Midnight Ride, Industrial Dawn by Robert Martello

Author:Robert Martello
Language: eng
Format: epub
Publisher: Johns Hopkins University Press
Published: 2010-09-01T04:00:00+00:00

The Search for Sheathing

In his search for copper sheathing, Stoddert took on a technological challenge that had vexed naval experts for more than one thousand years. It had been known since Roman times that all oceangoing wooden ships, especially ones cruising in tropical or Mediterranean waters, faced hull problems as their service life grew long. Most wooden hulls acquired a “sea mat” of unwanted marine life within six to eight months, starting with clusters of barnacles but soon including vast masses of seaweed or other debris. This “mat” could be four inches thick and weigh more than one hundred tons, running the risk of rotting the hull, sinking the boat, decreasing its speed, or ruining its maneuverability. A second and far more serious threat resulted from the onslaught of shipworms such as the Teredo navalis. These creatures weakened hulls by boring into planks, turning ship bottoms into “leaky sieves.” Ship hulls usually became dangerously weakened in one or two years and the expensive refitting process required months of hard work, during which time the ship occupied precious dry dock space.30 A solution to this problem would not only save money and labor, but would increase the number of operating ships in the fleet at any time by decreasing the need for tedious dry dock repairs. The mid-eighteenth-century British navy tried using combinations of different types of wood, lead sheathing, tar, hair, and paper to prolong hull life, with no success. Copper sheeting finally provided a solution, greatly prolonging a ship’s working life by deterring or killing sea creatures that attempted to adhere to it.

The first ship to receive an experimental layer of copper sheeting upon its hull was Britain’s HMS Alarm, coppered in 1758. By 1763, the British navy recognized the effectiveness of that technique and by the end of 1781 almost the entire British fleet had coppered hulls. One historian commented that copper sheathing represented “the most important technical innovation to be implemented by the naval protagonists during the American War of Independence.”31 Contemporaries echoed this praise, and copper-sheathing technology received many accolades from naval officers: British Admiral Thomas Graves reported that wooden ships could not act in concert with copper-sheathed vessels because the wood hulls could not keep up, while other captains attributed some of their combat successes to maneuverability granted by copper sheathing, such as Admiral Lord George Rodney’s capture of six Spanish ships of the line in 1780. After one engagement an angry French naval commander complained that British copper sheathing allowed the British captain “to manoeuvre as he thought proper, and take any advantage that wind or weather might give him to avoid action if he judged it advisable to do so.” Responding to the economic impacts of this new technology, British Navy Comptroller Charles Middleton estimated that copper sheathing might double the number of ships at sea at any time. As a result, he gave coppering precedence over all other ship repairs, including fitting ships with improved guns such as carronades.32

Unfortunately, copper sheathing produced

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