title: Trident (UK nuclear programme)

text: During the early part of the Second World War, the United Kingdom (UK) had a nuclear weapons project, code-named Tube Alloys, which the 1943 Quebec Agreement merged with the American Manhattan Project to create a combined American, British, and Canadian project. The British government expected that the United States (US) would continue to share nuclear technology, which it regarded as a joint discovery, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical co-operation. Fearing a resurgence of US isolationism, and losing its own great power status, the British government resumed its own development effort. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952. The subsequent British development of the hydrogen bomb, and a fortuitous international relations climate created by the Sputnik crisis, facilitated the amendment of the McMahon Act, and the 1958 US–UK Mutual Defence Agreement (MDA), which allowed Britain to acquire nuclear weapons systems from the US, thereby restoring the nuclear Special Relationship.


title: Trident (UK nuclear programme)

text: During the 1950s, Britain's nuclear deterrent was based around the V-bombers of the Royal Air Force (RAF), but developments in radar and surface-to-air missiles made it clear that bombers were becoming increasingly vulnerable, and would be unlikely to penetrate Soviet airspace by the mid-1970s. To address this problem, the UK embarked on the development of a Medium Range Ballistic Missile called Blue Streak, but concerns were raised about its own vulnerability, and the British government decided to cancel it and acquire the American Skybolt air-launched ballistic missile. In return, the Americans were given permission to base the US Navy's Polaris boats at Holy Loch in Scotland. In November 1962, the American government cancelled Skybolt. John F. Kennedy, then President of the United States, and Harold Macmillan, then UK Prime Minister, negotiated the Nassau Agreement, under which the US would sell Polaris systems for UK-built submarines. This was formalised in the Polaris Sales Agreement.


title: Trident (UK nuclear programme)

text: The first British Polaris ballistic missile submarine (SSBN), , was laid down by Vickers-Armstrongs at its yard at Barrow-in-Furness in Cumbria on 26 February 1964. She was launched on 15 September 1965, commissioned on 2 October 1967, and conducted a test firing at the American Eastern Range on 15 February 1968. She was followed by , which was completed by Vickers-Armstrongs on 29 September 1968; and two boats built by Cammell Laird in Birkenhead: , which was completed on 15 November 1968; and , which was completed on 4 December 1969. The four boats were based at HMNB Clyde at Faslane on the Firth of Clyde, not far from the US Navy's base at Holy Loch, which opened in August 1968. It was served by a weapons store at nearby RNAD Coulport. HM Dockyard, Rosyth, was designated as the refit yard for the 10th Submarine Squadron, as the Polaris boats became operational.


title: Trident (UK nuclear programme)

text: Polaris proved to be reliable, and its second-strike capability conferred greater strategic flexibility than any previous British nuclear weapons system. However it had a limited lifespan, and was expected to become obsolete by the 1990s. It was considered vital that an independent British deterrent could penetrate existing and future Soviet anti-ballistic missile (ABM) capabilities. An ABM system, the ABM-1 Galosh, defended Moscow, and NATO believed the USSR would continue to develop its effectiveness. The deterrent logic required the ability to threaten the destruction of the Soviet capital and other major cities. To ensure that a credible and independent nuclear deterrent was maintained, the UK developed an improved warhead package Chevaline, which replaced one of the three warheads in a Polaris missile with multiple decoys, chaff, and other defensive countermeasures. Chevaline was extremely expensive; it encountered many of the same issues that had affected the British nuclear weapons projects of the 1950s, and postponed, but did not avert, Polaris's obsolescence.


title: Trident (UK nuclear programme)

text: The Conservative Party had a strong pro-defence stance, and supported the British nuclear weapons programme, although not necessarily at the expense of conventional weapons. The rival Labour Party had initiated the acquisition of nuclear weapons, but in the late 1950s its left wing pushed for a policy of nuclear disarmament, resulting in an ambiguous stance. While in office from 1964 to 1970 and 1974 to 1979, it built and maintained Polaris, and modernised it through the secret Chevaline programme. In opposition in the early 1980s, Labour adopted a policy of unilateral nuclear disarmament.


title: Trident (UK nuclear programme)

text: More important than political differences was a shared sense of British national identity. Britain was seen as an important player in world affairs, its economic and military weaknesses offset by its membership of NATO and the Group of Seven, its then active membership of the European Union, its permanent seat on the UN Security Council, its leadership of the Commonwealth of Nations, and the nuclear Special Relationship with the US. To accept a position of inferiority to its ancient rival, France, was unthinkable. Moreover, the UK sees itself as a force for good in the world with a moral duty to intervene, with military force if need be, to defend both its interests and its values. By the 1980s, possession of nuclear weapons was considered a visible sign of Britain's enduring status as a great power in spite of the loss of the British Empire, and had become a component of the national self-image.


title: Trident (UK nuclear programme)

text: The Cabinet Secretary, Sir John Hunt briefed Cabinet on Polaris on 28 November 1977, noting that a possible successor might take up to 15 years to bring into service, depending on the nature of system chosen, and whether it was to be developed by the UK, or in collaboration with France or the US. With the recent experience of Chevaline in mind, the option of a purely British project was rejected. A study of the options was commissioned in February 1978 from a group chaired by the Deputy Under-Secretary of State at the Foreign Office, Sir Antony Duff, with the Chief Scientific Adviser to the Ministry of Defence, Sir Ronald Mason. The Duff-Mason Report was delivered to the Prime Minister, James Callaghan, in parts on 11 and 15 December. It recommended the purchase of the American Trident I C-4 missile then in service with the US Navy. The C-4 had multiple independently targetable re-entry vehicle (MIRV) capability, which was needed to overcome the Soviet ABM defences.


title: Trident (UK nuclear programme)

text: Callaghan approached President Jimmy Carter in January 1979, who responded positively, but did not commit. The Carter administration's main priority was the SALT II Agreement with the Soviet Union, which limited nuclear weapons stockpiles. It was signed on 18 June 1979, but Carter faced an uphill battle to secure its ratification by the US Senate. MIRV technology had proved to be a major loophole in the 1972 SALT I Agreement, which limited numbers of missiles but not warheads. During the SALT II negotiations the US had resisted Soviet proposals to include the British and French nuclear forces in the agreement, but there were concerns that supplying MIRV technology to the UK would be seen by the Soviets as violating the spirit of the non-circumvention clause in SALT II.


title: Trident (UK nuclear programme)

text: Callaghan was succeeded by Margaret Thatcher after the general election on 3 May 1979, and she discussed the issue with Carter in October, who agreed to supply C-4, but he asked that the UK delay a formal request until December in order that he could get SALT II ratified beforehand. In the meantime, the MDA, without which the UK would not be able to access US nuclear weapons technology, was renewed for five more years on 5 December, and the MISC 7 cabinet committee formally approved the decision to purchase C-4 the following day. When Thatcher met with Carter again on 17 December, he still asked for more time, but the Soviet invasion of Afghanistan on 24 December ended all hope of Senate ratification of SALT II, clearing the way for the sale to proceed.


title: Trident (UK nuclear programme)

text: The British government hoped that Trident could be secured on the same terms as Polaris, but when its chief negotiator, Robert Wade-Gery, sat down with his American counterpart, David L. Aaron, in March 1980, he found this was not the case. Instead of the 5 per cent levy in recognition of US research and development (R&D) costs agreed to in the Polaris Sales Agreement, a 1976 law now required a "pro rata" fixed fee payment; the levy would have been approximately $100 million, however the fixed fee amounted to around $400 million.


title: Trident (UK nuclear programme)

text: The law could be waived if the President determined that it was in the interest of the US to do so, but for that the Carter administration wanted undertakings that the UK would raise defence spending by the same amount, or pay the cost of US forces manning Rapier batteries and Ground Launched Cruise Missile (GLCM) sites in the UK. On 2 June 1980, Thatcher and the US Secretary of Defense, Harold Brown, agreed to $2.5 billion for the C-4 missile system, plus a 5 per cent R&D levy, British personnel for the Rapier batteries, and an expansion of the US base on Diego Garcia, which had assumed great importance since the Soviet invasion of Afghanistan. The Secretary of State for Defence, Francis Pym, informed Cabinet of the decision to purchase Trident on 15 July 1980, and announced it in the House of Commons later that day. The agreement was effected by amending the Polaris Sales Agreement, changing "Polaris" to "Trident".


title: Trident (UK nuclear programme)

text: However, on 4 November 1980, Ronald Reagan was elected president. Part of his election platform was to modernise the US strategic nuclear forces. On 24 August 1981, the Reagan administration informed the British government of its intention to upgrade its Trident to the new Trident II D-5 missile by 1989, and indicated that it was willing to sell it to the UK. Despite the name, the D-5 was not an improved version of the C-4, but a completely new missile. Its purchase had already been considered in the Duff-Mason report, but had been rejected, as its additional capability—the extended range from —was not required by the UK, and it was more expensive. Exactly how much more expensive was uncertain, as it was still under development. At the same time, the British government was well aware of the costs of not having the same hardware as the US. Nor did the Reagan administration promise to sell D-5 on the same terms as the C-4. To pay for Trident, the British government announced deep cuts to other defence spending on 25 June 1981.


title: Trident (UK nuclear programme)

text: Negotiations commenced on 8 February, with the British team again led by Wade-Gery. The Americans were disturbed at the proposed British defence cuts, and pressed for an undertaking that the aircraft carrier be retained in service, which they felt was necessary to avert trouble over the Belizean–Guatemalan territorial dispute. They accepted a counter-offer that Britain would retain the two landing platform dock ships, and , for which the Americans reduced the R&D charge. Under the agreement, the UK would purchase 65 Trident II D-5 missiles that would operate as part of a shared pool of weapons based at Naval Submarine Base Kings Bay in the US. The US would maintain and support the missiles, while the UK would manufacture its own submarines and warheads to go on the missiles. The warheads and missiles would be mated in the UK. This was projected to save about £500 million over eight years at Coulport, while the Americans spent $70 million upgrading the facilities at Kings Bay. The sale agreement was formally signed on 19 October 1982 by the British Ambassador to the United States, Sir Oliver Wright, and the US Secretary of State, George Shultz.


