A report describing how a secret weapons testing site lost warheads off the coast of Kewstoke can finally be revealed.

St Thomas' Head, near Sand Bay, was for nearly 70 years a top secret military base, but in 2003 the site was formally decommissioned after misplacing 135kg of live ordnance the previous year.

The Underwater Shock and Explosions Trial Range at St Thomas' Head was a weapons testing site leased from the Ministry of Defence (MoD) by private defence contractor QinetiQ.

Weston Mercury: The gated entrance to the facility still bear warning signs.The gated entrance to the facility still bear warning signs. (Image: Charlie Williams)

The site saw frequent use during the Second World War when the area was used as an air gunnery and bombing range by the Department of Miscellaneous Weapons Development (DMWD).

The site also helped to conduct trials on the Barnes Wallis 'bouncing bomb', in collaboration with HMS Birnbeck and further locations in the area.

Situated on 11 acres of land leased from the National Trust, the area was vital to the development of weapons as it enjoyed the second fastest tidal range in the world along the Bristol Channel. This meant ordnance could be quickly covered and disposed of.

Weston Mercury: Post-war structures at the site still remain on the beach.Post-war structures at the site still remain on the beach. (Image: Charlie Williams)

From the 1970's onwards, the range was used to dispose of surplus munitions and ordnance.

The site ceased operations as a testing range in 2003 after an investigation detailed 'comprehensive failings' by staff at the facility.

QinetiQ vacated the site shortly following publication of the inquiry. Since then the range has been left to decay.

A Freedom of Information request submitted to the House of Lords Library can now reveal why the site was closed.

Timeline of Events

The facility planned to dispose of 40 mine demolition disposal units, 750 Swingfire missile warheads, and 5 Mk 11 depth charges at Woodspring Bay during a seven-day window between February 26 to March 5, 2002.

On March 3, a pallet of 20 warheads, eight bar mines and explosive charges was placed on the seabed for destruction the following morning.

The Officer of the Watch - responsible for disposals at the facility - inspected the bay at 3.49am and noticed one of the three pallets left on the beach was missing, but after an immediate search of the area no pallet or part pallet had been located by the team.

However, staff at the site continued with the planned destruction of the remaining 15 pallets of warheads later that day.

Weston Mercury: St Thomas' Head explosion trial, c.2000.St Thomas' Head explosion trial, c.2000. (Image: Archant)

The relevant authorities at the MoD was not informed of the loss until 4pm, this left a 12-hour window from the point staff first realised of the loss for the pallet of explosives to drift into the estuary.

At 5pm that evening, Avon and Somerset police and the coastguard at Swansea was then informed of the loss and a large-scale search operation ensued, with the help of RAF helicopters.

Search teams subsequently failed to locate the missing pallet of warheads. Further search operations were formally suspended in 2003.

Weston Mercury: Defused ordnance washed-up on the shoreline at the facility.Defused ordnance washed-up on the shoreline at the facility. (Image: Charlie Williams)

Weston Mercury: Defused ordnance washed-up at the site.Defused ordnance washed-up at the site. (Image: Charlie Williams)

The Findings

The inquiry, led by the Director Defence Ordnance Safety Group (DOSG) and the Chief Inspector of Explosives at the MoD, detailed a 'severe breakdown of communication' between MoD Shoeburyness - which commanded the site - and the St Thomas’ Head team.

Weston Mercury: The watch tower and other buildings at the test site, c.2000.The watch tower and other buildings at the test site, c.2000. (Image: Archant)


Weston Mercury: The watch tower overlooks the Severn Estuary at St Thomas' Head, c.2000.The watch tower overlooks the Severn Estuary at St Thomas' Head, c.2000. (Image: Archant)

The report said there was 'confusion' regarding the authority to detonate large-scale explosives at the facility, stating that 'at no time was there any authority for the ensuing full-scale demolition programme to be carried out'.

The use of a wooden pallet to place the explosives and a conflict of interest between the MoD and QinetiQ through the safety manager, was also criticised by the inquiry.

It said: "Demolition was carried out without an appropriate or formally approved trials safety certificate.

"There was no permanent QinetiQ trials safety manager (QTSM) based at Weston, and the acting QTSM had only given authority for the one shot demolition trial and did not feel competent to give approval.

"St Thomas’ Head had no license for multiple, mixed round demolition programmes to be undertaken on the beach."

Weston Mercury: The watch tower foundations are some of what remain.The watch tower foundations are some of what remain. (Image: Charlie Williams)

The report attributed 'incorrect fastening' of the munition’s pallet into the clay seabed as the cause for the loss of ordnance. This had allowed the pallet to drift, forced by strong tidal currents, the morning of March 3, 2002.

The report concluded there was a 'significant and unacceptable delay in informing the appropriate authorities of the loss of munitions'.

The range safety certificate and the explosives licences for storage and processing was withdrawn from the site March 18, 2002 immediately following the incident, but it wasn’t until 2003 when the facility was formally decommissioned by the MoD.

The MoD and QinetiQ were approached for comment.