Windy Posted February 1, 2015 Share Posted February 1, 2015 The use of copper sheathing was first suggested in 1708 by Charles Perry, though it was rejected by the Navy Board on grounds of high cost and perceived maintenance difficulties. The first experiments with copper sheathing were made in the late 1750s: the bottoms and sides of several ships' keels and false keels were sheathed with copper plates. In 1761 the experiment was expanded, and the 32-gun frigate HMS Alarm was ordered to have her entire bottom coppered, in response to the terrible condition in which she returned from service in the West Indies. HMS Alarm was chosen because in 1761 a letter had been sent regarding the ship's condition, saying that the worms from the waters had taken a significant toll on the ship’s wooden hull. Before the copper plates were applied the hull was covered with Soft stuff, which was simply hair, yarn and brown paper. The copper performed very well both in protecting the hull from invasion by worm and in preventing the growth of weed for, when in contact with water, the copper produced a poisonous film, composed mainly of oxychloride, that deterred these marine organisms. Furthermore, as this film was slightly soluble it gradually washed away, leaving no way in which marine life could attach itself to the ship. However, it was soon discovered by the Admiralty that the copper bolts used to hold the plates to the hull had reacted with the iron bolts used in the construction of the ship, rendering many bolts nearly useless. In 1766, because of the poor condition of the iron bolts, Alarm's copper was removed. After this experiment, and deterred by the unanticipated and not understood electrolytic reaction between the copper and iron, lead sheathing was tried again, though it was found to be unsuitable to the task, as the plates tended to fall from the hull alarmingly quickly. By 1764 a second vessel, HMS Dolphin had been sheathed in copper, specifically to prepare it for a voyage of discovery in tropical waters. Dolphin 's hull was inspected in 1768 after the ship had twice circumnavigated the world; there was significant corrosion of the iron components of the hull, and these had to be replaced. In 1769 another attempt was made at coppering a ship's hull, this time on a new ship that had been constructed using bolts made from a copper alloy. The results were far more favourable this time, but the onset and intensification of the war with America prevented the re-bolting of the Royal Navy's ships necessary to allow a full-scale coppering programme. From Wikipedia, the free encyclopedia The first Naval Action with Englands copper bottomed ships was 12th April 1782, in the Saints Islands... The result: Total French defeat... 2 Link to comment Share on other sites More sharing options...
Illusive Tabby Posted February 1, 2015 Share Posted February 1, 2015 A lovely read. I had known that ships keels were lined with copper to deter weed growth, though I had never bothered to learn how or why. Thanks for the information! Link to comment Share on other sites More sharing options...
Windy Posted February 1, 2015 Author Share Posted February 1, 2015 It also gave the Royal Navy a DECISIVE speed advantage over NON copper bottomed ships, as was played out over the next 10 years... Link to comment Share on other sites More sharing options...
Brigand Posted February 1, 2015 Share Posted February 1, 2015 This topic has been discussed earlier: Protecting your underwater hull: Cleaning, graving and sheeting. ~Brigand Link to comment Share on other sites More sharing options...
Schwerpunkt Posted February 2, 2015 Share Posted February 2, 2015 Although it did cause the loss of Ramillies (97) and Centaur (74) off Newfoundland in 1782 [due to corroded bolts]. Link to comment Share on other sites More sharing options...
Portsdown Posted February 2, 2015 Share Posted February 2, 2015 Important point ref Coppering. Perhaps they key factor in making it affordable was the discovery of the "Great Lode" on Parys Mountain in Angelsey in 1768. Copper prices plummeted and the UK basically controlled the European supply.http://en.wikipedia.org/wiki/Parys_MountainWith reference to ship losses there were supposedly a number due to 'Robber Bolts' where the copper bolts used to hold ships together had a section removed in the centre, with the ends left in place so everything looked ok. The copper removed was sold and the ship broke apart early, preferably (from the thief's point of view) far out at sea. Link to comment Share on other sites More sharing options...
Steel Posted February 3, 2015 Share Posted February 3, 2015 I love how the iron bolts, copper plate and salt water in effect turned the whole boat into a battery perhaps the largest batter the world would see for a hundred years and know one ever knew. Link to comment Share on other sites More sharing options...
Crossfader Posted February 3, 2015 Share Posted February 3, 2015 The result: Total French defeat... well now, isnt that something of a tradition... im sure Bis18mark70 would know a thing or two on that subject Link to comment Share on other sites More sharing options...
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