Has anyone planned with this in mind?

define sharper than scale

I like the idea but you want to keep in mind that these areas can also be where most track issues will show up, so make sure easy access is provided.

Quarter inch scale representations of curvatures not tighter than used on full size railroads.

Bruce

This is the rough plan so far and hope it will give me all the access I need, Joe.  Open access areas are shaded.  All the tiny details aren't worked out yet, especially at the left end. 

Bruce

What is your minimum radius for visible curves?

Carl,

  I couldn't begin to tell.  It might sound like a crazy line of attack but I won't be working off of any exact measurements, like those from computer programs.  If curves appear gradual enough to look scale then that's good enough.  Of course I plan to keep the tightest hidden curves at a minimum 072 if not greater.

Edit:  I did a rough guesstimate on what I consider the sharpest visible curve illustrated and it works out to about a 13' radius...or 156".  Too tight?

Bruce

Bruce

I cant see it.

  Photo loading outside of the Hoopla attachment tool, doesn't allow for easy picture view adjusting.

 No easy veiw without downloading, finding, & opening again in a new program, then deleting it later.     

Good luck 

Carl,

  I couldn't begin to tell.  It might sound like a crazy line of attack but I won't be working off of any exact measurements, like those from computer programs.  If curves appear gradual enough to look scale then that's good enough.  Of course I plan to keep the tightest hidden curves at a minimum 072 if not greater.

 

Edit:  I did a rough guesstimate on what I consider the sharpest visible curve illustrated and it works out to about a 13' radius...or 156".  Too tight?

 

Bruce

13' Radius is just shy of 054 curve in 3 rail. It appears your drawing shows mixing 3 rail curve sections. your rolling stock and locomotive choices would be limited. I hope you are not looking to purchase a UP 9000 class or 85' boxcars and full scale autoracks!

I'm not going to start defining every nuance, teaching how to use a computer or rehashing grade 5 math.  Stop hijacking this topic.

Bruce

13' radius is 26' diameter, which equals 312" or a curve size of 312 or O312.  Good luck in getting a trammel bar to lay it out.   I like your idea of laying your track be feel. If it feels right, its good.

Am I the only one thay chuckled when first seeing this track plan?  

Nothing personal, you gotta use the space that is available.  

  Don't you just love it.

Bruce,

It's one heck of a good idea. It's going to be a bugger-bear buying track. But that's what makes this hobby enjoyable. Tinplaters started doing exactly what you're wanting to do years ago. Above all else, enjoy yourself.

Nick,

As a matter of fact,   You Betcha! I Love It. 

Was wondering when someone would mention that.  No matter how many times I redesign it, I get the same rude result.  It only seemed natural to first display the plan in the Organic topic.  

Bruce

Anyone else done it?

Bruce - This is a technique that is decades old.  Tried and True.  It's a good idea.

Thanks Nick,

Regarding the track, the real bear will be finding enough from any one company to buy here in Canada.  I've chosen Atlas but even that isn't written in stone....GarGraves/Ross being the alternative. Obviously a lot of flex track is involved but I will utilize sectional curves in those hidden areas.  I figure rather than trying to create accurate bends from flex, sectional will help speed up track laying.

Bruce

Not a hi-jack, an interest. Thanks for your efforts

 Command file write.

Point well taken, especially since this is the second warning here about good track laying.   The areas with the most amount of compound curves will require special attention.  Since the tightest curves will be hidden I won't need to super elevate them, which should reduce the possibility of string lining.

  With a single mainline that meanders through the countryside, the layout theme will replicate a '50's branch line, rather than a big Broadway operation.  That said, the personality of the layout will stink of the neglected, war weary operation that never recovered before the complete implosion of North American railroading.  I hope to create a real contrast between a poor railroad against the backdrop of a prosperous '50's environment.  So far I'm going with the basic coal and wood as a source of income, but that could easily change in time.  Somewhere I'll locate an interchange with a first class line....a reason for the little road's existance and a diorama to show off modern equipment.

Boy, I'm really getting ahead of myself again.  I must be stoned on fiberglass?

Bruce

All layouts are learning experiences.  Keep us appraised of your progress.

And so it begins...

Thought I'd revisit this topic now that construction of the organic design has begun.   The lower staging tracks were pretty rudimentary, but through some rearranging I managed to squeeze in one more track than planned. 

Where to begin?  When designing support around the track plan, ease of construction/deconstruction for test fitting helps speed the process.  Instead of the conventional curved cutouts of plywood for roadbed, I chose slabs of 8' by half inch laminated pine boards, 12" wide.  These were cut at angles to form curves, whereas the flowing straights can be either laid on 6" boards for single track or jigsawed to shape from 12" ones.  It's all the more convenient rather than slugging around 4'X8' sheets of plywood in a confined area

Here is where it started and already I have disassembled the upper level to adjust supporting and change it's path.  Still, the jumping off point over the staging yard was a logical beginning to allow for proper height spacing in this area.  It was decided ( an after thought ) an opening in the grid frame above the yard throat would make access easier once all is done.  As things progress you'll see what's planned for over that opening.

Over to the left sections of wide board transition onto straight 4" and 6" boards.  Using L girder construction allows for flexibility in support construction, where your only obstacle is grade percentage.  In between the 2 basic levels, the lead track from the staging yard rises from below.  Although things look pretty geometric right now, the flowing aspect of my plan will become clear once track is laid.  But then, I'm getting ahead of myself again.  More progress soon,

Bruce

For What It's Worth

"A 1° curve has a radius of 5729.65 feet. Curves of 1° or 2° are found on high-speed lines. A 6° curve, about the sharpest that would be generally found on a main line, has a radius of 955.37 feet. On early American railroads, some curves were as sharp as 400 ft radius, or 14.4°. Street railways have even sharper curves. The sharpest curve that can be negotiated by normal diesel locomotives is not less than 250 ft radius, or 23°. It is not difficult to apply spirals, in which the change of curvature is proportional to distance, to the ends of a circular curve. Circular curves are a good first approximation to an alignment.

 

The sharpest curve the Big Boys could negotiate was a 20 degree curve. The tenders, with their five rigid axles and one lead truck, were prone to causing problems on curves."

Therefore, a 20° curve will have a diameter of (5729.65/20x12/48x2=) 143.24 inches in 1:48 scale.

You can approximate what a real curve diameter in inches would be in O-Gauge 1:48 scale by dividing 2865 by the degree of curvature. (5729.65x12/48x2 = 2864.48)

Example of curvatures converted to diameter in inches for O-Gauge, 1:48 scale:

23° = 2865/23.3 = Ø124.6 inches (minimum for diesel locomotives)

20° = 2865/20 = Ø143 inches (Big Boy absolute tightest, slow speed)

14.4° = 2865/14.4 = Ø199 inches (sharp curve, early American railroad)

6° = 2865/60 = Ø477 inches (sharpest on mainline)

Alex

Thanks for the specifications, Alex.  I can rule out high speed mainlines or Big Boy motive power on this road.  What i'm modelling is not intended to be a first class operation.   As with many aspects of modelling in O in confined space, there will need to be compromises.  Hopefully in the worst cases I can create the illusion of broad curves yet still have the majority of the sections where minimums are achieved.  The only areas where I'll know exact diameters will be hidden sectional track of 072, or roughly 40 degree curves, if I've calculated correctly.  You can see some of those track sections pictured, being used as templates for roadbed positioning.  Outside of those sections, all else is freelance, following no precise plan.  Even the above plan from back in April has been highly modified since then.  But I still retain the initial idea of hiding all the tight curves.

Bruce