Like the two earlier variants -- the classic caisson spar and the truss spar -- this one is the brainchild of Ed Horton at Technip Offshore.
The move from the caisson spar, with its full-depth cylindrical steel hard-tank, to the truss variant involved replacing the lower portion of tank with a truss framework and horizontal plates to dampen heave.
While the first three spars (Neptune, Genesis and Hoover/Diana) were caisson type, the following nine were all truss designs, allowing steel weight and draft to be reduced.
Now
