A hull is the watertight body of a ship or boat. The hull may open at the top, or it may be or covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast; the line where the hull meets the water surface is called the waterline. There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges, to a needle-sharp surface of revolution in the case of a racing multihull sailboat; the shape is chosen to strike a balance between cost, hydrostatic considerations and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. In a typical modern steel ship, the hull will have watertight decks, major transverse members called bulkheads. There may be intermediate members such as girders and webs, minor members called ordinary transverse frames, frames, or longitudinals, depending on the structural arrangement.
The uppermost continuous deck may be called the "upper deck", "weather deck", "spar deck", "main deck", or "deck". The particular name given depends on the context—the type of ship or boat, the arrangement, or where it sails. In a typical wooden sailboat, the hull is constructed of wooden planking, supported by transverse frames and bulkheads, which are further tied together by longitudinal stringers or ceiling, but not always there is a centerline longitudinal member called a keel. In fiberglass or composite hulls, the structure may resemble wooden or steel vessels to some extent, or be of a monocoque arrangement. In many cases, composite hulls are built by sandwiching thin fiber-reinforced skins over a lightweight but reasonably rigid core of foam, balsa wood, impregnated paper honeycomb or other material; the earliest proper hulls were built by the Ancient Egyptians, who by 3000 BC knew how to assemble wooden planks into ahull. See also: Hull Hulls come in many varieties and can have composite shape, but are grouped as follows: Chined and Hard-chined.
Examples are the flat-bottom, v-bottom, multi-bottom hull. These types have at least one pronounced knuckle throughout most of their length. Moulded, round soft-chined; these hull shapes all have smooth curves. Examples are the round bilge, semi-round bilge, s-bottom hull. Displacement hull: here the hull is supported or predominantly by buoyancy. Vessels that have this type of hull travel through the water at a limited rate, defined by the waterline length, they are though not always, heavier than planing types. Planing hull: here, the planing hull form is configured to develop positive dynamic pressure so that its draft decreases with increasing speed; the dynamic lift reduces the wetted surface and therefore the drag. They are sometimes flat-bottomed, sometimes V-bottomed and more round-bilged; the most common form is to have at least one chine, which makes for more efficient planing and can throw spray down. Planing hulls are more efficient at higher speeds, although they still require more energy to achieve these speeds.
An effective planing hull must be as light as possible with flat surfaces that are consistent with good sea keeping. Sail boats that plane must sail efficiently in displacement mode in light winds. Semi-displacement, or semi-planing: here the hull form is capable of developing a moderate amount of dynamic lift. At present, the most used form is the round bilge hull. In the inverted bell shape of the hull, with a smaller payload the waterline cross-section is less, hence the resistance is less and the speed is higher. With a higher payload the outward bend provides smoother performance in waves; as such, the inverted bell shape is a popular form used with planing hulls. A chined hull consists of straight, tall, long, or short plates, timbers or sheets of ply, which are set at an angle to each other when viewed in transverse section; the traditional chined hull is a simple hull shape because it works with only straight planks bent into a curve. These boards are bent lengthwise. Plywood chined boats made of 8' x 4' sheets have most bend along the long axis of the sheet.
Only thin ply 3–6 mm can be shaped into a compound bend. Most home-made constructed boats are chined hull boats. Mass-produced chine powerboats are made of sprayed chop strand fibreglass over a wooden mold; the Cajun "pirogue" is an example of a craft with hard chines. Benefits of this type of hull is the low production cost and the flat bottom, making the boat faster at planing. Sail boats with chined hull make use of a dagger keel. Chined hulls may have one of three shapes: Flat-bottom chined hulls Multi-chined hulls V-bottom chined hulls. Sometimes called hard chine; each of these chine hulls use. The flat bottom hull has high initial stability but high drag. To counter the high drag hull forms are narrow and sometimes tapered at bow and stern; this leads to poor stability. This is countered by using heavy interior ballast on sailing versions, they are best suited to sheltered inshore waters. Early racing power boats were flat aft; this produced maximum lift and a smooth,fast ride in flat water but this hull form is unsettled in waves.
