Gotham Central is a 90x60cm Z Scale urban setting micro-layout

 
 
  TRACKPLAN & BASEBOARDS     TRACK & BALLASTING
             
  BASIC SCENERY     work in progress...
             
 
 
 
 
The track plan for Gotham Central is deliberately simple. A self-contained inner oval of track with a 195mm radius (T1), an inner oval of track with 220mm radius (T2), and an outer semi-circle with 245mm radius (T3) are all there is to it (apart from a siding off the innermost track, existing mostly for scenic purposes only).

Continuous running is possible on both T1 and T2, but the latter has two turnouts that also allow the track to continue straight on, in parallel with T3.

  
 
  It is this feature that provides a hybrid function of a) stand-alone double-track continuous run layout and b) connectivity as a 180° curved "module".

Whilst not going for a modular layout per se, this provides the option to expand the layout at a future point in time in case this should become an option compatible with storage space availability.
 
 

 
 
Based on positive previous experience, I opted to use polystyrene boards and a sheet of 10mm poplar plywood as baseboard and trackbed.
 
The types of polystyrene available from DIY stores most commonly used for modelling purposes are XPS (extruded polystyrene, Styrofoam) and EPS (expanded polystyrene, Styropor). XPS has a higher density (28–45 kg/m3) and therefore higher stiffness in comparison to EPS (15-30 kg/m3), whereas the latter is a lot lighter in weight (effectively made up of 98% air) and easier to cut and sculpt (although a lot messier than XPS). But since rigidity and stability was the prime requirement, the layout base is made up of two sheets of 30mm XPS (cut to the correct size using a jigsaw with a fine tooth blade) and then topped with a 10mm sheet plywood top.  
 
The bottom XPS layer (#3) is the base, the second sheet (layer #2) adds another 30mm height but is also cut down in places to represent below track level scenery, and the plywood (layer #1) adds further stability and provides a solid base for the track.
 
 

The pre-planned sections for scenery below track level were cut away from the plywood sheet and the mid-section (layer 2) of the XPS (using a hot-wire cutter for the latter). All three layers are then locked together using special polystyrene glue, and the result is a lightweight yet sturdy layout base.

Following this, a liberal coat of acrylic paint sealed the plywood baseboard top - track ballasting and scenicking involves no small amount of a mix of water and glue to fix it all in place, and baseboards that haven't been sealed this way may well start to warp.
 
         
 
 
Positive previous experience in terms of stability, track geometry options and visuals made Rokuhan my choice of track for Gotham Central. Joining individual pieces of track together is made easy by the fact that the metal rail joiners have an additional double-hook plastic connector in the molded base of the track, which also adds stability. Fixing track pieces securely in place is a prerogative for trouble-free running of trains. There are several ways of doing that; some modellers glue down the track, but Rokuhan provides a "hidden alternative".
 

  All but the shortest track pieces come with guiding holes pre-moulded into the ballast base, but unlike other track brands they are invisible until drilled out from below - an easy job using a Dremel with an ultra fine drill and a low rpm setting.

The resulting small hole is just right to take Märklin's Z Scale tracknails (#08999), my prefered method of fixing down Z Scale track. They are minute and visually unobtrusive, yet provide a reliable and strong connection between the plywood baseboard and the track. They can simply be pushed home with a set of pliers and therefore don't even require a hammer, avoiding potential damage to the track.

An important aspect of laying multiple parallel tracks is to maintain proper spacing, and the wide availability of laser-cut or 3D-printed items for Z Scale provides various simple but effective tools to ensure this.

  

 
All of this ensures that the track is properly joined, level, and fixed securely to the baseboard. In terms of trouble-free running, this is essentially all that's needed. There are, however, a few improvements that can be added to bring the visuals closer to what railroad tracks look like in the real world.

In order to counteract the lateral forces acting on a train running through curved track (and thus reduce friction and excessive wear of the wheels on the outer rail), the track is laid with a cant, i.e. the outer rail is raised above the inner rail, which creates a banked turn.
 
 

Given their low weight (and resulting low lateral forces), models do not require "super elevated track" in order to run smoothly through a curve as long as the train is run at reasonable speeds.

