Anyone who has the Kalmbach book on benchwork by LinnWestcott will recognise the term “riser” to describe the cross section used to hold the sub road-bed up. Instead of using wood I used aluminium angle and this seems to have worked well so far. In spite of having a bit of a an obsession about using thick track base, I took a risk and used 9mm ply on this layout (not pictured) to keep the weight down. I may live to regret this decision but not as much as using 12mm mdf on QW which caused me problems.