title: Trident (UK nuclear programme)

text: The Trident programme was projected to cost £5 billion, including the four submarines, the missiles, new facilities at Coulport and Faslane and the contribution to Trident II D-5 R&D. It was expected to absorb 5 per cent of the defence budget. As with Polaris, the option for a fifth submarine (allowing two to be on patrol at all times) was discussed, but ultimately rejected. Thatcher's popularity soared as a result of the British victory in the Falklands War, in which the ships that the Americans had insisted be retained played a crucial part. Trident's future was secured the following year when the Conservative Party won the 1983 general election, defeating a Labour Party that had pledged to cancel Trident. The first Trident boat, was ordered on 30 April 1986. In view of the Labour Party's continued opposition to Trident, Vickers insisted that the contract include substantial compensation in the event of cancellation.


title: Trident (UK nuclear programme)

text: The Trident programme was initiated during the Cold War, and it was designed to provide an ongoing independently controlled deterrent against major threats to the security of the UK and its NATO allies, including threats posed by non-nuclear weapons.


title: Trident (UK nuclear programme)

text: To provide an effective deterrent, the Trident system was intended to "pose a potential threat to key aspects of Soviet state power" whilst being invulnerable to a surprise or pre-emptive nuclear strike. As with Polaris, Trident was owned and operated by the UK but committed to NATO and targeted in accordance with plans set out by the organisation's Supreme Allied Commander Europe, who is traditionally a senior figure in the US military. Under the terms of the Polaris Sales Arrangement, the US does not have a veto on the use of British nuclear weapons, which the UK may launch independently, but this would only occur if "supreme national interests" required it.


title: Trident (UK nuclear programme)

text: The final decision on firing the missiles is the responsibility of the prime minister, who, upon taking office, writes four identical letters of last resort, one of which is locked in a safe on board each of the "Vanguard"-class submarines. If contact with the UK is lost, the commanding officer of a submarine has to follow the instructions in the letter if they believe that the United Kingdom has suffered an overwhelming attack. Options include retaliating with nuclear weapons, not retaliating, putting the submarine under the command of an ally or acting as the captain deems appropriate. The exact content of the letters is never disclosed, and they are destroyed without being opened upon a new prime minister taking office.


title: Trident (UK nuclear programme)

text: By the time of the first "Vanguard" patrol in December 1994, the Soviet Union no longer existed, and the government adjusted its nuclear policy in the following years. Trident's missiles were "detargetted" in 1994 ahead of "Vanguard"s maiden voyage. The warheads are not aimed at specific targets but await co-ordinates that can be programmed into their computers and fired with several days' notice.


title: Trident (UK nuclear programme)

text: Under the terms of the 1987 Intermediate-Range Nuclear Forces Treaty with the Soviet Union, the US withdrew its surface naval nuclear weapons and short-range nuclear forces. The GLCMs were withdrawn from the UK in 1991, and the Polaris submarine base at Holy Loch was closed in 1992. The last US warheads in British service under Project E, the B57 nuclear depth bombs and the Lance missiles and W48 nuclear artillery shells used by the British Army of the Rhine, were withdrawn in July 1992. The British Conservative government followed suit. The deployment of ships carrying nuclear weapons caused embarrassment during the Falklands War, and in the aftermath it was decided to stockpile them ashore in peacetime. The nuclear depth bombs were withdrawn from service in 1992, followed by the WE.177 free-fall bombs used by the Royal Navy and RAF on 31 March 1998. This left Trident as Britain's sole nuclear weapons system.


title: Trident (UK nuclear programme)

text: Although Trident was designed as a strategic deterrent, the end of the Cold War led the British government to conclude that a sub-strategic—but not tactical—role was required, with Trident missiles assuming the role formerly handled by the RAF's WE.177 bombs. The 1994 Defence White Paper stated: "We also need the capability to undertake nuclear action on a more limited scale in order to ... halt aggression without inevitably triggering strategic nuclear exchanges". A later statement read: "We also intend to exploit the flexibility of Trident to provide the vehicle for both sub-strategic and strategic elements of our deterrent … as an insurance against potential adverse trends in the international situation". On 19 March 1998, the Defence Secretary, George Robertson, was asked to provide a statement "on the development of a lower-yield variant of the Trident warhead for the sub-strategic role". He replied, "the UK has some flexibility in the choice of yield for the warheads on its Trident missiles".


title: Trident (UK nuclear programme)

text: The UK has not declared a no first use policy regarding launching a nuclear attack; former British defence secretary Geoff Hoon stated in 2002 and 2003 that the UK would be willing to attack rogue states with them if nuclear weapons were used against British troops. In April 2017 Defence Secretary Michael Fallon confirmed that the UK would use nuclear weapons in a "pre-emptive initial strike" in "the most extreme circumstances". Fallon stated in a parliamentary answer that the UK has neither a 'first use' or 'no first use' in its nuclear weapon policy so that its adversaries would not know when the UK would launch nuclear strikes.


title: Trident (UK nuclear programme)

text: In March 2021, the UK suggested a shift in nuclear policy in its Integrated Defence Review, stating that the UK would reserve the right to use nuclear weapons in the face of weapons of mass destruction, which includes "emerging technologies that could have a considerable impact", including cyber technologies, to chemical or biological weapons. This marks a shift from existing UK policy, in that nuclear weapons would only be launched against another nuclear power or in response to extreme chemical or biological threats. It did, however, stress that the UK would not use or threaten to use nuclear weapons against any non-nuclear weapon party to the Treaty on the Non-Proliferation of Nuclear Weapons 1968, but only if the state is not in "material breach" of the Treaty's obligations. The shift in language comes after the UK lifted the cap on the number of Trident nuclear warheads it can stockpile by 40% from 180 to 260 warheads "in recognition of the evolving security environment". The UK has also stated it would no longer declare how many deployable warheads it has in a new policy of deliberate ambiguity. The move is intended to cement the UK's status as a nuclear power and a US defence ally. Labour Party Leader Keir Starmer, although supporting nuclear deterrence, criticised the new policy and questioned why Prime Minister Boris Johnson believed that increasing the stockpile was necessary. Kate Hudson of the Campaign for Nuclear Disarmament warned against the start of a "new nuclear arms race".


title: Trident (UK nuclear programme)

text: Four "Vanguard"-class submarines were designed and built at Barrow-in-Furness by Vickers Shipbuilding and Engineering, now BAE Systems Submarines, the only shipbuilder in the UK with the facilities and expertise to build nuclear submarines. Even so, £62 million worth of new shipbuilding and dock facilities were added for the project, with the Devonshire Dock Hall built specially for it. The initial plan was to build new versions of the "Resolution"-class, but in July 1981 the decision was taken to incorporate the new Rolls-Royce PWR2 pressurised water reactor. From the outset, the "Vanguard" submarines were designed with enlarged missile tubes able to accommodate the Trident II D-5. The missile compartment is based on the system used on the American , although with capacity for only 16 missiles, rather than the 24 on board an "Ohio" boat. The boats are significantly larger than the "Resolution" class, and were given names formerly associated with battleships and aircraft carriers, befitting their status as capital ships. An important consideration was the depth of the Walney Channel, which connected Barrow to the Irish Sea, which limited the draft to , while the "Ohio"-class boats had a draft of . Each boat is long and in diameter, and carries a crew of 150 officers and ratings.


title: Trident (UK nuclear programme)

text: The submarines use a tactical-information and weapons-control system called the Submarine Command System Next Generation. This system was developed in collaboration with Microsoft, and is based on the same technology as Windows XP, which led the media to give it the nickname "Windows for Submarines", with the UK Defence Journal fact checking group countering claims the vessels run on Windows XP. In addition to the missile tubes, the submarines are fitted with four torpedo tubes and carry the Spearfish torpedo, allowing them to engage submerged or surface targets at ranges up to . Two SSE Mark 10 launchers are also fitted, allowing the boats to deploy Type 2066 and Type 2071 decoys, and a UAP Mark 3 electronic support measures (ESM) intercept system is carried. A "Core H" reactor is fitted to each of the boats during their long-overhaul refit periods, ensuring that none of the submarines will need further re-fuelling.


title: Trident (UK nuclear programme)

text: Thatcher laid the keel of the first boat, HMS "Vanguard", on 3 September 1986, and it was commissioned on 14 August 1993. She was followed by her sisters, , which was laid down on 3 December 1987 and commissioned on 7 January 1995; , which was laid down on 16 February 1991 and commissioned on 2 November 1996; and , which was laid down on 1 February 1993 and commissioned on 27 November 1999. The first British Trident missile was test-fired from "Vanguard" on 26 May 1994, and she began her first patrol in December of that year. According to the Royal Navy, at least one submarine has always been on patrol ever since.


title: Trident (UK nuclear programme)

text: In British service, Trident II missiles are fitted with a thermonuclear warhead called Holbrook. The warhead has a choice of two warhead yields the highest of which is thought to be , with a lower yield in the range of . The UK government was sensitive to charges that the replacement of Polaris with Trident would involve an escalation in the numbers of British nuclear weapons. When the decision to purchase Trident II was announced in 1982, it was stressed that while American Trident boats carried 24 missiles with eight warheads each, a total of 192 warheads, British Trident boats would carry no more than 128 warheads—the same number as Polaris. In November 1993, the Secretary of State for Defence, Malcolm Rifkind, announced that each boat would deploy no more than 96 warheads. In 2010 this was reduced to a maximum of 40 warheads, split between eight missiles. The consequent reduction in warhead production and refurbishment was estimated to save £22 million over a ten-year period.


title: Trident (UK nuclear programme)

text: The warheads are primarily constructed at AWE Aldermaston, with other parts being made at other AWE facilities such as Burghfield. The British government insists the warhead is indigenously designed, but analysts including Hans M. Kristensen with the Federation of American Scientists believe that it is largely based on the US W76 design. Under the 1958 US–UK Mutual Defence Agreement the UK is allowed to draw upon US warhead design information, but constructing and maintaining warheads for the Trident programme is the responsibility of AWE. US President George H. W. Bush authorised the transfer of nuclear warhead components to the UK between 1991 and 1996. The first Holbrook warhead was finished in September 1992 with production probably ending in 1999. Each warhead is housed in a cone-shaped re-entry vehicle made in the US called the Mk 4 and is the same reentry vehicle used by the US Navy with its W76 warhead. This shell protects it from the high temperatures experienced upon re-entry into Earth's atmosphere. The Trident warhead's fusing, arming and firing mechanisms are carefully designed so that it can only detonate after launch and ballistic deployment.


