Thanks, people!
Mason, yes quite thin. We got plenty of cut-offs from a local dealer for some loose change, and found that 30 mm is a good strength. They were ripped lengthwise to give two roughly 15 mm strong pieces with irregular surfaces. Any stronger than that is awkward to handle. We made some smaller spires from 100x100x250 mm pieces without Styrodur core, though.
Andrew, I made the pipes some time ago as part of my industrial range. The larger pieces I used here have never been released yet, as I had never used them. This might change soon

These are from the
same batch. The ones Andym mentioned are way smaller.
Andym, thanks for the heads-up. I'll see if I can find an equivalent in our local DIY market.
And on to a few more pictures...
Full view of the upper two-thirds:

Most of the vegetation was done by Mrs Zafarelli in the night before we left for Tactica. Scratchbuilt tree, lots of repainted plastic plants, dyed foam leftovers, floral wire and ground foam. And dryed potting soil underneath it all. Doesn't really show in the pictures, though


Lift from the lowest to the topmost level. I don't really like the finish of the rails (had nothing on hand other than MDF), and will probably rebuild them from sheet plastic.

Left cave entrance. If you enter and turn right, you will emerge in the last picture


Detail of the crane. The claw will be replaced for something more suitable to transport goods and people up to the platform.

And a view of the front cave entrance. The machinery which is fed by the pipeline is visible in the background.
