U. S. Navy submarine USS Greeneville in dry dock following collision with a fishing boat. The Ehime Maru incident Ehime-Maru --> See also Ehime Maru and USS Greeneville collision On 9 February

Holland America Line's passenger cruise ship MS Zaandam drydocked at Grand Bahama Shipyard, Freeport, Grand Bahama in January 2003. The Holland America Line was founded in 1873 as the Dutch-America Steamship Company, a shipping and passenger line A cruise ship or cruise liner is a Passenger ship used for pleasure voyages where the voyage itself and the ship's amenities are part of the experience Freeport is a city and Free trade zone on the island of Grand Bahama, located approximately 100 mi (160 km east-northeast of Fort Lauderdale,

A drydock is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Drydocks are used for the construction, maintenance, and repair of ships, boats, and other watercraft.

History

Ptolemaic Egypt

According to the ancient Greek author Athenaeus of Naucratis, the drydock was invented in Ptolemaic Egypt, some time after the death of Ptolemy IV Philopator (reigned 221-204 BC):

Since Athenaeus recorded the event 400 years later (around 200 AD), there is sufficient reason to believe that drydocks had been known throughout classical antiquity.

China

Drydocks appeared in China by 1070 A. The history of Science and Technology in China is both long and rich with many contributions to science and technology D. In 1088, Song Dynasty scientist and statesman Shen Kuo (1031–1095) wrote in his Dream Pool Essays:

Renaissance Europe

Floating Dock. Woodcut from Venice (1560)

In Europe, the first drydock, and the oldest surviving drydock, was commissioned by Henry VII of England at HMNB Portsmouth in 1495 (see The Tudors and the Royal Navy). Her Majesty's Naval Base (HMNB Portsmouth ( HMS ''Nelson'') is one of three operating bases for the Royal Navy (the others being HMNB Clyde and The Tudor era was a critical one in the development of the Royal Navy. Possibly the earliest description of a floating dock comes from a small Italian book printed in Venice in 1560, called Descrittione dell'artifitiosa machina. ^[3] In the booklet, an unknown author asks for the privilege of using a new method for the salvaging of a grounded ship and then proceeds to describe and illustrate his approach. The included woodcut shows a ship flanked by two large floating trestles, forming a roof above the vessel. The ship is pulled in an upright position by a number of ropes hanging down from the roof.

Modern times

The Harland and Wolff cranes in Belfast, Northern Ireland. Harland and Wolff Heavy Industries is a diversified heavy industrial company specialising in Shipbuilding, Ship breaking, Offshore construction Belfast ( is the capital city of Northern Ireland and the seat of government in Northern Ireland. Northern Ireland (Tuaisceart Éireann Ulster Scots: Norlin Airlann) is a Country within the United Kingdom, lying in the northeast of

Harland and Wolff Heavy Industries in Belfast, is currently the largest in the world and is close to the slipway on which the ill-fated RMS Titanic was constructed. Harland and Wolff Heavy Industries is a diversified heavy industrial company specialising in Shipbuilding, Ship breaking, Offshore construction Belfast ( is the capital city of Northern Ireland and the seat of government in Northern Ireland. Construction The Titanic was a White Star Line ocean liner built at the Harland and Wolff shipyard in Belfast, Ireland The massive cranes are named after the Biblical figures Samson and Goliath. Samson and Goliath are twin Shipbuilding Gantry cranes situated at Queen's Island Belfast, Northern Ireland. Samson, Shimshon ( Hebrew: שמשון, Standard Šimšon Tiberian Šimšôn; meaning Goliath ( גָּלְיָת, Standard Hebrew Golyat, Tiberian Hebrew Golyāṯ, Arabic: جالوت Jalut (Muslim Goliath stands 96m tall, while Samson is taller at 106m.