title: Trident (UK nuclear programme)

text: On 25 February 2020, the UK released a Written Statement outlining that the current UK nuclear warheads will be replaced and will match the US Trident SLBM and related systems. Earlier, it was reported that Commander US Strategic Command, Admiral Charles Richard, mentioned in a Senate hearing that the UK was already working to replace its warheads, matching the future US W93 warhead.


title: Trident (UK nuclear programme)

text: , the UK had a stockpile of 215 warheads, of which 120 are operationally available. In 2022 the UK Government announced that "the UK will move to an overall nuclear weapon stockpile of no more than 260 warheads." British SSBNs on patrol carried a maximum of 40 warheads and 8 missiles. In 2011 it was reported that British warheads would receive the new Mk 4A reentry vehicles and some or all of the other upgrades that US W76 warheads were receiving in their W76-1 Life Extension Program. Some reports suggested that British warheads would receive the same arming, fusing and firing system (AF&F) as the US W76-1. This new AF&F system, called the MC4700, would increase weapon lethality against hard targets such as missile silos and bunkers.


title: Trident (UK nuclear programme)

text: Due to the distance of between AWE Aldermaston and the UK's nuclear weapon storage depot at RNAD Coulport, Holbrook (Trident) warheads are transported by road in heavily armed convoys by Ministry of Defence Police. According to a pressure group, between 2000 and 2016 the vehicles were involved in 180 incidents, ranging from delays and diversions because of accidents, protests, or bad weather, to a sudden loss of power in one of the lorries, which halted a convoy and caused a double lane closure and a tailback on the M6 motorway. The group's analysis stated the incidents were more frequent in the years 2013–2015.


title: Trident (UK nuclear programme)

text: Trident II D-5 is a submarine-launched ballistic missile built by Lockheed Martin Space Systems in Sunnyvale, California, and deployed by the US Navy and the Royal Navy. The British government contributed five per cent of its research and development costs under the modified Polaris Sales Agreement. The development contract was issued in October 1983, and the first launch occurred in January 1987. The first submarine launch was attempted by in March 1989. This attempt failed because the plume of water following the missile rose to a greater height than expected, resulting in water being in the nozzle when the motor ignited. Once the problem was understood, simple changes were quickly made, but the problem delayed the entry into service of Trident II until March 1990.


title: Trident (UK nuclear programme)

text: Trident II D-5 is more sophisticated than its predecessor, Trident I C-4, and has a greater payload capacity. All three stages of the Trident II D-5 are made of graphite epoxy, making the missile much lighter than its predecessor. The first test from a British "Vanguard"-class submarine took place in 1994. The missile is long, weighs , has a range of , a top speed of over (Mach 17.4) and a circular error probable (CEP) accuracy to within "a few feet". It is guided using an inertial navigation system combined with a star tracker, and is not dependent on the American-run Global Positioning System (GPS).


title: Trident (UK nuclear programme)

text: The 1998 Strategic Defence Review announced that the number of missile bodies would be limited to the 58 already purchased or under order, and the Royal Navy would not receive the final seven missiles previously planned. This saved about £50 million. The UK missiles form a shared pool with the Atlantic squadron of the US Navy "Ohio"-class SSBNs at Kings Bay. The pool is "co-mingled" and missiles are selected at random for loading on to either nation's submarines. The first Trident boat, HMS "Vanguard", collected a full load of 16 missiles in 1994, but "Victorious" collected only 12 in 1995, and "Vigilant", 14 in 1997, leaving the remaining missile tubes empty.


title: Trident (UK nuclear programme)

text: By 1999, six missiles had been test fired, and another eight were earmarked for test firing. In June 2016, a Trident II D-5 missile "veered off in the wrong direction towards America" after being launched from "Vengeance" off the coast of Florida. The incident was not revealed until January 2017; the "Sunday Times" reported that Downing Street had "covered up" the incident "just weeks before the crucial House of Commons vote on the future of the missile system." Subsequent media reports said this was at the request of the US. Successful Royal Navy test firings had occurred in 2000, 2005, 2009 and 2012. They are infrequent due to the missile's £17 million cost. By August 2016 there had been 161 successful test firings of the Trident II D-5 missile since 1989, the most recent being from in August 2016. Fewer than 10 test flights have been failures, and the Royal Navy is not known to have had a previous failure.


title: Trident (UK nuclear programme)

text: In the 1990s, the total acquisition cost of the Trident programme was £9.8 billion, about 38 per cent of which was incurred in the US. In 2005–06, annual expenditure for the running and capital costs was estimated at between £1.2 billion and £1.7 billion and was estimated to rise to £2bn to £2.2 billion in 2007–08, including Atomic Weapons Establishment costs. Since Trident became operational in 1994, annual expenditure has ranged between 3 and 4.5 per cent of the annual defence budget, and was projected to increase to 5.5 per cent of the defence budget by 2007–08. An important factor in the cost was the exchange rate between the dollar and the pound, which declined from $2.36 in September 1980 to $1.78 in March 1982.


title: Trident (UK nuclear programme)

text: The principle of Trident's operation is known as Continuous At-Sea Deterrence (CASD), which means that at least one submarine is always on patrol. Another submarine is usually undergoing maintenance and the remaining two are in port or on training exercises. During a patrol, the submarine is required to remain silent and is allowed to make contact with the UK only in an emergency. It navigates using mapped contour lines of the ocean floor and patrols a series of planned "boxes" measuring several thousand square miles. A aerial trails on the surface behind the submarine to pick up incoming messages. Most of the 150 crew never know where they are or where they have been. The 350th patrol commenced on 29 September 2017. On 15 November 2018, a reception was held at Westminster to mark 50 years of CASD.


title: Trident (UK nuclear programme)

text: Only the prime minister or a designated survivor can authorise the missiles to be fired. These orders would likely be issued from the Pindar command bunker under Whitehall in central London. From there, the order would be relayed to the Commander, Task Force 345 (CTF 345) operations room at the Northwood Headquarters facility in Hertfordshire, the only facility allowed to communicate with the "Vanguard" commander on patrol. Communications are relayed via IP over VLF from a transmitter site at Skelton near Penrith. Two personnel are required to authenticate each stage of the process before launching, with the submarine commander only able to activate the firing trigger after two safes have been opened with keys held by the ship's executive and weapon engineer officers. A parliamentary answer states that commanding officers of Royal Navy ballistic submarines receive training in the 'Law Of Armed Conflict'.


title: Trident (UK nuclear programme)

text: Trident is based at HMNB Clyde on the west coast of Scotland. The base consists of two facilities — Faslane Naval Base on Gare Loch near Helensburgh, and an ordnance depot with 16 concrete bunkers set into a hillside at Coulport, to the west. Faslane was constructed and first used as a base during the Second World War. This location was chosen as the base for nuclear-armed submarines at the height of the Cold War because of its position close to the deep and easily navigable Firth of Clyde. It provides for rapid and stealthy access through the North Channel to the patrolling areas in the North Atlantic, and through the GIUK gap between Iceland and Scotland to the Norwegian Sea. Also based there are nuclear-powered fleet submarines (SSNs). RNAD Coulport is used to store the nuclear warheads and has docking facilities where they are loaded onto submarines before going on patrol and unloaded when they return to the base. Repair and refit of the "Vanguard"-class submarines takes place at HMNB Devonport near Plymouth, Devon.


title: Trident (UK nuclear programme)

text: According to senior RAF officers the retirement of the Nimrod maritime patrol aircraft in 2011 gave Russia the potential to gain "valuable intelligence" on the country's nuclear deterrent. As a result, plans to buy Northrop Grumman MQ-4C Triton unmanned aerial vehicles were reportedly considered. The Strategic Defence and Security Review 2015 announced that nine Boeing P-8 Poseidon maritime patrol aircraft would be purchased for the RAF. They became operational on 3 April 2020.


title: Trident (UK nuclear programme)

text: The Campaign for Nuclear Disarmament (CND) was a national movement founded in the late 1950s, initially in opposition to nuclear testing. It reached its peak around 1960, by which time it had evolved into a broader movement calling for Britain to unilaterally give up nuclear weapons, withdraw from NATO, and end the basing of nuclear-armed aircraft in the UK. The end of atmospheric nuclear testing, internal squabbles, and activists focusing their energies on other causes led to a rapid decline, but it revived in the early 1980s in the wake of the Thatcher government's December 1979 decision to allow the deployment of GLCMs in the UK under the NATO Double-Track Decision, and the announcement of the decision to purchase Trident in July 1980. Membership leapt from 3,000 in 1980 to 50,000 a year later, and rallies for unilateral nuclear disarmament in London in October 1981 and June 1982 attracted 250,000 marchers, the largest ever mass demonstrations in the UK up to that time.


title: Trident (UK nuclear programme)

text: The 1982 Labour Party Conference adopted a platform calling for the removal of the GLCMs, the scrapping of Polaris and the cancellation of Trident. This was reaffirmed by the 1986 conference. While the party was given little chance of winning the 1983 election in the aftermath of the Falklands War, polls had shown Labour ahead of the Conservatives in 1986 and 1987. In the wake of Labour's unsuccessful performance in the 1987 election, the Labour Party leader, Neil Kinnock, despite his own unilateralist convictions, moved to drop the party's disarmament policy, which he saw as a contributing factor in its defeat. The party formally voted to do so in October 1989.


title: Trident (UK nuclear programme)

text: Pro-independence Scottish political parties—the Scottish National Party (SNP), Scottish Green Party, Scottish Socialist Party (SSP) and Solidarity—are opposed to the basing of the Trident system close to Glasgow, Scotland's largest city. Some members and ex-members of those parties, such as Tommy Sheridan and Lloyd Quinan, have taken part in blockades of the base. For a major House of Commons vote in 2007, the majority of Scottish members of parliament (MPs) voted against upgrading the system, while a substantial majority of English and Welsh MPs voted in favour. The house backed plans to renew the programme by 409 votes to 161.


