The International Maritime Organization (IMO), known as the Inter-Governmental Maritime Consultative Organization (IMCO) until 1982, is a specialised agency of the United Nations responsible for regulating shipping. The IMO was established following agreement at a UN conference held in Geneva in 1948 and the IMO came into existence ten years later, meeting for the first time in 1959. Headquartered in London, United Kingdom, the IMO currently has 174 member states and three associate members.
The IMO's primary purpose is to develop and maintain a comprehensive regulatory framework for shipping and its remit today includes safety, environmental concerns, legal matters, technical co-operation, maritime security and the efficiency of shipping. IMO is governed by an assembly of members and is financially administered by a council of members elected from the assembly. The work of IMO is conducted through five committees and these are supported by technical subcommittees. Other UN organisations may observe the proceedings of the IMO. Observer status is granted to qualified non-governmental organisations.
IMO is supported by a permanent secretariat of employees who are representative of the organisation's members. The secretariat is composed of a Secretary-General who is periodically elected by the assembly, and various divisions such as those for marine safety, environmental protection and a conference section.
|International Maritime Organization|
|Formation||17 March 1948|
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|Headquarters||London, United Kingdom|
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Inter-Governmental Maritime Consultative Organization (IMCO) was formed in order to bring the regulation of the safety of shipping into an international framework, for which the creation of the United Nations provided an opportunity. Hitherto such international conventions had been initiated piecemeal, notably the Safety of Life at Sea Convention (SOLAS), first adopted in 1914 following the Titanic disaster. IMCO's first task was to update that convention; the resulting 1960 convention was subsequently recast and updated in 1974 and it is that convention that has been subsequently modified and updated to adapt to changes in safety requirements and technology.
When IMCO began its operations in 1959 certain other pre-existing conventions were brought under its aegis, most notable the International Convention for the Prevention of Pollution of the Sea by Oil (OILPOL) 1954. The first meetings of the newly formed IMCO were held in London in 1959. Throughout its existence IMCO, later renamed the IMO in 1982, has continued to produce new and updated conventions across a wide range of maritime issues covering not only safety of life and marine pollution but also encompassing safe navigation, search and rescue, wreck removal, tonnage measurement, liability and compensation, ship recycling, the training and certification of seafarers, and piracy. More recently SOLAS has been amended to bring an increased focus on maritime security through the International Ship and Port Facility Security (ISPS) Code. The IMO has also increased its focus on smoke emissions from ships.
In January 1959, IMO began to maintain and promote the 1954 OILPOL Convention. Under the guidance of IMO, the convention was amended in 1962, 1969, and 1971.
As oil trade and industry developed, many people in the industry began to recognise a need for further improvements in regards to oil pollution prevention at sea. This became increasingly apparent in 1967, when the tanker Torrey Canyon spilled 120,000 tons of crude oil when it ran aground entering the English Channel
The Torrey Canyon grounding was the largest oil pollution incident recorded up to that time. This incident prompted a series of new conventions.
IMO held an emergency session of its Council to deal with the need to readdress regulations pertaining to maritime pollution. In 1969, the IMO Assembly decided to host an international gathering in 1973 dedicated to this issue. The goal at hand was to develop an international agreement for controlling general environmental contamination by ships when out at sea.
During the next few years IMO brought to the forefront a series of measures designed to prevent large ship accidents and to minimise their effects. It also detailed how to deal with the environmental threat caused by routine ship duties such as the cleaning of oil cargo tanks or the disposal of engine room wastes. By tonnage, the aforementioned was a bigger problem than accidental pollution.
The most significant thing to come out of this conference was the International Convention for the Prevention of Pollution from Ships, 1973. It covers not only accidental and operational oil pollution but also different types of pollution by chemicals, goods in packaged form, sewage, garbage and air pollution.
The original MARPOL was signed on 17 February 1973, but did not come into force due to lack of ratifications. The current convention is a combination of 1973 Convention and the 1978 Protocol. It entered into force on 2 October 1983. As of May 2013, 152 states, representing 99.2 per cent of the world's shipping tonnage, are involved in the convention.
In 1983 the IMO established the World Maritime University in Malmö, Sweden.
