Source: Museum of London (see reference below).
At 6.52 pm on Friday 19 January 1917 a munitions factory exploded in Silvertown, a docklands district of east London. Fifty tonnes of TNT went up in a disaster that is still London's largest explosion. Seventy-three people were killed, 400 were injured, some critically, 900 properties (including 600 houses) were destroyed and 70,000 were damaged, including some in central London. The noise of the explosion was heard in many distant parts of southeast England. A gasometer in North Greenwich received the full force of the blast and released 200,000 m3 of gas in a massive fireball (Wikipedia 2017). Up to 1000 rescue workers were sent to the site. The explosion cost the British State £1.8 million, of which £10,173,595 was paid in compensation to third parties. Ten per cent of the compensation went to the owners of the TNT factory, who managed to restore part of the works to functionality.
The Museum of London has digitised and put on line 24 plate photographs of the damage, which were taken for insurance and litigation purposes by the contemporary photographer John H. Avery (Museum of London 2017).
This event is singular for two reasons. First, it is little known and unremembered (in London or elsewhere), even though there are two memorials to it. To be fair, London historians and some of the descendants of those who were killed did mark the centenary of the event. However, the explosion is seldom referred to in accounts of London's wartime or Edwardian history.
Of course, loss of life in civilian catastrophes that occur during war is not usually considered to be particularly newsworthy. Munitions have to be made in great haste, often by people with little training or expertise: the factory in Silvertown produced 10 tonnes of TNT a day, although with very poor risk management, according to the official enquiry into the disaster. During the First World War, about 600 people were killed in munitions factories in accidental explosions (Historic England 2017). During the Second World War, a farm was obliterated by an explosion in the English Midlands: that is to say, not merely all the buildings, but the fields as well. The incident passed almost without comment. One is put in mind of the greatest railway disaster of all time, at Balvano in southern Italy in 1944, where the death toll probably exceeded 1,000, and the event is virtually unknown (Barneschi 2005, 2014.).*
The second reason why the Silvertown explosion is worthy of comment here is because it has its centenary in the same year as that of the Halifax, Nova Scotia, ship explosion. In my earlier piece in this blog, I argued that the Halifax incident was the start of academic studies of disaster. The Silvertown event was the exact opposite. The official report into the explosion was not released to the public for almost 40 years. What a contrast!
*Since writing this, Dr Ilan Kelman has corrected me: 1,500 died when the 26 December 2004 tsunami swept a train off the tracks in Sri Lanka, so Balvano is "one of the two worst railway disasters".
The 1917 Silvertown explosion ignited about 50 tonnes of TNT. The blast, which was heard 150 km away, smashed windows up to 13 km away. The Richard Montgomery contains almost 30 times as much TNT. What would it do to the windows of the Shard and other City skyscrapers, and what would be the effect upon people at street level?
Barneschi, G. 2005. Balvano 1944: i segreti di un disastro ferroviario ignorato. Testimonianze fra cronaca e storia. 1939-1945: seconda guerra mondiale. Mursia, Milano, 290 pp.
Barneschi, G. 1914. Balvano 1944. Indagine su un disastro rimosso. Edizione, Novecento, Libreria Editrice Goriziana, Gorizia, 339 pp.
Historic England 2017. First World War: accidental explosions. https://historicengland.org.uk/whats-new/first-world-war-home-front/what-we-already-know/land/first-world-war-accidental-explosions/ (accessed 4 February 2017)
Museum of London 2017. Silvertown explosion. http://collections.museumoflondon.org.uk/online/group/25204.html (accessed 4 February 2017)
Wikipedia 2017. Silvertown explosion. https://en.wikipedia.org/wiki/Silvertown_explosion (accessed 4 February 2017)