Simon Cooke, Managing Director of 6 Alpha Associates, a specialist risk company with particular expertise in the assessment and management of offshore UXO, who co-authored CIRIA’s report, speaks to PES about the extent of the UXO threat and the current risk mitigation options available to offshore developers.
Over 70 years have passed since the end of the Second World War, and the North Sea has witnessed limited warfare since. Yet the legacy left by the dropping of thousands of tonnes of bombs in two World Wars and the subsequent dumping of expired munitions is so great that the Construction Industry Research and Information Association (CIRIA) has recently announced official guidelines for marine UXO management.
In the two World Wars, naval mines were used extensively on both sides. Thousands of tonnes of mines were laid in the North Sea, at surface level or just below, ready to explode the minute an enemy vessel came into contact with them. Given the number of mines laid, inevitably a proportion of them did not detonate, eventually losing their buoyancy and sinking to the bottom of the ocean.
Unfortunately, records kept at the time didn’t manage to document the location of all the mines laid, so we can only make an educated approximation of the number and location of those left behind after VE Day. Furthermore, due to weather and seabed mobility, many of the mines whose locations may have been accurately documented, will have migrated during the seventy-year period since they were originally laid.
