A 60-year-old German bomb from the second World War weighing 500kg was safely detonated off the coast of northwest England yesterday after being found in a routine operation by a Royal Navy minesweeper in the mouth of the River Mersey.
The find prompted an immediate safety alert and two Irish Sea ferries, the Mersey Viking and Dublin Viking, with more than 250 passengers and crew on board, were ordered to stop. They were held at the Mersey Bar for five hours before being allowed to dock at Birkenhead.
The bomb, designed to penetrate fortified docks, submarine pens and concrete slipways, was found in mud in the Mersey near Morpeth Dock at Birkenhead opposite the port of Liverpool.
It is thought to be one of about 20,000 dropped by the German air force on the port of Liverpool during the second World War and might have been disturbed during dredging work in connection with the Twelve Quays Irish Sea ferry terminal.
The bomb's discovery led to the closure of the busy Wallasey tunnel for almost an hour during the rush hour, with traffic diverted to the Birkenhead tunnel. A rail tunnel under the Mersey was also closed.
A Royal Navy diver attached a lifting bag to the device at low tide and raised it to within three metres of the surface.
A navy inflatable boat towed the bomb out into the Irish Sea but paused off Crosby to allow the two ferries and five merchant ships to pass. The journey then continued off Formby where the bomb was detonated after plastic explosives had been attached.