After the framed sections were anchored to the walls and levelled, we began to build the peninsula. It is rather large so it was designed to be cut into several sections should the need arise to move the layout. The construction is a bit different from the frames around the wall in that we used ‘L’ girders instead of just the plain flat frames. L girders provide a great deal of support over long distances with minimal material and legs. The peninsula is about 16′ long and the L girders support it very solidly with only six legs.
Here are the L girders with some of the cross members installed. Some of the legs are temporary:
Once the benchwork framing was in place we began the task of cutting all of the 3/4″ plywood into the various shapes required. Some of the pieces in the flat areas like the main yard and the service area were fairly large. The rest of the plywood was cut “cookie cutter” style to follow the path of the railroad in the elevated sections. The cookie cutter pieces ranged in width from 4 1/2″ for single tracks to 6 1/2″ for double tracks. The extra width will provide space for ditches and signals.
Considerable time was spent planning the cutting to reduce waste and we did pretty well in that regard. There was less than 1/2 sheet leftover out of the 12 sheets we used. We used a model railroad CAD program called 3rd PlanIt to design the layout and to do the detailed drawings for all the cutting patterns. The program allowed us to fit all the various pieces closely together on each sheet.
Below is a sample of one of the cutting diagrams. In this case, most of the sheet will be flat but part of the subroadbed will transition into a grade. The red lines indicate where the cuts will be made:
Every point was plotted starting for a 0″-0″ starting point, usually on one corner of each sheet. The measurements were plotted out latitudinally and longditudinally every six inches or so. We were able to draw complex curves fairly easily, although I will admit that there were a few goof ups along the way. Henk Blom did most of the plotting and Richard Spearing did most of the cutting, both with help from others of course.
The next step was to install the plywood pieces. Most of them fit exactly as planned, but a couple required some jury rigging. The flat sections of the subroadbed were glued and screwed into place. The cookie cutter sections were place on 1″ x 4″ risers every 16″ or so, and the risers were then adjusted to get the desired grade. We left the ends of the cookie cutter sections a bit longer than needed so that we could trim them to fit exactly at the joints. The joints were reinforced with 3/4″ splice plates.
We repeated the same plotting and cutting process with the 1/2″ Homasote roadbed. Homasote, for those of you who are not familiar with it, is a paper based product that is fairly soft and easy to work with. It is used to reduce noise created by running trains, and it accepts and holds track nails quite well. The nails can be simply pushed in with a pair of pliers. The Homasote was screwed down but not glued. Leaving the glue out will make any future changes to the track position much easier.
Here is a view with the cookie cutter sections and the Homasote installed:
Here is a closeup picture with the Homasote mounted on top of the plywood subroadbed. The edges of the Homasote will be bevelled to a 45 degree angle to form one side of the ditches:
Once the Homasote was down we installed the cork roadbed. This reduces the noise further and it also provides a prototypical profile for placing the ballast when we start to do the scenery. The cork was glued down and we used copious quantities of push pins to hold it in place while the glue dried. Getting the cork properly aligned with where the track will be is essential. Some of it had to be done a couple of times. For the larger flat areas like the main yard we used sheet cork where there would not normally be ditches. You can see some of the pins in the picture above.
Here is Ron (center), Richard (right) and Dave (myself) working on the cork:
Stay tuned for Part Four of the layout progress article.