Northrop Grumman Newport News Shipbuilding's Dry Dock 12 is the largest drydock in the USA. Northrop Grumman Shipbuilding ( NGS) formerly called Northrop Grumman Newport News ( NGNN) or Newport News Shipbuilding and Drydock Company The Saint-Nazaire's Chantiers de l'Atlantique owns one of the biggest in the world : 3937 feet x 196. See also the St Nazaire Raid Saint-Nazaire ( Breton: Sant-Nazer) is a town and ''commune'' in the Loire-Atlantique département Chantiers de l'Atlantique is one of the world's largest Shipyards based in Saint-Nazaire, France. 850 feet.

Types

The brig Stockholm in one of the historical drydocks on the island Beckholmen in central Stockholm. In nautical terms, a brig is a vessel with two square-rigged masts For an article about Beckholmen in Finland see Pikisaari. ---- History The original name of the island Biskopsholmen ("Bishop's ('stɔkhɔlm is Sweden 's Capital and its largest City. It is the site of the national Swedish government, the parliament, and the

Graving Dock

The classic form of drydock, properly known as graving dock, is a narrow basin, usually made of earthen berms and concrete, closed by gates or by a caisson, into which a vessel may be floated and the water pumped out, leaving the vessel supported on blocks. In Geotechnical engineering, a caisson is a retaining watertight structure used for example to work on the foundations of a Bridge pier, The keel blocks as well as the bilge block are placed on the floor of the dock in accordance with the "docking plan" of the ship.

Some fine-tuning of the ship's position is done by scuba divers while there is still some water left to manoeuvre it about. Scuba diving is swimming underwater, or taking part in another activity while using a Scuba set. It is extremely important that supporting blocks conform to the structural members so that the ship is not damaged when its weight is supported by the blocks. Some ASW warships have protruding sonar domes, requiring that the hull of the ship be supported several meters from the bottom of the drydock. Anti-submarine warfare (ASW or in older form A/S is a branch of Naval warfare that uses surface Warships Aircraft, space craft or other Submarines Sonar (which started as an Acronym for sound navigation and ranging) is a technique that uses Sound propagation (usually underwater to navigate

Once the remainder of the water is pumped out, the ship can be freely inspected or serviced. When work on the ship is finished, water is allowed to re-enter the dry dock and the ship is carefully refloated.

Modern graving docks are box-shaped, to accommodate the newer, boxier ship designs, whereas old drydocks are often shaped like the ships that are planned to be docked there. This shaping was advantageous because such a dock was easier to build, it was easier to side (support) the ships, and less water had to be pumped away.

U. S. Navy ballistic missile submarine USS Michigan inside a flooded drydock

Drydocks used for building Navy vessels may occasionally be built with a roof. USS Michigan in popular culture In the game SOCOM II US Navy SEALs, USS Michigan is ordered to take up station off the coast of This is done to prevent spy satellites from taking pictures of the drydock and any ships or submarines that may be in it. A spy satellite (officially referred to as a reconnaissance satellite) is an Earth observation satellite or Communications satellite deployed for During World War II covered drydocks were frequently used by submarine fleets to protect them from enemy air raids, however their effectiveness in that role diminished after the Second World War. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including A submarine is a Watercraft that can operate independently below water as distinct from a Submersible that has only limited underwater capability Today covered drydocks are usually used only when servicing or repairing a fleet ballistic missile submarine. A ballistic missile submarine is a Submarine equipped to launch Ballistic missiles ( SLBMs) Another advantage of covered drydocks is that one can work independent of the weather. This can save considerable time.