title: Trident (UK nuclear programme)

text: Faslane Peace Camp is permanently sited near Faslane naval base. It has been occupied continuously, albeit in different locations, since 12 June 1982. In 2006, a year-long protest at Trident's base at Faslane aimed to blockade the base every day for a year. More than 1,100 people were arrested.


title: Trident (UK nuclear programme)

text: During the 2020 coronavirus pandemic a letter was circulated to MPs by the Bertrand Russell Peace Foundation which stated, “It is completely unacceptable that the UK continues to spend billions of pounds on deploying and modernising the Trident Nuclear Weapon System when faced with the threats to health, climate change and world economies that Coronavirus poses.” Signatories included Commander Robert Forsyth RN (Ret'd), a former nuclear submariner; Commander Robert Green RN (Ret'd), a former nuclear-armed aircraft bombardier-navigator and Staff Officer (Intelligence) to CINFLEET in the Falklands War; and Commander Colin Tabeart RN (Ret'd), a former Senior Engineer Officer on a Polaris submarine. Following this the MoD updated its online instruction notice to staff on public communications to say, “All contact with the media or communication in public by members of the armed forces and MoD civilians where this relates to defence or government business must be authorised in advance”.


title: Trident (UK nuclear programme)

text: The Royal United Services Institute (RUSI), a British defence and security think tank, released a paper in July 2010 assessing four possible options for maintaining both an effective nuclear deterrent and also reducing costs in light of anticipated budget restrictions. These proposals were motivated by the fact that funding for the Trident renewal programme now had to come from the core Ministry of Defence budget. Four alternatives were considered: Trident submarines on continuous patrol; Trident submarines not on patrol continuously; attack submarines armed with nuclear cruise missiles; and land-based nuclear weapons. The paper concluded that "given the opportunity costs for conventional capabilities that current plans for Trident renewal are due to incur over the next decade...there is now a growing case for a re-examination of whether there are less expensive means of pursuing this objective. A key element of such a review is likely to be a reconsideration of the need to maintain a commitment to CASD in strategic circumstances that are now very different from those in which it was first introduced."


title: Trident (UK nuclear programme)

text: The 2013 Trident Alternatives Review was an 18-month study led by the Cabinet Office that was aimed at establishing whether or not there were credible alternatives to the UK's submarine-based CASD. Accordingly, the review analysed a range of delivery systems and warhead designs with respect to their affordability and effectiveness against potential targets. Ultimately, the Trident Alternatives Review came to the conclusion that there were alternatives to Trident that "would enable the UK to be capable of inflicting significant damage such that most potential adversaries around the world would be deterred", but none would "offer the same degree of resilience as the current posture". The review asserted that whether or not cruise missile-based systems offer a credible alternative was contingent upon a political judgement on whether the UK could accept a "significant increase in vulnerability" and a reduction in who it could deter.


title: Trident (UK nuclear programme)

text: The publication of the report was met with a mixed reception from different political parties and non-governmental organisations (NGOs) in the field of non-proliferation and disarmament. While it was welcomed by the prime minister, David Cameron, as having confirmed the necessity of like-for-like replacement of Trident, Liberal Democrat cabinet minister Danny Alexander deemed it a demonstration of the fact there are "credible and viable alternatives to the UK's current approach to nuclear deterrence." NGOs including the British American Security Information Council (BASIC), a non-proliferation and disarmament think-tank, criticised the report for its limited scope and its failure to engage with a wider array of considerations related to nuclear weapons, including environmental and humanitarian issues.


title: Trident (UK nuclear programme)

text: In 2011, BASIC launched an independent cross-party Commission to initiate a deeper national debate on the UK's nuclear weapons policy and examine questions around the contentious issue of Trident renewal. The Commission operated under the chairmanship of former Labour Secretary of State for Defence, Lord Browne of Ladyton; former Conservative Defence and Foreign Secretary, Sir Malcolm Rifkind; and Sir Menzies Campbell, former leader of the Liberal Democrats and Shadow Foreign Secretary. After three years' of deliberation, the Commission released its final report on 1 July 2014. It suggested, with important caveats, that the UK should retain a nuclear deterrent. The conclusion acknowledged that "it remains crucial that the UK show keen regard for its position within the international community and for the shared responsibility to achieve progress in global nuclear disarmament."


title: Trident (UK nuclear programme)

text: BASIC's interpretation of the report also focused on this point, emphasising that the commissioners "agreed that the health of the global strategic environment, particularly nuclear non-proliferation, is critical to national security and is a central consideration. They talk of the need for Britain to maintain its 'glide path down towards disarmament', to ensure that the renewal decisions the next government will be taking have consistency with the trajectory set by successive recent governments, and that the UK should continue to be 'at the forefront of the multilateral disarmament process.'"


title: Trident (UK nuclear programme)

text: The "Vanguard"-class submarines were built with a 25-year life expectancy, taking them into the 2020s. Trident II D-5 missiles are expected to continue in service until at least 2040 following an upgrade. A December 2006 Ministry of Defence white paper, entitled "The Future of the United Kingdom's Nuclear Deterrent", recommended that the nuclear weapons should be maintained and outlined measures that would do so until the 2040s. It advocated the currently preferred submarine-based system, as it remained the cheapest and most secure deterrence option available. Costs for this option are estimated at £15–20 billion based on:


title: Trident (UK nuclear programme)

text: These 2006/07 prices would equate to about £25bn for the Successor-class submarines as they were provisionally named; the 2011 Initial Gate report confirmed estimates of £2-3bn each for the warheads and infrastructure. These cost estimates exclude the "Vanguard" five-year life extension and decommissioning, and it is unclear if new Trident missiles will need to be purchased for the life extension programme. Running costs would be about £1.5 billion per year at 2006 prices. The paper suggested parts of the existing Trident system be refitted to some extent to prolong their lives. However, the relatively short (five years) life extension potential of the "Vanguard" class meant that a new class of SSBNs should replace it in the 2020s. The first boat of the new SSBN class would take 17 years to be designed and built, making a five-year life extension of the "Vanguard" class necessary.


title: Trident (UK nuclear programme)

text: A decision on the renewal of Trident was made on 4 December 2006. Prime Minister Tony Blair told MPs it would be "unwise and dangerous" for the UK to give up its nuclear weapons. He outlined plans to spend up to £20bn on a new generation of submarines for Trident missiles. He said submarine numbers may be cut from four to three, while the number of nuclear warheads would be cut by 20% to 160. Blair said although the Cold War had ended, the UK needed nuclear weapons, as no-one could be sure another nuclear threat would not emerge in the future.


title: Trident (UK nuclear programme)

text: On 14 March 2007, the Labour government won House of Commons support for the plans to renew the submarine system. The proposals were passed by a majority of 248. Despite a clarification that the vote was just for the concept stage of the new system, 95 Labour MPs rebelled, and it was only passed with the support of the opposition Conservative Party. It was the first time MPs had been given the chance to vote on whether the UK should remain a nuclear power, and the biggest rebellion since the beginning of the 2003 Iraq War.


title: Trident (UK nuclear programme)

text: The Labour government proposed that the final decision to manufacture should be made in 2014. The new 2010 coalition government agreed "that the renewal of Trident should be scrutinised to ensure value for money." Research and development work continued with an Initial Gate procurement decision, but the Main Gate decision to manufacture a replacement was rescheduled for 2016, after the 2015 general election. The vote on whether to order the Successor-class was held on 18 July 2016 in the House of Commons; the motion passed with a significant majority, extending the programme's life until at least the 2060s. Although 48 Labour MPs voted against it, 41 did not vote, and 140 Labour votes were cast in favour of the motion.


title: Trident (UK nuclear programme)

text: The 2010 Strategic Defence and Security Review concluded that the Successor-class submarines would have eight operational missiles carrying no more than 40 operational warheads between them. This would allow the UK to reduce its stocks of operational warheads from 160 to 120, and the overall stockpile from no more than 225 to no more than 180. They would be carried in a 12-missile Common Missile Compartment designed in collaboration with the US which could accommodate the current Trident II D-5 missiles and any replacement missile once the D-5 reaches the end of its expected life in the 2040s.


title: Trident (UK nuclear programme)

text: Two non-representative polls of experts from the RUSI and the Royal Institute of International Affairs (commonly known as Chatham House) were conducted in 2010. The RUSI found a majority for those who think the benefits of Trident outweigh the costs (53%) compared to those that think the costs outweigh the benefits (13%) or are evenly balanced (34%). The Chatham House poll found a minority in favour of Trident replacement (22%), with more in favour of replacing with a cheaper system (43%) and 29% saying the UK should not replace Trident at all.


title: Trident (UK nuclear programme)

text: In April 2015, a YouGov poll found that 38% of people thought that Trident should be replaced in full, 28% wanted to replace it with a cheaper system, 19% thought the UK should completely give up its nuclear weapons, and 15% did not know. In September 2015, a Survation poll found that 29% agreed that Trident should be reformed to make it cheaper, 26% that it should be renewed in full, and 18% that it should be scrapped. 27% did not know. Nuclear weapons are not the nation's biggest issue, with just 2% of people saying that it was nation's biggest worry in May 2015, compared to 21% in June 1987.


title: Trident (UK nuclear programme)

text: In February 2016, BAE Systems began design work on prototypes of the new submarines. The Successor class was officially named the on 21 October 2016. The submarines were expected to become operational starting in 2028, with the current fleet phased out by 2032.


title: Trident (UK nuclear programme)

text: In October 2015, Reuters estimated it would cost £167 billion over its 30-year lifespan, or £5.56 billion per year; this figure was disputed by Michael Fallon. The Ministry of Defence put the cost of building, testing and commissioning the replacement vessels at £31 billion (plus a contingency fund of £10 billion) over 35 years. This amounts to 0.2 per cent of government spending, or 6 per cent of defence spending. Crispin Blunt, Chair of the Foreign Affairs Select Committee, estimated in July 2016 that the programme would cost £179 billion in total over its lifetime.


