Monday, May 28, 2007

Junk

A junk is a Chinese marine vessel. The English name comes from Malay dugong or jong. Junks were initially developed during the Han Dynasty (220 BC-200 AD) and further evolved to symbolize one of the most successful ship types in history.
The organization and flexibility of junk sails make the junk easy to sail, and fast. Unlike a conventional square rigged ship the sails of a junk can be moved inward, toward the long axis of the ship, allow the junk to sail into the wind.
The sails include more than a few horizontal members ("battens") which provide shape and strength. -The sails can also be easily reefed and familiar for fullness, to accommodate various wind strengths. The battens also make the sails more resistant than traditional sails to large tears, as a tear is naturally limited to a single "panel" between battens. Junk sails have much in common with the most aerodynamically well-organized sails used today in windsurfers or catamarans, although their design can be traced back as early the 3rd century AD.
The standing chains are simple or absent. The sail-plan is also extending out between multiple masts, allowing for a powerful sail surface, and a good repartition of efforts, an innovation adopted in the West around 1304. [Citation needed] The rig allows for good marine into the wind.

Sunday, May 20, 2007

Hydrofoil

It is a boat with wing-like foils mounted on struts under the hull. As the craft put into its speed the hydrofoils make better enough lift for the boat to become foil borne - i.e. to raise the hull up and out of the water. This consequence has a great decrease in drag and a corresponding increase in speed.
Early hydrofoils worn U-shape foils. Hydrofoils of this type are recognized as surface-piercing since portions of the U-shape hydrofoils will rise over the water surface when foil borne. Modern hydrofoils make use of T-shape foils which are fully submerged. Fully submerged hydrofoils are fewer subjected to the effects of wave action, and are therefore steadier at sea and are more relaxed for the crew and passengers. This type of pattern, however, is not self-stabilizing. The angle of attack on the hydrofoils wants to be adjusted endlessly in accordance to the changing conditions, a control process that is performed by computers. Failure to make the proper adjustments will result in the foil borne hull dipping aggressively back into the sea.

Sunday, May 13, 2007

Fishing boat

A fishing boat can range from two-person enjoyment fishing boats up to 7-8 ton commercial fishers that can drag in over a billion fish at one time. Island nations like Japan rely on the fishing industry to give food. Fishing is also well-liked in places like the U.S, where it is often done for sport rather than for food. Fishing is extremely fixed in the American culture.
A lot of marinas and harbors cater to fishing boats and sport boats. It is an extensive array of business that make its living helpful for and service this boating and fishing community. Both leisure fishermen and commercial enterprises share the majority harbors.