The cell spar -- a slimmed down version of its spar predecessors -- is a cluster of at least six to eight vertical steel tubes supporting a light-weight deck. Each tube is about 15 feet in diametre, as opposed to a single cylindrical hull typically of around 100 feet. The concept resembles grain silos bunched together.
With no provision for drilling or dry trees, the topsides payload on such a cell spar might be about 2500 tonnes.
