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Brief review of developments in IMO steering gear regulations and in the consequent requirements of classification societies is accompanied by a review of ram and rotary vane equipment by Hatlapa Donkin Brown Bros Frydenbo and Tenfjord.

Basic principals of the Bjorkman `Coulombi Egg' design of mid-deck tanker explained with attention to the control of oil spillage in event of collision or grounding.

Probability-based design promises the production of well-designed systems. Its basic advantage is the inclusion of more information into the design process than would generally be included in conventional design practices. Here the focus is on the application of probability-based design to establish a consistent code for tankers. An approach has been developed for formulating a code for design of ship structures to achieve uniform structural safety (reliability index) independent of ship size of magnitude of the design variables. The approach is based on the PSF (partial safety factor) format and a prescribed reliability level determined from calibration with existing classification society rules. Examples are presented for determining criteria for section modulus and initial scantlings of tankers. Formulations are based on material yield strength buckling ultimate strength and fatigue reliability.

The ultimate limit state performance is evaluated of an AFRAMAX-class hypothetical double hull oil tanker structure designed by the IACS CSR (Common Structural Rules) method compared with the same class-type tanker structure designed by IACS pre-CSR method. The ultimate strengths of stiffened plate structures in deck and bottom parts under combined in-plane and out-of-plane actions and hull girder against vertical bending moment are computed for the two designs and the resulting computations are compared. The ALPS-ULSAP program is used for the ultimate limit state assessment of stiffened plate structures while the ALPS-HULL program is used for the progressive hull collapse analysis. ANSYS non-linear FEA method which uses more refined technology is also used for the same purpose. The insights and developments obtained from the present study are addressed.

The paper presents the work carried out by the Instituto Mexicano del Petroleo (IMP) during the last years regarding the development of local rules for the design and reassessment of marine pipelines. This work takes into account environmental and operational conditions in the Gulf of Mexico as well as economic implications of these facilities within Mexican social and political fields. The costs for Petroleos Mexicanos (Pemex) of a possible failure of a marine pipeline are also considered. The results will be incorporated in a Norm of Reference to Pemex being the first regulating national document in this area.

As an alternative to Liquefied Natural Gas (LNG) technology Compressed Natural Gas (CNG) has emerged as a useful strategy to economically monetise natural gas in short-haul trades or certain geographic locations. William J Sember Vice President of Energy Development at ABS has his say.