title: Trident (UK nuclear programme)

text: For the 2018/19 financial year the National Audit Office found that spending on the nuclear deterrent will cost £5.2 billion, or 14% of the defence budget, with £600 million of contingency funding used. Costs were projected at about £51 billion over the following 10 years, £2.9 billion above the projected budget which already anticipated finding £3 billion of savings, which the "Daily Telegraph" described as a £6 billion shortfall.


title: Biochar

text: Biochar is the lightweight black residue, made of carbon and ashes, remaining after the pyrolysis of biomass. Biochar is defined by the International Biochar Initiative as "the solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment". Biochar is a stable solid that is rich in pyrogenic carbon and can endure in soil for thousands of years.


title: Biochar

text: The refractory stability of biochar leads to the concept of pyrogenic carbon capture and storage (PyCCS), i.e. carbon sequestration in the form of biochar. It may be a means to mitigate climate change.<ref name="DOI10.1038/ncomms1053">


title: Biochar

text: </ref> Biochar may increase the soil fertility of acidic soils and increase agricultural productivity.


title: Biochar

text: The word "biochar" is a late 20th century English neologism derived from the Greek word , "bios", "life" and "char" (charcoal produced by carbonisation of biomass). It is recognised as charcoal that participates in biological processes found in soil, aquatic habitats and in animal digestive systems.


title: Biochar

text: Pre-Columbian Amazonians produced biochar by smoldering agricultural waste (i.e., covering burning biomass with soil) in pits or trenches. It is not known if they intentionally used biochar to enhance soil productivity. European settlers called it "terra preta de Indio". Following observations and experiments, a research team working in French Guiana hypothesized that the Amazonian earthworm "Pontoscolex corethrurus" was the main agent of fine powdering and incorporation of charcoal debris in the mineral soil.


title: Biochar

text: Biochar is a high-carbon, fine-grained residue that is produced via pyrolysis; it is the direct thermal decomposition of biomass in the absence of oxygen (preventing combustion), which produces a mixture of solids (the biochar proper), liquid (bio-oil), and gas (syngas) products.


title: Biochar

text: Gasifiers produce most of the biochar sold in the United States. The gasification process consists of four main stages: oxidation, drying, pyrolysis, and reduction. Temperature during pyrolysis in gasifiers is , in the reduction zone and in the combustion zone.


title: Biochar

text: The specific yield from pyrolysis is dependent on process conditions such as temperature, residence time, and heating rate. These parameters can be tuned to produce either energy or biochar. Temperatures of produce more char, whereas temperatures above favor the yield of liquid and gas fuel components. Pyrolysis occurs more quickly at higher temperatures, typically requiring seconds rather than hours. The increasing heating rate leads to a decrease of biochar yield, while the temperature is in the range of . Typical yields are 60% bio-oil, 20% biochar, and 20% syngas. By comparison, slow pyrolysis can produce substantially more char (≈35%); this contributes to soil fertility. Once initialized, both processes produce net energy. For typical inputs, the energy required to run a "fast" pyrolyzer is approximately 15% of the energy that it outputs. Pyrolysis plants can use the syngas output and yield 3–9 times the amount of energy required to run.


title: Biochar

text: Besides pyrolysis, torrefaction and hydrothermal carbonization processes can also thermally decompose biomass to the solid material. However, these products cannot be strictly defined as biochar. The carbon product from the torrefaction process contains some volatile organic components, thus its properties are between that of biomass feedstock and biochar. Furthermore, even the hydrothermal carbonization could produce a carbon-rich solid product, the hydrothermal carbonization is evidently different from the conventional thermal conversion process. Therefore, the solid product from hydrothermal carbonization is defined as "hydrochar" rather than "biochar".


title: Biochar

text: The Amazonian pit/ trench method harvests neither bio-oil nor syngas, and releases , black carbon, and other greenhouse gases (GHGs) (and potentially, toxicants) into the air, though less greenhouse gasses than captured during the growth of the biomass. Commercial-scale systems process agricultural waste, paper byproducts, and even municipal waste and typically eliminate these side effects by capturing and using the liquid and gas products. The 2018 winner of the X_Prize_Foundation for atmospheric water generators harvests potable water from the drying stage of the gasification process. The production of biochar as an output is not a priority in most cases.


title: Biochar

text: Smallholder farmers in developing countries easily produce their own biochar without special equipment. They make piles of crop waste (e.g., maize stalks, rice straw or wheat straw), light the piles on the top and quench the embers with dirt or water to make biochar. This method greatly reduces smoke compared to traditional methods of burning crop waste. This method is known as the top down burn or conservation burn.


title: Biochar

text: In a centralized system, unused biomass is brought to a central plant for processing into biochar. Alternatively, each farmer or group of farmers can operate a kiln. Finally, a truck equipped with a pyrolyzer can move from place to place to pyrolyze biomass. Vehicle power comes from the syngas stream, while the biochar remains on the farm. The biofuel is sent to a refinery or storage site. Factors that influence the choice of system type include the cost of transportation of the liquid and solid byproducts, the amount of material to be processed, and the ability to supply the power grid.


title: Biochar

text: Common crops used for making biochar include various tree species, as well as various energy crops. Some of these energy crops (i.e. Napier grass) can store much more carbon on a shorter timespan than trees do.


title: Biochar

text: For crops that are not exclusively for biochar production, the Residue-to-Product Ratio (RPR) and the collection factor (CF), the percent of the residue not used for other things, measure the approximate amount of feedstock that can be obtained. For instance, Brazil harvests approximately 460 million tons (MT) of sugarcane annually, with an RPR of 0.30, and a CF of 0.70 for the sugarcane tops, which normally are burned in the field. This translates into approximately 100 MT of residue annually, which could be pyrolyzed to create energy and soil additives. Adding in the bagasse (sugarcane waste) (RPR=0.29 CF=1.0), which is otherwise burned (inefficiently) in boilers, raises the total to 230 MT of pyrolysis feedstock. Some plant residue, however, must remain on the soil to avoid increased costs and emissions from nitrogen fertilizers.


title: Biochar

text: Various companies in North America, Australia, and England sell biochar or biochar production units. In Sweden the 'Stockholm Solution' is an urban tree planting system that uses 30% biochar to support urban forest growth.


title: Biochar

text: At the 2009 International Biochar Conference, a mobile pyrolysis unit with a specified intake of was introduced for agricultural applications.<ref name="biomassmag.com/article_id=3091"></ref>


title: Biochar

text: Alternatively, "thermo-catalytic depolymerization", which utilizes microwaves, has been used to efficiently convert organic matter to biochar on an industrial scale, producing ≈50% char.


title: Biochar

text: The physical and chemical properties of biochars as determined by feedstocks and technologies are crucial. Characterization data explain their performance in a specific use. For example, guidelines published by the International Biochar Initiative provide standardized evaluation methods. Properties can be categorized in several respects, including the proximate and elemental composition, pH value, and porosity. The atomic ratios of biochar, including H/C and O/C, correlate with the properties that are relevant to organic content, such as polarity and aromaticity. A van-Krevelen diagram can show the evolution of biochar atomic ratios in the production process. In the carbonization process, both the H/C and O/C ratios decrease due to the release of functional groups that contain hydrogen and oxygen.


title: Biochar

text: Production temperatures influence biochar properties in several ways. The molecular carbon structure of the solid biochar matrix is particularly affected. Initial pyrolysis at 450–550 °C leaves an amorphous carbon structure. Temperatures above this range will result in the progressive thermochemical conversion of amorphous carbon into turbostratic graphene sheets. Biochar conductivity also increases with production temperature. Important to carbon capture, aromaticity and intrinsic recalcitrance increases with temperature.


title: Biochar

text: Biomass burning and natural decomposition releases large amounts of carbon dioxide and methane to the Earth's atmosphere. The biochar production process also releases (up to 50% of the biomass), however, the remaining carbon content becomes indefinitely stable. Biochar carbon remains in the ground for centuries, slowing the growth in atmospheric greenhouse gas levels. Simultaneously, its presence in the earth can improve water quality, increase soil fertility, raise agricultural productivity, and reduce pressure on old-growth forests.


title: Biochar

text: Biochar can sequester carbon in the soil for hundreds to thousands of years, like coal. Early works proposing the use of biochar for carbon dioxide removal to create a long-term stable carbon sink were published in the 2010s. This technique is advocated by scientists including James Hansen and James Lovelock.


title: Biochar

text: A 2010 report estimated that sustainable use of biochar could reduce the global net emissions of carbon dioxide (), methane, and nitrous oxide by up to 1.8  billion tonnes carbon dioxide equivalent (e) per year (compared to the about 50 billion tonnes emitted in 2021), without endangering food security, habitats, or soil conservation. However a 2018 study doubted enough biomass would be available to achieve significant carbon sequestration. A 2021 review estimated potential removal from 1.6 to 3.2 billion tonnes per year.


title: Biochar

text: In 2021 the cost of biochar ranged around European carbon prices, but was not yet included in the EU or UK Emissions Trading Scheme.


title: Biochar

text: In developing countries, biochar derived from improved cookstoves for home-use can contribute to lower carbon emissions if use of original cookstove is discontinued, while achieving other benefits for sustainable development.


title: Biochar

text: Biochar offers multiple soil health benefits in degraded tropical soils, but is less beneficial in temperate regions. Its porous nature is effective at retaining both water and water-soluble nutrients. Soil biologist Elaine Ingham highlighted its suitability as a habitat for beneficial soil micro organisms. She pointed out that when pre-charged with these beneficial organisms, biochar promotes good soil and plant health.


title: Biochar

text: Biochar reduces leaching of "E-coli" through sandy soils depending on application rate, feedstock, pyrolysis temperature, soil moisture content, soil texture, and surface properties of the bacteria.


title: Biochar

text: Biochar can improve water quality, reduce soil emissions of greenhouse gases, reduce nutrient leaching, reduce soil acidity, and reduce irrigation and fertilizer requirements. Under certain circumstances biochar induces plant systemic responses to foliar fungal diseases and improves plant responses to diseases caused by soilborne pathogens.


