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Waterline

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The waterline is the line where the hull of a ship meets the surface of the water .

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34-515: A waterline can also refer to any line on a ship's hull that is parallel to the water's surface when the ship is afloat in a level trimmed position. Hence, waterlines are a class of "ships lines" used to denote the shape of a hull in naval architecture lines plans. The load line (also known as Plimsoll line) is the waterline which indicates the legal limit to which a ship may be loaded for specific water types and temperatures in order to safely maintain buoyancy . For vessels with displacement hulls ,

68-801: A MOU with KEPCO , Zodiac Maritime and KSOE to assess rule requirements for the safe operation and regulatory compliance of nuclear powered bulk carriers and container ships to be designed and built by the consortium . Lloyd's Register is known best for the classification and certification of ships and inspects and approves important components and accessories, including life-saving appliances, marine pollution prevention, fire protection, navigation, radio communication equipment, deck gear, cables, ropes, and anchors . LR's Rules for Ships LR's Rules for Ships are derived from principles of naval architecture and marine engineering , and govern safety and operational standards for numerous merchant, military, and privately owned vessels. LR's Rules govern

102-569: A load line. It was not until 1930 (the 1930 Load Line Convention) that there was international agreement for universal application of load line regulations. In 1966 the International Convention on Load Lines was concluded in London which re-examined and amended the 1930 rules. The 1966 convention has since seen amendments in 1971, 1975, 1979, 1983, 1995 and 2003, none of which has entered into force. The original "Plimsoll mark"

136-446: A number of topics including: Specific editions of the rules are available to cater for merchant ships, naval ships, trimarans , special purpose vessels and offshore structures. A ship is known as being in class if she meets all the minimum requirements of LR's Rules , and such a status affects the possibility of a ship getting insurance. Class can be withdrawn from a ship if she is in violation of any regulations and does not maintain

170-659: A ship has been overloaded. The exact location of the load line is calculated and verified by a classification society and that society issues the relevant certificates. This marking was invented in 1876 by Samuel Plimsoll . In the Middle Ages, the Venetian Republic , the Republic of Genoa and the Hanseatic League required ships to show a load line. In the case of Venice this was a cross marked on

204-422: A ship's load line survey – due once every five years. Such a survey includes an inspection of the hull to make sure that the load line has not been altered. Numerous other inspections such as the condition of hatch and door seals, safety barriers, and guard rails are also performed. Upon completion the ship is allowed to be operated for another year, and is issued a load line certificate. Lloyd’s Register provide

238-423: Is 1.8 m (5 ft 11 in) for a vessel 75 m (246 ft) or less in length and 2.3 m (7 ft 7 in) for a vessel 125 m (410 ft) or more in length with intermediate heights for intermediate lengths. A poop or raised quarterdeck is also required if the length is less than 100 m (330 ft). The letter L prefixes the load line marks to indicate a timber load line. Except for

272-504: Is a technical and professional services organisation and a maritime classification society , wholly owned by the Lloyd’s Register Foundation, a UK charity dedicated to research and education in science and engineering. The organisation dates to 1760. Its stated aims are to enhance the safety of life, property, and the environment, by helping its clients (including by validation , certification , and accreditation ) to improve

306-411: Is called load line mark or Plimsoll mark (positioned amidships ), the marks for other conditions are named after the condition suffixed with "load line" (e.g. winter load line). The purpose of a load line is to ensure that a ship has sufficient freeboard (the height from the waterline to the main deck) and thus sufficient reserve buoyancy . The freeboard of commercial vessels is measured between

340-406: Is one thirty-sixth of the summer timber load draft below the summer timber load line. The tropical timber load line is one forty-eighth of the summer timber load draft above the summer timber load line. The timber fresh and the tropical timber fresh load lines are calculated in a similar way to the freshwater and tropical freshwater load lines, except that the displacement used in the formula

374-418: Is that of the vessel at her summer timber load draft. If this cannot be ascertained, then these marks will be one forty-eighth of the timber summer draft above the timber summer and timber tropical marks, respectively. The timber winter North Atlantic load line is at the same level as the winter North Atlantic load line. Passenger ships having spaces which are adapted for the accommodation of passengers and