The IMO headquarters are located in a large purpose-built building facing the River Thames on the Albert Embankment, in Lambeth, London. The organisation moved into its new headquarters in late 1982, with the building being officially opened by Queen Elizabeth II on 17 May 1983. The architects of the building were Douglass Marriott, Worby & Robinson. The front of the building is dominated by a seven-metre high, ten-tonne bronze sculpture of the bow of a ship, with a lone seafarer maintaining a look-out. The previous headquarters of IMO were at 101 Piccadilly (now the home of the Embassy of Japan), prior to that at 22 Berners Street in Fitzrovia and originally in Chancery Lane.
To become a member of the IMO, a state ratifies a multilateral treaty known as the Convention on the International Maritime Organization. As of 2018, there are 173 member states of the IMO, which includes 172 of the UN member states plus the Cook Islands. The first state to ratify the convention was the United Kingdom in 1949. The most recent members to join were Armenia and Nauru, which became IMO members in January and May 2018, respectively.
Most UN member states that are not members of IMO are landlocked countries. These include Afghanistan, Andorra, Bhutan, Botswana, Burkina Faso, Burundi, Central African Republic, Chad, Kyrgyzstan, Laos, Lesotho, Liechtenstein, Mali, Niger, North Macedonia, Rwanda, South Sudan, Swaziland, Tajikistan and Uzbekistan. However, the Federated States of Micronesia, an island nation in the Pacific Ocean, is also a non-member.
The IMO consists of an Assembly, a Council and five main Committees: the Maritime Safety Committee; the Marine Environment Protection Committee; the Legal Committee; the Technical Co-operation Committee and the Facilitation Committee. A number of Sub-Committees support the work of the main technical committees.
IMO is the source of approximately 60 legal instruments that guide the regulatory development of its member states to improve safety at sea, facilitate trade among seafaring states and protect the maritime environment. The most well known is the International Convention for the Safety of Life at Sea (SOLAS), as well as International Convention on Oil Pollution Preparedness, Response and Co-operation (OPRC). Others include the International Oil Pollution Compensation Funds (IOPC). It also functions as a depository of yet to be ratified treaties, such as the International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea, 1996 (HNS Convention) and Nairobi International Convention of Removal of Wrecks (2007).
IMO regularly enacts regulations, which are broadly enforced by national and local maritime authorities in member countries, such as the International Regulations for Preventing Collisions at Sea (COLREG). The IMO has also enacted a Port State Control (PSC) authority, allowing domestic maritime authorities such as coast guards to inspect foreign-flag ships calling at ports of the many port states. Memoranda of Understanding (protocols) were signed by some countries unifying Port State Control procedures among the signatories.
Conventions, Codes and Regulations:
Recent initiatives at the IMO have included amendments to SOLAS, which upgraded fire protection standards on passenger ships, the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) which establishes basic requirements on training, certification and watchkeeping for seafarers and to the Convention on the Prevention of Maritime Pollution (MARPOL 73/78), which required double hulls on all tankers.
In December 2002, new amendments to the 1974 SOLAS Convention were enacted. These amendments gave rise to the International Ship and Port Facility Security (ISPS) Code, which went into effect on 1 July 2004. The concept of the code is to provide layered and redundant defences against smuggling, terrorism, piracy, stowaways, etc. The ISPS Code required most ships and port facilities engaged in international trade to establish and maintain strict security procedures as specified in ship and port specific Ship Security Plans and Port Facility Security Plans.
The IMO has a role in tackling international climate change. The First Intersessional Meeting of IMO's Working Group on Greenhouse Gas Emissions from Ships took place in Oslo, Norway (23–27 June 2008), tasked with developing the technical basis for the reduction mechanisms that may form part of a future IMO regime to control greenhouse gas emissions from international shipping, and a draft of the actual reduction mechanisms themselves, for further consideration by IMO's Marine Environment Protection Committee (MEPC). The IMO participated in the 2015 United Nations Climate Change Conference in Paris seeking to establish itself as the "appropriate international body to address greenhouse gas emissions from ships engaged in international trade". Nonetheless, there has been widespread criticism of the IMO's relative inaction since the conclusion of the Paris conference, with the initial data-gathering step of a three-stage process to reduce maritime greenhouse emissions expected to last until 2020. The IMO has also taken action to mitigate the global effects of ballast water and sediment discharge, through the 2004 Ballast Water Management Convention, which entered into force in September 2017.
The IMO is also responsible for publishing the International Code of Signals for use between merchant and naval vessels. IMO has harmonised information available to seafarers and shore-side traffic services called e-Navigation. An e-Navigation strategy was ratified in 2005, and an implementation plan was developed through three IMO sub-committees. The plan was completed by 2014 and implemented in November of that year. IMO has also served as a key partner and enabler of US international and interagency efforts to establish Maritime Domain Awareness.
On 4 December 2018 it was reported that at least 34 member countries of the International Maritime Organization supported Ukraine with respect to Russia’s armed military attack on Ukrainian boats on the Ukrainian and international waters near the Kerch Strait that occurred on 25 November 2018.
The governing body of the International Maritime Organization is the Assembly which meets every two years. In between Assembly sessions a Council, consisting of 40 Member States elected by the Assembly, acts as the governing body. The technical work of the International Maritime Organization is carried out by a series of Committees. The Secretariat consists of some 300 international civil servants headed by a Secretary-General.
The current Secretary-General is Kitack Lim (South Korea), elected for a four-year term at the 106th session of the IMO Council in June 2015 and at the 27th session of the IMO's Assembly in November 2015. His mandate started on 1 January 2016.
It is regulated in the Article 28(a) of the Convention on the IMO:
(a) The Maritime Safety Committee shall consider any matter within the scope of the Organization concerned with aids to navigation, construction and equipment of vessels, manning from a safety standpoint, rules for the prevention of collisions, handling of dangerous cargoes, maritime safety procedures and requirements, hydrographic information, log-books and navigational records, marine casualty investigation, salvage and rescue, and any other matters directly affecting maritime safety.
(b) The Maritime Safety Committee shall provide machinery for performing any duties assigned to it by this Convention, the Assembly or the Council, or any duty within the scope of this Article which may be assigned to it by or under any other international instrument and accepted by the Organization.
(c) Having regard to the provisions of Article 25, the Maritime Safety Committee, upon request by the Assembly or the Council or, if it deems such action useful in the interests of its own work, shall maintain such close relationship with other bodies as may further the purposes of the Organization
The Maritime Safety Committee is the most senior of these and is the main Technical Committee; it oversees the work of its nine sub-committees and initiates new topics. One broad topic it deals with is the effect of the human element on casualties; this work has been put to all of the sub-committees, but meanwhile, the Maritime Safety Committee has developed a code for the management of ships which will ensure that agreed operational procedures are in place and followed by the ship and shore-side staff.
The MSC and MEPC are assisted in their work by a number of sub-committees which are open to all Member States. The committees are:
The names of the IMO sub-committees were changed in 2013. Prior to 2013 there were nine Sub-Committees as follows:
Resolution MSC.255(84), of 16 May 2008, adopts the Code of the International Standards and Recommended Practices for a Safety Investigation into a Marine casualty or Marine Incident. It is also known as the Casualty Investigation Code.
Chandrika Prasad Srivastava KCMG, ComIH, IAS (Retd.) (8 July 1920 – 22 July 2013) was a retired Indian civil servant, international administrator and diplomat.Deadweight tonnage
Deadweight tonnage (also known as deadweight; abbreviated to DWT, D.W.T., d.w.t., or dwt) or tons deadweight (TDW) is a measure of how much weight a ship can carry, not its weight, empty or in any degree of load. DWT is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.DWT is often used to specify a ship's maximum permissible deadweight (i.e. when she is fully loaded so that her Plimsoll line is at water level), although it may also denote the actual DWT of a ship not loaded to capacity.Efthymios Mitropoulos
Efthymios (Thimio) E. Mitropoulos (Greek: Ευθύμιος Μητρόπουλος; born 30 May 1939 in Piraeus, Greece) was the seventh Secretary-General of the International Maritime Organization (IMO), a United Nations agency. Mitropoulos was elected as Secretary-General on 18 June 2003 during the 19th session of the International Maritime Organization Council. His four-year term started on 1 January 2004, and then was extended until 31 December 2011 by the IMO Council on 9 November 2006. He was succeeded by Koji Sekimizu. Mitropoulos was an accomplished chief engineer officer, coast guard officer, rear admiral, shipping economist, marine technologist, harbor master, lecturer, chancellor, chairman, and author of books about shipping economics and policy, merchant vessels, and navigation safety, among other shipping-related subjects.Greek shipping
Greece is a maritime nation by tradition, as shipping is arguably the oldest form of occupation of the Greeks and has been a key element of Greek economic activity since ancient times. Today, shipping is the country's most important industry worth $9 billion in 2015, 4% of the country's GDP. If related businesses are added, the figure jumps to $17 billion or 7.5% of GDP, employs about 192,000 people (4% of the workforce), and shipping receipts are about 1/3 of the nation's trade deficit.
