Ships Create a Noisy Underwater
The underwater world now has noise pollution similar to our neibourhood. The marine life gets affected in this noise. But the effects are not quite known. The researchers of Scripps Institution of Oceonography at the University of California, San Diego are doing research in this noise of underwater world. The noise levels underwater in 2003 to 2004 were 10 to 12 decibels higher than in 1964 to 1966. As the large number of ships move around in the sea, they do create a lot of noise due to their following factors:
1. High speed.
2. Propulsion power for individual ships.
Ships are large floating vessel capable of crossing open waters.
The term formerly was applied to sailing vessels with three or more masts; today it usually denotes a vessel of more than 500 tons’ (450 metric tons’) displacement. The largest ships today are enormous oil tankers, some of which are 500,000 tons (450,000 metric tons) deadweight. Other specialized ships (containerships) carry general freight in standardized containers that can be easily loaded, unloaded, and transferred.
Battleship is capital ship of the world’s navies from c. 1860, when it began to replace the wooden-hulled ship of the line, until World War II, when it was superseded by the aircraft carrier.
It combined large size, powerful guns, and heavy armour with fairly high speed and great cruising radius. The most powerful could hit targets at a range of more than 20 mi (30 km) and absorb heavy damage while remaining afloat and continuing to fight. It originated in early ironclad vessels with mixed sail and steam propulsion, such as the French armoured frigate Gloire (1859). In 1906 HMS Dreadnought revolutionized battleship design by introducing steam-turbine propulsion and an array of ten 12-in. (305-mm) guns. In World War II (1939-45) battleships were used mainly for specialized tasks such as bombarding enemy coastal defenses in amphibious warfare. After the Persian Gulf War (1990-91), the U.S. decommissioned its last two active battleships.
Brig are two-masted sailing ship with square rigging on both masts. Brigs were both naval and mercantile vessels. As merchantmen, they often followed coastal trading routes, but ocean voyages were not uncommon, and some were even used for whaling and sealing.
Clipper ship is the classic sailing ship of the 19th century, renowned for its beauty, grace, and speed.
Apparently originating with the small, swift coastal packet known as the Baltimore clipper, the true clipper evolved first in the U.S. (c. 1833) and later in Britain.
Corvette is a fast naval vessel smaller than a frigate.
Dhow is one- or two-masted Arab sailing vessel, usually with lateen rigging (slanting, triangular sails), common on the Red Sea and the Indian Ocean.
Frigate is either of two different types of warships, of the 17th-19th centuries and of World War II and after.
The sailing ship known as a frigate was a three-masted, fully rigged vessel, often carrying 30-40 guns in all.
Junk is a classic Chinese sailing vessel of ancient unknown origin, still in wide use.
High-sterned, with a projecting bow, the junk carries up to five masts on which are set square sails consisting of panels of linen or matting flattened by bamboo strips. Each sail can be spread or closed at a pull, like a Venetian blind. The massive rudder takes the place of a keel. Chinese junks were sailing to Indonesian and Indian waters by the early Middle Ages.
Longship or Viking ship is a sail-and-oar vessel widely used in northern Europe for more than 1,500 years.
It was a 45-75-ft (14-23-m) galley with up to 10 oars on a side, a square sail, and a 50-60-man capacity. Double-ended and built with overlapped planks, it was exceptionally sturdy in high seas. Examples have been found from as early as 300 BC.
Oceon liners are large merchant ship that visits designated ports on a regular schedule, carrying whatever cargo and passengers are available on the date of sailing.
The first liners were operated in the North Atlantic, notably by Samuel Cunard of Britain, beginning in 1840. Their heyday lasted from the late 19th to the mid-20th century. Many were extraordinarily luxurious.
Schooner is a sailing ship rigged with fore-and-aft sails on its two or more masts.
Though apparently developed from a 17th-century Dutch design, the first genuine schooner was built in the American colonies, probably at Gloucester, Mass., in 1713, by Andrew Robinson.
Yacht is a sail- or motor-driven vessel used for racing or recreation.
The term is popularly applied to large recreational engine-powered boats; the sailboats known as yachts and used for racing are usually light and comparatively small. Until the mid-19th century, yachts were designed along the lines of naval craft such as schooners and cutters. Yacht design was greatly affected by the 1851success of the America in the race that established the America’s Cup.In the 20th century, notably after World War II, smaller racing and recreational craft became more common.
