My Z Scale modular layout is very much the result of "trial and error": much of what has materialized in the end happened to do so because something else went wrong or didn't work at all - or because I changed my mind.
Here's a brief account of how it all came together in the end.



Z is the smallest commercially established electric model railway scale with a ratio of 1:220 and a track gauge of a quarter of an inch (6,5mm) - making it only 72% the size of N Scale and a mere 40% of H0 Scale - and therefore offers the possibility of running trains in a confined amount of space which simply would not be possible in other modelling scales.
As a result, you can build a self-contained continuous run layout similar to those in other modelling scales - but in drastically smaller overall dimensions. For example, the rather complex trackplan shown here only measures 24"x48" (60x120 cm) yet offers continuous running (even twice around) along with several spurs and the potential to model scenic variety. You might just be able to shoehorn this into that space with N Scale but only by using very tight curves, markedly shorter straights, and foresaking much of the pointwork. And of course it would be absolutely impossible in H0.  

Grey River Northern Trackplan (c) David K. Smith


It's almost something of a business card for Z Scale - the diminutive continuous-run layout. However, even these "shrinking layouts" tend to have a footprint which makes them noticeable, because even Z requires an area of approximately 20"x20" (50x50 cm) for continuous running, i.e. for a full circle of track with reliable operation of medium and larger locomotives. And although this may be small in comparison to other modelling scales, it is still potentially obtrusive in living quarters which are not exclusively designated "model railroad space".

So even though a good many layouts, books and websites made me want to plan and build and run a Z Scale US prototype layout for the longest time - that continuous running footprint continued to bother me, small as it certainly was. I was deep in armchair modelling mode, waiting for an inspiring revelation so that I could finally get going.

  When it finally came, it did so in the shape and form of a train speeding down the track.

Watching CSX freights blast through Wildwood FL completely changed my perspective on what a Z Scale layout could (and in my case should) look like - not the least because seeing the actual trains trackside made the scale's true space saving qualities become apparent to me. It struck me that Z Scale was ideal to replicate precisely what I was seeing here - trains speeding by or trundling by or awaiting their turn to get back on their way from A to B.

Previously focused on minimum space continuous run layouts which also incorporated some amount of switching, the trackside experience at Wildwood made me reconsider that layout formula. Continuous running yes, but in a more linear orientation, just like the yard layout at Wildwood. Zooming in on this linear perspective, I was struck by just how amazingly narrow modular "shelves" would be possible thanks to the cross-section dimensions of Z scale track.
  This is because the overall footprint over ties of Z Scale track is only half an inch (12.4 mm) for a single line of straight track. The width required by a double track line is therefore no wider than a mere 1.6 inches (40 mm) when using track with a permanent plastic roadbed base imitating ballast.

Clearly nothing would take advantage of precisely this space saving quality offered by Z scale more than a modular layout made up of several narrow oblong segments (i.e. "shelves" in model railroading terminology).



Further thinking and measuring revealed that Z scale makes it possible to have modules with a width of just 6 inches (15 cm) for a double track line including an ample scenic shoulder on both sides along the permanent way, these modules would not only be great space savers - but also easy to carry about, easy to set up, easy to store.
Which is just the ticket for someone wanting a layout which is not permanently on display but easy to set up and dismantle again in a sensible amount of time. It was just the inspirational input I had needed.
  In a tongue-in-cheek tip of my hat to my locus amoenus, my inspirational "pleasant place", I decided to name my modular system Seaboard Modules - Wildwood FL was an important point in the network of the Seaboard Air Line, which in turn became the Seaboard Coast Line and then the Seaboard System; all of which is where the S in today's CSX stems from. Besides, the stylized "Double S" Seaboard System logo is also a perfect fit for symbolizing modular layout segments.  
Settling on a standard width of 150mm (6"), the length of the individual modular elements is totally flexible as long as it is a multiple of 110mm, the standard length unit as defined by Märklin and used as such by all Z scale track systems since.
To connect modules reliably, one piece of standard track length is used on both sides. This means that e.g. on a module of 770mm length a total of 660mm of track is laid down so that there is a "blank" space of 55mm on each end. A standard length piece of track can then be used to bridge this gap across two modules, ensuring optimal running and power flow.  
Designed in principle to be completely straight, any form of modular layout element can be incorporated and joined easily to any number of additional elements.
The double track setup is designed for continuous running in such a way that a train running in one direction on one track will eventually return running in the opposite direction on the second track. For obvious reasons, any string of straight Seaboard Modules therefore requires a turning loop at each end to enable this form of continuous running, creating an overall track layout in a so-called "dogbone" shape.

Wikipedia defines "dogbone layouts" as an arrangement of a continuous loop where the sides of an oval are squeezed together so that they look like a double-track section with a loop at each end (where the trains turn around). They come in several varieties, depending on how the loops are set up - on the Seaboard Modules I opted to have a straight line to one side of the loop modules, i.e. a "drooping dogbone" configuration, rather than fashioning them like a true dogbone which bulges out on both sides. That way, the modules can fit flush against e.g. a wall.

The resulting layout is modular, but its elements are not modules in the sense that they follow any general standard dimensions which would allow them to be joined up with other modules following the same specifications (such as Z-Bend Track). They are built according to my own preferences and requirements and intended only to make up my own layout, which can expand (or not) according to the space and time available, as well as be set up differently for different running sessions.


