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Winchester Paston & Portsmouth » Blog Archive » Module Design

Module Design

Posted on June 7th, 2010, by Mike

My N-Trak module was designed initially as an exercise to see just how much could be made to happen within the standard 24″ by 48″ dimensions of a regular module, and adhering to all the N-Trak standards for curvature, tangents, etc. I came up with a design that actually worked pretty well to tell one more piece of the WP&P story, which is its interchange with the Norfolk & Western’s Shenandoah Valley main line.

Boyce Junction Track Plan

Firstly, the one thing I always found uninteresting about N-Trak layouts is the rectilinearity of the main lines – the three main tracks run parallel to each other and to the layout edge, all the way around the giant rectangular layout. So I knew I needed to inject one of John Armstrong’s “cosmetic curves” into the design, to break up this rigidity. But symmetry in the curve wouldn’t be much better, as it would register with viewers that the curvature was still constrained to the rectangle. Our human eyes are dang good at detecting symmetry. So I made my front two main tracks wiggle through an S-curve that is weighted towards one side.

The third main (the “branch line”) actually is symmetrical, but since it flows through as the interchange route between two apparent mains, this symmetry is disguised. I ended up cheating on N-Trak standards slightly here, since the design was based on Peco’s medium radius turnouts yet I opted to fit the long-radius turnouts instead. This forced the curve between the tracks to something more like 15 inch radius, but since the diverging route of the turnouts acts sort of as an easement coming into this curve from each direction, there have been no problems with the short stretch of tight curve. I did have some issues with the bridge at the start of the turnout, though, since the long radius turnout has to sit partially on the bridge. Certain long engines had enough overhang to catch on the girders, which forced me to disassemble and rebuild the bridge with spacers spreading the girders a bit further.

Actual Boyce Virginia

I worked out the track plan long before I looked into the geography of the region, but I was pleased to discover that the real town of Boyce, Virginia, had some features which would match up nicely. Primarily, it is located along the N&W mainline, but I also found a stream and a road that closely matched the configuration of my module plan. What was lacking, of course, was any sort of interlocking, since the WP&P is a fictional railroad that never actually ran through this town. But if one takes my module plan and rotates it like so:

Rotated Boyce Junction

… then you can see how it maps onto the real aerial photo. I edited the photo to add in my route and the basic track configuration, as below:

Fictional Boyce Virginia

This shows that the old interchange sufficed for a while, with one N&W main intersecting one WP&P main and a single set-out track adjacent to the N&W main. Then, after merger with N&W in 1967, heavier traffic routing between Winchester and Roanoke called for a new N&W double-track main that bends towards Winchester, relegating the old N&W main to become just a second set-out track.

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