Defence Nuclear Materials are moved using the following transport means: Trident NWs are contained within PD AWG 516 packages.
These are kept on Load Transfer Platform Trolleys (LTPT) until moved by crane or put onto Truck Cargo Heavy Duty (TCHD) carriers.
[2] The TCHDs containing the weapons are escorted in a convoy of MoD vehicles commanded by a Ministry of Defence (MDP) Chief Inspector.
The convoy maintains contact by radio and telephone with Task Control, MDP Central Information Room, Wethersfield, Essex, which monitors its movement, and with the civil police force through whose area it is passing.
[7] The convoy is tracked by the Task Control, MOD Police (MDP) Central Information Room in Wethersfield, Essex and the Special Safety Cell (SSC) in Ensleigh, Bath.
The vehicles were purchased by the MOD for use in their then current role from the Royal Air Force (RAF) Nuclear Weapon Convoy Group and transferred to D NM&NARG en bloc in 2002.
MDP motorcyclists and traffic car officers make arrests and then hand over responsibility to the local Police Force.
The RAF maintains response teams at a number of bases along the flight route which are brought to immediate readiness during the transit of the aircraft through their area.
All used fuel movements are escorted by the MDP SEG, who travel in a further two rail vehicles arranged at either end of the container transporter.
Additional staff familiar with the load and capable of providing technical support during the journey, travel with the MDP SEG.
[1] Transport containers for nuclear weapons, SNM and new and used reactor fuel, provide protection from impact, mechanical stress and fire.
In the event of an incident, control passes to Ministry of Defence Nuclear Accident Response Organisation (NARO).
Defence Nuclear Material Transport Contingency Arrangements are in place in case of accidents involving DNMs.
A serious vehicle collision or an aircraft crash combined with multiple failures of the MoD's secret protective measures could mean that the weapon might not remain single-point safe.
The report puts the overall yearly risk of an "inadvertent yield" in the UK at 2.4 in a billion, mainly due to the possibility of an aircraft crashing onto a nuclear weapons road convoy.