Title: Feasibility study of prestressed concrete tanker ships

Author(s): Johannes Moe

Publication: Journal Proceedings

Volume: 71

Issue: 12

Appears on pages(s): 617-626

Keywords: beams (supports); concrete construction; costs; girders; high strength concretes; hulls (structures); offshore concrete structures; prestressed concrete; shipbuilding;

DOI: 10.14359/7105

Date: 12/1/1974

Abstract:
The study includes trial design of a number of pre-stressed concrete and steel ships. A very high strength concrete is used and a conventional topology is assumed for the concrete ships. The hollow longitudinal beams of the bottom structure, ship sides, etc., are optimized using nonlinear programming. Similar optimization is carried out in designing the hull girder cross section. Minimum weight is used as criterion. Cost of construction is found to be slightly lower for concrete than for steel, but cost of cargo transportation is somewhat higher for the concrete alternatives, due to the heavy structural weight. Prestressed concrete seems to be competitive for stationary or semi-stationary storage tanks. The developments in offshore concrete technology and the changes in relative costs of materials, etc., are presently so rapid that several of the assumptions and statements in this paper, which are based on a study completed early in 1972, may today be obsolete. While the recent increases in steel prices have improved the relative merit of concrete ships, the increases in fuel prices act in the opposite direc- tion. It is still hoped that this study may contain some items of more lasting interest. The general theme of the paper certainly deserves further attention. [Author]