Computer analysis of longitudinal strength of ships

Abstract

The purpose of the work was to produce a programme to calculate as accurately as possible the distributions of weight and buoyancy of a vessel, leading to the determination of sheer force and bending moment at each of 101 equally spaced ordinates overall. Calculations may be performed for still water or sine wave conditions. The programme, which provides tabular and/or graphical output, is written in Elliott Autocode and is in the Applications Group library of Elliott Automation Limited. It is extensively labelled and is flow charted throughout, the symbols used being those of the British Standards Institution, and illustrated in the glossary. A fairly detailed look into the ‘end lengths’ suggested by Lloyd’s (their Rpt. SR 64/15) has been undertaken in connection with the distribution of the continuous material. Ordinate tilting has been used, in the main, as opposed to ‘base swinging’ techniques, the reasons being fully explained in the text. The programme was approved by Lloyd’s Register of Shipping in August 1966, (except for those parts relating to (i) the coffin method for the continuous material and (ii) the application in a sine wave - which parts Lloyd's did hot check). It has also been further successfully tested by them in November, 1966. Comparisons with programmes written by Vickers Armstrong’s Limited, Barrow in Furness, B.S.R.A., Walls end, and the Naval Architecture Department of Glasgow University, on the same topic are included as an Appendix. Graphical results obtained by Lloyd's, B.S.R.A's and by this programme for one locally built vessel are included, for purposes of comparison. Results illustrated in the thesis are in both tabular and graphical form throughout.