ECONOMICS OF HIGH-TENSILE STEEL IN SHIP HULLS

During the last decade there has been an increase in the use of high-tensile steel in ship hulls. Initially, high-tensile steel was used in the deck and bottom structure, but lately it has also been used in side-structure and transverse elements. This has given more optimised ships, in terms of both reduced steel weight/investment costs and increased earning potential by increased deadweight. The reduction in the scantlings due to high- tensile steel has in some cased given higher repair costs due to an increased number of fatigue cracks and steel replacement due to corrosion. A net present value assessment of the total cost benefit is therefore performed for a life span of 20 years with extensive, partial or moderate use of high-tensile steel versus mild steel. The analysis studies important factors to reduce life-cycle costs of ship hull structures, and aims to increase the awareness of the implications of using high-tensile steel in ship hulls. A VLCC complying with the DnV rules for fatigue and corrosion protection is used as a case study. The cost benefits are evaluated and consider investment costs, including steel weight, material price, coating systems, and production costs for different grades of high-tensile steel application, and operating costs including maintenance strategies, corrosion margins, fatigue, repair costs, etc. Since most of the cost items are uncertain estimates of the future, a probabilistic method is applied. This approach gives additional benefit in providing valuable sensitivity measures.

  • Supplemental Notes:
    • Marine Structures, v 7 n 1, 1994, p 31 [20 p, 11 ref, 7 tab, 8 fig]
  • Authors:
    • L seth, R
    • Sekkesaeter, G
    • Valsgrd, S
  • Publication Date: 1994

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00716297
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Feb 28 1996 12:00AM