The multi chine h
A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the horizontal structure that forms the "roof" of the hull, strengthening it and serving as the primary working surface. Vessels have more than one level both within the hull and in the superstructure above the primary deck, similar to the floors of a multi-storey building, that are referred to as decks, as are certain compartments and decks built over specific areas of the superstructure. Decks for some purposes have specific names; the main purpose of the upper or primary deck is structural, only secondarily to provide weather-tightness and support people and equipment. The deck serves as the lid to the complex box girder, it resists tension and racking forces. The deck's scantling is the same as the topsides, or might be heavier if the deck is expected to carry heavier loads; the deck will be reinforced around deck fittings such as cleats, or bollards. On ships with more than one level, deck refers to the level itself.
The actual floor surface is called the sole, the term deck refers to a structural member tying the ships frames or ribs together over the keel. In modern ships, the interior decks are numbered from the primary deck, #1, downward and upward. So the first deck below the primary deck will be #2, the first above the primary deck will be #A2 or #S2; some merchant ships may alternatively designate decks below the primary deck machinery spaces, by numbers, those above it, in the accommodation block, by letters. Ships may call decks by common names, or may invent fanciful and romantic names for a specific deck or area of that specific ship, such as the Lido deck of the Princess Cruises' Love Boat. Equipment mounted on deck, such as the ship's wheel, fife rails, so forth, may be collectively referred to as deck furniture. Weather decks in western designs evolved from having structures fore and aft of the ship clear. Eastern designs developed earlier, with efficient middle decks and minimalist fore and aft cabin structures across a range of designs.
In vessels having more than one deck there are various naming conventions, alphabetically, etc. However, there are various common historical names and types of decks: 01 level is the term used in naval services to refer to the deck above the main deck; the next higher decks are referred to as the 02 level, the 03 level, so on. Although these are formally called decks, they are referred to as levels, because they are incomplete decks that do not extend all the way from the stem to the stern or across the ship. Afterdeck an open deck area toward the stern-aft. Berth deck: A deck next below the gun deck, where the hammocks of the crew are slung. Boat deck: Especially on ships with sponsons, the deck area where lifeboats or the ship's gig are stored. Boiler deck: The passenger deck above the vessel's boilers. Bridge deck: The deck area including the helm and navigation station, where the Officer of the Deck/Watch will be found known as the conn An athwartships structure at the forward end of the cockpit with a deck somewhat lower than the primary deck, to prevent a pooping wave from entering through the companionway.
May refer to the deck of a bridge. Flight deck: A deck from which aircraft take off or land. Flush deck: Any continuous unbroken deck from stem to stern. Forecastle deck: A partial deck above the main deck under which the sailors have their berths, extending from the foremast to the bow. Freeboard deck: assigned by a classification society to determine the ship's freeboard. Gun deck: on a multi-decked vessel, a deck below the upper deck where the ships' cannon were carried; the term referred to deck for which the primary function was the mounting of cannon to be fired in broadsides. However, on many smaller and unrated vessels the upper deck and quarterdeck bore all of the cannons but were not referred to as the gun deck. Hangar deck: A deck aboard an aircraft carrier used to store and maintain aircraft. Half-deck: That portion of the deck next below the forecastle or quarterdeck, between the mainmast and the cabin. Helicopter deck: Usually located near the stern and always kept clear of obstacles hazardous to a helicopter landing.
