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On 25 October 2003, the , a United States Navy nuclear-powered ''Los Angeles''-class submarine ran aground while performing routine maneuvers in the harbour of La Maddalena, Sardinia. Approximately 9 million dollars worth of damage were done to the submarine, and it was out of service for seven months. An investigation into the accident revealed that basic navigational errors combined with equipment failures were to blame for the submarine running into the rocky shallows. ==Timeline of events leading up to the accident== The US Navy investigation into the incident revealed a pattern of navigation, procedural and equipment errors leading up to the accident. * December 2001 The commander of ''Hartford''’s home squadron in Groton, stated that navigation practices in the squadron ''"do not uniformly meet the submarine force's exacting professional standards."'' * July 2002 An instructor at the Naval Submarine Base in Groton warned that ''Hartford''’s navigation team needed to improve how it set up for a turn, and also how it logged the boat's position on maritime charts. * Early 2003 While the crew completed the ''preparation for overseas movement'' certification "numerous plotting errors" were observed. It was noted that the crew seemed to have difficulty planning turns and failed to make the turns on track on three separate occasions. The boat's navigation team later passed the certification, and overall the boat was rated in the top third of the fleet for training readiness. * 14 April 2003 During a simulation the navigation team twice approached a navigation channel outside the correct track. * 3 June 2003 On a second occasion during a simulation, the navigation team were told to be more aggressive about making sure the boat was on track when it was in a channel. * 7 June 2003 An assessment of piloting practices on ''Hartford'' turned up 13 deficiencies and crucially, that when the navigation team could not fix the boat's position on charts, the boat did not slow down. * 9 October 2003 USS ''Hartford'' departs from Groton for the Mediterranean. * 20 October 2003 ''Hartford'' arrives at La Maddalena in Sardinia. Berthing outboard of the at the tender . An evaluator from submarine squadron 22 gave Hartford's navigation team an "average" score as the boat pulled into the submarine base at La Maddalena. But he also noted: * * The navigation team was not reconciling their primary navigation system with their backup system frequently enough to catch discrepancies in the systems. * * On an approach into a turn the navigation team went seven minutes between obtaining fixes of the boat's position, more than double the three-minute standard. * * The crewman fixing the boat's position on a maritime chart was too slow, at worst taking 1 minute and 15 seconds, when it should take no longer than 35 seconds. * * The boat's fathometer, which measures the water under the keel, was set to fathoms, the boat's charts indicated depth in meters, and the warning system was based on feet. * 24 October 2003 ''Hartford'' was scheduled to leave for her patrol, but problems developed with her sonar system, and the patrol was delayed while the submarine waited for replacement parts. * 25 October 2003 Visibility in the harbour was excellent and winds were between 12 and 15 knots (22 to 28 km/h) from the east. USS ''Springfield'' departed, and was coming into the tender to take ''Springfield''’s place. While this was taking place, USS ''Hartford'' was ordered to go outside the harbor. * * 11:55 ''Hartford'' eased away from her tender and moved into the channel. As plotted the trip would consist of four turns, the longest leg of the course being about 1.75 nautical miles (3.24 km). The submarine should have reached the open sea in approximately 34 minutes. However, within minutes the boat's Voyage Management System, which provides the navigation team with electronic navigation charts and automatic fixes of the boat's position, crashed. The crew attempted to clear the fault by repeatedly rebooting the system. These attempts to fix the problem were unsuccessful. * * 12:09 The navigation team noticed a four knot (7.4 km/h) difference in the speed readouts of the Ring laser gyroscope navigator and the electromagnetic log, two other key pieces of navigation equipment. * * 12:22 The captain ordered the boat to increase speed to 12 knots (22 km/h) from the planned speed of 9.5 knots (17.6 km/h). At approximately the same time, the assistant navigator and an electronics technician left the control room to try to determine what was causing the equipment failures. The captain was never notified that key members of the navigation crew had left their stations. * * 12:28 The bridge ordered the turn into the third leg of the trip, almost 500 yards (450 meters) early. As a result of the equipment failures, a waypoint was entered into the Global positioning system incorrectly, putting the turning point several hundred yards off the correct location. * * 12:30 The navigation team makes an attempt to fix the boat's position on the charts. The investigation found the boat was about 400 yards (365 meters) closer to Bisce Island than the position the crew plotted. * * 12:34 The ''Hartford'' turns into the fourth leg of her course out of the harbor. It is not clear who ordered this turn. The ''Hartford'' turns to the north-northeast and is traveling at almost 10 knots (18 km/h). * * 12:36 The navigation team makes a tentative fix on the boat's position but they are unable to confirm it. There is growing concern on the bridge about the lack of a plotted position: the executive officer asks the navigation team, ''"Nav, where the fuck are we?"'', the captain asks the XO ''"do we have anything at all working down there?"''. * * 12:37 The sailor watching the fathometer warns the navigation team that the water depth under the hull is decreasing, and was now just 100 feet (30 meters). On board a tug boat that had been escorting the ''Hartford'' out of the harbour, the Italian Coast Guard liaison noticed that ''Hartford'' was not following the normal northern course out of La Maddalena. He attempts to call the ''Hartford'' on the radio and a cell phone without success. * * 12:37:30 The fathometer watch alerts the navigation team to the fact that the depth under the hull is now just 83 feet (25 meters), * * 12:37:45 Again the fathometer watch warns that the water level is down to just 50 feet (15 meters). * * 12:40 ''Hartford'' strikes the bottom about 1100 yards (1000 meters) off Bisce Island. The boat begins to slow. Afraid that the boat would be stranded on the rocks, the squadron commodore, Captain Greg Parker, who is on board the ''Hartford'' orders ''"Speed on."'' * * The first collision is followed by two more impacts, the second of these is the worst, rolling the boat 10 to 12 degrees onto her port side, and lifting her out of the water 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「USS Hartford grounding」の詳細全文を読む スポンサード リンク
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