The HMS Royal Oak, a 600ft long 29,000 ton battleship, was torpedoed and sunk by a German U-boat just six weeks into World War II (October 1939), with the loss of 833 lives. Since then, the vessel has remained a war grave upturned on her starboard side at the bottom of the Scapa Flow in Orkney, Scotland, in up to 30 metres of water. In recent years, the rate of seepage of the diesel oil on board had increased, giving rise to environmental and safety concerns.

On UK Ministry of Defence (MOD) orders oil from the first outer hull was successfully extracted, leaving diesel oil still to be removed from the inner hull.

The equipment to extract the oil was designed and manufactured Briggs in conjunction with S&MO (MoD Salvage & Marine Operations) it is based on Hot Tapping technology and techniques, a 2,000 bar Zone II diesel-driven jetting unit complete with standard abrasive water-cutting equipment allows its specialist operators to cut into the hull of the vessel and remove furnace oil from the bunker tanks. MoD divers deploy the equipment and use cameras fitted on their helmets and an ROV to monitor and record operations.

The special operations team is supported by Briggs Marines dive support vessels; the MV Cameron together with the MV Guardwell and MV Josine and two sullage barges. In total a quantity of 172 tonnes of oil has successfully been removed.

These annual operations have significantly helped reduce the leakage of oil from the HMS Royal Oak. The continuous programme to empty all her fuel tanks in the future should ensure that no more oil seeps into Scapa Flow, protecting its environmentally vulnerable waters from further pollution.