Taking a break from structure building (actually, just having trouble figuring out how to paint the Tofu Shed...), I diverted to laying down the basic groundwork. Being a portable layout, I would be using extruded foam insulation boards. This for several reasons; sound dampening, keep the weight down, and the foam is easy to work with for terrain effects. For the base, I used two layers of .5" pink foam on top of the door. I glued the foam with PL-300. A good product but it takes a hell of a lot of time to cure and it has to have "mechanical assistance" when drying. That took a day.
Now with a solid 1" foam base, I could add the next level for the industries. Unfortunately, I hit a bit of a snag with this. The track plan had tunnels, so a thickness of 3" is recommended for adequate clearance. But the length of track for the grade is only 16" long. Doing the math gave a very steep grade of 19 per cent. Too steep as I did some experiments with the engines and wagons. A few attempts later it was possible to have a 2" raised section, which was only a grade of 12 per cent. Engines could do the hill with one to two wagons at a time. But this meant the track plan had to be modified accordingly, so back to SCARM...
I removed the tunnels which caused shortening of the sidings, but on the plus side, I have now incorporated a three-track fiddle yard to the left. Visually hidden of course by various scenery elements. It was then off to the DIY and get some 2" styro-foam. I chose a less dense material for the upper area as I will have to drill access for feeder wires and such. After some time on the old three-wheel bandsaw, I glued down the upper level with the same adhesive and left that overnight.
I'll be "excavating" the base foam to give it more depth, as some if will be a dumping ground. Also some of the tracks currently on ground will be replaced by bridges, as well as various gantry cranes and other equipment. All those older sci-fi kits will have a new purpose. Luckily I am well stocked in rusty paints, washes and pigments!