Crossovers, S curves in yards

I'm in need of a little advice in regards to crossovers and S curves in yards.

I know conventional wisdom is to include a length of straight track that is as long as your longest loco or rolling stock between crossovers and S curves. But does this hold true in yards, as well? From photos I've seen of some layouts, it appears not.

Can you ignore the conventional wisdom in areas where speed is greatly restricted?

I'm modeling the transition era, so probably no rolling stock more than 50 feet, and using locos like an SW-9 or GP-9 in the yard (and maybe an 0-8-0 or 0-6-0 someday). Code 80 track, and Atlas Custom Line #6 turnouts.

What's your experience? Thanks in advance!

Jim

 

Especially with the shorter cars you shouldn't have to worry at all about it. I'm working on a small urban harbor terminal layout and will have a yard that really can't avoid some S-curves, but I'm modeling roughly the same period, and same car lengths (even shorter locos).

 

It can look pretty goofy on a side-by-side crossover with #4's and long cars, as the car ends kick in and out. It doesn't 'look right', necessarily, but you won't have problems as long as you have truck-mount couplers. Mix body-mounts in there and other bad things can happen. Prototype switches for crossovers are rarely tighter than #8, usually #10.

I've had no trouble at all with ANYTHING using truck mounts, #6 switches, Atlas C80 on mainline crossovers, and #4's in yards with 15' centers. The bigger issue is often electrical pickup with those switches at slow speeds and an SW-type loco. All the pickups have to be working, and the points have to be hot and clean or you'll easily stall. You seriously might want to be looking at Peco C55 electrofrogs if you haven't spent money yet. It's not the geometry (because its very comperable) but it really is the electrical reliability and prevention of stalling at low speed. I've gone on a program of replacing all C80 with Peco C55 on industrial and yard track, electrofrogs only, just because of that.

 

Re S curves, it's relative. If you put two 9.75 inch radius curves in opposite direction right next to each other, that's a much worse case than connecting a 19 inch radius curve to the diverging leg of an Atlas code 80 #6 turnout to create a parallel track.

I'm not sure how a crossing would add value in a yard. Do you really want a crossing, or do you want a double slip switch?

You mention that you are using code 80 track and Atlas code 80 #6 turnouts. In the realm of code 80, I am a big fan of Peco code 80 turnouts, and have used them a lot with Atlas code 80 sectional track. I like the Peco code 80 turnouts partly because they have the built-in spring which allows reliable manual operation without any additional gear, and partly because I find they give me fewer derailments than the similar Atlas code 80 turnouts (without doing any tweaking of either). Note that my comparison is based on what are called Atlas #4 and Peco #6 turnouts, which despite their different numbers have almost identical sizes and diverging angles. I have no direct experience with the Atlas code 80 #6 turnouts, and I am not talking about the Code 55 offerings of either company here. And if you really want something with a built-in remote switch machine, that might change the economics. The Peco turnouts cost more money.

Peco also offers a short code 80 turnout which has a 9 inch diverging radius, which is useful where you are very constrained for space.

 

Jim,Unless you're fixing to operate your yard switcher at light speed you will have no problems.

There's nothing more then I would enjoy doing then giving the MR layout "expert wanna be" that muddle the water about "S" curves a swift kick with my old steel toed cowboy boots..

 

Crossovers are used quite a bit in real world yards to allow a yard to effectively be split into 2 yards and to give escape routes for locomotives.

 

If you can't put a straight long enough to accomodate the wheelbase of a car, the backup rule is stick the reverse curves as close together as possible. Don't think you're helping by putting in a straight section that's too short--that's the worst.

Yes, number sixes at yard speeds is fine, if the track is laid well. I concur completely.

 

Thanks, all, for your responses. I'm happy with what I'm hearing, that the straights aren't that vital in yard crossovers and S curves.

A few responses to your comments:

For those of you pushing the Peco turnouts, you have me considering it. But I've got 15 Atlas Custom Line turnouts currently in service, and they haven't given me any problems ... even with an old LifeLike SW I picked up used and which doesn't run all that well (and which will be retired very shortly). Everything else (a mix of 4- and 6-axle Atlas and LifeLike engines) runs through 'em smoothly ... even at a slow-speed creep. So while I guess I'm open to the Pecos, I'm still leaning toward Atlas.

