Shipwreck (accident)
Encyclopedia
A shipwreck can refer to a wrecked ship
or to 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, or the destruction of the ship at sea by violent weather. This article will deal mainly to the event and its causes.
of Swedish warship Wasa in Stockholm
harbour 1628. She was too narrow, had too little ballast
and her lower cannon deck had too low freeboard for good seaworthiness.
Poor design allowed the ferry MS Herald of Free Enterprise to put to sea with open roll-on/roll-off bow doors, with tragic consequences.
Failure or leaking of the hull
is a serious problem that can lead to the loss of buoyancy
or the free surface effect
and the subsequent sinking of the vessel. Even the hulls of large modern ships have cracked in heavy storm
s. Leaks between the hull planks of wooden vessels are a particular problem.
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 engine
s, sail
s 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 storm
s, a common result is that the ship is unable to avoid natural hazards like rocks
, shallow water or tidal race
s. 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.
.
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.
Wind causes wave
s 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:
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.
). 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
). Should it run aground beyond economic salvage, it becomes a wreck.
In extreme cases, where the ship's cargo is either highly combustible (such as oil
, natural gas
or gasoline
) or explosive (nitrate
s, fertilizer
s, 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 Halifax Explosion
.
Many shipwrecks have occurred when the crew of the ship allowed the ship to collide with rocks, reef
s, iceberg
s, or other ships. Collision has been one of the major causes of shipwreck. Accurate navigation is made more difficult by poor visibility in bad weather. Also, many losses happened before modern navigation aids such as GPS
, radar
and sonar
were available. Until the 20th century, the most sophisticated navigational tools and techniques available - dead reckoning
using the magnetic compass, marine chronometer
(to calculate longitude
) and ships logbook
(which recorded the vessel's heading and the speed measured by log
) or celestial navigation
using marine chronometer
and sextant
- were sufficiently accurate for journeys across oceans, but these techniques (and in many cases also the charts) lacked the precision to avoid reefs close to shore. The 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 Longitude Act to improve the aids available for navigation. Marine chronometer
s were as revolutionary in the 19th century as GPS is today. However the cost of these instruments could be prohibitive, sometimes resulting in tragic consequences for ships that were still unable to determine their longitude, as in the case of the Arniston
.
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 South Atlantic showed that previous maps were in some places in error by several kilometres.
Over the centuries, many technological and organisational developments have been used to reduce accidents at sea including:
Shipwreck
A shipwreck is what remains of a ship that has wrecked, either sunk or beached. Whatever the cause, a sunken ship or a wrecked ship is a physical example of the event: this explains why the two concepts are often overlapping in English....
or to 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, or the destruction of the ship at sea by violent weather. This article will deal mainly to the event and its causes.
Causes
Factors for the loss of a ship may include:- poor designNaval architectureNaval architecture is an engineering discipline dealing with the design, construction, maintenance and operation of marine vessels and structures. Naval architecture involves basic and applied research, design, development, design evaluation and calculations during all stages of the life of a...
or failure of the ship's equipment or pressure hullSubmarine hullThe term light hull is used to describe the outer hull of a submarine, which houses the pressure hull, providing hydrodynamically efficient shape, but not holding pressure difference... - instability, due to poor design, improperly stowed cargoCargoCargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...
, cargo that shifts its position or the free surface effectFree Surface EffectThe free surface effect is one of several mechanisms which can cause a craft to become unstable and roll over . It refers to the tendency of liquids — and of aggregates of small solid objects, like seeds, gravel, or crushed ore which can act as liquids — to slosh about: to move in response to...
. - navigationNavigationNavigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
errors and other human errors, leading to collisionCollisionA collision is an isolated event which two or more moving bodies exert forces on each other for a relatively short time.Although the most common colloquial use of the word "collision" refers to accidents in which two or more objects collide, the scientific use of the word "collision" implies...
s (with another ship, rocks, an icebergIcebergAn iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...
