Of those of you who follow his guidelines, regarding ‘Squares’…how well does his 28" dimension for conventional curves work for Mainline use?
I am planning my layout and trying to figure out if I’ll be able to use longer passenger cars on a conventional curve based on that 28" ‘square’ dimension…or do I need to stick with broad curves?
Also…I plan on using code 100 flex track…(and this is a stupid question that shows my ignorance)…but how does one get a 28" curve or a 34" broad curve if they used sectional code 100 track? Aren’t there only 18" and 22" curves that are most readily available in sectional??? I was wondering if he assumed that most people lay their own track or use flex…and the 28"/34" curves were used in the book based on that…
You don’t get 28" or 34" curves in sectional track. Flextrack or lay your own. There are little gauges available that fit inside the rails and force the flextrack to a uniform curve.
I think 28" curves should work for most passenger cars. If you have them close coupled with diaphragms (the covered walkways between cars) there may be some binding. Or worse on S cuves.
I use minimum 30" curves on the main and full size passenger looks OK but not fantastic. Running is fine. Easements help a lot and superelevation helps a little. Don’t use an excess of the latter for long cars and tight curves though.
Hopefully someone else can provide you with a more definitive answer for 28" radius.
Glad you brought this subject up. I recently purchased Armstrongs track planning book.
It made me totally rethink the layout I was trying to plan.
I still haven’t arrived at a final layout plan.
The scale I am working with is HO.
The room I have is 15 feet 5 inches wide, by 31 feet long, with an alcove on one end that comes in 4 feet and is 5 feet 10 inches long, giving me 11 feet width at that end, but I can
I have room to do one of several things to accomodate this.
I can build a 26 foot long by 6 foot wide main section with one or two 6 foot wide by 4 foot long sections off of either end, or close to either end of the 26 foot long section, and make it entirely walk around, or I can have a 26 ft by 6ft main section divided in the middle with a backdrop divider ( 3 feet either side), then off of both ends of the 26 foot section , go all the way to my backwall of my basement( another 7 feet to the wall, and run a 24 to 36 inch wide section along the wall , 26 feet to the end and tie it back into the 6 by 26 foot center section at the other end of the 6ft wide by 26ft long section.
This will entail having either one or two liftout gate sections, follwing the design in MRR December 1999 issue, using magnetic cabinet latches.
This will allow me more options as to final trackage layout design, and more mainline footage.
Sorry I don’t have a drawing to post yet.
But the 6 foot wide sections would allow for a larger radius turns, and I plan on at least 2 main line thru lines,( possibly 3) with various sidings for industries.
Benches will be 1x4’s with cross slat pieces made of 1x4’s like bed slat type frames, with 4x8 x 2 inch blue foam, with another 2x4x 8 foam board cut into two equal pieces and joined with another 4x8 to create the 6 foot wide sections.
Planned height is 48 to 50 inches.
Using foam for two reasons, easy to work with, and it is lightweight and I may move this who
Good, but the largest you can fit is a better way to go. I used his book to get an IDEA of what fit. I did the final design with 3rd planet and AutoCadd. His book was dead on as to cars and what you needed to have for space.
No such thing as a stupid question only stupid answers. My $.02 on that is if this is your madien voyage into layouts the code 100 felxtrack and the turnouts and such to match are a good choice. To make it look better you could use Code 83 flex on the sidings or just go code 83. Pros and cons of Code 83. For the good side, looks better. Bad side, you can not use a Kadee delayed magnet between the rails with out machining the magnet down to fit, (designed for code 100). Turnouts and such are becoming readly available for code 83, code 100 are NEVER hard to find.
A REAL good thing abouit code 100 is that it is easy to mix sectional and flextrack. Do not worry about the radius deal just draw the radius on the tabel, foam etc and lay down the track. The EASEMENT is simple with f
It helped me!
Still pondering a mulititude of possible designs.
Decisions, decisions.
Layout construction party this weekend!
My house, beer and pizza and coffee free!
The 28 inch square allows for a 24 inch radius curve and a 26.5 inch radius curve, plus 1.5 inch clearance outside the wider curve. The NMRA defines 24 inches as conventional curve radius in HO, and says that full-length passenger cars should handle it if proper easements are provided.