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408-542: The Indian Register of Shipping , LR for Lloyd's Register , NK for Nippon Kaiji Kyokai and RI for the Registro Italiano Navale . These letters are approximately 115 millimetres in height and 75 millimetres in width (4.5 by 3.0 in). The load line length is referred to during and following load line calculations. The letters on the load line marks have the following meanings: For

442-470: The hull speed is defined by, among other things, the waterline length . In a sailing boat, the waterline length can change significantly as the boat heels , and can dynamically affect the speed of the boat. In the aircraft design the term waterline designates a horizontal reference line used in alignment checks. The base line of the aircraft is designated as waterline 0 (zero). The location of this base line varies on different types of aircraft. However,

476-561: The 1860s, after increased loss of ships due to overloading, a British MP, Samuel Plimsoll , took up the load line cause against strong opposition. A Royal Commission on unseaworthy ships was established in 1872, and in 1876 the United Kingdom Merchant Shipping Act made the load line mark compulsory, although the positioning of the mark was not fixed by law until 1894 . In 1906, laws were passed requiring foreign ships visiting British ports to be marked with

510-457: The best classification "A1", from which the expression A1 or A1 at Lloyd's is derived, first appeared in the 1775–76 edition of the Register. The Register, with information on all seagoing, self-propelled merchant ships of 100 gross tons or greater, is published annually. A vessel remains registered with Lloyd's Register until it is sunk, wrecked , hulked , scrapped or withdrawn from

544-488: The carriage of cargo alternatively may have one or more additional load line marks corresponding to the subdivision drafts approved for the alternative conditions. These marks show P1 for the principal passenger condition, and P2 , P3 , etc., for the alternative conditions; however, in no case is any subdivision load line mark placed above the deepest load line in saltwater. Lloyd%27s Register Lloyd's Register Group Limited , trading as Lloyd's Register ( LR ),

578-447: The first known register of its type. Between 1800 and 1833, a dispute between shipowners and underwriters resulted in each group publishing a list—the "Red Book" and the "Green Book" . Both parties came to the verge of bankruptcy. They reached agreement in 1834 to unite and form Lloyd’s Register of British and Foreign Shipping, establishing a General Committee and charitable values. In 1914, with an increasingly international outlook,

612-555: The group’s operating arm, Lloyd’s Register Group Limited. In 2020, Lloyd's Register sold its Energy business and in 2021 sold its Business Assurance & Inspection Services division. In 2022, LR acquired OneOcean Group, a marine software and digital services company, to head up a new digital services division. Lloyd's Register is unaffiliated with Lloyd's of London , but emerged from the same professional and social circles that historically met at Lloyd's Coffee House , from which both organisations took their name. The organisation

646-527: The last 250 years with the industrial revolutions - from a time when steam engines were developed for mechanical production to the digital and cyber technology of today. The latter developments are reflected, among other things, in the acquisition of Senergy, an integrated energy service provider, in 2013 and Nettitude, a cyber security specialist in 2018. Lloyd’s Register has built a portfolio of digital, data and software solutions including greenfencetm, RTAMO and Seasafe. In January 2024, Lloyd's Register signed

680-455: The legal limit to which a ship may be loaded for specific water types and temperatures in order to safely maintain buoyancy , particularly with regard to the hazard of waves that may arise. The load line is a waterline that corresponds to the maximum draft of the ship, thus yet another name, load waterline . Varying water temperatures will affect a ship's draft , because warm water is less dense than cold water, providing less buoyancy. In

714-457: The lowest point of the uppermost continuous deck at side and the waterline and this must not be less than the freeboard marked on the load line certificate issued to that ship. All commercial ships, other than in exceptional circumstances, have a load line symbol painted amidships on each side of the ship. This symbol is also permanently marked, so that if the paint wears off it remains visible. The load line makes it easy for anyone to determine if

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748-412: The minimum requirements specified by the company. However, exceptional circumstances may warrant special dispensation from Lloyd's Register. Any alteration to the vessel, whether it is a structural alteration or machinery, must be approved by Lloyd's Register before it is implemented. Ships are inspected on a regular basis by a team of Lloyd's Register surveyors, one of the most important inspections being

