Transportation efficiency in eighteenth-century merchant vessels

Abstract

A key ingredient in New England’s shipping successes was the speed with which its vessels completed their voyages. The principle research on this subject was completed by Gary Walton and published in its first form in 1967. Walton was ahead of his time in identifying the importance of a detailed study of colonial shipping and linking it to a broader Atlantic World. He draws several conclusions. First, that technological change between 1675 and 1775 was minimal in the industry. Second, costs and crew sizes declined due to increases in security after the Royal Navy eliminated piracy. Third, idle time in port decreased, leading to more efficiencies in acquiring cargo. Fourth, and finally, vessel speeds were stagnant throughout the period and were 1.6 to 1.97 knots for the voyage south between New England and the West Indies and 1.31 to 2.09 knots for the return trip. Averages calculated by Walton indicate speeds of between 1.6 and 1.8 knots, with the southbound legs slightly faster. I agree with Walton on all of his conclusions except for the last. Careful study of 145 logbooks chronicling the voyages of Massachusetts’s vessels in the West Indies trade indicates that the median vessel speed over the approximately 1,500 nautical miles from Boston to the islands was 2.71 knots and the mean speed approached 2.84 knots. In fact, the median southbound speed was five per cent slower than the trip home. In practical terms, this meant that according to Walton the time it took to travel 1,500 nautical miles averaged a minimum of almost 35 days. According to the logbooks, however, merchant mariners completed voyages between New England and the West Indies in slightly more than 25 days on average, 28 per cent faster than Walton figured.