Brake failures, vehicle breakdowns, false alarms, and map-reading errors are among dozens of safety incidents which have plagued convoys carrying nuclear weapons and military special nuclear materials on Britain's roads over the last seven years, according to documents released under the Freedom of Information Act (available to download at the bottom of this article).
70 individual safety incidents involving the convoy were recorded by the Ministry of Defence over the period between July 2007 to December 2012, according to records provided to Nukewatch by the Ministry following the request. 56 of these were classed as 'engineering incidents' and the remaining 14 as 'operational incidents'.
Convoys of Trident nuclear warheads travel by road several times each year between the Atomic Weapons Establishment in Berkshire, where they are manufactured and maintained, and the Royal Naval Armaments Depot at Coulport on Loch Long in the west of Scotland, where they are stored and loaded onto Trident submarines. Special nuclear materials – plutonium, tritium, and highly enriched uranium and components fabricated from these materials for use in the UK's nuclear weapons and submarine programmes - are also transported less frequently to and from the Atomic Weapons Establishment.
The most visible of the incidents recorded occurred on Monday 25 July 2011, when a convoy command vehicle broke down near Junction 20 of the M6 motorway in Cheshire late in the afternoon.
According to the convoy commander's report, the vehicle “suffered a sudden and dramatic loss of power and was forced to pull onto the hard shoulder of the motorway together with the rest of the convoy assets”. The convoy pulled onto the hard shoulder of the motorway for repairs “causing a minor obstruction of the near-side lane”. Although the FOI papers state that the fault took just twenty minutes to repair, a post on the 'Trucknet' chat forum by a trucker who witnessed the breakdown observes that two lanes of the motorway were coned off while the repairs were underway, which “caused about 10 miles of queues”.
The cause of the incident “proved to be somewhat of a mystery” because, although a fuel system failure was suspected as having caused the problem, “the vehicle had been filled prior to the operation and there was no sign of leakage”. Following the incident fuel systems across the vehicle fleet were checked and rectified.
In July 2010 a convoy strayed “unintentionally off route” as the result of an error by the escort commander. Stopping the convoy and rejoining the correct route resulted in a delay of 45 minutes to the journey time. Convoys were regularly re-routed or delayed to avoid road traffic accidents, severe weather, or heavy congestion on the route ahead, and on one occasion in March 2012 a convoy was re-routed “due to proximity of low flying” at a MoD establishment.
On another occasion a fuse box failure left the tractor unit of one warhead carrier truck unusable, requiring a spare unit to be used to complete the journey, and on another occasion the spare tractor itself broke down.
Recurring problems with warhead carrier trailer heat monitor alarms, which were triggered four times on false alerts between September 2011 and December 2012, resulted in the alarm system software needing an upgrade, and problems with ageing vehicle location systems on the warhead carriers also required installation of a replacement system.
As well as trucks carrying the warheads themselves, vehicles in the convoy security escort also suffered problems. In June 2012 a convoy was halted to investigate a “suspension system defect” in one of the armoured escort vehicles which accompany the warhead carriers. During the unplanned stop a manhole cover collapsed underneath a second escort vehicle, requiring a vehicle safety check. During a convoy run in January 2012 a gun port flap on a convoy escort vehicle “opened inadvertently”, and during the same operation a “brake fault” was discovered on a fire tender accompanying the convoy.
Jane Tallents of Nukewatch, which monitors nuclear warhead convoys and campaigns against their risks, said: “Some of the safety incidents on the list provided by the Ministry of Defence were relatively serious and, had bad luck caused events to play out in a different way, could have resulted in harm to motorists or the convoy crew or damage to the deadly cargo being carried by the convoy.
“It only takes a moment's though to see that, far from being a benign ‘insurance policy’ which keeps the public safe, nuclear weapons actually increase the risks that we all face.
“The Ministry of Defence should not be moving nuclear weapons around the country if it can't guarantee to do so safely.”
Read the Ministry of Defence documents about convoy mishaps here: