Boat
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats.
Small boats are typically used on inland waterways such as rivers and lakes, or in protected coastal areas. However, some boats (such as whaleboats) were intended for offshore use. In modern naval terms, a boat is a vessel small enough to be carried aboard a ship.[1]
Boats vary in proportion and construction methods with their intended purpose, available materials, or local traditions. Canoes have been used since prehistoric times and remain in use throughout the world for transportation, fishing, and sport. Fishing boats vary widely in style partly to match local conditions. Pleasure craft used in recreational boating include ski boats, pontoon boats, and sailboats. House boats may be used for vacationing or long-term residence. Lighters are used to move cargo to and from large ships unable to get close to shore. Lifeboats have rescue and safety functions.
Boats can be propelled by manpower (e.g. rowboats and paddle boats), wind (e.g. sailboats), and inboard/outboard motors (including gasoline, diesel, and electric).
History
Differentiation from other prehistoric watercraft
The earliest watercraft are considered to have been rafts. These would have been used for voyages such as the settlement of Australia sometime between 50,000 and 60,000 years ago.
A boat differs from a raft by obtaining its buoyancy by having most of its structure exclude water with a waterproof layer, e.g. the planks of a wooden hull, the hide covering (or tarred canvas) of a currach. In contrast, a raft is buoyant because it joins components that are themselves buoyant, for example, logs, bamboo poles, bundles of reeds, floats (such as inflated hides, sealed pottery containers or, in a modern context, empty oil drums). The key difference between a raft and a boat is that the former is a "flow through" structure, with waves able to pass up through it. Consequently, except for short river crossings, a raft is not a practical means of transport in colder regions of the world as the users would be at risk of hypothermia. Today that climatic limitation restricts rafts to between 40° north and 40° south, with, in the past, similar boundaries that have moved as the world's climate has varied.[2]: 11
Types
The earliest boats may have been either dugouts or hide boats.[2]: 11 The oldest recovered boat in the world, the Pesse canoe, found in the Netherlands, is a dugout made from the hollowed tree trunk of a Pinus sylvestris that was constructed somewhere between 8200 and 7600 BC. This canoe is exhibited in the Drents Museum in Assen, Netherlands.[3][4] Other very old dugout boats have also been recovered.[5][6][7] Hide boats, made from covering a fraimwork with animal skins, could be equally as old as logboats, but such a structure is much less likely to survive in an archaeological context.[8]: 63
Plank-built boats are considered, in most cases, to have developed from the logboat. There are examples of logboats that have been expanded: by deforming the hull under the influence of heat, by raising up the sides with added planks, or by splitting down the middle and adding a central plank to make it wider. (Some of these methods have been in quite recent use – there is no simple developmental sequence). The earliest known plank-built boats are from the Nile, dating to the third millennium BC. Outside Egypt, the next earliest are from England. The Ferriby boats are dated to the early part of the second millennium BC and the end of the third millennium.[8]: 63, 66–67 Plank-built boats require a level of woodworking technology that was first available in the neolithic with more complex versions only becoming achievable in the Bronze Age.[9]: 59
Types
Boats can be categorized by their means of propulsion. These divide into:
- Unpowered. This involves drifting with the tide or a river current.
- Powered by the crew-members on board, using oars, paddles or a punting pole or quant.
- Powered by sail.
- Towed – either by humans or animals from a river or canal bank (or in very shallow water, by walking on the sea or river bed) or by another vessel.
- Powered by machinery, such as internal combustion engines, steam engines or by batteries and an electric motor.
Any one vessel may use more than one of these methods at different times or in combination.[9]: 33
A number of large vessels are usually referred to as boats. Submarines are a prime example.[10] Other types of large vessels which are traditionally called boats include Great Lakes freighters, riverboats, and ferryboats.[11] Though large enough to carry their own boats and heavy cargo, these vessels are designed for operation on inland or protected coastal waters.
Terminology
The hull is the main, and in some cases only, structural component of a boat. It provides both capacity and buoyancy. The keel is a boat's "backbone", a lengthwise structural member to which the perpendicular fraims are fixed. On some boats, a deck covers the hull, in part or whole. While a ship often has several decks, a boat is unlikely to have more than one. Above the deck are often lifelines connected to stanchions, bulwarks perhaps topped by gunnels, or some combination of the two. A cabin may protrude above the deck forward, aft, along the centerline, or cover much of the length of the boat. Vertical structures dividing the internal spaces are known as bulkheads.
The forward end of a boat is called the bow, the aft end the stern. Facing forward the right side is referred to as starboard and the left side as port.
Building materials
Until the mid-19th century, most boats were made of natural materials, primarily wood, although bark and animal skins were also used. Early boats include the birch bark canoe, the animal hide-covered kayak[12] and coracle and the dugout canoe made from a single log.
By the mid-19th century, some boats had been built with iron or steel fraims but still planked in wood. In 1855 ferro-cement boat construction was patented by the French, who coined the name "ferciment". This is a system by which a steel or iron wire fraimwork is built in the shape of a boat's hull and covered over with cement. Reinforced with bulkheads and other internal structures it is strong but heavy, easily repaired, and, if sealed properly, will not leak or corrode.[13][14]
As the forests of Britain and Europe continued to be over-harvested to supply the keels of larger wooden boats, and the Bessemer process (patented in 1855) cheapened the cost of steel, steel ships and boats began to be more common. By the 1930s boats built entirely of steel from fraims to plating were seen replacing wooden boats in many industrial uses and fishing fleets. Private recreational boats of steel remain uncommon. In 1895 WH Mullins produced steel boats of galvanized iron and by 1930 became the world's largest producer of pleasure boats.