Carl, CAPFlyer hit it on the head: I'm talking about crossovers, not a crossing.

Brakie, my concern about S curves goes all the way back to the writings of John Armstrong, who made a pretty good case for avoiding 'em. And while I'm not a huge fan of a lot of his designs, I certainly hold him in higher regard than those run-of-the-mill "MR layout expert wanna-bes," as you put it. I've had pretty good luck in HO following Armstrong's advice, so much so that I'm always a bit startled when I see photos of layouts that break this particular commandment. I've never dared try it before, and as a newcomer to N scale it's good to hear from you and other old hands that it's OK to live a little dangerously in this regard.

acptulsa, I'd never heard of your "backup rule" before, but it makes some sense.
Thanks again, everyone. Now if something goes wrong, I have you to blame!:tb-biggrin:

Jim

 

Hi,
the straight is built-in when using #6 or #4 switches. When you build a crossover with standard Atlas or Peco turnouts you'll have a rather long straight between the curves. The large radius of those switches, much larger then the standard curves, is helping lots too; it is working like an easement.
If S-curves cause a problem, it depends on the radius of the curve and the length of your equipment. Of course the speed of your train, among many more factors, is important too.
Any straight between two curves turning the opposite way helps. Though, if it is enough to prevent derailments, depends on the radii and equipment again.
Yes, John Armstrong knew what he was talking about. Keep in mind that pics are hard to judge. What seems to be a dangerous S-curve on a photo might be a well constructed piece of trackwork, with a long enough straight, with easements and moderate radii. It can't be said enough, the difference between pushing a long cut of modern autoracks over a crossover or S-curve or a short cut of older coal hoppers might be beyond imagination.
Paul

Brakie should be ashamed and calm down a bit. Just use his boots for walking.

 

Paulus,There's been so much garbage put out over the years about this and that and that is what I'm speaking out against.The "experts" has complicated the simple and overstated the obvious so much it has become confusing.

I been in this hobby far longer then many of MR's so called layout "experts" and I've many layouts that included small S curves and will vouch they're not as evil as many "experts" will have you to believe..

Ever see a crossover made from Atlas HO "snap" switches?

As long as you use 40' cars and 4 axle switchers-or nothing bigger then a 0-6-0 you're ok..I don't recommend such crossovers but,one uses what one needs on ridiculously small switching layout-in this case a 1x5' HO "time saver".

 

brakie has a point. Lay your track (provisionally) and see how it works. My experience has been that track laying technique is usually the culprit, and once you've done your best, live with it. Between myself and the best that I've seen in my N-trak club, there's a wide margin of skill. My skills have improved with a lot of re-do's, but are still short of the best I know.

It is important that the appearance of your track in plan and realization satisfies yourself.

 

hi Larry,
first of all I responded to the use of your boots; they are meant for walking.
The original poster used #6 switches in a yard; the straight part is already build in and he is using equipment from the transition era, so he will not encounter any problems.
IMHO it is better to be pretty clear in modelrailroading: if your standards are not appropriate you might be in for some nasty surprises. The OP could have been just lucky or quite knowledge-able; I have seen a lot of "newbies" trying in vain to push their new and expensive consists of autoracks through yardtracks.
How come?

I am from the John Armstrong era, and use some easy rules of thumb based on the prototype length of my longest car. Divide by 2,5 and you have the minimum radius, divide by 10 and you have the switchnumber in case of crossovers. The length of the train is rather important, if your trains are short you could go down a bit on the switch number. When pushing 25 cars through a crossover or as you have done, just a cut of three on a small ISL is completely different, you are in an other league.
The question remains should newbies know it all, or do they have to learn the hardway? Just knowing that not anything will go without problems over just anything, could lead to asking more specific questions and might result in more sensible shopping behaviour.
And yes, short cuts of short cars with low speeds will almost go over everything, even over S curves made of two snap-switches, as long as your trackwork is not to kinky.
Bill's statement about appearence is completely beside the point, so are his experiences. Most clubs do use standards, due to those "not-that-immaculate" trackwork will indeed be the culprit.