, etc.) or running aground - bad weather
- warfare, piracyPiracyPiracy is an act of robbery or criminal violence at sea. The term can include acts committed on land, in the air, or in other major bodies of water or on a shore. It does not normally include crimes committed against persons traveling on the same vessel as the perpetrator...
, mutinyMutinyMutiny is a conspiracy among members of a group of similarly situated individuals to openly oppose, change or overthrow an authority to which they are subject...
, or sabotageSabotageSabotage is a deliberate action aimed at weakening another entity through subversion, obstruction, disruption, or destruction. In a workplace setting, sabotage is the conscious withdrawal of efficiency generally directed at causing some change in workplace conditions. One who engages in sabotage is...
including: gunGunA gun is a muzzle or breech-loaded projectile-firing weapon. There are various definitions depending on the nation and branch of service. A "gun" may be distinguished from other firearms in being a crew-served weapon such as a howitzer or mortar, as opposed to a small arm like a rifle or pistol,...
s, torpedoTorpedoThe modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es, depth chargeDepth chargeA depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
s, mineNaval mineA naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
s, bombBombA bomb is any of a range of explosive weapons that only rely on the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy...
s and missileMissileThough a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...
s. - fire
- overloading - either cargo or icing, and displacement exceeding the plimsoll lineWaterlineThe term "waterline" generally refers to the line where the hull of a ship meets the water surface. It is also the name of a special marking, also known as the national Load Line or Plimsoll Line, to be positioned amidships, that indicates the draft of the ship and the legal limit to which a ship...
- intentional sinking (scuttlingScuttlingScuttling is the act of deliberately sinking a ship by allowing water to flow into the hull.This can be achieved in several ways—valves or hatches can be opened to the sea, or holes may be ripped into the hull with brute force or with explosives...
)- to form an artificial reefArtificial reefAn artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block ship passage, or improve surfing....
- for wreck divingWreck divingWreck diving is a type of recreational diving where shipwrecks are explored. Although most wreck dive sites are at shipwrecks, there is an increasing trend to scuttle retired ships to create artificial reef sites...
- use as a target shipTarget shipA target ship is a vessel — typically an obsolete or captured warship — used for naval gunnery practice or for weapons testing.-Rationale:Sinking redundant warships is an effective way of testing new weapons and warships in as realistic a manner as possible. Whilst practice torpedoes are fired...
for training or testing weapons - as a blockshipBlockshipA blockship is a ship deliberately sunk to prevent a river, channel, or canal from being used.It may either be sunk by a navy defending the waterway to prevent the ingress of attacking enemy forces, as in the case of HMS Hood at Portland Harbour; or it may be brought by enemy raiders and used to...
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 scamFalse insurance claimsInsurance fraud or false insurance claims are insurance claims filed with the intent to defraud an insurance provider.-Health insurance fraud:...
- to form an artificial reef
Design and equipment failure
The hallmark of a shipwreck due to poor design is the capsizeCapsize
Capsizing is an act of tipping over a boat or ship to disable it. The act of reversing a capsized vessel is called righting.If a capsized vessel has sufficient flotation to prevent sinking, it may recover on its own if the stability is such that it is not stable inverted...
of Swedish warship Wasa in Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
harbour 1628. She was too narrow, had too little ballast
Ballast tank
A ballast tank is a compartment within a boat, ship or other floating structure that holds water.-History:The basic concept behind the ballast tank can be seen in many forms of aquatic life, such as the blowfish or argonaut octopus, and the concept has been invented and reinvented many times by...
and her lower cannon deck had too low freeboard for good seaworthiness.
Poor design allowed the ferry MS Herald of Free Enterprise to put to sea with open roll-on/roll-off bow doors, with tragic consequences.
Failure or leaking of the hull
Hull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
is a serious problem that can lead to the loss of buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
or the free surface effect
Free Surface Effect
The free surface effect is one of several mechanisms which can cause a craft to become unstable and roll over . It refers to the tendency of liquids — and of aggregates of small solid objects, like seeds, gravel, or crushed ore which can act as liquids — to slosh about: to move in response to...
and the subsequent sinking of the vessel. Even the hulls of large modern ships have cracked in heavy storm
Storm
A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface, and strongly implying severe weather...
s. Leaks between the hull planks of wooden vessels are a particular problem.