title: Biochar

text: Biochar's impacts are dependent on its properties as well as the amount applied, although knowledge about the important mechanisms and properties is limited. Biochar impact may depend on regional conditions including soil type, soil condition (depleted or healthy), temperature, and humidity. Modest additions of biochar reduce nitrous oxide () emissions by up to 80% and eliminate methane emissions, which are both more potent greenhouse gases than .


title: Biochar

text: Studies reported positive effects from biochar on crop production in degraded and nutrient–poor soils. The application of compost and biochar under FP7 project FERTIPLUS had positive effects on soil humidity, crop productivity and quality in multiple countries. Biochar can be adapted with specific qualities to target distinct soil properties. In Colombian savanna soil, biochar reduced leaching of critical nutrients, created a higher nutrient uptake, and provided greater nutrient availability. At 10% levels biochar reduced contaminant levels in plants by up to 80%, while reducing chlordane and DDX content in the plants by 68 and 79%, respectively. However, because of its high adsorption capacity, biochar may reduce pesticide efficacy. High-surface-area biochars may be particularly problematic.


title: Biochar

text: Biochar may be ploughed into soils in crop fields to enhance their fertility and stability, and for medium- to long-term carbon sequestration in these soils. It has meant a remarkable improvement in tropical soils showing positive effects in increasing soil fertility and in improving disease resistance in West European soils. The use of biochar as a feed additive can be a way to apply biochar to pastures and to reduce methane emissions.


title: Biochar

text: Application rates of appear to be required to produce significant improvements in plant yields. Biochar costs in developed countries vary from $300–7000/tonne, generally impractical for the farmer/horticulturalist and prohibitive for low-input field crops. In developing countries, constraints on agricultural biochar relate more to biomass availability and production time. A compromise is to use small amounts of biochar in lower cost biochar-fertilizer complexes.


title: Biochar

text: Switching from "slash-and-burn" to "slash-and-char" farming techniques in Brazil can decrease both deforestation of the Amazon basin and carbon dioxide emission, as well as increase crop yields. Slash-and-burn leaves only 3% of the carbon from the organic material in the soil. Slash-and-char can retain up to 50%. Biochar reduces the need for nitrogen fertilizers, thereby reducing cost and emissions from fertilizer production and transport. Additionally, by improving soil's till-ability, its fertility and its productivity, biochar-enhanced soils can indefinitely sustain agricultural production, whereas slash/ burn soils quickly become depleted of nutrients, forcing farmers to abandon the fields, producing a continuous slash and burn cycle. Using pyrolysis to produce bio-energy does not require infrastructure changes the way, for example, processing biomass for cellulosic ethanol does. Additionally, biochar can be applied by the widely used machinery.


title: Biochar

text: Biochar is hygroscopic due to its porous structure and high specific surface area. As a result, fertilizer and other nutrients are retained for plants' benefit.


title: Biochar

text: Doug Pow, a Western Australian farmer, explored the use of biochar mixed with molasses as stock fodder. He asserted that in ruminants, biochar can assist digestion and reduce methane production. He also used dung beetles to work the resulting biochar-infused dung into the soil without using machinery. The nitrogen and carbon in the dung were both incorporated into the soil rather than staying on the soil surface, reducing the production of nitrous oxide and carbon dioxide. The nitrogen and carbon added to soil fertility. On-farm evidence indicates that the fodder led to improvements of liveweight gain in Angus-cross cattle.


title: Biochar

text: Doug Pow won the Australian Government Innovation in Agriculture Land Management Award at the 2019 Western Australian Landcare Awards for this innovation. Pow's work led to two further trials on dairy cattle, yielding reduced odour and increased milk production.


title: Biochar

text: Research into aspects involving pyrolysis/biochar is underway around the world, but was still in its infancy. From 2005 to 2012, 1,038 articles included the word "biochar" or "bio-char" in the topic indexed in the ISI Web of Science. Research is in progress by Cornell University, University of Edinburgh (which has a dedicated research unit), University of Georgia, the Agricultural Research Organization (ARO) of Israel, Volcani Center, and University of Delaware.


title: Biochar

text: Long-term effects of biochar on carbon sequestration has been examined using soil from arable fields in Belgium with charcoal-enriched black spots dating from before 1870 from charcoal production mound kilns. Topsoils from these 'black spots' had a higher organic C concentration [3.6 ± 0.9% organic carbon (OC)] than adjacent soils outside these black spots (2.1 ± 0.2% OC). The soils had been cropped with maize for at least 12 years which provided a continuous input of C with a C isotope signature (δ13C) −13.1, distinct from the δ13C of soil organic carbon (−27.4 ‰) and charcoal (−25.7 ‰) collected in the surrounding area. The isotope signatures in the soil revealed that maize-derived C concentration was significantly higher in charcoal-amended samples ('black spots') than in adjacent unamended ones (0.44% vs. 0.31%; p = 0.02). Topsoils were subsequently collected as a gradient across two 'black spots' along with corresponding adjacent soils outside these black spots and soil respiration, and physical soil fractionation was conducted. Total soil respiration (130 days) was unaffected by charcoal, but the maize-derived C respiration per unit maize-derived OC in soil significantly decreased about half (p < 0.02) with increasing charcoal-derived C in soil. Maize-derived C was proportionally present more in protected soil aggregates in the presence of charcoal. The lower specific mineralization and increased C sequestration of recent C with charcoal are attributed to a combination of physical protection, C saturation of microbial communities and, potentially, slightly higher annual primary production. Overall, this study evidences the capacity of biochar to enhance C sequestration through reduced C turnover.


title: Biochar

text: Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. Laboratory studies have evidenced effects of biochar on C-mineralization using signatures.


title: Biochar

text: Fluorescence analysis of biochar-amended soil dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-carbon in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-carbon in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar. The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. These finding suggested that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.


title: Biochar

text: Research and practical investigations into the potential of biochar for coarse soils in semi-arid and degraded ecosystems are ongoing. In Namibia biochar is under exploration as climate change adaptation effort, strengthening local communities' drought resilience and food security through the local production and application of biochar from abundant encroacher biomass.


title: Biochar

text: In recent years, biochar has attracted interest as a wastewater filtration medium as well as for its adsorbing capacity for the wastewater pollutants.


title: DEET

text: "N","N"-Diethyl-"meta"-toluamide, also called DEET () or diethyltoluamide, is the most common active ingredient in insect repellents. It is a slightly yellow oil intended to be applied to the skin or to clothing and provides protection against mosquitoes, flies, ticks, fleas, chiggers, leeches and many biting insects.


title: DEET

text: DEET was developed in 1944 by Samuel Gertler of the United States Department of Agriculture for use by the United States Army, following its experience of jungle warfare during World War II. It was originally tested as a pesticide on farm fields, and entered military use in 1946 and civilian use in 1957. It was used in Vietnam and Southeast Asia.


title: DEET

text: In its original form, known as "bug juice", the application solution was composed of 75% DEET and 25% ethanol. Later, a new version of the repellent was developed by the U.S. Army and the USDA. This formulation consisted of DEET and a mixture of polymers that extended its release and reduced its evaporation rate. This extended-release application was registered by the Environmental Protection Agency in 1991.


title: DEET

text: A slightly yellow liquid at room temperature, it can be prepared by converting "m"-toluic acid (3-methylbenzoic acid) to the corresponding acyl chloride using thionyl chloride (SOCl), and then allowing that product to react with diethylamine:


title: DEET

text: DEET is an extremely effective insect repellant, the most effective available. It is effective against a variety of invertebrates, including ticks, flies, mosquitos, and some parasitic worms. DEET is suspected to affect two pathways in mosquitos: it affects odorant receptors at a distance, and it affects chemoreceptors upon contact. The exact mechanisms are still being researched, but the two most likely hypotheses are the "smell and avoid hypothesis" (that DEET has an unpleasant odor to insects), and the "confusant hypothesis" (that smelling DEET confuses insects).


title: DEET

text: The concentration of DEET in products may range from less than 10 percent to nearly 100 percent. Concentrations of 10 to 30 percent are recommended for infants and children. DEET should not be used on children under 2 months of age.


title: DEET

text: DEET is often sold and used in spray or lotion in concentrations up to 100%. "Consumer Reports" found a direct correlation between DEET concentration and hours of protection against insect bites. 100% DEET was found to offer up to 12 hours of protection while several lower concentration DEET formulations (20–34%) offered 3–6 hours of protection. Other research has corroborated the effectiveness of DEET. The Centers for Disease Control and Prevention recommends 30–50% DEET to prevent the spread of pathogens carried by insects.


title: DEET

text: A 2008 study found that higher concentrations of DEET have an improved ability to repel insects through fabric.


title: DEET

text: As a precaution, manufacturers advise that DEET products should not be used under clothing or on damaged skin, and that preparations be washed off after they are no longer needed or between applications. DEET can act as an irritant; in rare cases, it may cause severe epidermal reactions. Other symptoms that can occur are breathing difficulty, burning eyes, or headaches.


title: DEET

text: ... this repellent has been subjected to more scientific and toxicologic scrutiny than any other repellent substance. ... DEET has a remarkable safety profile after 40 years of use and nearly 8 billion human applications. Fewer than 50 cases of serious toxic effects have been documented in ... medical literature since 1960 ... Many of these cases of toxic effects involved long-term, heavy, frequent, or whole-body application of DEET. No correlation has been found between the concentration of DEET used and the risk of toxic effects. ... When applied with common sense, DEET-based repellents can be expected to provide a safe as well as a long-lasting repellent effect ... under circumstances in which it is crucial to be protected against arthropod bites that might transmit disease.


title: DEET

text: When DEET is used in combination with insecticides for cockroaches it can strengthen the toxicity of carbamate, an acetylcholinesterase inhibitor. These 1996 findings indicate that DEET has neurological effects on insects in addition to known olfactory effects, and that its toxicity is strengthened in combination with other insecticides.


