With the turnouts in place, the next step is to fill in the places between them with lengths of flex track. I again used Walthers Shinohara Code 83 Nickel-Silver track, in 1‑meter (39.37‑in) lengths of "flex track", which can be curved and bent into lovely curves and which matches the turnouts that I have been using. Laying out the flex track was much simpler than laying out the turnouts, since there was no need for fancy cross-wiring on the underside. I did, however, have to pay close attention to where the electrical blocks would start and end, and also make provisions for getting power to each section of flex track. That is the only way to ensure power everywhere.

The cork roadbed was already in place, and marked with a centerline for the flex track, so fitting the track consisted merely of bending the curve as desired, and trimming the ends with a clipper. I came to appreciate the Xuron Track Cutting Pliers, which make a clean cut of it. Track sections that share the same block are connected with metal track joiners, and sections from different electrical blocks are joined with insulated plastic ones. The electrical power to each section is run using stiff solid copper wires that are specially shaped to fit neatly into the outer groove of the rail, and run down through holes drilled vertically through the cork roadbed and the foam board. The top end of the wire is stripped and given one 90° bend towards the track and then another orthoganal to the first in order to fit immediately adjacent to the rail. The wires are then securely soldered directly to the rails on the outside edges, where they are inconspicuous.

I secured the track temporarily using straight pins through the ties that had holes already through them. The track remained in this condition for some time, while I worked on the electrical connections below. By "some time" mean a couple of years, at least, as the electrical work was very time-consuming.

It turns out that the delay was a good thing, because as the layout endured two winters and summers in the sunroom, I observed that the track moved much more than I had anticipated. I performed the initial assembly in the winter, in a relatively cold room, and butted the track sections at what I thought was a reasonable gap. I even estimated the gap by taking two pristine sections of flex track, of precisely the same length (at STP) and left one in the cold sunroom while placing the other near the wood stove to heat it. I had figured on a 1‑mm gap for each 1‑m section, or an expansion of about 0.1%. In the summer, however, when the track warmed up, it expanded enough to bust the rails from the ties around the curves, and I had to trim off another millimeter off each section. Lesson learned: If you are subjecting your track to extreme temperatures of a poorly-insulated sunroom (where temperatures may fluctuate between, say, 5°C and 50°C, or 40°F and 120°F), allow for an expansion of about 0.2%, or 2 mm per 1‑m section of flex track.

One special case in track-laying is in accounting for the turntable and roundhouse. The design allowed for up to perhaps 12 leads off the turntable, so I proceeded to lay those out along the angles that I had marked earlier. I took my cue from the angles inherent to the roundhouse, into which rails must be carefully fed after having been stripped of most of the ties. Note that the track around the turntable is not set up on a cork roadbed, since it will all be finished at the same grade. It turns out that the height of the "lip" on the turntable base is nearly the same as that of the ties under the rails, so that it matches nicely with track attached directly to the foam layer. The two feeder tracks that are on cork are gradually sunk into the foam to match it at the top of the cork.

Here is a photo of the turntable tracks and the original turntable:

A further note on the turntable. The first Walthers 90' (scale) programmable and remote control motorized turntable that I purchased failed to operate after a few years. Their technical support suggested that there was this one resistor on the control board that would fail. I replaced that resistor on my board, but it failed again some time later. That tells me that it is an inadequate design. Walthers said that they could not help because the supplier in the Netherlands (or was it Denmark?) would not support the product. That left all owners of failed turntables in a lurch. And Walthers would not make good on it; they just "passed the buck" to the manufacturer. One possibility would have been to develop a new control board, using an Arduino or Raspberry Pi or something. This would require understanding the nature of communications between the controller and the turntable, but when I asked, Walthers said that they could not provide that information, either. I was distraught, with a dead turntable in the middle of the layout.

Eventually (a few years later) Walthers re-issued the turntable with and updated controller. Since this was an integral part of the layout, I had to purchase the new one (as something like $300!) or have a dead turntable. I am still salty that Walthers would not make good on their failed turntables.

Anyway... Here's another pic of the yard having finished the initial layout of flex track (Now, wouldn't it have been cool to have two more feet for each yard track?):

Note how there are gaps in the ties at the juncture of each piece of track. These are because there is not room for an ordinary tie beneath the track joiners:

Many many ties had to be individually re-shaped to allow clearance for the rail joiners. About four or five per track join:

Note in the following photo the little orange LEDs that adorn the end of each yard track. These are discussed in the electrical section, but the idea is that whichever yard track is led to based on the position of the turnouts is marked by the lit LED, and a corresponding LED on the control panel. Clever, eh?

Before I could actually secure the track with glue, however, there was one large missing piece that had to be dealt with. Between the intermodal yard and the roundhouse is a small canyon that must be bridged before the track can be finished.

Time out to build the trestles! This was not so much track work as scenery, though it could be argued either way. At any rate, most of the trestle construction is covered in the scenery section. A significant effort in track work, however, presented itself in the hand-building of the ties atop the trestle. The regular flex track has a tie spacing much too large for credibility for a trestle, so I had to build the ties from balsa stained a walnut color, and attach the rails to them using Micro-Engineering rail spikes. In the following photo, you can see some of these track spikes, which are used for each tie, with spikes on both sides of each rail, two rails per trestle, and two trestles. Over 400 spikes! After that exercise, I have a whole 'nother level of respect for those who handbuild their own layouts.

Up until this point, and during a long period of track tuning (getting the curves just so, re-gapping the joins, and getting the turnouts to work smoothly, the track had been secured to the cork roadbed simply using straight pins. Now that everything seemed to be working smoothly, it was time to commit: All the track now got glued down using the following method, applied section by section:

1. Wet the section by spraying with a mix of water and dish soap, which ensures that the surface tension is lost and the water can creep into tight spaces (like under the ties), giving the glue a path to follow.
2. Apply a 50/50 mix of glue and water, with a bit of dish soap in it, liberally to the track ties, so that it can soak beneath the ties. Be careful not to get glue on the moving parts of the turnouts (the points), though!
3. Weight down each section with something, so that there is good contact between the ties and the roadbed. I used heavy books and even some rocks sitting on rolls of duct tape (my daughter has about 20 of these in various colors) set on their edges. These help to distribute the load of weight along the track section being glued.
4. I let each section sit and dry overnight, so it took about two weeks to get everything glued down.

But at last the track was properly secured.