Equipment failure caused the shipwreck of cruiseferry
Cruiseferry
A cruiseferry is a ship that combines the features of a cruise ship with a Ro-Pax ferry. Many passengers travel with the ships for the cruise experience, staying only a few hours at the destination port or not leaving the ship at all, while others use the ships as means of...
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 engine
Engine
An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...
s, sail
Sail
A sail is any type of surface intended to move a vessel, vehicle or rotor by being placed in a wind—in essence a propulsion wing. Sails are used in sailing.-History of sails:...
s or rigging
Rigging
Rigging is the apparatus through which the force of the wind is used to propel sailboats and sailing ships forward. This includes masts, yards, sails, and cordage.-Terms and classifications:...
, can lead to the loss of a ship. When the ship's movement is determined only by currents or the wind and particularly by storm
Storm
A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface, and strongly implying severe weather...
s, a common result is that the ship is unable to avoid natural hazards like rocks
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
, shallow water or tidal race
Tidal race
Tidal race is a natural occurrence whereby a fast moving tide passes through a constriction resulting in the formation of waves, eddies and hazardous currents...
s. 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
Instability is caused by the centre of mass of the ship rising above the metacenter resulting in the ship tipping on its side or capsizingCapsize
Capsizing is an act of tipping over a boat or ship to disable it. The act of reversing a capsized vessel is called righting.If a capsized vessel has sufficient flotation to prevent sinking, it may recover on its own if the stability is such that it is not stable inverted...
.
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.
Bad weather
Poor weather can cause several problems:- wind
- low visibility
- cold
Wind causes wave
Ocean surface wave
In fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Waves in the...
s 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
Windage
Windage is a force created on an object by friction when there is relative movement between air and the object.There are two causes of windage:# the object is moving and being slowed by resistance from the air...
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
- anchorAnchorAn anchor is a device, normally made of metal, that is used to connect a vessel to the bed of a body of water to prevent the vessel from drifting due to wind or current. The word derives from Latin ancora, which itself comes from the Greek ἄγκυρα .Anchors can either be temporary or permanent...
, preferably on the leewardWindward and leewardWindward is the direction upwind from the point of reference. Leeward is the direction downwind from the point of reference. The side of a ship that is towards the leeward is its lee side. If the vessel is heeling under the pressure of the wind, this will be the "lower side"...
side of a landformLandformA landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...
Many losses of sailing ships were caused by sailing, with a following wind, so far into a bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
that the ship became trapped upwind of a lee shore
Lee shore
The terms lee shore and windweather or ward shore are nautical terms used to describe a stretch of shoreline. A lee shore is one that is to the lee side of a vessel - meaning the wind is blowing towards it. A weather shore has the wind blowing from inland over it out to sea...
, 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
Brittle
A material is brittle if, when subjected to stress, it breaks without significant deformation . Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound. Brittle materials include most ceramics and glasses ...
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.
Fire
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. CospatrickCospatrick (ship)
The Cospatrick was a wooden 3-masted full-rigged sailing ship that was the victim of one of the worst shipping disasters to a merchant ship during the 19th century. The ship caught fire south of the Cape of Good Hope on 17 November 1874 while on a voyage from Gravesend, England to Auckland, New...
). 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
MS Achille Lauro
MS Achille Lauro was a cruise ship based in Naples, Italy. Built between 1939 and 1947 as MS Willem Ruys, a passenger liner for the Rotterdamsche Lloyd. It is most remembered for its 1985 hijacking...
). Should it run aground beyond economic salvage, it becomes a wreck.
