The edge members of the deck frame are 150 x 50 x 3 RHS. The corners had
to be bolted, as we couldn't lift the complete frame into position in one piece.
There was nowhere to put bolted flanges on the outside of the frame, so these
were placed inside, just a short distance from each corner. Photo shows
the two side frames temporarily attached. For final assembly, a five
metre beam went between these flanges. The flanges have a deep chamfer
at the top. After final assembly, this was filled with weld to add stiffness.