Hurricane deck:, the upper deck a light deck, erected above the frame of the hull. Lido deck: Open area at or near the stern of a passenger ship, housing the main outdoor swimming pool and sunbathing area. Lower deck: the deck over the hold, orig. only of a ship with two decks. Synonym for berth deck. Alternative name for a secondary gun deck Main deck: The principal deck of a vessel. Middle or Waist deck the working area of the deck. Orlop deck: The deck or part of a deck where the cables are stowed below the waterline, it is the lowest deck in a ship. Poop deck: The deck forming the roof of a poop or poop cabin, built on the upper deck and extending from the mizzenmast aft. Promenade deck: A "wrap-around porch" found on passenger ships a
An oil tanker known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: product tankers. Crude tankers move large quantities of unrefined crude oil from its point of extraction to refineries. For example, moving crude oil from oil wells in Nigeria to the refineries on the coast of the United States. Product tankers much smaller, are designed to move refined products from refineries to points near consuming markets. For example, moving gasoline from refineries in Europe to consumer markets in Nigeria and other West African nations. Oil tankers are classified by their size as well as their occupation; the size classes range from inland or coastal tankers of a few thousand metric tons of deadweight to the mammoth ultra large crude carriers of 550,000 DWT. Tankers move 2,000,000,000 metric tons of oil every year. Second only to pipelines in terms of efficiency, the average cost of oil transport by tanker amounts to only two or three United States cents per 1 US gallon.
Some specialized types of oil tankers have evolved. One of these is a tanker which can fuel a moving vessel. Combination ore-bulk-oil carriers and permanently moored floating storage units are two other variations on the standard oil tanker design. Oil tankers have been involved in a number of high-profile oil spills; as a result, they are subject to operational regulations. The technology of oil transportation has evolved alongside the oil industry. Although human use of oil reaches to prehistory, the first modern commercial exploitation dates back to James Young's manufacture of paraffin in 1850. In the early 1850s, oil began to be exported from Upper Burma a British colony; the oil was moved in earthenware vessels to the river bank where it was poured into boat holds for transportation to Britain. In the 1860s, Pennsylvania oil fields became a major supplier of oil, a center of innovation after Edwin Drake had struck oil near Titusville, Pennsylvania. Break-bulk boats and barges were used to transport Pennsylvania oil in 40-US-gallon wooden barrels.
But transport by barrel had several problems. The first problem was weight: they weighed 64 pounds, representing 20% of the total weight of a full barrel. Other problems with barrels were their expense, their tendency to leak, the fact that they were used only once; the expense was significant: for example, in the early years of the Russian oil industry, barrels accounted for half the cost of petroleum production. In 1863, two sail-driven tankers were built on England's River Tyne; these were followed in 1873 by the first oil-tank steamer, built by Palmers Shipbuilding and Iron Company for Belgian owners. The vessel's use was curtailed by U. S. and Belgian authorities citing safety concerns. By 1871, the Pennsylvania oil fields were making limited use of oil tank barges and cylindrical railroad tank-cars similar to those in use today; the modern oil tanker was developed in the period from 1877 to 1885. In 1876, Ludvig and Robert Nobel, brothers of Alfred Nobel, founded Branobel in Azerbaijan, it was, during the late 19th century, one of the largest oil companies in the world.
Ludvig was a pioneer in the development of early oil tankers. He first experimented with carrying oil in bulk on single-hulled barges. Turning his attention to self-propelled tankships, he faced a number of challenges. A primary concern was to keep the cargo and fumes well away from the engine room to avoid fires. Other challenges included allowing for the cargo to expand and contract due to temperature changes, providing a method to ventilate the tanks; the first successful oil tanker was Zoroaster, which carried its 242 long tons of kerosene cargo in two iron tanks joined by pipes. One tank was forward of the midships engine room and the other was aft; the ship featured a set of 21 vertical watertight compartments for extra buoyancy. The ship had a length overall of 184 feet, a beam of 27 feet, a draft of 9 feet. Unlike Nobel tankers, the Zoroaster design was built small enough to sail from Sweden to the Caspian by way of the Baltic Sea, Lake Ladoga, Lake Onega, the Rybinsk and Mariinsk Canals and the Volga River.