In 2015, the Greek Merchant Navy controlled the world's largest merchant fleet, in terms of tonnage, with a total DWT of 334,649,089 tons and a fleet of 5,226 Greek-owned vessels, according to Lloyd's List. Greece is also ranked in the top for all kinds of ships, including first for tankers and bulk carriers.
Many Greek shipping companies have their headquarters located either in Athens or London and New York City, and are run by Greek traditional shipping families which are notable for their great wealth and influence in the international maritime industry, such as the Onasis, Vardinoyannis, Latsis, Livanos, Angelicoussis, Niarchos, Angelopoulos and Goulandris. The 7th Secretary General (2003-2011) of the International Maritime Organization was Efthymios Mitropoulos.Gross tonnage
Gross tonnage (often abbreviated as GT, G.T. or gt) is a nonlinear measure of a ship's overall internal volume. Gross tonnage is different from gross register tonnage. Neither gross tonnage nor gross register tonnage should be confused with measures of mass or weight such as deadweight tonnage or displacement.
Gross tonnage, along with net tonnage, was defined by The International Convention on Tonnage Measurement of Ships, 1969, adopted by the International Maritime Organization in 1969, and came into force on July 18, 1982. These two measurements replaced gross register tonnage (GRT) and net register tonnage (NRT). Gross tonnage is calculated based on "the moulded volume of all enclosed spaces of the ship" and is used to determine things such as a ship's manning regulations, safety rules, registration fees, and port dues, whereas the older gross register tonnage is a measure of the volume of only certain enclosed spaces.High-speed craft
A high-speed craft (HSC) is a high-speed water vessel for civilian use, also called a fastcraft or fast ferry. The first high-speed craft were often hydrofoils or hovercraft, but in the 1990s catamaran and monohull designs become more popular and large hydrofoils and hovercraft are no longer built. Most high-speed craft serve as passenger ferries, but the largest catamarans and monohulls also carry cars, buses, large trucks and freight.
In the 1990s there were a variety of builders, but many ship builders have withdrawn from this market so the construction of the largest fast ferries, up to 127 metres, has been consolidated to two Australian companies, Austal of Perth and Incat of Hobart. There is still a wide variety of builders for smaller fast catamaran ferries between 24 and 60 metres.
Hulled designs are often powered by pump-jets coupled to medium-speed diesel engines. Hovercraft are usually powered by gas turbines or diesel engines driving propellers and impellers.
The design and safety of high-speed craft is regulated by the International Convention for the Safety of Life at Sea (SOLAS) Convention, Chapter 10, High-Speed Craft (HSC) Codes of 1994 and 2000, adopted by the Maritime Safety Committee of the International Maritime Organization (IMO).
In accordance with SOLAS Chapter 10 Reg. 1.3, high-speed crafts are crafts capable of a maximum speed, in metres per second (m/s), equal to or exceeding:
where = volume of displacement in cubic metres corresponding to the design waterline, excluding craft of which the hull is supported clear above the water surface in non-displacement mode by aerodynamic forces generated by ground effect.High Commission of Ghana, London
The High Commission of Ghana in London is the diplomatic mission of Ghana in the United Kingdom.The High Commission operates two separate offices: at 13 Belgrave Square, London, SW1X 8PN, and at 104 Highgate Hill, London N6 5HE, as well as an Honorary Consulate in 17 Bellevue Road, Ayr KA7 2SA Glasgow, Scotland, and a Consulate at 1 Marine Terrace, Dun Laoghaire, Dublin A96 KD86, Ireland.The Passports, Immigration, Recruitment, Education, Trade & Investment, Police Liaison and International Maritime Organization Sections are all located in the building at 104 Highgate Hill, Highgate.High Commission of Kenya, London
The Kenya High Commission in London was established in 1963 to pursue Kenya’s national interest in the United Kingdom. The diplomatic mission in London is also accredited to the International Maritime Organization, and the Commonwealth of Nations.
Kenya and the UK enjoy cordial relations, and the mission's mandate is to forge closer relations between the people of Kenya and the people of United Kingdom in pursuit of deeper bilateral and multilateral cooperation in trade and investments, culture, science and technology as well as other fields for mutual benefit.
The High Commission is housed in one of a group of Grade II* listed buildings in Portland Place.IMO number
The International Maritime Organization (IMO) number is a unique reference for ships, registered ship owners and management companies. IMO numbers were introduced to improve maritime safety and security and to reduce maritime fraud. They consist of the three letters "IMO" followed by unique seven-digit numbers, assigned under the International Convention for the Safety of Life at Sea (SOLAS).International Code of Signals
The International Code of Signals (ICS) is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp ("blinker"), flag semaphore, radiotelegraphy, and radiotelephony. The International Code is the most recent evolution of a wide variety of maritime flag signalling systems.International Maritime Dangerous Goods Code
IMDG Code or International Maritime Dangerous Goods Code is accepted as an international guideline to the safe transportation or shipment of dangerous goods or hazardous materials by water on vessel. IMDG Code is intended to protect crew members and to prevent marine pollution in the safe transportation of hazardous materials by vessel. It is recommended to governments for adoption or for use as the basis for national regulations.s mandatory in conjunction with the obligations of the members of united nation government under the International Convention for the Safety of Life at Sea (SOLAS) and the International Convention for the Prevention of Pollution from Ships (MARPOL 73/78).
It is intended for use not only by the mariner but also by all those involved in industries and services connected with shipping. Contains advice on terminology, packaging, labeling, placarding, markings, stowage, segregation, handling, and emergency response. The HNS Convention covers hazardous and noxious substances that are included in the IMDG code.
The code is updated and maintained by the CCC (formerly DSC) Sub-Committee of the International Maritime Organization every 2 years.
IMG Code in calendar year 2017 is the either the 2014 Edition; Incorporating Amendment 37-14 or 2016 Edition; Incorporating Amendment 38-16. Both the 2014 Edition and the 2016 Edition were voluntary in 2017. The 2016 Edition becomes mandatory in 2018 and will again be voluntary in 2019 when the 2018 Edition will also be in use.Lambeth
Lambeth () is a district in Central London, England, in the London Borough of Lambeth. It is situated 1 mile (1.6 km) south of Charing Cross. The population of the London Borough of Lambeth was 303,086 in 2011. The area experienced some slight growth in the medieval period as part of the manor of Lambeth Palace. By the Victorian era the area had seen significant development as London expanded, with dense industrial, commercial and residential buildings located adjacent to one another. The changes brought by World War II altered much of the fabric of Lambeth. Subsequent development in the late 20th and early 21st centuries has seen an increase in the number of high-rise buildings. The area is home to the International Maritime Organization.List of High Commissioners of Australia to the United Kingdom
The High Commissioner of Australia to the United Kingdom is an officer of the Australian Department of Foreign Affairs and Trade and the head of the High Commission of the Commonwealth of Australia to United Kingdom of Great Britain and Northern Ireland in London. The position has the rank and status of an Ambassador Extraordinary and Plenipotentiary and is currently held by former Attorney-General George Brandis. The High Commissioner also serves as Australia's Permanent Representative to the International Maritime Organization (since 1959), a Trustee of the Imperial War Museum and Australia's Commonwealth War Graves Commissioner.London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter
The Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972, commonly called the "London Convention" or "LC '72" and also abbreviated as Marine Dumping, is an agreement to control pollution of the sea by dumping and to encourage regional agreements supplementary to the Convention. It covers the deliberate disposal at sea of wastes or other matter from vessels, aircraft, and platforms. It does not cover discharges from land-based sources such as pipes and outfalls, wastes generated incidental to normal operation of vessels, or placement of materials for purposes other than mere disposal, providing such disposal is not contrary to aims of the Convention. It entered into force in 1975. As of September 2016, there were 89 Parties to the Convention.Neal Blewett
Neal Blewett, AC (born 24 October 1933), Australian politician, was an Australian Labor Party member of the Australian House of Representatives representing the Division of Bonython, South Australia from 1977 to 1994.Net register tonnage
Net register tonnage (NRT, nrt, n.r.t.) is a ship's cargo volume capacity expressed in "register tons", one of which equals to a volume of 100 cubic feet (2.83 m3). It is calculated by subtracting non-revenue-earning spaces i.e. spaces not available for carrying cargo, for example engine rooms, fuel tanks and crew quarters, from the ship's gross register tonnage. Net tonnage is thus used in situations where a vessel's earning capacity is important, rather than its mere size. Net register tonnage is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement.
