In Model Railroad Planning 2005 at page 90, Lloyd Miller had a planning tip to allow for #6 turnouts at a #4 angle.
Essentially, the first ladder switch's (all switches are #6) diverting rail is followed by a short piece of 48" radius track - to get to a #4 angle. The second ladder switch main is aligned with the straight #4 angle and the diverting rail is attached a short piece of 48" radius to form the third yard track on a tangent. The third ladder switch's main is aligned the same as the second ladder switch and thereafter etc. etc. To accomodate this, the second yard track comes off from the first yard track by a #6 switch after the first ladder switch.
I have number 6s in the yard. I model 1955 so most of my cars are 40-50 foot long, I don't have a coach yard so passenger trains run through. With the switching being done by 0-8-0s and SWs I could get by with number 4s. So far the only number 4s I've used are in a couple tight places in industrial areas.
I say go as big as the space you have allows and in tight spaces, do what the prototype does and use a small radius. If you read the special instuctions in an Employee Timetable you will find that most railroads served industries where the turns were too tight to permit some equipment to operate.
This is from the IC St Louis District Employee Timetable Number 65 effective Sunday October 30, 1955. New Athens - AutoStove Foundry Track -- 2400, 2500, 2600, 2700, 2800, 8000 class engines must not go beyond frog.
Those were all large 4-8-2, 2-10-2 and 2-8-4 locomotives and the frog was too tight for those engines to use. That didn't stop the railroad from serving that industry or even using those locomotives to service it. It just made an interesting operating problem for the crews. Something one might consider on an operations oriented layout.
Jeff White
Alma, IL
#4's on mine, nothing longer than a 72' center beam, and slow speed in yards anyways... My yard ladder does not see main line speeds, as "speed racer" is not one of my engineers.
Only ever had one issue, and that was a track guage issue, one diverging leg of one turnout was tighter than it should have been, at the very end of the rail, but fixed with a wood tie and extra spike or two when I found it. (On a Walthers Shinohara too... Odd.) I just sliced off the end plastic tie, replaced with a wood one, and added in rail spikes. (Good thing I was learning how to hand lay, I had all the required materials!)
Not had a single derailment on that ladder since.
I did not run 89' cars on the layout to start with, as they look a little odd on 18" minimum Radii. New (planned) layout will have bigger curves, with a 22" minimum, but then the 89' cars will be mainline run-through traffic only, no need to enter the yard. For those whose long cars enter the yard, #5's would add a touch more length, but still be nice and compact for a yard.
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
The yard is 51 inches off the floor and it is 30 inches wide.
Rio Grande. The Action Road - Focus 1977-1983
I use #6 turnouts in my yards. I find that #4 turnouts have too sharp of an angle, and #8 turnouts are unnecessarily long. So, for me, #6 turnouts are the perfect compromise, or should I say, the perfect solution.
Rich
Alton Junction
riogrande, how wide is your yard and how high off the floor is it?
Number sixes for mine.
I wish I had more space or a longer run but yes, biggest switch you can manage is best practices. If I were super cramped for space, I might compromise with #5 maybe.
Here is a photo with more of the yard filled in for engine service and caboose track and an industry lead. The 4 turnouts at the lower left are #8 code 83 and one code 70 (Walthers/Shinohara) for the crossover - to minimize S curve effects on long cars crossing:
Jim,Mighty find looking yard you got going there.
I usually recommand the biggest switch one can use like on a basement filler,go with size 10s on the main and size 8 in the yard.
On a room filler size 6s will work.
And on the smaller layouts and ISLs that is cramp for space go with a size 4 or better still is a Peco medium switch.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
YMMV of course. But it's challenging enough to get trains to runs smoothly and be derailment free that I personally do not want the extra element of trying to get 89' rolling stock through short turnouts and S curves resultant in some configurations. My choice is to stick with #6 turnouts and my advise to others is to do the same if long rolling stock is to be used. Number 6 turnouts are simply geometrically more forgiving and they are a reasonable compromise between space and performance. I note that there are plenty of experienced modelers who are following that type of yard design, which to me is a consensus that it is a wise choice.
The in-progress photo below shows my smallish yard which employs mostly #6 turnouts and a few #8 for a crossover and a turnout into a 2 track TOFC yard. More track has been laid since then but it was handy to post.
riogrande5761The answer really depends, as others have alluded to, on the length of rolling stock you plan on running. If you limit your self to 50' or maybe 60' rolling stock then #4 may be ok.
Jim,If you look at my photo then you can see where 89' cars would have no issues going through those switches since the key is smoothness without a abrupt "S" curve coming off the diversion route.A small gentle "S" curve shouldn't be a issue with cars upto 72'.