In extreme cases, where the ship's cargo is either highly combustible (such as oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
, natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
or gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
) or explosive (nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
s, fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...
s, ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
) a fire onboard may result in a catastrophic conflagration
Conflagration
A conflagration or a blaze is an uncontrolled burning that threatens human life, health, or property. A conflagration can be accidentally begun, naturally caused , or intentionally created . Arson can be accomplished for the purpose of sabotage or diversion, and also can be the consequence of...
or explosion
Explosion
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. An explosion creates a shock wave. If the shock wave is a supersonic detonation, then the source of the blast is called a "high explosive"...
. Such disasters may have catastrophic results, especially if the disaster occurs in a harbour, such as the Halifax Explosion
Halifax Explosion
The Halifax Explosion occurred on Thursday, December 6, 1917, when the city of Halifax, Nova Scotia, Canada, was devastated by the huge detonation of the SS Mont-Blanc, a French cargo ship, fully loaded with wartime explosives, which accidentally collided with the Norwegian SS Imo in "The Narrows"...
.
Navigation errors
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, iceberg
Iceberg
An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...
s, or other ships. Collision has been one of the major causes of shipwreck. Accurate navigation is made more difficult by poor visibility in bad weather. Also, many losses happened before modern navigation aids such as GPS
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
, radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
and sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
were available. Until the 20th century, the most sophisticated navigational tools and techniques available - dead reckoning
Dead reckoning
In navigation, dead reckoning is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course...
using the magnetic compass, marine chronometer
Marine chronometer
A marine chronometer is a clock that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation...
(to calculate longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
) and ships logbook
Logbook
A logbook was originally a book for recording readings from the chip log, and is used to determine the distance a ship traveled within a certain amount of time...
(which recorded the vessel's heading and the speed measured by log
Chip log
A chip log, also called common log, ship log or just log, is a navigation tool used by mariners to estimate the speed of a vessel through water.-Construction:...
) or celestial navigation
Celestial navigation
Celestial navigation, also known as astronavigation, is a position fixing technique that has evolved over several thousand years to help sailors cross oceans without having to rely on estimated calculations, or dead reckoning, to know their position...
using marine chronometer
Marine chronometer
A marine chronometer is a clock that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation...
and sextant
Sextant
A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight...
- were sufficiently accurate for journeys across oceans, but these techniques (and in many cases also the charts) lacked the precision to avoid reefs close to shore. The Scilly naval disaster of 1707
Scilly naval disaster of 1707
Scilly naval disaster of 1707 is an umbrella term for the events of 22 October 1707 that led to the sinking of a British naval fleet off the Isles of Scilly. With four large ships and more than 1,400 sailors lost in stormy weather, it was one of the greatest maritime disasters in the history of...
, which claimed nearly 2,000 lives and was one of the greatest maritime disasters in the history of the British Isles
History of the British Isles
The history of the British Isles has witnessed intermittent periods of competition and cooperation between the people that occupy the various parts of Great Britain, Ireland, and the smaller adjacent islands, which together make up the British Isles, as well as with France, Germany, the Low...
, is attributed to the mariner's inability to find their longitude. This led to the Longitude Act to improve the aids available for navigation. Marine chronometer
Marine chronometer
A marine chronometer is a clock that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation...
s were as revolutionary in the 19th century as GPS is today. However the cost of these instruments could be prohibitive, sometimes resulting in tragic consequences for ships that were still unable to determine their longitude, as in the case of the Arniston
Arniston (ship)
The Arniston was an East Indiaman ship that was wrecked on 30 May 1815 during a storm at Waenhuiskrans, near Cape Agulhas, South Africa with the loss of 372 lives and only 6 survivors...
.
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
Chart
A chart is a graphical representation of data, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie 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
South Georgia and the South Sandwich Islands
South Georgia and the South Sandwich Islands is a British overseas territory and overseas territory of the European Union in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands, known as the South Sandwich...
in the South Atlantic showed that previous maps were in some places in error by several kilometres.