However, Rokuhan offers banked track for curves of 195mm radius and upwards in their range, and seeing a train tilt slightly as it runs through a curve does add an extra touch of realism - which is why all curves on Gotham Central are superelevated. It's a matter of taste, but it adds a little extra visual detail.

  
 
Almost all modellers will agree that the clean and shiny appearance of model track doesn't resemble what the real railroads run on at all - rails on the prototype always display a variation of rust, dirt, grime and other residue from trains. As with fixing down track, different methods and preferences exist as to how weathering is applied to the rails; for Gotham Central, track weathering is done using track painting pens.
 
  Woodland Scenics offers three colour options ("rusty rail", "steel rail", "weathered tie"). The rust colour pen usually needs two applications unless the darker "steel rail" is applied as a base colour. The result looks good and is done a lot quicker and tidier than by paintbrush.  
 
The top of the rails then needs to be wiped clean in order to ensure that electrical conductivity is not reduced by the weathering.

All of this is an attempt to artifically recreate what happens quite naturally to real track. If done properly, the rust and grime adds an amazing level of realism in comparison to "untreated" track straight from the blister pack. But even in Z Scale there is more to recreating realistic track: adding ballast. Using Rokuhan track means that a ballast shoulder is already molded in place, but some additional ballasting goes a long way in making it all look more realistic.
 

I use Woodland Scenics gray ballast in "fine" grade (B75). It is just a bit lighter in colour than the Rokuhan trackbase, but for even more convincing visuals a thin black (and/or brown) wash can be applied. I use a small food storage box to provide a portable "ballast hopper" from which small quantities are spread out along the edge of the moulded ballast base of the Rokuhan track, using a regular size teaspoon - the back of which can be used to tamp down the ballast in a nice even slope to the height of the sleepers.

  

 
The ballast is then fixed permanently in place. Traditionally this is done using a 1:1 mix of white glue and water, but for the sake of convenience and in order to avoid a glossy finish I have found myself more and more using Woodland Scenics Scenic Cement™, which dries to a clear matte finish.
 
  Without any "pre-treatment" (such as spraying the ballast with IPA), I simply apply the scenic cement by taking advantage of its capillary force. Because the scenic glue has a lower surface tension than the ballast and scenic material (thanks to the "wetting" agent it contains), applying the mix close to the edge of the ballast (area #1 in the picture) results in the watered down glue being drawn in and seeping into the dry ballast by itself - or rather by its capillary force (2). Ultimately the effect is similar to blotting paper or household tissues sucking up liquids, and it leaves the ballast almost completely undisturbed (3). The illustration used here shows a piece of Z scale track, but the principle obviously applies regardless of scale.
 
Letting the capillary force do its magic does however result in a slightly slower procedure. Starting at the edges of the area to be treated, patience is required to then let the scenic cement work its way properly into the ballast and scenic material (which might take a minute or two). Additional scenic cement is then only applied to the areas which have already soaked up the mix, saturating them to the point where the mix then seeps into the adjoining area of dry ballast and scatter material. It is definitely a patience game, but then ballasting shouldn't be rushed anyway.
 
     
 
         
 
 
 
Even though the layout's scenery is split up into distinct segments ("vignettes"), certain basic elements need to be defined ahead of any detail secenery work.
 
  The running lines pass under the top layer scenery in several points on the layout - which requires careful measuring of rolling stock in order to ensure sufficient clearances. Usually, double stack container cars are the tallest piece of rolling stock - but it turns out that the extended pantograph of a GG1 reaches up significantly higher.  
 
  Another basic scenic element is the foundation for the top layer (which carries no track, only streets, bridges and houses).

Cut from lightweight yet stable styrofoam, it provides the scenic contours for the upper level scenery; several different "vignettes" will be built up on top of this foundation.

  
 
 
 

 

Any commercial products mentioned here are purely bona fide indications of what I have been using myself.
I have no connection to any manufacturing companies nor do I profit from listing any products or brands.
 

 

page created 18 February 2024
last updated 15 November 2024