When one is force to build in a limited space one needs to plan his yard ahead and keep it smooth as possible.The same applies to a small ISL a abrupt curve coming off a switch making a sharp "S"curve is no bodies friend.
Two snap switches can make a crossover while they're ugly with a sharp S curve one can get by using them with short 36-42' cars and 4 axle diesels or a 0-6-0 or 0-6-0T. Been there and done that but,a snap switch crossover would be the very last thing I would recommand doing.
The answer really depends, as others have alluded to, on the length of rolling stock you plan on running. If you limit your self to 50' or maybe 60' rolling stock then #4 may be ok.
I have passenger cars, auto racks and TOFC flat cars so #6 is my absolute minimum. I would suggest to the OP that #5 would be a minimum às a compromise.
cuyama dante The Walthers/Shinohara Code 83 units are true #4s; however, the radius through the points is 26". My six-axle E-8s and PAs negotiate these #4s smoothly. Of course, the challenge in a yard is shoving strings of cars. Since the PECO Code 83 #5s are about the same length overall as the Walthers #4 (out of the box), I like them for freight yards, with the higher frog number a nice bonus.
dante The Walthers/Shinohara Code 83 units are true #4s; however, the radius through the points is 26". My six-axle E-8s and PAs negotiate these #4s smoothly.
Of course, the challenge in a yard is shoving strings of cars. Since the PECO Code 83 #5s are about the same length overall as the Walthers #4 (out of the box), I like them for freight yards, with the higher frog number a nice bonus.
On my 2012 HO layout I went from Atlas Custom Line #4s to Peco medium switches and haven't looked back.
danteThe Walthers/Shinohara Code 83 units are true #4s; however, the radius through the points is 26". My six-axle E-8s and PAs negotiate these #4s smoothly.
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cuyama Note that not all "#4"s are the same. a couple of the folks posting here used Atlas CustomLine #4s, which actually have about a #4 1/2 frog. So they are a little gentler than a true #4 like Walthers and thus work a little better in yards. PECO's Code 83 #5 is also a good choice for freight yards. (As are PECO's "Medium" in Code 75 and Code 100, although the curved diverging leg bothers some folks in terms of appearance.)
Note that not all "#4"s are the same. a couple of the folks posting here used Atlas CustomLine #4s, which actually have about a #4 1/2 frog. So they are a little gentler than a true #4 like Walthers and thus work a little better in yards.
PECO's Code 83 #5 is also a good choice for freight yards. (As are PECO's "Medium" in Code 75 and Code 100, although the curved diverging leg bothers some folks in terms of appearance.)
The Walthers/Shinohara Code 83 units are true #4s; however, the radius through the points is 26". My six-axle E-8s and PAs negotiate these #4s smoothly.
Dante
I use #5s, and 72 foot centerbeam flats have no problems.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
As far as the "S" curve I think it depends on the yard design and switch type. Pictured below is Atlas C83 Custom Line #4 switch.
This alternative arrangement avoids the S curve noted above. I used it for my fictional yard in Silverton. It may work depending on how things are where you need it.
BTW, the 4-track yard central here is all #4, while most everything else is #6.
Mike Lehman
Urbana, IL
cuyama
I use WS#5s on the ladders and WS#6s elsewhere in the yards. My BLI 2-10-4 and Rapido coaches handle the #5s just fine.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Ok. Thanks..I see what your calling a "S". I've seen that but,I don't consider it "S" but,YMMV.
For me its not enough to worry about.
Hi,
I've got a fair sized (11x15 w/lower level) HO layout and use Atlas #4, #6, and #8 turnouts. The 8s are great for high speed crossovers and and 6s are good for all the other mains.
I use 6s in the yard where longer cars may go, but mostly I use 4s. The obvious reason is space, and of course I had a lot of them when the layout was built.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
woodmanI have no idea what an 'S" curve is or how I would end up with one in a yard?
I have no idea what an 'S" curve is or how I would end up with one in a yard?
BRAKIENot sure where the "S" curve comes from that was mention above and if there is one then its so minor it doesn't cause issues.
There is a modest s-curve formed by the first two turnouts in a traditional straight yard ladder.
First I agree a #6 is nice if you have the room but,#4s would as well.
I use #4s on my ISLs have no issue even when I use my Southern or N&W SD40-2 or my Atlas N&W SD35 shoving two 79' centerbeams..
Not sure where the "S" curve comes from that was mention above and if there is one then its so minor it doesn't cause issues.
What Steve said! (Very eloquently too I might add).
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Simple answer as large as possible.
#4 may be too sharp and #8 may be overkill. #6 is a good trade off.
Remember you will have s curves to deal with and you will be backing trains across the swithches.
Steve