The UK Ministry of Defence (MoD) has played down the significance of the recent failed test launch of a Trident II (D5) submarine-launched ballistic missile (SLBM).

The test failure, first reported by The Sun newspaper, occurred on 30 January 2024, when the nuclear-powered ballistic missile submarine HMS Vanguard tested an unarmed Trident II SLBM off the coast of Florida. It has been reported that the missile’s first-stage boosters did not ignite, leaving it to drop into the ocean nearby. The missile was supposed to have flown for around 6,000 km before entering the sea between Brazil and West Africa.

The test was intended to be the final hurdle for HMS Vanguard, one of the Royal Navy’s four SSBNs, to re-enter service following a GBP 500 million (EUR 584 million) overhaul.

UK Defence Secretary Grant Shapps, who was on board HMS Vanguard for the launch, issued a written statement to the UK Parliament on 21 February 2024 that read, “The test reaffirmed the effectiveness of the UK’s nuclear deterrent, in which the government has absolute confidence. The submarine and crew were successfully certified and will rejoin the operational cycle as planned. On this occasion an anomaly did occur, but it was event specific and there are no implications for the reliability of the wider Trident missile systems and stockpiles. Nor are there any implications for our ability to fire our nuclear weapons, should the circumstances arise in which we need to do so.”

Tobias Ellwood, the former chairman of the House of Commons Defence Committee, told GB News that the failure was caused by test equipment strapped to the missile and that “the actual rocket didn’t fire because of the testing equipment”.

However, the failed test is the second successive launch failure for UK Tridents. In 2016 another unarmed Trident II, launched from the SSBN HMS Vengeance, suffered a serious malfunction that saw it travel in the wrong direction and automatically self-destruct.

The Trident II SLBM has been the sole weapon of the UK’s nuclear deterrent since the WE.177 freefall nuclear bomb was retired from UK service in 1998.

HMS Vanguard leaving HMNB Devonport in May 2023 after a seven-and-a-half year refit. Despite a failed Trident SLBM test on 30 January 2024, UK Defence Secretary Grant Shapps stated on 21 February 2024 that the “submarine and crew were successfully certified and will rejoin the operational cycle as planned”. (Photo: Crown Copyright)