In 1883, oil tanker design took a large step forward. Working for the Nobel company, British engineer Colonel Henry F. Swan designed a set of three Nobel tankers. Instead of one or two large holds, Swan's design used several holds which spanned the width, or beam, of the ship; these holds were further subdivided into starboard sections by a longitudinal bulkhead. Earlier designs suffered from stability problems caused by the free surface effect, where oil sloshing from side to side could cause a ship to capsize, but this approach of dividing the ship's storage space into smaller tanks eliminated free-surface problems. This approach universal today, was first used by Swan in the Nobel tankers Blesk and Lux. Others point to another design of Colonel Swan, as being the first modern oil tanker, it adopted the best practices from previous oil tanker designs to create the prototype for all subsequent vessels of the type. It was the first dedicated steam-driven ocean-going tanker in the world and was the first ship in which oil could be pumped directly into the vessel hull instead of being loaded in barrels or drums.
It was the first tanker with a horizontal bulkhead. The ship w
The Panama Canal is an artificial 82 km waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean. The canal is a conduit for maritime trade. Canal locks are at each end to lift ships up to Gatun Lake, an artificial lake created to reduce the amount of excavation work required for the canal, 26 m above sea level, lower the ships at the other end; the original locks are 34 m wide. A third, wider lane of locks was constructed between September 2007 and May 2016; the expanded canal began commercial operation on June 26, 2016. The new locks allow transit of larger, post-Panamax ships, capable of handling more cargo. France began work on the canal in 1881, but stopped due to engineering problems and a high worker mortality rate; the United States took over the project in 1904 and opened the canal on August 15, 1914. One of the largest and most difficult engineering projects undertaken, the Panama Canal shortcut reduced the time for ships to travel between the Atlantic and Pacific Oceans, enabling them to avoid the lengthy, hazardous Cape Horn route around the southernmost tip of South America via the Drake Passage or Strait of Magellan.
Colombia and the United States controlled the territory surrounding the canal during construction. The US continued to control the canal and surrounding Panama Canal Zone until the 1977 Torrijos–Carter Treaties provided for handover to Panama. After a period of joint American–Panamanian control, in 1999, the canal was taken over by the Panamanian government, it is now operated by the government-owned Panama Canal Authority. Annual traffic has risen from about 1,000 ships in 1914, when the canal opened, to 14,702 vessels in 2008, for a total of 333.7 million Panama Canal/Universal Measurement System tons. By 2012, more than 815,000 vessels had passed through the canal, it takes 11.38 hours to pass through the Panama Canal. The American Society of Civil Engineers has ranked the Panama Canal one of the seven wonders of the modern world; the earliest mention of a canal across the Isthmus of Panama occurred in 1534, when Charles V, Holy Roman Emperor and King of Spain, ordered a survey for a route through the Americas that would ease the voyage for ships traveling between Spain and Peru.
Such a route would have given the Spanish a military advantage over the Portuguese. In 1668, the English physician and philosopher Sir Thomas Browne speculated in his encyclopaedic endeavour Pseudodoxia Epidemica - "some Isthmus have been eat through by the Sea, others cut by the spade: And if policy would permit, that of Panama in America were most worthy the attempt: it being but few miles over, would open a shorter cut unto the East Indies and China". In 1788, American Thomas Jefferson Minister to France, suggested that the Spanish should build the canal since it would be a less treacherous route for ships than going around the southern tip of South America, that tropical ocean currents would widen the canal thereafter. During an expedition from 1788 to 1793, Alessandro Malaspina outlined plans for its construction. Given the strategic location of Panama and the potential offered by its narrow isthmus separating two great oceans, other trade links in the area were attempted over the years.
