Depth charge: how seabed bombs are driving offshore innovation

In May 2016 the residents of a quiet street in Oxford became the latest participants in a drama played out somewhere in the UK on an almost monthly basis: a mass evacuation triggered by the discovery of an unexploded Second World War bomb.

The incident – swiftly dealt with by experts – was the latest in an apparently growing number of similar discoveries. Last year, in London alone, more than nine wartime German bombs were discovered. Many of which were still capable of inflicting devastation on a massive scale.

And yet for every item of unexploded ordnance (UXO) that’s found on land, experts estimate that there could be tens of thousands more lying on the seabed around the UK: the explosive legacy of two world wars, decades of test-firing and dubious munitions-dumping practices that only ended in the 1990s.

For most of the 20th century this wasn’t an issue. Engineers working in the oil and gas sector would occasionally encounter the odd item, and fishing trawlers would sometimes land an unexpectedly hazardous catch, but the bottom of the sea was generally seen as the safest place for it. However, thanks to the relatively recent and rapid growth of the UK’s offshore renewables sector this is no longer the case.