title: DEET

text: In the DEET Reregistration Eligibility Decision (RED) in 1998, the United States Environmental Protection Agency (EPA) reported 14 to 46 cases of potential DEET-associated seizures, including four deaths. The EPA states: "... it does appear that some cases are likely related to DEET toxicity," which may underreport the risk as physicians may fail to check for history of DEET use or fail to report cases of seizure subsequent to DEET use.


title: DEET

text: In 1997, the Pesticide Information Project of Cooperative Extension Offices of Cornell University stated that "Everglades National Park employees having extensive DEET exposure were more likely to have insomnia, mood disturbances and impaired cognitive function than lesser exposed co-workers".


title: DEET

text: When used as directed, products containing between 10% and 30% DEET have been found by the American Academy of Pediatrics to be safe to use on children, as well as adults, but the Academy recommends that DEET not be used on infants less than two months old.


title: DEET

text: Citing human health reasons, Health Canada barred the sale of insect repellents for human use that contained more than 30% DEET in a 2002 re-evaluation "based on a human health risk assessment that considered daily application of DEET over a prolonged period of time". The agency recommended that DEET-based products be used on children between the ages of 2 and 12 only if the concentration of DEET is 10% or less and that repellents be applied no more than 3 times a day, children under 2 should not receive more than 1 application of repellent in a day and DEET-based products of any concentration should not be used on infants under 6 months. Some experts recommend against applying DEET and sunscreen simultaneously since that would increase DEET penetration; Xiaochen Gu, a professor at the University of Manitoba’s faculty of Pharmacy who led a study about mosquitos, advises that DEET should be applied 30 or more minutes later.


title: DEET

text: A 2020 study performed by students within the University of Florida's College of Public Health and Health Professions analyzed data from the National Health and Nutrition Examination Survey and identified 1,205 participants who had "DEET metabolic levels recorded at or above detection limits". They analyzed biomarkers related to systemic inflammation, immune, liver, and kidney functions, and found no "evidence that DEET exposure has any impact on the biomarkers identified."


title: DEET

text: DEET may be measured in blood, plasma, or urine by gas or liquid chromatography-mass spectrometry to confirm a diagnosis of poisoning in hospitalized patients or to provide evidence in a medicolegal death investigation. Blood or plasma DEET concentrations are expected to be in a range of 0.3–3.0 mg/L during the first 8 hours after dermal application in persons using the chemical appropriately, >6 mg/L in intoxicated patients and >100 mg/L in victims of acute intentional oral overdose.


title: DEET

text: DEET is an effective solvent, and may dissolve some watch crystals, plastics, rayon, spandex, other synthetic fabrics, and painted or varnished surfaces including nail polish. It also may act as a plasticizer by remaining inside some formerly hard plastics, leaving them softened and more flexible. DEET is incompatible with rayon, acetate, or dynel clothing.


title: DEET

text: Though DEET is not expected to bioaccumulate, it has been found to have a slight toxicity for fresh-water fish such as rainbow trout and tilapia, and it also has been shown to be toxic for some species of freshwater zooplankton. DEET has been detected at low concentrations in water bodies as a result of production and use, such as in the Mississippi River and its tributaries, where a 1991 study detected levels varying from 5 to 201 ng/L.


title: DEET

text: A 1975 study analyzed the effects of DEET on communities of freshwater organisms native to Chinese waterways and found that compared to other commercial insect repellants, DEET was moderately toxic to aquatic organisms. The most-at-risk organisms were algae colonies which often experienced "significant biomass decline and community composition shift[s]" when exposed to DEET at 500 ng/L.<ref name="pmidhttps://doi.org/10.1016/j.ecoenv.2019.109881"> </ref>


title: Cricket field

text: A cricket field is a large grass field on which the game of cricket is played. Although generally oval in shape, there is a wide variety within this: some are almost perfect circles, some elongated ovals and some entirely irregular shapes with little or no symmetry – but they will have entirely curved boundaries, almost without exception. There are no fixed dimensions for the field but its diameter usually varies between 450 feet (137 m) and 500 feet (150 m) for men's cricket, and between and for women's cricket. Cricket is unusual among major sports (along with golf, Australian rules football and baseball) in that there is no official rule for a fixed-shape ground for professional games. On most grounds, a rope demarcates the perimeter of the field and is known as the "boundary".


title: Cricket field

text: Within the boundary and generally as close to the centre as possible will be the "square" which is an area of carefully prepared grass upon which cricket pitches can be prepared and marked for the matches. The pitch is where batsmen hit the bowled ball and run between the wickets to score runs, while the fielding team tries to return the ball to either wicket to prevent this.


title: Cricket field

text: The ICC Standard Playing Conditions define the minimum and maximum size of the playing surface for international matches. Law 19.1.3 of ICC Men's Test Match Playing Conditions as well as ICC Men's One Day International Playing Conditions states: 19.1.3 The aim shall be to maximise the size of the playing area at each venue. With respect to the size of the boundaries, no boundary shall be longer than 90 yards (82.29 metres), and no boundary should be shorter than 65 yards (59.43 metres) from the centre of the pitch to be used.The equivalent ICC playing conditions (Law 19.1.3) for international women's cricket require the boundary to be between and from the centre of the pitch to be used.


title: Cricket field

text: In addition, the conditions require a minimum three-yard gap between the "rope" and the surrounding fencing or advertising boards. This allows players to dive without risk of injury.


title: Cricket field

text: The conditions contain a grandfather clause, which exempts stadiums built before October 2007. However, most stadiums which regularly host international games easily meet the minimum dimensions.


title: Cricket field

text: A typical Test match stadium would be larger than these defined minimums, with over of grass (having a straight boundary of about 80m). In contrast an association football field needs only about of grass, and an Olympic stadium would contain of grass within its 400m running track, making it difficult to play international cricket in stadiums not built for the purpose. Nevertheless, Stadium Australia which hosted the Sydney Olympics in 2000 had its running track turfed over with 30,000 seats removed to make it possible to play cricket there, at a cost of A$80 million. This is one of the reasons cricket games generally cannot be hosted outside the traditional cricket-playing countries, and a few non-Test nations like Canada, the UAE and Kenya that have built Test standard stadiums.


title: Cricket field

text: Most of the action takes place in the centre of this ground, on a rectangular clay strip usually with short grass called the pitch. The pitch measures (1 chain) long.


title: Cricket field

text: At each end of the pitch three upright wooden stakes, called the stumps, are hammered into the ground. Two wooden crosspieces, known as the bails, sit in grooves atop the stumps, linking each to its neighbour. Each set of three stumps and two bails is collectively known as a wicket. One end of the pitch is designated the "batting end" where the batsman stands and the other is designated the "bowling end" where the bowler runs in to bowl. The area of the field on the side of the line joining the wickets where the batsman holds his bat (the right-hand side for a right-handed batsman, the left for a left-hander) is known as the off side, the other as the leg side or on side.


title: Cricket field

text: Lines drawn or painted on the pitch are known as creases. Creases are used to adjudicate the dismissals of batsmen, by indicating where the batsmen's grounds are, and to determine whether a delivery is fair.


title: Cricket field

text: For limited overs cricket matches, there are two additional field markings to define areas relating to fielding restrictions. The "circle" or "fielding circle" is an oval described by drawing a semicircle of 30 yards (27.4 m) radius from the centre of each wicket with respect to the breadth of the pitch and joining them with lines parallel, 30 yards (27.4 m) to the length of the pitch. This divides the field into an infield and outfield and can be marked by a painted line or evenly spaced discs. The close-infield is defined by a circle of radius 15 yards (13.7 m), centred at middle stump guard on the popping crease at the end of the wicket, and is often marked by dots.


title: Bettany Hughes

text: Bettany Mary Hughes (born May 1967) is an English historian, author and broadcaster, specialising in classical history. Her published books cover classical antiquity and myth, and the history of Istanbul. She is active in efforts to encourage the teaching of the classics in UK state schools. Hughes was appointed OBE in 2019.


title: Bettany Hughes

text: Hughes was raised in West London. She is the daughter of the actor Peter Hughes, and the sister of the cricketer and journalist Simon Hughes. She was educated at Notting Hill and Ealing High School in Ealing, and at St Hilda's College, Oxford, where she graduated with a degree in ancient and modern history.


title: Bettany Hughes

text: She is a visiting research fellow at King's College London, formerly a tutor for Cambridge University's Institute of Continuing Education, and an honorary fellow at Cardiff University.


title: Bettany Hughes

text: Hughes has written and presented many documentary films and series on both ancient and modern subjects. In 2009, she was awarded the Naomi Sargant Special Award for excellence in educational broadcasting, and in 2012 she was awarded the Norton Medlicott Award for services to history by the Historical Association, of which she is an honorary fellow.


title: Bettany Hughes

text: In 2010 she gave the Hellenic Institute's Tenth Annual lecture "Ta Erotika: The Things of Love", and in 2011 gave the Royal Television Society's Huw Wheldon Memorial Lecture, in which she argued that history on television is thriving and enjoying a new golden age. In 2011 she chaired the Orange Prize for Fiction, the UK's only annual book award for fiction written by women.


title: Bettany Hughes

text: Hughes is a patron of The Iris Project, a charity that promotes the teaching of Latin and Greek in UK state schools. She is an honorary patron of Classics For All, a national campaign to get classical languages and the study of ancient civilisations back into state schools. She is an advisor to the Foundation for Science, Technology and Civilisation which aims to foster large-scale collaborative projects between East and West.


title: Bettany Hughes

text: She was elected as a Fellow of the Society of Antiquaries of London (FSA) on 3 March 2017. She was appointed Officer of the Order of the British Empire (OBE) in the 2019 Birthday Honours for services to history.


title: Bettany Hughes

text: Hughes is a vegetarian. In 2016, she delivered the British Humanist Association's annual Voltaire Lecture.


title: Bettany Hughes

text: "The Hemlock Cup" was included in The New York Times Bestseller List. It was chosen as Book of the Year by "The Daily Telegraph", and it was featured as a "Book of the Week" on BBC Radio 4. It was shortlisted for a Writer's Guild Award.


title: Bettany Hughes

text: "Istanbul" was reviewed by "The New York Review of Books" and was shortlisted for the Runciman Award in 2018.


