As always I try to work with cheap, readily available materials. Preferably found around my house. However I realised a project of this scope meant going out and spending a little cash. So I invested in some plastic pipes (as in plumbing pipes), of diameters from 16mm to 40mm, and a few new tools including my very own guillotine.
The main tank superstructure will be made from some nice solid 2mm card stock. I think it came off the back of a photo print I bought a while ago. Then for a nice paint finish I'm going to cover the whole lot in some thin plasticard.