Unexploded bombs littering European coastal waters provide a dangerous new challenge for wind farm developers. PES examines all the issues surrounding this potentially explosive situation.
The seas around Europe have been martially contested for hundreds of years and such warfare, in particular the Second World War, has left a potentially lethal legacy of unexploded devices on and below the seabed. It is estimated that 10 per cent of military ordnance deployed during the Second World War did not go off. Naval mines and air delivered iron bombs present the greatest danger; they are still “live” and dangerous today and are euphemistically referred to as “Unexploded Ordnance” (UXO); Clearly, UXO may pose a potential risk to the building and maintenance of offshore renewable energy projects.
This seabed contamination includes residue from defensive barrage minefields that were not fully cleared at the end of the war, torpedoes from naval battles, artillery fired from land to sea, dumped munitions and shipwrecks – the most dangerous being the USS Richard Montgomery, which went aground on sand banks off Sheerness, UK, approximately in 1944, 17.2km due west of the Kentish Flats wind farm site. It is categorised as a dangerous wreck as although some munitions have been removed, it is estimated that there are still 1400 tonnes remaining in the vessel today.
Due to its proximity to London the Thames Estuary was heavily targeted by German bombers and naval activity during the Second World War.The principle targets for German bombing raids were the London Docks in the East End, and the key industrial areas of the Medway. However, it is known that very large numbers of bombs were dropped over the Thames Estuary, either through mistaken targeting or as a way of dumping excess munitions before returning across the North Sea. The same was also true of Allied bombers returning from missions in mainland Europe, many of which were known to dump excess munitions before landing. Furthermore, the importance of the Thames ports to allied shipping means that the outer Estuary was extensively mined by both sides. This activity, combined with aerial bombing and the activity of German U-boats also lead to the loss of shipping loaded with munitions within the Estuary.