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How do squares work in track planning?

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How do squares work in track planning?
Posted by NWP SWP on Monday, December 04, 2017 8:35 PM

I have read about the "squares" or "squaresquares" concept and I have read John Armstrongs Track Planning For Realistic Operation but I still do not fully understand the squares method of track planning. Can anyone please explain how it works?

Steven

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Modeling the combined lines of the Southern Pacific, Western Pacific, and Northern Pacific after a fictional Depression Era merger forming the SouthWestern Pacific and NorthWestern Pacific Railroads. SP, WP, and NP operations remain independent but also operate alongside NWP and SWP equipment.

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Posted by dknelson on Monday, December 04, 2017 8:44 PM

If you have the book by Armstrong it may take a "read" or two but it is fairly clear.

If you imagine your minimum acceptable radius - let's say 26" inches -- then you think of the size square it would take to have a 90 degree right angle curve with that radius.  That is your square.  So for purposes of fitting a track plan into your available space, how many such squares do you have north/south to work with, how many east/west to work with.  It is a way of thinking about available space so that you do not end up compromising on your minimum acceptable radius.

Dave Nelson

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Posted by NWP SWP on Monday, December 04, 2017 8:48 PM

So does a curve start in one corner and go to the other or does it not matter where the turn starts along the side of the square.

Steven

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Modeling the combined lines of the Southern Pacific, Western Pacific, and Northern Pacific after a fictional Depression Era merger forming the SouthWestern Pacific and NorthWestern Pacific Railroads. SP, WP, and NP operations remain independent but also operate alongside NWP and SWP equipment.

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Posted by GraniteRailroader on Monday, December 04, 2017 9:44 PM

The "Square" is the space it takes for your layouts minimum radius to complete a 90 degree turn.

So planning things like corners, peninsulas, et al, you can plan it out in "squares", and then adjust for easements and other things afterwords.

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Posted by cuyama on Monday, December 04, 2017 10:11 PM

Armstrong’s squares are a way to get a rough idea of what fits. The explanation in Track Planning for Realistic Operation is complete and clear if one takes the time to study it.

What some posting here are leaving out is that the dimension of an Armstrong square is actually the minimum radius plus 2 times the track-center-to-track-center dimension.

Edit: And even that might not be quite enough if one wishes to allow for some buffer space around the edge of the benchwork (which is a good idea). 

Byron

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Posted by carl425 on Monday, December 04, 2017 10:54 PM

Byron's explanation matches my understanding of the Armstrong square.  However, I don't understand why anyone comfortable with a computer would do track planning on paper.  There are some very competent track planning programs available and some of them are even free.  3rdPlanit, XtrackCAD and SCARM seem to be the top 3.

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Posted by NWP SWP on Monday, December 04, 2017 10:58 PM

I may be an member of the iGeneration but I work better with pencil and paper.

Steven

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Modeling the combined lines of the Southern Pacific, Western Pacific, and Northern Pacific after a fictional Depression Era merger forming the SouthWestern Pacific and NorthWestern Pacific Railroads. SP, WP, and NP operations remain independent but also operate alongside NWP and SWP equipment.

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Posted by GraniteRailroader on Tuesday, December 05, 2017 5:55 AM

What some posting here are leaving out is that the dimension of an Armstrong square is actually the minimum radius plus 2 times the track-center-to-track-center dimension.

 

Mea culpa! Going from memory and knew I missed something!

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Posted by SeeYou190 on Tuesday, December 05, 2017 6:15 AM

Sketching on paper, especially "Doodling by the Squares" is definitely the easiest way to noodle through your ideas.

.

Computers are useful for the final plan I suppose, but even then, are lacking compared to an actual layout mockup.

.

-Kevin

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Happily modeling the STRATTON & GILLETTE RAILROAD located in a world of plausible nonsense set in August, 1954.

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Posted by rrinker on Tuesday, December 05, 2017 7:52 AM

 The beauty of the squares method is that as long as you don;t cheat and fit more into a square than truly fits - you can doodle anywhere you have something to write with, no rulers needed. Heck you get an idea walking past some kids playing hopscotch (does anyone still do that?) you can borrow their chalk and sketch your idea right there on the sidewalk (when we didn't have chalk we used a rock to carve lines). 

 What fits and what doesn't fit in a square is well covered in Armstrong's text. The whole idea is to get the basic form on the layout without precision drawing - once you have a 'finalized' squares drawing you can make an accurate drawing using rulers and templates or a computer program.

