<P> Despite these advances, Maine was out of date by the time she entered service, due to her protracted construction period and changes in the role of ships of her type, naval tactics and technology . It took nine years to complete, and nearly three years for the armor plating alone . The general use of steel in warship construction precluded the use of ramming without danger to the attacking vessel . The potential for blast damage from firing end on or cross-deck discouraged en échelon gun placement . The changing role of the armored cruiser from a small, heavily armored substitute for the battleship to a fast, lightly armored commerce raider also hastened her obsolescence . Despite these disadvantages, Maine was seen as an advance in American warship design . </P> <P> Maine is best known for her loss in Havana Harbor on the evening of 15 February 1898 . Sent to protect U.S. interests during the Cuban revolt against Spain, she exploded suddenly, without warning, and sank quickly, killing nearly three quarters of her crew . The cause and responsibility for her sinking remained unclear after a board of inquiry investigated . Nevertheless, popular opinion in the U.S., fanned by inflammatory articles printed in the "yellow press" by William Randolph Hearst and Joseph Pulitzer, blamed Spain . The phrase, "Remember the Maine! To hell with Spain!", became a rallying cry for action, which came with the Spanish--American War later that year . While the sinking of Maine was not a direct cause for action, it served as a catalyst, accelerating the approach to a diplomatic impasse between the U.S. and Spain . </P> <P> The cause of Maine's sinking remains a subject of speculation . In 1898, an investigation of the explosion was carried out by a naval board appointed under the McKinley Administration . The consensus of the board was that Maine was destroyed by an external explosion from a mine . However, the validity of this investigation has been challenged . George W. Melville, a chief engineer in the Navy, proposed that a more likely cause for the sinking was from a magazine explosion within the vessel . The Navy's leading ordnance expert, Philip R. Alger, took this theory further by suggesting that the magazines were ignited by a spontaneous fire in a coal bunker . The coal used in Maine was bituminous coal, which is known for releasing firedamp, a gas that is prone to spontaneous explosions . There is stronger evidence that the explosion of Maine was caused by an internal coal fire which ignited the magazines . This was a likely cause of the explosion, rather than the initial hypothesis of a mine . The ship lay at the bottom of the harbor until 1911 . A cofferdam was then built around the wreck . The hull was patched up until the ship was afloat, then towed to sea and sunk . The Maine now lies on the sea - bed 3,600 feet (1,100 m) below the surface . </P> <P> The delivery of the Brazilian battleship Riachuelo in 1883 and the acquisition of other modern armored warships from Europe by Brazil, Argentina and Chile shortly afterwards, alarmed the United States government, as the Brazilian Navy was now the most powerful in the Americas . The chairman of the House Naval Affairs Committee, Hilary A. Herbert, stated to Congress: "if all this old navy of ours were drawn up in battle array in mid-ocean and confronted by Riachuelo it is doubtful whether a single vessel bearing the American flag would get into port ." These developments helped bring to a head a series of discussions that had been taking place at the Naval Advisory Board since 1881 . The board knew at that time that the U.S. Navy could not challenge any major European fleet; at best, it could wear down an opponent's merchant fleet and hope to make some progress through general attrition there . Moreover, projecting naval force abroad through the use of battleships ran counter to the government policy of isolationism . While some on the board supported a strict policy of commerce raiding, others argued it would be ineffective against the potential threat of enemy battleships stationed near the American coast . The two sides remained essentially deadlocked until Riachuelo manifested . </P>

What was the cause of the explosion of the battleship maine
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