Effects of Control Systems on Optimization of Ship Size for Navigation in Restricted Waters of the Great Lakes

Abstract

The study examined the question of how alteration of traditional channel clearances (i.e., three times ship width for channels, and seven to eight times vessel beam for traffic) would affect the economics of increasing the ship's dimensions. First there was a study of ship dimension optimization, holding draft constant, to meet Great Lakes depth constraints. It was found that the optimum_sized vessel is approximately 1,250' in length, 156' in width, and has a 27.2' draft (maximum allowable without dredging). &&The second task was to estimate the costs required to modify channels and harbors to accommodate. the optimally_sized ship. &&It was estimated the dredging costs would be $6 - $7 billion (1977 value) if the current channel/ship dimension relationships were maintained. This investment could be reduced to less than one billion dollars if the channel/ship dimensions were altered so that ships about 50 percent wider were permitted to operate in the same width channel. The savings (in excess of $5.0 billion) would be available for investment in advanced ship control systems to maintain the original traffic safety factors. The exact amount of reinvestment into emplacing the control systems would be a function of the safety margin desired.