Improved Efficiencies in Truss Spar Designs Without Dry Transportation Constraints

Abstract

Truss Spars that are designed to accommodate dry transportation encounter certain constraints because the overall length and hard tank diameter of the Spar cannot exceed the limits of the transport vessel. When these constraints are removed, hulls can be longer. Increased length allows the fixed ballast and hard tank steel weights to be reduced. Although the truss steel weight is increased for deeper drafts, there is an overall savings in steel when the hard tank and soft tank are taken into account. The heave response of a Spar can be adversely affected by tensioners used to support TTRs. Deeper drafts can improve heave response and an additional heave plate can be introduced if necessary.