Over the centuries, many technological and organisational developments have been used to reduce accidents at sea including:
- International Regulations for Preventing Collisions at SeaInternational Regulations for Preventing Collisions at SeaThe International Regulations for Preventing Collisions at Sea 1972 are published by the International Maritime Organization , and set out, inter alia, the "rules of the road" or navigation rules to be followed by ships and other vessels at sea in order to prevent collisions between two or more...
- PilotagePilotagePilotage is the use of fixed visual references on the ground or sea by means of sight or radar to guide oneself to a destination, sometimes with the help of a map or nautical chart. People use pilotage for activities such as guiding vessels and aircraft, hiking and Scuba diving...
aids including lighthouseLighthouseA lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....
s and sea markSea markA sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage aid which identifies the approximate position of a maritime channel, hazard and administrative area to allow boats, ships and seaplanes to navigate safely....
s - Basic navigationNavigationNavigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
tools such as the magnetic compass, nautical chartNautical chartA nautical chart is a graphic representation of a maritime area and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land , natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids...
, marine chronometerMarine chronometerA marine chronometer is a clock that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation...
, sextantSextantA sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. Making this measurement is known as sighting the object, shooting the object, or taking a sight...
, log and sounding lineSounding lineA sounding line or lead line is a length of thin rope with a plummet, generally of lead, at its end. Regardless of the actual composition of the plummet, it is still called a "lead."... - Advanced navigation tools such as radio communication, radar navigationRadar navigationMarine and aviation radar systems can provide very useful navigation information in a variety of situations. When a vessel is within radar range of land or special radar aids to navigation, the navigator can take distances and angular bearings to charted objects and use these to establish arcs of...
, gyrocompassGyrocompassA gyrocompass is a type of non-magnetic compass which bases on a fast-spinning disc and rotation of our planet to automatically find geographical direction...
, sonarSonarSonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
, hyperbolic Radio navigationRadio navigationRadio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
and satellite navigation - Inspection of shipbuildingShipbuildingShipbuilding is the construction of ships and floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history.Shipbuilding and ship repairs, both...
quality and maintenance of seaworthiness of the ship such as "A1 at Lloyd'sA1 (shipping)In shipping, the designation A1 is a symbol used to denote quality of construction and material. In the various shipping registers ships are classed and given a rating after an official examination, and assigned a classification mark, which appears in addition to other particulars in those...
" - IntelligenceMilitary intelligenceMilitary intelligence is a military discipline that exploits a number of information collection and analysis approaches to provide guidance and direction to commanders in support of their decisions....
and better defences to protect the ship from acts of violence, war and piracy - Use of fireproof/nonflammable materials to prevent fires from spreading rapidly, and modern fire-fighting agents such as gases and foams that do not compromise the buoyancy and stability of the vessel as quickly as water.
- Built-in devices to delay flooding long enough for rescue ships to retrieve survivors and/or tow the ship to the nearest shipyardShipyardShipyards and dockyards are places which repair and build ships. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance and basing activities than shipyards, which are sometimes associated more with initial...
for repairs, such as watertight compartments and pumps.
See also
- ShipwreckShipwreckA shipwreck is what remains of a ship that has wrecked, either sunk or beached. Whatever the cause, a sunken ship or a wrecked ship is a physical example of the event: this explains why the two concepts are often overlapping in English....
- Flotsam and jetsamFlotsam and jetsamIn maritime law, flotsam, jetsam, lagan and derelict describe specific kinds of wreck.The words have specific nautical meanings, with legal consequences in the law of admiralty and marine salvage....
- List of shipwrecks
- List of disasters
- List of maritime disasters
Further reading
- Hans Blumenberg, Shipwreck with Spectator: Paradigm of a Metaphor for Existence (Cambridge, Massachusetts: MIT Press, 1997)
External links
- Maritimequest Shipwreck Database (Downloadable Excel file)
- Shipwrecks and Smuggling - a learning resource from the British Library archives
- Shipwrecks UK, providing context, thematic information and detail for more than 45,000 shipwrecks in the seas surrounding Britain and Ireland, including revealing maps.