                                       --Randy

 


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Posted by riogrande5761 on Tuesday, December 05, 2017 10:29 AM

I've read and worn out my copy of John Armstrongs Track Plannning for Realistic Operation.  However, his square's principle is something I've never found to be useful to me - just the way my brain works.  The rest of his book has been very useful however.

Rio Grande.  The Action Road

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Posted by wjstix on Thursday, December 07, 2017 1:04 PM

To help visualize the 'squares', imagine having four 2' by 2' squares of plywood, and putting them together into a square (4' by 4'). Then put a circle of 22" radius and 18" radius track on top of the plywood, keeping the track equally distant from the edges. You would have four 'Armstrong squares', each showing a 90 degree curve with your minimum radius (18") and what you'd need for a second track (22").

You could add two squares with straight track separating the curves to make an oval, but you would have to add two more squares to have enough space to add a reverse track cutting across the middle.

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Posted by selector on Thursday, December 07, 2017 4:44 PM

I understand why the concept of the squares confounds some of us.  It took me a while to figure it out, so I didn't see what Armstrong was getting at right away.

Two key concepts to bear in mind:

a. The squares have to contain two, not one, but two nested curves as one would a double main. If you want double mains, you must separate them by a minimum amount, and also get both of them, nested, to stay roughly parallel on substantial changes of direction (AKA 'curves'). Armstrong says to do this for your minimum main line radius, plus add the minimum side clearance for an outside curve.  Notice that he has that dotted outside curve approaching only to a certain minimal distance from the two edges of the box [that's the safety zone for tumbling rolling stock]; and

b. The curve of the two nested mains has to subtend an angle of 90 deg. This is important because, on a slab of plywood, your corners require the same change of direction to keep the trains on the surface...90 deg...as a minimum.  Approach those corners obliguely and you'll need even more curvature.  The square helps you to plan that 90 deg curve, PLUS a portion of another curve, meaning adding yet another box beside the first one.  So, by adding curves of various degrees, you also are required to add their host boxes.  The total number of boxes, aside from where you find yourself placing them so that you can follow your track plan, also add up to the square footage you'll need and the dimensions for the framing you'll need for all those degrees and side-clearances to work well. 

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Posted by dknelson on Thursday, December 07, 2017 6:47 PM

carl425

Byron's explanation matches my understanding of the Armstrong square.  However, I don't understand why anyone comfortable with a computer would do track planning on paper.  There are some very competent track planning programs available and some of them are even free.  3rdPlanit, XtrackCAD and SCARM seem to be the top 3. 

While there are indeed many track planning programs out there, it would appear that the learning curve must be more challenging for many users because I see so many layout plans with almost Maerklin-like regularity of tangents, curves and angles, and straight track relentlessly following the edges of the presumed benchwork.  

I also see computer derived exceptions to that, so clearly it is possible, but it seems to me many, many users do not get to that step.

One reason to stick with pencil on paper (Armstrong by the way had an electric eraser, and I suspect had he lived he would have adapted to the computer design programs because so many clients requested changes and do-overs) is the ability to improvise with a "photographer's curve" as he so often did.  That is just one example.  I think you have to get pretty deep into the user's manual and tutorials to get to that point, or at least so it seems from the visible evidence.

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Posted by Anonymous on Thursday, December 07, 2017 8:11 PM

I think the rather "squarish" look of many a track plan has more to do with the way people think than their ability to work with the CAD tool of their choice. Maybe John Armstrong´s track planning method has also contributed to that.

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Posted by carl425 on Thursday, December 07, 2017 9:57 PM

Sir Madog
I think the rather "squarish" look of many a track plan has more to do with the way people think than their ability to work with the CAD tool of their choice.

I think Ulrich is right - it's not the arrow, it's the indian.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by NWP SWP on Thursday, December 07, 2017 10:35 PM

Do artists sketch their art on a computer and then print it? I think not! I think hand drawn track plans are the best for preliminary planning and then CAD can be useful to make a digital version and work out the kinks. One thing I have learned is that hand laying track allows a lot more flexibility than factory track.

Steven

Crooner, Imagineer, High School Senior, and President of the NWP-SWP System.