782-413: The organisation changed its name to Lloyd's Register of Shipping. The Society printed the first Register of Ships in 1764 in order to give both underwriters and merchants an idea of the condition of the vessels they insured and chartered: ship hulls were graded by a lettered scale (A being the best), and ship's fittings (masts, rigging, and other equipment) were graded by number (1 being the best). Thus

816-574: The planes of all waterlines above and below the zero waterline are parallel. The waterline number (WL or W.L.) in the US is expressed in inches , values increase upwards. Two typical alignments for the base line are the tip of the nose (negative WL are possible) or the "nominal ground plane" (measurements will be nonnegative). This article related to shipbuilding is a stub . You can help Misplaced Pages by expanding it . Load line (watercraft) The load line , also known as Plimsoll line , indicates

850-409: The purposes of load line marks, freshwater is considered to have a density of 1,000 kg/m (62 lb/cu ft) and typical seawater 1,025 kg/m (64 lb/cu ft). Freshwater marks make allowance for the fact that the ship will float deeper in freshwater than saltwater. A ship loaded to her fresh water mark in fresh water will float at her summer mark once she has passed into seawater at

884-458: The register by the vessel's owner. The Register was published formerly by the joint venture company of Lloyd's Register-Fairplay, which was formed in July 2001 by the merger of Lloyd's Register's Maritime Information Publishing Group and Prime Publications Limited . Lloyd's Register sold its share of the venture to IHS Markit in 2009. The American Lloyd’s Registry of American and Foreign Shipping

918-553: The safety and performance of complex projects, supply chains and critical infrastructure. In July 2012, the organisation converted from an industrial and provident society to a company limited by shares, named Lloyd’s Register Group Limited, with the new Lloyd’s Register Foundation as the sole shareholder. At the same time the organisation gave to the Foundation a substantial bond and equity portfolio to assist it with its charitable purposes. It will benefit from continued funding from

952-437: The same displacement . Similarly, if loaded to her tropical freshwater mark she will float at her tropical seawater mark once she passes into seawater. Certain vessels are assigned timber freeboards, but before these can be assigned, certain additional conditions have to be met. One of these conditions is that the vessel must have a forecastle of at least 0.07 the length of the vessel and of not less than standard height, which

986-414: The same way, fresh water is less dense than salinated or seawater , with a similar lessening effect upon buoyancy. The rules for international load lines are defined by the International Convention on Load Lines from 1966. For inland water transport regional, national or local rules apply. Load lines are indicated by special markings on the hull . The marking for the main load line, the summer load line,

1020-432: The side of the ship, and of Genoa three horizontal lines. The first 19th-century loading recommendations were introduced by Lloyd's Register in 1835, following discussions among shipowners, shippers and underwriters. Lloyd's recommended freeboards as a function of the depth of the hold (three inches per foot of depth, 250 mm/m). These recommendations, used extensively until 1880, became known as "Lloyd's Rule". In

1054-420: The timber winter North Atlantic freeboard, the other freeboards are less than the standard freeboards. This allows these ships to carry additional timber as deck cargo, but with the facility to jettison this cargo. The letters on the timber load line marks have the following meanings: The summer timber load line is arrived at from the appropriate tables in the load line rules. The winter timber load line

Waterline - Misplaced Pages Continue

1088-517: Was a circle with a horizontal line through it to show the maximum draft of a ship. Additional marks have been added over the years, allowing for different water densities and expected sea conditions. Letters may also appear to the sides of the mark indicating the classification society that has surveyed the vessel's load line. The initials used include AB for the American Bureau of Shipping , BV for Bureau Veritas , VL for DNV GL , IR for

1122-473: Was established in 1857, and the American Lloyd’s Register of American and Foreign Shipping issued from at least 1859 until at least 1883 by the "Board of American Lloyd's". Lloyd's Register's main office is located in London at 71 Fenchurch Street . Lloyd's Register also operates in more than 70 locations, serving clients based in 182 countries. Lloyd's Register has changed and expanded over

1156-529: Was named after a seventeenth-century coffee house in London that was frequented by merchants, marine underwriters, and others associated with shipping. The coffee house owner, Edward Lloyd , helped them to exchange information by circulating a printed sheet of all the news he heard. In 1760, the Register Society was formed by the customers of the coffee house who assembled the Register of Shipping ,

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