Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

Estimation of fatigue damage and extreme response for a jack-up platform

Results from four different methods for stochastic dynamic response analysis of a proposed jack-up platform are compared. This structure exhibits both significant dynamic amplification and non-linear transfer of sea elevation into load effects. Both estimation of extreme response and fatigue damage are considered. The most complex procedure based on time-domain simulation and step-by-step integration is employed as a benchmark for assessment of three simplified methods. The simplifications consist of various types of linearization in conjunction with transfer function approximations. Applicability of the methods to structures with increasingly non-linear behaviour and dynamic amplification is briefly discussed.     

Deregulation policy and revitalization of Singapore's bunker supply industry: An appraisal

High bunkering standards are important for ship operators and port authorities for a variety of reasons. When problems arise they may have serious consequences for a port's image. Faced with a range of difficulties, since 1985 Singapore has attempted to revitalize and modernize its bunkering industry, deploying market deregulation to raise service quality and expand consumption. This policy is assessed in terms of its quantitative and qualitative consequences, and as an example of the outcomes of deregulation. Early price reductions achieved substantial market growth, but low-cost bunkering has more recently been significant as a counterbalance to new quality problems generated by unsupervized competition. These have necessitated substantial policy responses in the 1990s which are only now overcoming the setbacks caused by the unregulated market.     

The econometric testing of investment incentives: A cointegrated approach

Thie paper re-examines the link between shipping investment and investment incentives, first explored in this journal by Marlow, and subsequently developed by mcWilliams et al. in the July-September issue. Examination of the ststistical properties of the data reveals that some of McWilliams' results may be flawed. A modified version of the Marlow model is estimated. checking for statistical and economic consistency, using cointegration, checking for statistical and economic consistency, using cointegration techniques. The estimated model resolves marlow's original challenge, but does not appear to be as robust as could be wished.