The Beirut explosion which killed at least 135 people and levelled much of the Lebanese capital’s port is “unquestionably” one of the largest non-nuclear blasts in history.
According to calculations by British engineering experts from the University of Sheffield, the explosion was the equivalent of 1,000 to 1,500 tonnes of TNT – a blast intensity which would support the belief that it was caused by the detonation of 2,750 tonnes of ammonium nitrate fertiliser, calculated based on the videos and photographs which have emerged since the disaster.
This is about a tenth of the intensity of the Hiroshima nuclear bomb but far bigger than any blast from a conventional weapon.
Professor Andy Tyas, an expert on blast protection engineering at the university, said: “There are simple rules of thumb relating the maximum expansion of the fireball to the size of the original explosive charge, and from some very approximate measurements from online video footage, we think the explosion is equivalent to something of the order of 1,000 to 1,500 tonnes of TNT.
“We have also analysed video footage of the time delay between the detonation and the arrival of the shock wave at points several hundred metres from the explosion and these broadly agree with this size of charge.
“If correct, that would mean this explosion had perhaps 10 per cent of the intensity of the Hiroshima bomb.
“Whatever the precise charge size, this is unquestionably one of the largest non-nuclear explosions in history – far bigger than any conventional weapon.”
The blast appeared to have been triggered by a fire that touched off a giant quantity of ammonium nitrate fertiliser stored for years in the port, exploding with the force of a moderately strong earthquake.