4-way switch, and the other one uses Ross' 3-way switch plus a #4. These are just ideas; you can come up with a nice 3 track yard using all #4s in that area, but the 3- and 4-way switches save space.  The 4-way switch's inside tracks are at 3.5" center-to-center, so they don't line up well without work with most commercially available engine houses (5-5.5").

The nice thing about RR-Track is you can try lots of different things (switches, curve radius, buildings) very easily until you come up with something you like.  Play around with it a little; you may come up with something great!

My plan is to use all tortoise switch machines, so I will have the ability to do that. My understanding was that #6's were sort of a standard for dual track crossovers. 

I'm learning a lot here. Thanks for the info.--

Jeffrey