One of the general characteristics of the (straight) intermediate modular segments formulated in the planning stage was that they would need to be easy to handle and easy to store - which quickly translates into "not too wide, not too long, and not too heavy". Given that with Z Scale you can really deflate things in a serious way, I set the standard width at 150mm (6").
  The length is variable as long as it is a multiple of the standard track length of 110mm, and was set at 770mm for the first module; the result is a very sleek and unconditionally portable "module".
990mm would seem like the maximum sensible length, but 770mm is a comfortable fit and also means that you can work on this segment of the layout almost anywhere - making them true "desktop modules".
The trackbed level is set at 50mm from the bottom edge of all modular segments. Side frames are cut to the predetermined shape of the landscape (e.g. including a cutout for a small stream in this case), including an angle leading up at both ends to 150mm. The idea is not so much as to "hide" the module connection ends but rather to provide some amount of protection and the possibility to store the module upright on one end without the risk of major damage. As a side effect, it also greatly adds to the overall rigid yet lightweight nature of the frame.  
An element of operational reliability (or lack thereof) which is built permanently into many layouts and modules are different track levels which result in grades when connected. Although Z Scale can handle inclines which conform to the standard rules of thumb applied to all modelling scales (i.e. anything below 2% is good and 3% should be the absolute limit), there is one difference: the potential to have really long trains puts an amount of pulling force on the couplers which can result in too much strain and, as a consequence, unwanted uncoupling.
  In order to ensure maximum operational ease and reliability grades on all Seaboard Modules are kept at 0% throughout. On a scenic level, the fact that the track runs completely flat can be made less apparent by having the terrain rise and fall to the sides of the right of way - an acceptable appraoch given that rugged mountain scenery is not an intended theme of this modular layout.
Micro-Trains Micro-Track with roadbed is the standard track system used for the intermediate modluar segments because of its appearance which replicates North American style track.
The noticeable difference lies in the size and spacing of the ties; in addition, Micro-Track (pictured to the right) has a slightly finer rail profile than e.g. Rokuhan track (left, which is based on Japanese and European standards).

The choice was also made because the huge disadvantage of Micro-Trains' track system - a very limited track geometry - didn't come into play on these modular segments as they will not feature anything other than basic trackwork configuration.



The two 180o loop arrangements required to turn the connected intermediate modular segments into a circular track for continuous running were initially planned as non-scenicked connections made up of several elements which would have been joined together almost like set pieces of trackwork. This conformed to the logic of the intermediate modules (purposely designed to be slim and unobtrusive) as fixed return loops tend to lose most if not all dimensional subtlety and end up being two, in comparison, very chunky pieces of layout.
There is, however, also the question of structural stability and operational reliability. In the end, I changed my mind, accepted a certain amount of space being taken up by the two 180o loop segments, and even turned one of them into a standalone minimum space layout.

An important decision tied to the loop modules is the minimum radius to be used. In order to be able to run modern six-axle locomotives and long wheelbase stock, the common standard Z Scale "large radius" of 220mm is an obvious choice; Rokuhan has since even added 245mm and 270mm to its large selection of curve radii, which would be even better but, obviously, take up even more space. However, Z Scale manufacturers will always ensure that their models run smoothly and realiably through 220mm radius curves (possibly excepting certain special models such as the UP "Big Boy" - which won't be running on this layout anyway).

In order for the 180o loop to align the outgoing track with the incoming track with the correct double track spacing an outward "s-curve" needs to be inserted using two 490mm radius track pieces (otherwise used in conjunction with switches to align the diverging track back into parallel).

This track configuration has a "footprint" of 20"x40" (50x100cm) as shown below, but if required the segment can be cut back to the width of the intermediate modules by following the tangent straight track inwards.

For Rokuhan track there is also the alternative of using a 25mm piece of straight track (R030) inserted into the middle of the 180o curve to achieve the correct distance between the two parallel tracks leading onto this segment (Micro-Trains lacks this piece in its Micro-Track geometry).

The "footprint" of this setup does not make considerable space saving economies over the 20"x40" (50x100cm) configuration, but the overall appearance is a much tighter piece of trackwork with a lot less flow and ease - which is why I opted for the "s-curve" setup.



There's hardly a better way to capture the thrill and the diversity of railfanning than in a series of Z scale modular elements, joined up to represent trainwatching vignettes, i.e. a series of small evocative scenes which fade out without definite borders. Model railroad design veteran John Armstrong used the term vignettes in his 1972 book on Creative Model Railroad Design to suggest a layout akin to a museum display or a theatrical stage, although back in his days he was still thinking of basement size pikes running H0 or even 0 Scale trains. Which is probably why it didn't have the effect on me those CSX freight trains running through Wildwood FL had.
  My interests in US railroads are broad and diverse, but have always been rooted east of the Mississippi. The broad thematic concept of a railfanning layout is therefore set into a very broad geographical context of the Eastern States of the US, and primarily those bordering on the East Coast.

The Seaboard Modules therefore stretch beyond the original Seaboard System (which reached from Miami to Richmond), although its successor CSX ultimately extended its operations well into New York State and Southern New England with the acquisition of parts of Conrail in 1999.

Not focusing on a specific geographic region, railroad or era within this general setting is not a bad thing in Z Scale anyway, as the selection of motive power and rolling stock still remains limited in comparison to larger modelling scales, even if things have progressed by leaps and bounds since 2012.

But even if the somewhat generic blueprint for both location and time provides me with the potential opportunity to model scenes stretching all along the Eastern Seaboard from Florida to Maine and across to the Great Lakes, set anytime from the mid-1950s to the current day, the idea is not to ultimately produce a string of modular segments which line up to form one long railroad line from South to North and then West in a proper geographical sequence.



page created 23 April 2012
page updated 14 February 2016