Facts on UK’s nuclear arsenal

13 Things You Need To Know About Britain’s Nuclear Arsenal, Buzzfed, Tom Chivers, 2 Oct 15

Jeremy Corbyn’s election as Labour leader has reignited the debate about whether to replace Britain’s nuclear weapons. Here are the facts about the missiles and the submarines that launch them.

1. Next year, Britain will decide whether to build a new generation of nuclear missile submarines.

Since 1998, the only nuclear weapons Britain has are Trident intercontinental ballistic missiles aboard four Vanguard-class submarines.

The submarines are expected to be retired in 2028. In 2007, MPs voted overwhelmingly (by 409 votes to 61) to replace them; a final decision will be taken in 2016…………….

4. A 100kt bomb detonated in the air over central London would probably kill about 250,000 people, almost instantly.

That’s before taking into consideration the effects of radioactive fallout.

(Technical note: The 250,000 figure has been worked out using Nukemap, thispopulation-measuring map, and a rule of thumb that the total dead caused by a nuclear explosion is roughly equivalent to the population inside the “5psi overpressure” radius.)………

7. According to the Royal Navy, the Trident missilehas a range of 4,000 nautical miles, or 7,500km.

That means that a submarine at its base in Faslane could hit targets in Nevada, or central India.

Within two minutes of launch the missile will be travelling at 6km a second, and can reach a target at maximum range in about 20 minutes……..

9. The Trident missiles are built, and owned, by the US, although the warheads and submarines are British-built.

The US weapons manufacturer Lockheed Martin builds the missiles, and provides the technical support to keep them operational………

11. When a new prime minister is elected, they give the commanders of each of the four submarines a sealed letter, known as the letter of last resort.

These letters contain orders of what to do in the event that the government has been destroyed, and the prime minister and the “second person” have been killed or incapacitated, in a nuclear attack on Britain.

When the prime minister leaves office, their orders are destroyed unopened. No one knows what Gordon Brown, Tony Blair, or any of their predecessors wrote in their letters of last resort, and what action would have been taken if there had been an attack.

12. There are believed to be four possible versions of the orders.According to the BBC’s documentary The Human Button, the four options are: To retaliate, with nuclear weapons, against the attacking state; not to retaliate; to use the commander’s own judgment; or to place the submarine under the command of an ally, for instance the United States or Australia.

13. It has been claimed that one of the ways that a submarine commander will know if the British government has been destroyed is if BBC Radio 4 stops broadcasting for several days in a row.According to Lord (Peter) Hennessy, author of The Secret State: Whitehall and the Cold War, 1945–1970, there are several tests, but one of them is to listen for theToday programme on Radio 4’s frequencies. If it isn’t heard for some days – Hennessy says three – it is taken to be evidence that the state has been destroyed and that the letters of last resort should be opened. http://www.buzzfeed.com/tomchivers/things-you-need-to-know-about-britains-nuclear-arsenal