Modeling the combined lines of the Southern Pacific, Western Pacific, and Northern Pacific after a fictional Depression Era merger forming the SouthWestern Pacific and NorthWestern Pacific Railroads. SP, WP, and NP operations remain independent but also operate alongside NWP and SWP equipment.

Hook'em Longhorns! 

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Posted by Anonymous on Thursday, December 07, 2017 11:59 PM

NWP SWP
Do artists sketch their art on a computer and then print it? I think not!

I wouldn´t be too sure about that! Smile

NWP SWP
I think hand drawn track plans are the best for preliminary planning and then CAD can be useful to make a digital version and work out the kinks.

The last time I used paper and a pen to draw a track plan was in the late 1960s. When I moved from bein an armchair model railroader to being an active one again a little over 20 years ago, I alwaays used a track planning CAD for creating my track plans - right oin the screen. It worked nicely for me!

NWP SWP
One thing I have learned is that hand laying track allows a lot more flexibility than factory track.

The use of flex track also helps! Not everyone dares to handlay switches.

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Posted by Choops on Friday, December 08, 2017 6:55 AM

The idea of the squares method is not to get a final design of your layout but to quickly sketch a rough plan anywhere you are.

Lets say your room is 24' x 16' and your minimum radius is 28"

your squares will be 32"

divide your room into squares you get 9 squares by 6 squares.

now if you are in a restaurant or at church or anywhere and an idea pops in your head you can quickly sketch on a napkin or scrap of paper a grid 9 x 6. Then knowing that a 90 degree turn or a 5 track yard throat will fit in a square you can sketch out your idea knowing it will most likely fit in the space you have.

Then you take this idea and draw it out later to scale as a final plan.

Steve

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Posted by rrinker on Friday, December 08, 2017 7:12 AM

And that ^ is exactly the point of Squares.

Try to find a first or second edition of Track Planning for Realistic Operation. The whole process going from empty room to figuring out what might fit by using the squares method to developing a preliminary plan to finally filling it out in detail is better covered in the earlier editions. The third edition cut some of that chapter and some of the intermediate illustrations to make room for the chapter on modern stuff like intermodal and flood loaders. I have a second and a third edition and there is a definite difference in the 'meat' of the chapter on planning that layout. 

 I have many years of CAD experience. I can't draw freehand to save my life, but give me a T square and some triangles and eraser shields and I can do a halfway decent mechanical drawing. I did originally doodle sketches of a new space, using squares, before moving on to CAD, although lately I've just been starting with CAD, getting an accurate room dimension and using that as a base layer, never drawing track objects or anything else in that layer. I then start the track design by drawing some circles of my minimum radius and start moving them around to see what fits. Since it's easy to erase lines, I lay in some tangent lines between the circles which allows me to see what sort of aisle space I've left myself. Repeat until satisfied with the basic arrangment - but there's one more step. Don;t leave all those straights connecting the curves perfectly straight! That's where all square layouts come from. Now, not evert interconnecting track can be curves, you need places for sidings and all that, but neither do they all have to be ramrod straight. I know 3rd Plan It lets you drag the track away from perfectly straight while maintaining radius requirements, maybe some of the others can do this as well. Also, when initially creating those tangent sections, I deliberately do not manually align them to be parallel with the walls.

                             --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Walt Con on Friday, December 08, 2017 10:52 AM

New to this forum, but understand the square layout, doodle on a scratch pad and when happy and smiling ear to ear put in on the computer or pencial and ruler and work out the details.

will also look for that book and get it for food for though

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Posted by cuyama on Saturday, December 09, 2017 4:53 PM

dknelson
One reason to stick with pencil on paper (Armstrong by the way had an electric eraser, and I suspect had he lived he would have adapted to the computer design programs because so many clients requested changes and do-overs) is the ability to improvise with a "photographer's curve" as he so often did.  That is just one example.  I think you have to get pretty deep into the user's manual and tutorials to get to that point, or at least so it seems from the visible evidence.

Respectfully disagree. The limitations are in the designer's mind, not the CAD tools.

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Posted by cuyama on Saturday, December 09, 2017 4:57 PM

Sir Madog
I think the rather "squarish" look of many a track plan has more to do with the way people think than their ability to work with the CAD tool of their choice. Maybe John Armstrong´s track planning method has also contributed to that.

Agree with the first statement, respectfully disagree with the second. Very, very few people use Armstrong’s by-the-squares method. And if they did, their track plans would be less slavishly “square” – Armstrong’s weren’t.

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