Floating drydock

The towboat, DAUPHIN I, in a floating drydock on the Mississippi river in Algiers, Louisiana

The battleship USS Iowa uses a floating dry dock during World War II. A battleship is a large heavily armored Warship with a main battery consisting of the largest Calibre of Guns Battleships were Construction See also Iowa class battleship, Armament of the Iowa class battleship Iowa was the lead ship of her class of " World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including

A floating drydock is a type of pontoon for dry docking ships, possessing floodable buoyancy chambers and a "U" shaped cross-section. Pontoon may refer to Pontoon (game, the Australian/Malaysian casino game Pontoon (card game, a chiefly British version of the card game A semi-submersible or semisubmersible is a Watercraft that can put much of its bulk underwater In Physics, buoyancy ( BrE IPA: /ˈbɔɪənsi/ is the upward Force on an object produced by the surrounding liquid or gas in which it is The walls are used to give the drydock stability when the floor is below the water level. When valves are opened the chambers are filled with water, the dry dock floats lower in the water, allowing a ship to be moved into position inside. For other uses see Valve (disambiguation. For the electronic component see Thermionic valve. When the water is pumped out of the chambers, the drydock rises and the deck is cleared of water, allowing work to proceed on the ship's hull.

Shipyards operate floating drydocks, among other means of hauling or docking vessels. The advantage of floating drydocks is that they can be moved all over the world and also can be sold second-hand. During World War II, the U.S. Navy used such (floating) drydocks extensively to provide maintenance in remote locations. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including One of these, the 850-foot AFDB-3, saw action in Guam, was mothballed near Norfolk, Virginia, and was eventually towed to Portland, Maine, to become part of Bath Iron Works' repair facilities. Guam ( Chamorro: cha Guåhån) officially the Territory of Guam, is an island in the western Pacific Ocean and is an organized unincorporated Norfolk is an Independent city in the Commonwealth of Virginia in the United States The Commonwealth of Virginia ( is an American state Portland is the largest city in the US state of Maine and the County seat of Cumberland County. The State of Maine ( is a state in the New England region of the northeastern United States of America, bordering the Atlantic Ocean Bath Iron Works (BIW is a Shipyard located on the Kennebec River in Bath Maine.

• Photos of USS Samuel B. Roberts on blocks in AFDB-3 in 1988

Modern floating drydock

Other ways of drydocking ships

Apart from graving docks and floating drydocks, ships can also be drydocked and launched by:

• Mobile boatlift (also called Travelift, for vessels up to 1000 metric tons)[1]
• Slipway, patent slip — For repair of smaller boats and the newbuilding launch of larger vessels
• Marine railway — For repair of larger ships up to about 3000 tons ship weight
• Shiplift — For repair as well as for newbuilding. A slipway, boat slip or just a slip, is a ramp on the shore by which Ships or Boats can be moved to and from the water The Patent slip was invented by Scotsman Thomas Morton in 1818 as a cheaper alternative to a Dry dock for Ship repair The Patent slip was invented by Scotsman Thomas Morton in 1818 as a cheaper alternative to a Dry dock for Ship repair A shiplift is a modern alternative for a Slipway, a floating dry dock or a graving dry dock. From 800 to 25000 ton shipweight

Uses other than for ships

Some drydocks are used during the construction of bridges, dams, and other large objects. For example, the drydock on the artificial island of Neeltje-Jans was used for the construction of the Oosterscheldekering, a large dam in the Netherlands that consists of 65 concrete pillars weighing 18,000 tonnes each. Neeltje-Jans is an Artificial island in the Netherlands in the province of Zeeland, halfway between Noord-Beveland and Schouwen-Duiveland The Oosterscheldekering ( Eastern Scheldt Storm surge barrier between the islands Schouwen-Duiveland and Noord-Beveland, is the largest of the The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands The pillars were constructed in a drydock and towed to their final place on the seabed.

Footnotes

See also

• Drydocks in science fiction
• Semi-submersible
• St. Nazaire Raid — an attack on a drydock during WW2. A space dock is a (currently fictional type of ' Dry dock ' for Spaceships or Starships However concept work has been undertaken on real space dock facilities A semi-submersible or semisubmersible is a Watercraft that can put much of its bulk underwater The St Nazaire Raid (also called Operation Chariot) was a successful British seaborne attack on the heavily defended docks of St World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including