The ill-fated Darien scheme was launched by the Kingdom of Scotland in 1698 to set up an overland trade route. Inhospitable conditions thwarted the effort and it was abandoned in April 1700. Numerous canals were built in other countries in the late early 19th centuries; the success of the Erie Canal in the United States in the 1820s and the collapse of the Spanish Empire in Latin America led to a surge of American interest in building an inter-oceanic canal. Beginning in 1826, US officials began negotiations with Gran Colombia, hoping to gain a concession for the building of a canal. Jealous of their newly obtained independence and fearing that they would be dominated by an American presence, the president Simón Bolívar and New Granada officials declined American offers; the new nation was politically unstable, Panama rebelled several times during the 19th century. Another effort was made in 1843. According to the New York Daily Tribune, August 24, 1843, a contract was entered into by Barings of London and the Republic of New Granada for the construction of a canal across the Isthmus of Darien.
They referred to it as the Atlantic and Pacific Canal, it was a wholly British endeavor. It was expected to be completed in five years. At nearly the same time, other ideas were floated, including a canal across Mexico's Isthmus of Tehuantepec. Nothing came of that plan, either. In 1846, the Mallarino–Bidlack Treaty, negotiated between the US and New Granada, granted the United States transit rights and the right to intervene militarily in the isthmus. In 1848, the discovery of gold in California, on the West Coast of the United States, created great interest in a crossing between the Atlantic and Pacific oceans. William H. Aspinwall, the man who won the federal subsidy for the building and operating the Pacific mail steamships at around the same time, benefited from this discovery. Aspinwall's route included steamship legs from New York City to Panama and from Panama to California, with an overland portage through Panama; the route between California and Panama was soon traveled, as it provided one of the fastest links between San Francisco and the East Coast cities, about 40 days' transit in total.
Nearly all the gold, shipped out of California went by the fast Panama route. Several new and larger paddle steamers were soon plying
The displacement or displacement tonnage of a ship is its weight based on the amount of water its hull displaces at varying loads. It is measured indirectly using Archimedes' principle by first calculating the volume of water displaced by the ship converting that value into weight displaced. Traditionally, various measurement rules have been in use. Today, metric tonnes are more used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed to its maximum load. Numerous specific terms are detailed below. Ship displacement should not be confused with measurements of volume or capacity used for commercial vessels, such as net tonnage, gross tonnage, or deadweight tonnage; the process of determining a vessel's displacement begins with measuring its draft This is accomplished by means of its "draft marks". A merchant vessel has three matching sets: one mark each on the port and starboard sides forward and astern; these marks allow a ship's displacement to be determined to an accuracy of 0.5%.
The draft observed at each set of marks is averaged to find a mean draft. The ship's hydrostatic tables show the corresponding volume displaced. To calculate the weight of the displaced water, it is necessary to know its density. Seawater is more dense than fresh water; the density of water varies with temperature. Devices akin to slide rules have been available, it is done today with computers. Displacement is measured in units of tonnes or long tons. There are terms for the displacement of a vessel under specified conditions: Loaded displacement is the weight of the ship including cargo, fuel, stores and such other items necessary for use on a voyage; these bring the ship down to its "load draft", colloquially known as the "waterline". Full load displacement and loaded displacement have identical definitions. Full load is defined as the displacement of a vessel when floating at its greatest allowable draft as established by a classification society. Warships have arbitrary full load condition established.
Deep load condition means stores, with most available fuel capacity used. Light displacement is defined as the weight of the ship excluding cargo, water, stores, crew, but with water in boilers to steaming level. Normal displacement is the ship's displacement "with all outfit, two-thirds supply of stores, etc. on board." Standard displacement known as "Washington displacement", is a specific term defined by the Washington Naval Treaty of 1922. It is the displacement of the ship complete manned and equipped ready for sea, including all armament and ammunition, outfit and fresh water for crew, miscellaneous stores, implements of every description that are intended to be carried in war, but without fuel or reserve boiler feed water on board. Naval architecture Hull Hydrodynamics Tonnage Dear, I. C. B.. Oxford Companion to Ships and the Sea. Oxford: Oxford University Press. ISBN 0-19-920568-X. George, William E.. Stability & Trim for the Ship's Officer. Centreville, Md: Cornell Maritime Press. ISBN 0-87033-564-2.