I don’t know if John Armstrong ever designed a layout for sectional track. His own was all hand-laid - O scale, outside third rail (except for one branch that ran with stud contacts a la Maerklin HO) I do know that you have to change the size of the squares if you change minimum radius. Tight (18") curves call for a 22 inch square side, while broad (30") curves require 33.5 inches. The 34 inch radius curves you mentioned, if defined as a minimum, would stretch your squares to 37.25 inches.
Note that the squares aren’t a straitjacket. They’re intended for use when layout planning is in the “quick sketch on the back of an envelope” phase, to (hopefully) help you avoid trying to cram ten pounds into a five pound bag. IMHO, nothing about a layout design is fin
It all really depends on what kind of equipment you intend to run. Full-length 85’ passenger cars with diaphragms might have trouble with 24" radius curves. Long frieght cars like articulated well cars and auto racks might have problems on 24" radius. 70’ passenger cars and 40 and 50’ freight cars should be fine. And then there’s the locomotives. Most of even the Big Boy models can operate on a 24" radius curve - even down to 18", but they sure look silly doing it. Smaller steam and 4-axle diesels will handly 24" and not even look bad doing it.
Hi Randy,
I took a look at your layout design and construction pictures on your website.
Your tables and foam top setup is where I got my idea for building mine.
I like the way you have the cross piece supports in your tables up on end rather than laying flat like bed slats…
Looking at your layout pictures gives me more ideas as to perhaps change some of my ideas.
I perhaps could go as wide as 36 inches on my benches, and go around the room.
How high does your layout set?
I can do much more with mine if I don’t use a "walk-in concept, but a instead a “closed around the room concept”
I know there is a lot of schools of thought between duck under and walk in layouts, but with an office chair on rollers, access would be easy.
Right now I have several different design ideas I may sketch out later today.
I have boxes of both cork and foam roadbed , and was wondering what your opinion is of both?
Your foamboard backdrops look easy enough to do, and much less expensive than mica board…
The NMRA recommendations can be found here http://www.nmra.org/standards/rp-11.html
These are minimums that should work for any manufacturer. Some manufacturers make their equipment so that it will negotiate an 18" curve even though the length exceeds the NMRA RP.
Every situation is different of course, but you want to use broader curves if they’ll fit.
If not try to use the NMRA’s minimums if at all possible.
But if you can only manage 18" radius curves then buy cars that are made for it.
Shinohara once offered code 100 sectional curves in radii up through 36", but I don’t think it’s a current-production item. You may be able to find some new old stock if you search, though.
Hey the K4Kid Its seems to me that your just ready to jump into a HUGE LAYOUT. Lets not forget its a huge task to build and mantain a massive layout. With that being said it sounds to me that you should take a look into a 2 level layout or even a mushroom layout. Dont think you need to have massive table tops to have the best layout.
You seem to want to have a Long main line PRR style and have long runs of trains with some really nice yards and shops. You can have 1 or 2 helix that can bring your trains down and up to each level and even to a 3rd level staging yard where you can have OFFLINE stuff happen.
Thanks gottaBreal,
I have had a couple smaller layouts.
Now that I have more room, I’d like to do something more.
Yes, I’ve been pondering the hassles of a larger layout, but then again it’s not as big as some of the
ones some friends of mine have.
I have considered just starting with a 24 foot by 6 foot wide setup, expand off of that later on.
At this size, I can place it in the center of the room, actually make it moveable, to be rolled off to one side for room use for other reasons.
I have alwas shied away from a helix, but maybe I could give it a try.
It basically would be three 8 foot sections, that can be easily unbolted, and electrical connections disconnected, easily.
I intend to make all connections at joints a “plug type” connection for ease of being able to move it, rather than have wires going every which direction.
Everyting would be labelled and a schematic drawn up.
Just imagine it as three or four, possibly 5 modules.
Much like making aircraft electrical harnesses which I have experience with.
Also been looking at two sections at 12 by 12 feet, forming an “L” shape.
Each one being 6 feet in width.
lends itself to some interesting configurations.
Also looked at 18 feet by 12 feet forming an “L”
Would be able to access all sides by walking around it…
Big enough but not too big.
