Shipbuilding

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See also Shipbuilding (song).

Men from Francisco de Orellana's expedition building a small brigantine, the San Pedro, to be used in the search for food

Shipbuilding is the construction of ships. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, originally called shipwrights, follow a specialized occupation that traces its roots to before recorded history.

Shipbuilding and ship repairs, both commercial and military, are referred to as the "naval sector". The dismantling of ships is called ship breaking. The construction of boats is a similar activity called boat building.

1 History
- 1.1 Shipwrights in England
2 Modern shipbuilding
3 See also
4 References
5 External links

[edit] History

Archaeological evidence indicates that humans arrived on New Guinea at least 60,000 years ago, probably by sea from Southeast Asia during an ice age period when the sea was lower and distances between islands shorter. (See History of Papua New Guinea.) The ancestors of Australian Aborigines and New Guineans went across the Lombok Strait to Sahul by boat over 50,000 years ago.

Evidence from ancient Egypt shows that the early Egyptians already knew how to assemble planks of wood into a watertight hull, using treenails to fasten them together, and pitch for caulking the seams. The "Khufu ship", a 43.6 m long vessel sealed into a pit in the Giza pyramid complex at the foot of the Great Pyramid of Giza in the Fourth Dynasty around 2,500 BC, is a full-size surviving example which may have fulfilled the symbolic function of a solar barque. The ships of the Eighteenth Dynasty were typically about 25 meters (80 ft) in length, and had a single mast, sometimes consisting of two poles lashed together at the top making an "A" shape. They mounted a single square sail on a yard, with an additional spar along the bottom of the sail. These ships could also be oar propelled.^[1]

The ships of Phoenicia seems to have been of a similar design. The Greeks and probably others introduced the use of multiple banks of oars for additional speed, and the ships were of a light construction, for speed and so they could be carried ashore.

Viking longships developed from an alternate tradition of clinker-built hulls fastened with leather thongs. Sometime around the 12th century, northern European ships began to be built with a straight sternpost, enabling the mounting of a rudder, which was much more durable than a steering oar held over the side. Development in the Middle Ages favored "round ships", with a broad beam and heavily curved at both ends.

The introduction of cannons onto ships encouraged the development of tumblehome, the inward slant of the abovewater hull, for additional stability, as well as techniques for strengthening the internal frame. This kind of considerations, as well as the demand for ships capable of operating safely in the open ocean, led to the documentation of design and construction practice in what had previously been a secretive trade, and ultimately the field of naval architecture. Even so, construction techniques changed only very gradually; the ships of the Spanish Armada were internally very similar to those of the Napoleonic Wars over two centuries later.

Iron was gradually adopted in ship construction, initially in small areas needing greater strength, then throughout, although initially copying wooden construction. Isambard Brunel's Great Britain of 1843 was the first radical new design; built entirely of iron, using stringers for strength, inner and outer hulls, and bulkheads to form multiple watertight compartments. Despite her success, many yards only went so far to use composite construction, with wooden timbers laid over an iron frame (the Cutty Sark is so constructed). Steel supplanted wrought iron when it became readily available in the latter half of the 19th century. Wood continued to be favored for the decks, and is still the rule as deckcovering for modern cruise ships.

[edit] Shipwrights in England

Shipbuilding in Flatford, John Constable, 1815.

During the 16th century Shipwrights in England were so few in number as to be granted direct employment by the Crown. The first list of ‘Master Shipwrights’ appointed ‘by Patent’ was issued by Henry VIII and included ‘John Smyth, Robert Holborn, Richard Bull and James Baker’ (father of Mathew Baker). Peter Pett the son of John was summoned from his place of residence, then at Harwich to work on the King’s Ships at Portsmouth, and in 1543 was granted a wage and fee for life (vadium et feodum). The authority for the letters patent not being by the usual Writ of Privy Seal, but ‘Per Ipsum Regent’, i.e, by ‘direct motion of the King’, Henry VIII.

On the 23 April 1548 Robert Holborn, Smyth and Bull received similar Patents, the very fact of which should be considered of some significance, and it was added as Shipwrights they should instruct others, by reason of their long and good service.

[edit] Modern shipbuilding

Shipbuilding for the United States effort in WWII (1943)

Design work, also called naval architecture, may be conducted using a ship model basin.

Modern ships, since roughly 1940, have been produced almost exclusively of welded steel. Early welded steel ships used steels with inadequate fracture toughness, which resulted in some ships suffering catastrophic brittle fracture structural cracks (see Liberty ship#Problems). Since roughly 1950, specialized steels such as ABS Steels with good properties for ship construction have been used.

Modern shipbuilding makes considerable use of prefabricated sections; entire multi-deck segments of the hull or superstructure will be built elsewhere in the yard, transported to the building dock or slipway, then lifted into place. This is known as Block Construction. The most modern shipyards pre-install equipment, pipes, electrical cables, and any other components within the blocks, to minimize the effort needed to assemble or install components deep within the hull once it is welded together.

Shipbuilding (which encompasses the shipyards, the marine equipment manufacturers and a large number of service and knowledge providers) is an important and strategic industry in a number of countries around the world. This importance stems from:

The large number of trade persons required directly by the shipyard and also by the supporting industries such as steel mills, engine manufacturers, etc.
A nation's need to manufacture and repair its own Navy and vessels that support its primary industries.

Historically, the industry has suffered from the absence of global rules and a tendency of (state-supported) over-investment due to the fact that shipyards offer a wide range of technologies, employ a significant number of workers and generate foreign currency income (as the shipbuilding market is dollar-based and a global one). Shipbuilding is therefore an attractive industry for developing nations. Japan used shipbuilding in the 1950s and 1960s to rebuild its industrial structure, Korea made shipbuilding a strategic industry in the 1970s and China is now in the process to repeat these models with large state-supported investments in this industry. As a result the world shipbuilding market suffers from over-capacities, depressed prices (although the industry experienced a price increase in the period 2003-2005 due to strong demand for new ships which was in excess of actual cost increases), low profit margins, trade distortions and wide-spread subsidisation. All efforts to address the problems in the OECD have so far failed, with the 1994 international shipbuilding agreement never entering into force and the 2003-2005 round of negotiations being suspended in October 2005 after no agreement was possible.

Where state subsidies have been removed and domestic policies do not provide support, in high cost nations shipbuilding has usally gone into steady, if not rapid, decline. The British shipbuilding industry is perhaps the most famous example of this. From a position in the early 1970s where British yards could still build the largest types of sophisticated merchant ships, British shipbuilders today have been reduced to a handful specialising in defence contracts and repair work. In the U.S.A., the Jones Act (which places restrictions on the ships that can be used for moving domestic cargoes) has meant that merchant shipbuilding has continued, but such protection has failed to penalise shipbuilding inefficiencies. The consequence of this is newbuilding contract prices that are far higher than those of any other nation building oceangoing ships.

Due to massive investment and low labour costs, China is likely to become the world's largest shipbuilding nation in terms of tonnage within the next 5 years, taking over this position from the current leader, South Korea. In terms of numbers of vessels built Japan also remains a leader, although this can be attributed to the conservatism of Japanese financiers and the low interest rates available on yen denominated loans as much as on the legendary build quality and productivity of Japanese shipyards.