title: Bogosort

text: In computer science, bogosort (also known as permutation sort, stupid sort, slowsort or bozosort) is a sorting algorithm based on the generate and test paradigm. The function successively generates permutations of its input until it finds one that is sorted. It is not considered useful for sorting, but may be used for educational purposes, to contrast it with more efficient algorithms.


title: Bogosort

text: Two versions of this algorithm exist: a deterministic version that enumerates all permutations until it hits a sorted one, and a randomized version that randomly permutes its input. An analogy for the working of the latter version is to sort a deck of cards by throwing the deck into the air, picking the cards up at random, and repeating the process until the deck is sorted. Its name is a portmanteau of the words "bogus" and "sort".


title: Bogosort

text: This code assumes that is a simple, mutable, array-like data structure—like Python's built-in —whose elements can be compared without issue.


title: Bogosort

text: If all elements to be sorted are distinct, the expected number of comparisons performed in the average case by randomized bogosort is asymptotically equivalent to , and the expected number of swaps in the average case equals . The expected number of swaps grows faster than the expected number of comparisons, because if the elements are not in order, this will usually be discovered after only a few comparisons, no matter how many elements there are; but the work of shuffling the collection is proportional to its size. In the worst case, the number of comparisons and swaps are both unbounded, for the same reason that a tossed coin might turn up heads any number of times in a row.


title: Bogosort

text: The best case occurs if the list as given is already sorted; in this case the expected number of comparisons is , and no swaps at all are carried out.


title: Bogosort

text: For any collection of fixed size, the expected running time of the algorithm is finite for much the same reason that the infinite monkey theorem holds: there is some probability of getting the right permutation, so given an unbounded number of tries it will almost surely eventually be chosen.


title: Cambridge United F.C.

text: Cambridge United Football Club is a professional association football club based in the city of Cambridge, England. They compete in EFL League One, the third tier of the English football league system. The club is based at the Abbey Stadium on Newmarket Road, approximately east of Cambridge city centre. The stadium has a capacity of 8,127, made up of terracing and seated areas.


title: Cambridge United F.C.

text: The club was founded in 1912 as Abbey United, and took the name Cambridge United in 1951. They played in local amateur leagues before joining the Southern League after finishing as runners-up of the Eastern Counties League in 1957–58. Under Bill Leivers's stewardship they were crowned Southern League Premier Division champions in 1968–69 and 1969–70, which helped to secure their election into the Football League in 1970. They won promotion out of the Fourth Division in 1972–73, but suffered immediate relegation. They won the Fourth Division title in 1976–77, and then secured promotion out of the Third Division the following season. They remained in the Second Division for six seasons, before they suffered consecutive relegations.


title: Cambridge United F.C.

text: Manager John Beck led United to promotion out of the Fourth Division via play-offs in 1990 and then the Third Division title in 1990–91, with the club reaching the Second Division play-offs the following season. Two relegations in three years left Cambridge United back in the fourth tier, before promotion was secured at the end of the 1998–99 campaign. They entered the Conference in 2005, after two relegations in four seasons, where they remained for nine seasons. They finished as Conference runners-up three times, being beaten in the play-off finals in 2008 and 2009, before eventually securing promotion after winning the 2014 play-off final. After spending seven seasons in League Two, Cambridge United were promoted to League One as runners-up under Mark Bonner.


title: Cambridge United F.C.

text: Although the club has traditionally worn amber and black at home, it has experimented with a number of designs of shirts including plain amber with black trim, amber and black squares, stripes and, amber with a black sash. The club had close links with Cambridge Regional College, a team that operated as a de facto reserve team between 2006 and 2014. The Cambridge United Community Trust perform a lot of charity work in the local community.


title: Cambridge United F.C.

text: The club was founded in 1912 as Abbey United, named after the Abbey district of Cambridge. A club called Cambridge United existed in Cambridge from 1909, but it was not linked to the club that exists today. The club played in local amateur leagues for many of its early years, moving from ground to ground around Cambridge (see Stadium below) before settling at the Abbey Stadium. In 1949 the club turned professional, and changed its name to Cambridge United in 1951. They played in the Eastern Counties League until finishing as runners-up in 1957–58, which saw them promoted to the Southern League. Three years later, Cambridge United reached the Premier Division of the Southern League.


title: Cambridge United F.C.

text: After election to the Football League in 1970, to replace Bradford (Park Avenue), the club was promoted from the Fourth Division after three seasons, but went straight back down.


title: Cambridge United F.C.

text: Following the appointment of Ron Atkinson as manager, Cambridge United won successive promotions which took them into the Second Division in 1978 – a mere eight years after joining the Football League. Atkinson had gone to West Bromwich Albion, a First Division club, in January 1978, and was succeeded by John Docherty, who oversaw the second promotion.


title: Cambridge United F.C.

text: Cambridge United peaked at eighth place in the Second Division in 1980. However, a terrible season in 1983–84 (setting a league record for most successive games without a win, 31, which was surpassed by Derby County in 2008) was followed by a further relegation in 1984–85 (equalling the then league record for most losses in a season, 33). These successive relegations, which also had a negative effect on the club's attendances as well as its finances, placed Cambridge United back in the Fourth Division, the lowest professional league in English football at the time. They had to apply for re-election in their first season back in the Fourth Division, and promotion would not be achieved for another four years.


title: Cambridge United F.C.

text: The early 1990s was the U's most successful period. Soon after the appointment of new manager John Beck, the club won the first ever appearance as a professional club at Wembley Stadium, the Fourth Division playoff final in May 1990, which secured promotion to the Third Division – the club's first promotion for 12 years. Dion Dublin scored the only goal in a game against Chesterfield. Under Beck, United gained promotion from the Fourth Division and had already reached the FA Cup quarter finals in 1990, and reached them again a year later, and winning the Third Division in 1991. United reached the play-offs in 1992, after finishing 5th in the Second Division, but failed in their bid to become founder members of the Premier League. This was the club's highest final league placing to date. The following season the club sacked John Beck and were relegated from the new First Division. Further relegation followed two seasons later. United returned to Division Two but were relegated in 2002 despite a successful run in the Football League Trophy which saw them reach the final which they lost 1–4 to Blackpool at the Millennium Stadium in Cardiff.


title: Cambridge United F.C.

text: In 2005, after 35 years in the Football League, Cambridge United were relegated into the Football Conference. This brought with it financial difficulties and the club filed for administration on 29 April. On 22 July 2005 the club came out of administration with a deal being struck with HM Revenue and Customs at the eleventh hour after the intervention of then sports minister Richard Caborn. Cambridge had sold their Abbey Stadium home earlier in the season for £1.9 million to keep the club afloat.


title: Cambridge United F.C.

text: On the eve of the 2006–07 season, it was announced that former Norwich City striker Lee Power would be the club's new chairman taking over from Brian Attmore's caretaking reign. Johnny Hon was also to rejoin the board as vice-chairman after John Howard's resignation on conflict of interests grounds (owing to his ownership of Bideawhile 445 Ltd, United's landlords). Jimmy Quinn was appointed manager soon after Power took charge and, after a difficult settling-in period which included a humiliating 5–0 loss to local rivals Histon, he guided Cambridge United away from another possible relegation by achieving five wins from their last seven games of the season.


title: Cambridge United F.C.

text: After signing several respected and experienced players at the non-league level in the following close season Quinn led Cambridge to their then longest ever unbeaten start to a season (2007–08), which stretched to twelve games. Off the field, United reported several major sponsorship deals which seemed to point towards increased financial security. Halfway through the season the chairman, Lee Power, resigned. He was replaced by Wayne Purser. United finished the season in 2nd place, qualifying for the play-offs. They beat Burton Albion in the semi-final, 4–3 on aggregate, but lost 1–0 to Exeter City in the final, played at Wembley Stadium.


title: Cambridge United F.C.

text: Following the play-off defeat many players left the club, culminating in the departure of manager Jimmy Quinn. Quinn was succeeded by former Southport manager Gary Brabin, who appointed Paul Carden as player-assistant manager. United finished the 2008–09 season again 2nd in the league, and also again reached the play-off final, overturning a 3–1 deficit to beat Stevenage Borough 4–3 on aggregate in the semi-final; however, they were beaten again at Wembley Stadium, 2–0 by Torquay United. Brabin was named as the Conference's Manager of the Season, but was sacked in the close-season after reportedly falling out with the chairman. He was replaced by Martin Ling, who resigned just eight days into the job, before the start of the 2009–10 season and was followed days later by chairman George Rolls. The new board re-appointed Ling as manager the following week.


title: Cambridge United F.C.

text: Cambridge finished Ling's first season in 10th place – not enough for a playoff place. The following season, on 6 January 2011, with Cambridge in a similar position to where they finished the previous season, the club's owners put the club up for sale citing the need for new funds to take the club forward. Despite interest being expressed from a number of parties, no new owner has yet been found. Later the same month, the club's landlords Grosvenor Group revealed the plans for a new community stadium, including potential new locations both within the city and outside it. At the start of 2011 Martin Ling was removed from his position as manager and replaced on a temporary basis by CRC manager Jez George. He managed to steer the club towards safety, finishing 17th, which led to George's role being made permanent. After having rebuilt the squad with players from the club's youth system and with astute signings in Harrison Dunk and Tom Shaw, George managed to lead Cambridge to a 9th-place finish, a huge improvement on their previous season. As well as the league, Jez George also took Cambridge to the quarter-final of the FA Trophy (which was the furthest they had reached at the time), but lost 2–1 at home to minnows, Wealdstone. Eleven games into the following season Jez George became Director of Football, and Richard Money was announced as the new head coach of the club. The club spent much of the season in mid-table, finishing in 14th position with 59 points. The squad was greatly revamped, and United started 2013–14 with a record-breaking 16 games unbeaten. Cambridge finished the season in second place, qualifying for the play-offs. After beating FC Halifax Town 2–1, on aggregate, in the semi-final, they won 2–1 against Gateshead in the final, held at Wembley Stadium, gaining promotion back to the Football League after a nine-year absence. The club also reached their first FA Trophy final, held at Wembley Stadium, where they beat Gosport Borough 4–0.