SHIPWRECKING is the event that caused the wreck , such as the striking of something that causes the ship to sink, the stranding of the ship on rocks, land or shoal, poor maintenance, or the destruction of the ship at sea by violent weather.
* 1 Causes
* 1.1 Design and equipment failure
* 1.2 Instability and foundering
* 1.3 Bad weather
* 1.4 Rogue waves
* 1.5 Fire
* 2 See also * 3 References * 4 Further reading * 5 External links
Factors for the loss of a ship may include:
* poor design or failure of the ship's equipment or hull - pressure
* instability, due to poor design, improperly stowed cargo , cargo
that shifts its position or the free surface effect .
* navigation errors and other human errors, leading to collisions
(with another ship, rocks, an iceberg , etc.) or running aground
* bad weather and powerful or large waves or gale winds: This often
leads to capsizing, also referred to as foundering.
* warfare, piracy , mutiny , or sabotage including: guns , torpedoes
, depth charges , mines , bombs and missiles .
* intentional sinking (scuttling )
* to form an artificial reef * for wreck diving * use as a target ship for training or testing weapons * as a blockship to create an obstacle to close a harbour, river, etc. against enemy ships * to prevent a ship from falling into an enemy's hands (e.g. Graf Spee ) * to destroy a derelict ship that poses a menace to navigation * as part of an insurance scam
DESIGN AND EQUIPMENT FAILURE
The hallmark of a shipwreck due to poor design is the capsize of
Swedish warship Wasa in
Equipment failure caused the shipwreck of cruiseferry Estonia in 1994. The stress of stormy seas on hull and bow especially caused the bow visor to break off, in turn tearing the watertight bow door open and letting seawater flow onto the car deck. She capsized with tragic consequences. Failure of pumps can lead to the loss of a potentially salvageable ship with only a minor leak or fire.
Failure of the means of propulsion, such as engines , sails or rigging , can lead to the loss of a ship. When the ship's movement is determined only by currents or the wind and particularly by storms, a common result is that the ship is unable to avoid natural hazards like rocks , shallow water or tidal races . Loss of propulsion or steering can inhibit a ship's ability to safely position itself in a storm, even far from land. Waves attacking a ship's side can overwhelm and sink it.
INSTABILITY AND FOUNDERING
Instability is caused by the centre of mass of the ship rising above the metacenter resulting in the ship tipping on its side or capsizing , which is often referred to as foundered or foundering. This can lead to a sinking if the openings on the upper side are not watertight at the time of the capsize. To remain buoyant, the hull of a vessel must prevent water entering the large air spaces of the vessel (known as downflooding). Clearly for the ship to float, the submerged parts of the hull will be watertight, but the upper parts of the hull must have openings to allow ventilation to compartments, including the engine room, for crew access, and to load and unload cargo. Large ships are designed with Compartments to help avoid foundering.
On 25 October 2012, the tall ship Bounty (a replica of the original
Poor weather can cause several problems:
* high winds * low visibility * cold weather * high waves
Wind causes waves which result in other difficulties. Waves make navigation difficult and dangerous near shallow water. Also, waves create buoyancy stresses on the structure of a hull. The weight of breaking waves on the fabric of the ship force the crew to reduce speed or even travel in the same direction as the waves to prevent damage. Also, wind stresses the rigging of sailing ships.
The force of the wind pushes ships in the direction of the wind. Vessels with large windage suffer most. Although powered ships are able to resist the force of the wind, sailing vessels have few defences against strong wind. When strong winds are imminent, sailing vessels typically have several choices:
* try to position themselves so that they cannot be blown into danger * shelter in a harbour * anchor , preferably on the leeward side of a landform
Many losses of sailing ships were caused by sailing, with a following wind, so far into a bay that the ship became trapped upwind of a lee shore , being unable to sail into the wind to leave the bay. Low visibility caused by fog , mist and heavy rain increase the navigator's problems. Cold can cause metal to become brittle and fail more easily. A build-up of ice can cause instability by accumulating high on the ship, or in severe cases, crush the hull if the ship becomes trapped in a freezing sea.
According to one scientist who studies rogue waves , "two large ships
sink every week on average, but the cause is never studied to the same
detail as an air crash. It simply gets put down to 'bad weather'."
Once considered mythical and lacking hard evidence for their
existence, rogue waves are now proven to exist and known to be a
natural ocean phenomenon. Eyewitness accounts from mariners and
damages inflicted on ships have long suggested they occurred; however,
their scientific measurement was only positively confirmed following
measurements of the "
Draupner wave ", a rogue wave at the Draupner
platform in the
Fire can cause the loss of ships in many ways. The most obvious way
would be the loss of a wooden ship which is burned until watertight
integrity is compromised (e.g. Cospatrick ). The detonation of cargo
or ammunition can cause the breach of a steel hull. An extreme
temperature may compromise the durability properties of steel, causing
the hull to break on its own weight. Often a large fire causes a ship
to be abandoned and left to drift (e.g.
MS Achille Lauro
In extreme cases, where the ship's cargo is either highly combustible
(such as oil , natural gas or gasoline ) or explosive (nitrates ,
fertilizers , ammunition ) a fire onboard may result in a catastrophic
conflagration or explosion . Such disasters may have catastrophic
results, especially if the disaster occurs in a harbour, such as the
Many shipwrecks have occurred when the crew of the ship allowed the
ship to collide with rocks, reefs , icebergs , or other ships.
Scilly naval disaster of 1707 , which claimed nearly 2,000 lives
and was one of the greatest maritime disasters in the history of the
British Isles , is attributed to the mariner's inability to find their
longitude. This led to the
Even today, when highly accurate navigational equipment is readily
available and universally used, there is still scope for error. Using
the incorrect horizontal datum for the chart of an area may mislead
the navigator, especially as many charts have not been updated to use
modern data . It is also important for the navigator to appreciate
that charts may be significantly in error, especially on less
frequented coasts. For example, a recent revision of the map of South
Georgia in the
Over the centuries, many technological and organizational developments have been used to reduce accidents at sea including:
International Regulations for Preventing Collisions at Sea
* ^ Morgenstein, Mark (29 October 2012). "Sandy claims \'Bounty\'
off North Carolina".