Royal Navy blows up bomb which shut London City Airport

Former Royal Navy Lt Cdr David Welch said German bombs are more dangerous than present-day explosives as they are an ‘unknown danger’ to bomb squads. 

Mr Welch said: ‘British and German bombs are more dangerous now than when they were first dropped, these items have been armed.

‘It is what we call blind because it has not functioned as intended but it is perfectly functional.

‘We never find a bomb which no longer has the oomph it did when it was dropped.

‘The danger it is presenting is unknown, but it’s not going to go off on its own, you have to do something to it, if you do not touch it, it won’t go off.

‘The Navy tend to drag them out by hand and put a strap around it and relocate it out to a safer area.

‘Water has a great dampening effect to the fragmentation.

‘So being underwater is far better than someone’s garden, but still at the bottom of the Thames you are going to get a fairly hefty noise and spray but not too much fragmentation.

‘Windows that are nearby could be broken and as it’s on the seabed there is a risk of ground shock.

‘They are moving it because of all the associated risks.’ 

Mr Welch added: ‘It’s still quite big, the 7/7 bombs were 5kg so it is bigger than those.

‘It’s quite a straight forward process, we do these about 20 or 30 times a year and the military do it quite a lot, it is one of those things where knowledge is definitely power.

‘It can still bite you if you do not act in an appropriate way and you could do something that could cause it to function.

‘But these divers can literally do it with their eyes closed.’ 

A boy retrieves an item from a rubble-strewn street after German bombing raids in the first month of the Blitz, September 1940

The Blitz began on September 7, 1940, and was the most intense bombing campaign Britain has ever seen.

Named after the German word ‘Blitzkrieg’, meaning lightning war, the Blitz claimed the lives of more than 40,000 civilians.

Between September 7, 1940, and May 21, 1941, there were major raids across the UK with more than 20,000 tonnes of explosives dropped on 16 British cities.

London was attacked 71 times and bombed by the Luftwaffe for 57 consecutive nights.

The City and the East End bore the brunt of the bombing in the capital with the course of the Thames being used to guide German bombers. Londoners came to expect heavy raids during full-moon periods and these became known as ‘bombers’moons’.

More than one million London houses were destroyed or damaged and of those who were killed in the bombing campaign, more than half of them were from London.

In addition to London’s streets, several other UK cities – targeted as hubs of the island’s industrial and military capabilities – were battered by Luftwaffe bombs including Glasgow, Liverpool, Plymouth, Cardiff, Belfast and Southampton and many more.

Deeply-buried shelters provided the most protection against a direct hit, although in 1939 the government refused to allow tube stations to be used as shelters so as not to interfere with commuter travel.

However, by the second week of heavy bombing in the Blitz the government relented and ordered the stations to be opened. Each day orderly lines of people queued until 4pm, when they were allowed to enter the stations.

Despite the blanket bombing of the capital, some landmarks remained intact – such as St Pauls Cathedral, which was virtually unharmed, despite many buildings around it being reduced to rubble.

Hitler intended to demoralise Britain before launching an invasion using his naval and ground forces. The Blitz came to an end towards the end of May 1941, when Hitler set his sights on invading the Soviet Union.