Keep in mind pics can be misleading, what seems to be a sharp curve without easements on a photo could be a piece of well laid out track on the layout.

One more remark is made by some-one not that knowledge-able. When two curves with a different orientation are connected any piece of straight track, how short it might be, will help. Of course easements and a longer piece of straight might be needed to get every train through that spot, pulled or pushed, short or long. When both curves have the same orientation, e.g. both are counterclockwise, a short piece of straight without easements even causes a problem.
Paul

 

Paul,Armstrong was good at his track laying there's no doubt about that however,there is no absolute rule beyond using common sense along with your eyes and fingers when it comes to smooth track work-that still remains the best method of track laying.

As far as newbies most try to learn to fast by reading books and not by hands on experience.I never overestimate a new modeler nor do I sell them short because ours is a very simple hobby that is complicated only by "experts" and "expert wanna bes".

Any 10 year old kid can lay smooth track after all snap track is simple to lay by following the instruction booklet that comes with train sets.Now add the newer train sets with Unitrack type track and its instant smoothness.

BTW..I came up in the era of Atlas HO flex track with fiber ties.

 

hi Larry,
it always amazes me how hard it is to read. The only point I made was about nasty surprises when the chosen standards are not appropriate. My first trainsets were from Märklin; i found out the hard way the expensive coaches could not be pushed through their turnouts without derailments, except when speeds were really slow. Even if the number of cars was very small, S-curves were still to much. The disappointment was huge, it took me so long to save the money needed.
By reading and listening to more experienced model railroaders I learned how to "plan" my trackwork and how to "plan" my shopping. Using common sense, my eyes and my fingertips had nothing to do with it.
BTW you will have good reasons to detest experts, the WWW is a very good source for " experts wanna Be's "; which is one of the reasons for my love for books. Track Planning for Realistic Operation by the late John Armstrong still is hard to beat. He is the kind of expert you could and should listen to.
Also with UniTrack you can make the wrong choices, it is not that smooth anyway. Learning , by reading or other wise, requires an open mind and perseverence. Both are not always present. My LHS owner is always telling me the difficulties he has in directing customers. Accepting a long cut of modern long autoracks in HO is probably not the best choice on a 8 x 4 often is a bridge to far. Then, just like me, you will have to learn the hard way.
After i read the book by John Armstrong 50 years ago I finally did understand what went wrong. Maybe model railroading is not that simple after all.
Paul

 

I consider "Track Planning for Realistic Operation" one of the best track books on the market even though the layouts are slightly dated.

A autorack can go around a 22" curve (the larger 4x8 curve) but,its not a very pretty sight.

I still fully believe common sense plays a major roll in our simple hobby.

 

Continue to believe that appearance matters, as I'm a modeller. If it "looks" right and "runs" right, then I'm quite happy. Touchy-feely is a good basis for practical work, and usually suffices. Of course, my touch and feel has been developed over time.

BTW, love Armstrong's book and articles as they give a solid basis for modelling through reference to real operations. There has been, I think, more than 50 years of technical development since. What can be done in Nscale today is amazing.

 

There's nothing common about common sense. As Paul alluded, you either acquire it through trusted sources or by learning from your own mistakes.

I started like most folks of a certain age, with Lionel and then on to HO and Atlas Snap Track. I learned some things didn't work, but was never sure precisely why until I read Mr. Armstrong's book. Suddenly, it became clear how one plans for realistic and reliable operation. That's the science. Actually getting reliable operation out of your track is the art. A good plan poorly executed with sloppy trackwork will not have a happy ending.

My initial question originated from the fact that Mr. Armstrong's advice has served me extremely well over the years. I am loathe to deviate from it. That's why I am interested in the success/failure of others who have ignored this particular piece of advice. Opinion doesn't matter. Evidence does.

Jim

 

Bill,
i think it is semantics, appearence only has to do with looks.
If it looks right, feels right, touches right, my wife shouldn't read this, it could still not run right. Then as Jim said science or knowledge is needed.
Bill your touch and feel have developed, maybe you aquired some knowledge afterall?
Paul