The search for Vancouver’s lost anchor

HMS Discovery and HMS Tender Chatham at anchor 1792 somewhere in the Straits

of Juan de Fuca

HMS Discovery was the expeditions lead ship

• H.M.S. Discovery was classified as a sloop carrying fourteen guns and was rated in Navy records as sixth rate. This type of vessel was originally a coal carrier refitted for exploration work. Her length was just under one hundred feet and she had a crew of one hundred. The DISCOVERY was refitted in 1797 as a bomb ship. Later, in 1827 she became a prison hulk. It is believed she was broken up in 1834.

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Captain George Vancouver

George Vancouver (1758-1798) was born in England and entered the Royal Navy in 1771 upon receiving an appointment from Captain James Cook. He accompanied Cook on his voyage around the world in 1772-74 and served as a midshipman on Cook’s explorations along the West coast of North America. Vancouver was promoted to commander of the ship Discovery in 1790.

Vancouver's expedition was well-outfitted, in 1792, and equipped with the finest scientific instruments available. His crew, totaling approximately 150 men, were handpicked. His flagship, the Discovery, was a sloop of war of some 340 tons, named after the ship on which Vancouver had accompanied Cook on his last voyage of exploration. Lt. William Broughton commanded the "Chatham", the second ship in Vancouver's expedition This is the ship of our interest.

CAPT. WILLIAM R. BROUGHTON

• William Broughton (1762-1821) was a British explorer who Commanded the ship called Chatham and discovered the Chatham Islands, south of New Zealand, in 1791.

• "In December 1790 George Vancouver was promoted to the command of an expedition to the west coast of America and Canada. He was to have command of the expedition on board HMS Discovery. His second-in-command, William Broughton, was to have charge of the tender HMS Chatham. The object of Vancouver's voyage was essentially two-fold. He was instructed to take over Nootka Island for Britain from the Spanish, and to survey the extensive north west coast of the American continent which included the possibility of discovering a north west passage to Europe. The voyage, which lasted almost five years, departed England on 1 April 1791. "

HMS Tender CHATHAM • The Chatham is in the

background tending over the beached Discovery. She was approximately - 100 tons.

• She was copper clad with 8 guns.

• Crew of 45.• Commander – Lt.W.R.

Broughton• Lieutenant – James Hanson –

Master - James Johnstone. • June 8th 1972 the Chatham

lost an anchor. • Efforts were made to recover

the anchor but all attempts failed.

Stream Anchor

• The Chatham lost her stream anchor

• Unlike the Bower, the stream anchor was smaller and was used in places where the much heavier Bower was not applicable

• Our Stream anchor is 6 to 9 feet in length – a square shank and weighing around 500 to 700 pounds. The fluke tip to tip is approximately 3 feet and the stock was made of English Oak, most likely, the marine wood boring organisms has consumed the stock.

Technology to locate the submerged Anchor

• Proton magnetometer

Geometrics has recently produced the first horizontal transverse marine magnetic gradiometer for high-sensitivity surveys. Applications include locating unexploded ordnance and marine archeology targets on the sea floor,

Without exception the first tool for search and locating of the anchor is the Proton mag.

                                                    

     

Other Technologies

• Another tool for search is the Side Scan Sonar.

• Another tool is the ROV (Remote operated vehicle)

• All technologies are interfaced with GPS positioning

Vessels