Hayler, William B.. American Merchant Seaman's Manual. Cambridge, Md: Cornell Maritime Press. ISBN 0-87033-549-9.. Turpin, Edward A.. Merchant Marine Officers' Handbook. Centreville, MD: Cornell Maritime Press. ISBN 0-87033-056-X. Navy Department. "Nomenclature of Naval Vessels". History.navy.mil. United States Navy. Retrieved 2008-03-24. Military Sealift Command. "Definitions and Equivalents". MSC Ship Inventory. United States Navy. Retrieved 2008-03-24. MLCPAC Naval Engineering Division. "Trim and Stability Information for Drydocking Calculations". United States Coast Guard. Retrieved 2008-03-24. United States of America. "Conference on the Limitation of Armament, 1922". Papers Relating to the Foreign Relations of the United States: 1922. 1. Pp. 247–266. United States Naval Institute. Proceedings of the United States Naval Institute. United States Naval Institute. Retrieved 2008-03-24
Q-Max is a type of ship a membrane type liquefied natural gas carrier. In the name Q-Max, "Q" stands for Qatar and "Max" for the maximum size of ship able to dock at the LNG terminals in Qatar. Ships of this type are the largest LNG carriers in the world. A ship of Q-Max size is 345 metres long and measures 53.8 metres wide and 34.7 metres high, with a draft of 12 metres. It has an LNG capacity of 266,000 cubic metres, equal to 161,994,000 cubic metres of natural gas, it is propelled by two slow speed diesel engines burning HFO, which are claimed to be more efficient and environmentally friendly than traditional steam turbines. In case of engine failure, the failed engine can be de-coupled allowing the ship to maintain a speed of 14 knots. Q-Max vessels are equipped with an on-board re-liquefaction system to handle the boil-off gas, liquefy it and return the LNG to the cargo tanks; the on-board re-liquefaction system allows a reduction of LNG losses, which produces economic and environmental benefits.
Overall, it is estimated that Q-Max carriers have about 40% lower energy requirements and carbon emissions than conventional LNG carriers. The quoted estimates do however ignore the additional fuel used to re-liquify boil off gas rather than burn the gas for fuel; the ships run on Heavy fuel oil, but the Rasheeda was retrofitted with gas-burning ability in 2015. Q-Max LNG carriers were ordered in 2005, they are built by Daewoo Shipbuilding & Marine Engineering. The installed Boil Off Gas re-liquefaction system is developed and delivered by Cryostar, approved and certified by Lloyds Register; the first Q-Max LNG carrier was floated out of dry-dock in November 2007. The naming ceremony was held on 11 July 2008 at Samsung Heavy Industries' shipyard on Geoje Island, South Korea. Known before its naming ceremony as Hull 1675, the ship was named Mozah by Her Highness Sheikha Mozah Nasser al-Misnad. Mozah was delivered on 29 September 2008, it is classed by Lloyd's Register. The first trip by a Q-Max tanker was completed by Mozah itself on 11 January 2009, when the tanker delivered 266,000 cubic metres of LNG to the Port of Bilbao BBG Terminal.
Days before, the vessel had transited the Suez Canal for the first time. Q-Max LNG carriers are operated by the STASCo (Shell International Trading and Shipping Company, London part of Shell International, they are owned by Qatar Gas Transport Company and they are chartered to Qatar's LNG producers Qatargas and RasGas. In total, contracts were signed for the construction of 14 Q-Max vessels. Fourteen sister vessels are in service named: Mozah, Al Mayeda, Mekaines, Al Mafyar, Umm Slal, Bu Samra, Al Ghuwairiya, Lijmiliya, Al Samriya, Al Dafna, Zarga and Rasheeda. All 14 Q-Max ships were delivered in 2008 through 2010. Q-Flex Ras Laffan Industrial City Tanker ships Ship sizes