Yet I have been giving this idea a lot of thought and research over the last 4 years.
And I have to credit the forums here( more than any other source) and MR magazine and one other magazine, and a lot of Kalmbach books( I have about 20 of them, plus some others) of which I have gained a lot of knowledge from.
I do have help to build any of these( all I have to do is beat them into submission, promise not to break their trains when I"m at their house, and feed them! ha ha ha!!) plus help them get all their "honey do’s done so they can come over to my house and play "tr
He did create a number of (~50) sectional track plans for Atlas. Unfortunately they don’t always work out, for example, mating a switch and a wye (that produce two converging tracks 148.5 degrees apart) with a crossing (that has leads 150 degrees apart). . .
Yes I bought one of those little blue Atlas planbooks 35 years ago when I was starting out, most (all?) of the plans were by John Armstrong.
People seem to not be including track-with-roadbed in the discussion, I guess you could call that sectional track. Bachmann makes code 100 track (Tru-Track) with curves from 15" up to 35.5" radius. Kato’s Unitrack goes up to about 31" I believe and is code 83.
I guess my orginal thought when I first asked was:
If 18" and 22" sectional is the most used in industry (at least sold, that is) not counting flex or hand layed track, then why are the ‘Squares’ 28" for conventional and 34" for broad curves?
I was wondering if I was missing some special ingredient that I should add to the 18" and 22" track…
Now, as I stated above, I am going with Atlas code 100 flex track. Mostly because it is the easiest to find and I have a whole slew of c. 1970 rolling stock, and I understand that code 100 is more forgiving than code 83. Personally, I am ok with the way code 100 will look after I lay the cork and ballast down.
I must say that I am a little confused on how to make my easements. So, I will have to re-read the book and go from there.
I really do want the widest curves my table space will allow (7’ x 13’) and wish to use inclines (2% max?) to the best advantage…and I also want the most forgiving turnouts, both for DCC reasons and for longer cars.
Ultimately, having said all that, In order to save space as much as I can…I was wondering what the sharpest curves being used out there were and still looked good and worked well with longer cars/engines going around it. I would not want a Big Boy or Challenger going around a bunch of 18" sectional track getting derailed, or making the curve but looking silly.
The squares have nothing at all to do with what sectional track is/was available, or what the manufacturers wanted to call “conventional”. The “sharp”, “conventional”, and “broad” descriptions were a way that Armstrong used to generally describe the curves required to support various classes or equipment. They fairly closely follow the NMRA suggestions seen here:
although they are really a generalization. So if you look at what you want to run, and determine conventional works, then using the squares method with the conventional size you can figure about what will fit. If you determine that a different radius will work for you, you can figure the size of a sqare by adding twice the center to center spacing to the minimum radius (that allows a double track, situation, space for sidings, etc., without violating the minimum radius you have decided on. Teh square system is meant to be a guide to tell you what will or won’t fit. If the squares say if doesn’t fit, you should probably think again. After using the squares to get a general feel of what you can design, you then do the detailed design. I don’t know where my (older and newer) copies of the book are hiding just now, but there is a step by step example in the back, if I am not mistaken.
The idea of easements is not change the radius of the curve from straight to the curve redius instantaneously. Armstrong’s pictures show the advantages pretty well, and point out that a sharper curve with an easement is actually better that a broader curve without (within reason, of course).
I’m not sure where the idea of laying the crosspieces flat liek bed slts even comes from. I saw it that way once or twice in a project layout story but the other 99% of the time it was always done the way I did mine.
36" may be too wide to reach across, unless you build low. Mine sections are 24" across, and even on the grand plan I wasn’t going to go any wider , to keep things accessible.
The top surface is 48" off the ground. That makes the underside a bit over 41" off the ground. I wanted to go higher, but my father in law is quite a bit shorter tha I am. If it was just for me, I probably would have run it up to 54-56" at the top. It would make ducking under a heck of a lot easier, too. In the grand scheme you would never need to duck under to make a run with your train, the completed section would become a coal mining area or some
There is one example of bedslat framing in Linn Westcott’s book. It was certainly not put in by him, since it is for a foam tabletop layout. Other than that instance I can’t think of any time that it would be useful.