The statistical analysis of the voyage data of three fast cargo ships

Abstract

Speed, power and weather data has been collected aboard two fast North Atlantic container ships, the M.V. ‘Dart Atlantic’, operated by Bibby Line Ltd., and the G.T.V. ‘Euroliner’, operated by Denholm Ship Management Ltd. In both cases the period of collection was about three weeks. In addition, eight months data extracted from the deck and engine room log books of a fast cargo ship was made available. These three sets of data have been analysed using multiple regression techniques, with speed as the dependent variable.

Significant speed variations with time, wave height and direction, wind speed and direction, displacement and sea temperature have been found. Empirical formulae are given for each ship which estimate the speeds in given conditions.

A correlation has been found between the speed losses of different ships in bad weather and a function calculated for each ship which contains n and the ship’s length, where $\mathrm{n}=\frac{\mathrm{dP}}{\mathrm{dV}}·\frac{\mathrm{V}}{\mathrm{P}}$ . It is proposed that this correlation could be used to facilitate the prediction of speed loss in bad weather.