Gross and net register tonnages were replaced by gross tonnage and net tonnage, respectively, when the International Maritime Organization (IMO) adopted The International Convention on Tonnage Measurement of Ships on 23 June 1969. The new tonnage regulations entered into force for all new ships on 18 July 1982, but existing vessels were given a migration period of 12 years to ensure that ships were given reasonable economic safeguards, since port and other dues are charged according to ship's tonnage. Since 18 July 1994 the gross and net tonnages, dimensionless indices calculated from the total moulded volume of the ship and its cargo spaces by mathematical formulae, have been the only official measures of the ship's tonnage. However, the gross and net register tonnages are still widely used in describing older ships.Net tonnage
Net tonnage (often abbreviated as NT, N.T. or nt) is a dimensionless index calculated from the total moulded volume of the ship's cargo spaces by using a mathematical formula. Defined in The International Convention on Tonnage Measurement of Ships that was adopted by the International Maritime Organization in 1969, the net tonnage replaced the earlier net register tonnage (NRT) which denoted the volume of the ship's revenue-earning spaces in "register tons", units of volume equal to 100 cubic feet (2.83 m3). Net tonnage is used to calculate the port duties and should not be taken as less than 30 per cent of the ship's gross tonnage.Net tonnage is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement. Also, unlike the net register tonnage, the net tonnage is unitless and thus can not be defined as "tons" or "net tons".SOLAS Convention
The International Convention for the Safety of Life at Sea (SOLAS) is an international maritime treaty which sets minimum safety standards in the construction, equipment and operation of merchant ships. The convention requires signatory flag states to ensure that ships flagged by them comply with at least these standards.
The current version of SOLAS is the 1974 version, known as SOLAS 1974, which came into force on 25 May 1980. As of November 2018, SOLAS 1974 had 164 contracting states, which flag about 99% of merchant ships around the world in terms of gross tonnage.SOLAS in its successive forms is generally regarded as the most important of all international treaties concerning the safety of merchant ships.Sister ship
A sister ship is a ship of the same class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They often share a common naming theme, either being named after the same type of thing (places, constellations, monarchs) or with some kind of alliteration. Often, sisters become more differentiated during their service as their equipment (in the case of naval vessels, their armament) are separately altered.
For instance, the U.S. warships USS Iowa, USS New Jersey, USS Missouri, and USS Wisconsin are all sister ships, each being an Iowa-class battleship.
The most famous sister ships were the White Star Line's RMS Olympic, RMS Titanic and HMHS Britannic. As with some other liners, the sisters worked as running mates. Other sister ships include the Royal Caribbean International's Explorer of the Seas and Adventure of the Seas.
Half-sister refers to a ship of the same class but with some significant differences. One example of half-sisters are the First World War-era British Courageous-class battlecruisers where the first two ships had four 15-inch (381 mm) guns, but the last ship, HMS Furious, had two 18-inch (457 mm) guns instead. Another example is the American Essex-class aircraft carriers of the Second World War that came in "long-hull" and "short-hull" versions.
Notable airships include the American sister ships USS Akron and USS Macon, and the German Hindenburg class airship's Hindenburg and Graf Zeppelin II.
The generally accepted commercial distinctions of a sister ship are the following:
Type: Identical main type (bullk, tank, RoRo, etc.)
Dry weight (DWT): ± 10% on the DWT (If the ship is 100,000 DWT, 90,000 to 110,000 DWT)
Builder: Identical shipbuilding company name (not the ship yard location or the country of build)The critical overriding criteria are the same hull design. For example, the popular TESS-57 standard design built by Tsunishi Shipbuilding are built in Japan, China, and the Philippines. All the ships of this design are classed as sister ships.
The International Maritime Organization defined sister ship in IMO resolution MSC/Circ.1158 in 2006. Criteria included these:
A sister ship is a ship built by the same yard from the same plans.
The acceptable deviation of lightship displacement should be between 1 and 2% of the lightship displacement of the lead ship, depending on the length of the ship.
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