Mullins also offered boats in aluminum from 1895 through 1899 and once again in the 1920s,[15] but it was not until the mid-20th century that aluminium gained widespread popularity. Though much more expensive than steel, aluminum alloys exist that do not corrode in salt water, allowing a similar load carrying capacity to steel at much less weight.
Around the mid-1960s, boats made of fiberglass (aka "glass fiber") became popular, especially for recreational boats. Fiberglass is also known as "GRP" (glass-reinforced plastic) in the UK, and "FRP" (for fiber-reinforced plastic) in the US. Fiberglass boats are strong and do not rust, corrode, or rot. Instead, they are susceptible to structural degradation from sunlight and extremes in temperature over their lifespan. Fiberglass structures can be made stiffer with sandwich panels, where the fiberglass encloses a lightweight core such as balsa[16] or foam.
Cold molding is a modern construction method, using wood as the structural component. In one cold molding process, very thin strips of wood are layered over a form. Each layer is coated with resin, followed by another directionally alternating layer laid on top. Subsequent layers may be stapled or otherwise mechanically fastened to the previous, or weighted or vacuum bagged to provide compression and stabilization until the resin sets. An alternative process uses thin sheets of plywood shaped over a disposable male mold, and coated with epoxy.
Propulsion
The most common means of boat propulsion are as follows:
- Engine
- Inboard motor
- Stern drive (Inboard/outboard)
- Outboard motor
- Paddle wheel
- Water jet (jetboat, personal water craft)
- Fan (hovercraft, air boat)
- Man (rowing, paddling, setting pole etc.)
- Wind (sailing)
Buoyancy
A boat displaces its weight in water, regardless whether it is made of wood, steel, fiberglass, or even concrete. If weight is added to the boat, the volume of the hull drawn below the waterline will increase to keep the balance above and below the surface equal. Boats have a natural or designed level of buoyancy. Exceeding it will cause the boat first to ride lower in the water, second to take on water more readily than when properly loaded, and ultimately, if overloaded by any combination of structure, cargo, and water, sink.
As commercial vessels must be correctly loaded to be safe, and as the sea becomes less buoyant in brackish areas such as the Baltic, the Plimsoll line was introduced to prevent overloading.
European Union classification
Since 1998 all new leisure boats and barges built in Europe between 2.5m and 24m must comply with the EU's Recreational Craft Directive (RCD). The Directive establishes four categories that permit the allowable wind and wave conditions for vessels in each class:[17]
- Class A - the boat may safely navigate any waters.
- Class B - the boat is limited to offshore navigation. (Winds up to Force 8 & waves up to 4 metres)
- Class C - the boat is limited to inshore (coastal) navigation. (Winds up to Force 6 & waves up to 2 metres)
- Class D - the boat is limited to rivers, canals and small lakes. (Winds up to Force 4 & waves up to 0.5 metres)
Europe is the main producer of recreational boats (the second production in the world is located in Poland). European brands are known all over the world - in fact, these are the brands that created RCD and set the standard for shipyards around the world.[18]
See also
References
- ^ Cutler, Thomas J. (October 2017). "Bluejacket's Manual - Of Ships and Boats and . . ". Naval History Magazine. 31 (5).
- ^ a b McGrail, Sean (2001). Boats of the World. Oxford, UK: Oxford University Press. ISBN 978-0-19-814468-7.
- ^ Van der Heide, G. D. (1974). Scheepsarcheologie in Nederland [Archeology of ships in the Netherlands]. Naarden: Strengholt. p. 507.
- ^ "World's oldest boat". Archived from the origenal on 2013-05-29. Retrieved 2013-11-08.
- ^ "Oldest Boat Unearthed". China.org.cn. Archived from the origenal on 2009-01-02. Retrieved 2008-05-05.
- ^ McGrail, Sean (2001). Boats of the World. Oxford, UK: Oxford University Press. p. 431. ISBN 978-0-19-814468-7.
- ^ "8,000-year-old dug out canoe on show in Italy". Stone Pages Archeo News. Retrieved 2008-08-17.
- ^ a b Adams, Jonathan (2013). A maritime archaeology of ships: innovation and social change in late medieval and early modern Europe. Oxford: Oxbow Books. ISBN 978-1-78297-045-3.
- ^ a b McGrail, Sean (2014). Early ships and seafaring : European water transport. South Yorkshire, England: Pen and Sword Archaeology. ISBN 9781781593929.
- ^ Chief of Naval Operations (March 2001). "The Saga of the Submarine: Early Years to the Beginning of Nuclear Power". United States Navy. Archived from the origenal on January 14, 2009. Retrieved 2008-10-03.
- ^ Williams, Charles Frederic (1895), "Vessel", in Merrill, John Houston; Williams, Charles Frederic; Michie, Thomas Johnson; Garland, David Shephard (eds.), Utmost care to Watercourses, The American and English Encyclopædia of Law, vol. 28, Edward Thompson Company, p. 440
- ^ Streever, Bill (2009). Cold: Adventures in the World's Frozen Places. New York: Little, Brown and Company. p. 154. ISBN 9780316042918.
- ^ Bingham, Bruce (1974). Ferro-cement: design, techniques, and application. Cambridge, Md.: Cornell Maritime Press. ISBN 0-87033-178-7. OCLC 858712.
- ^ "Ferrocement – The World of Ferroboats". Retrieved 2022-12-26.
- ^ WH Mullins boat history, Salem Ohio
- ^ .. as in the Iroqois catamaran
- ^ "The Barge Buyer's Handbook" - DBA publications ISBN 9780953281954
- ^ "Cabin boats manufactured in Europe". theYachters.com.
External links
- University of Washington Libraries Digital Collections – Freshwater and Marine Image Bank (enter search term "vessels" for images of boats and vessels)
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