Effect of ship size on the hull dimensionratiosof purse seiners

In the preliminary ship design stage, the first approximations of speed, stability, structure, weight,andcost, among others,are reached by selectingthe appropriatehull dimension ratios. This research was motivated by the noticeable lack of systematic data ontheseratios in the literature on American-type semi-industrial purse seiners. Regression analysis was performed to investigate the relationship between hull dimension ratios and vessel size from adatabase composed of 130 purse seiners of the Peruvian fleet. This work aimedto determine the effect of vessel size,as characterized by length,breadth, depth, gross tonnage, net tonnage, and fish hold capacity,on the main hull dimension ratios of purse seiners, i.e.,length/breadth, length/depth, and breadth/depth.A compilation of hull statistics for the ship attributes and ratios waselaborated, with the findings indicatingthat length significantly affects the slimness of American-type semi-industrial purse seiners,whosestructural strength and ship weight increasewithlength. These vesselsexhibit an invariable minimum stability according to standard criteria since a breadth-to-depth ratio of 2 is maintained. In this vein,depth is halfthe valueof breadth. The other parametersdo not affect thehull dimensionratios. The estimated regression equations and the patternspre-sented in this researchcan be used in the preliminary design stage of American-type semi-industrial purse seiners.