Swinoujscie, Poland The following is an update to an article featured in our September UXO E-Newsletter.
Hundreds of residents were evacuated as Polish military divers began a delicate operation to deactivate a massive WWII bomb in a channel near the Baltic Sea. The five-ton device, nicknamed "Tallboy" and also known as an "earthquake bomb," was dropped by the Royal Air Force in an attack on a Nazi warship in 1945.
The ordnance was discovered last year during dredging operations near the port city of Swinoujscie in the far northwest of Poland. The area was part of Germany during the war.
According to Grzegorz Lewandowski, a spokesman for the Polish Navy's 8th Coastal Defence Flotilla based in Swinoujscie, "It's a world first. Nobody has ever defused a Tallboy that is so well preserved and underwater."
The operation, which is expected to take a week to complete, will be a slow process as only one diver at a time is allowed to work on the bomb because of the risks. According to Lewandowski, "The first two or three days will be preparations. Our bomb disposal divers will scrape around the bomb, which is embedded in the bottom of the channel at a depth of 12 meters. Only its nose is sticking out. It's a very delicate job. The tiniest vibration could detonate the bomb."
A controlled explosion has been ruled out for fear of destroying a bridge some 500 meters away. Instead, navy divers will use a technique known as deflagration to burn the explosive charge without causing a detonation, using a remotely controlled device to pierce through the shell.
The bomb is 19 feet long and contains 2.4 tons of explosives, equivalent to around 3.6 tons of TNT. Tallboys were designed to explode underground next to a target, triggering shock waves that would cause destruction.