London’s Biggest Explosion. Silvertown 1917

Tomorrow will see the 105th anniversary of the biggest explosion that London has ever seen and considering all of the industry, terrorism and world wars then that is saying something. However as is often the way with these things, to a great extent it was an entirely avoidable disaster albeit with the mitigating circumstances of war.

A few minutes before seven, on the evening of January 19th, 1917, people who happened to be out of doors in London noticed a vivid red glow in the sky in an easterly direction. Many of the people were standing at the doors watching the fire that had broken out, and not realising the terrible danger they were in. Suddenly there was a deafening roar, a fountain of flaming debris was projected high into the air and this spread out like a fiery rose, dropping death and destruction over the whole district.

This is a contemporary photo of another munitions factory explosion in 1917.

The force of the explosion sent pieces of machinery, some weighing several tonnes, flying through the air with the result that cottages and factory buildings that were not wrecked by the concussion, were crushed and battered by the hail of fragments that came raining down upon them.Several streets of houses were converted into heaps of rubble in a second. Those that escaped total destruction remained as mere skeletons among the wreckage.

What had happened? On 19th January 1917, a devastating fire and explosion broke out in the melting pot room of the Brunner Mond Munitions Factory at Silvertown in West Ham, in the East End of London. The factory was being used to purify trinitrotoluene (TNT).

After the fire broke out, West Ham Fire Brigade, based at Silvertown Fire Station, attended the scene. The station was only three years old and just a few yards away from the factory. At 1852hrs , approximately 50 tonnes of the TNT contained within the factory exploded with catastrophic results. West Ham station was completely destroyed and two firefighters were killed instantly alongside many factory works and local residents. A total of 73 people were killed in the blast and more than 400 people were seriously injured.The explosion was so severe, the sounds of it were clearly heard at the Royal Residence at Sandringham, Norfolk, more than 100 miles away. The blast was so powerful, the fire engine from Silvertown Fire Station was found over a quarter of a mile away.

As a report from the Times wrote… ‘The scene immediately after the explosion beggared description. The burning debris had started fires in many of the factories and mills nearby, which became roaring furnaces as the night progressed. In all directions, people who had escaped serious injury were picking themselves up in a dazed condition. Mothers were frantically looking about for their little ones, many of whom were buried in the ruins, while on the pavements were the bodies of the pedestrians who had been struck as they were walking along.

The epicentre of the 1917 Silvertown Explosion

As a spectacle, England will probably never see its equal. In all directions, great buildings were blazing, fire engines and ambulances were dashing up from all parts of London, hundreds of volunteers were at work rescuing the injured and searching the ruins for bodies. Homeless people were wandering off to neighbouring districts where every available hall had been thrown open to give them shelter.’

In 1915 a huge political scandal had wracked wartime Britain…. a shortage of artillery shells to shoot at an enemy in a trench war that would surely be one by the country that could blast the other to pulp the first. It brought the government down and led to a successful campaign by David Lloyd George for a national munitions policy. The result was a coalition government with Lloyd George as minister of munitions, and a huge demand for existing factories to be quickly converted to munitions production.

The Brunner Mond Factory in Silvertown had been built in 1893 to produce caustic soda. Production had stopped in 1912 which meant a fully equipped chemical plant lay idle. When approached by Lord Moulton who headed the Explosives Supply Department, Brunner Mond & Co agreed to convert it to TNT purification, despite the fact that 3,000 people lived nearby. Bruner Mond later said ‘The company strongly expressed their reluctance to carry out such a dangerous manufacture in a densely populated district; but the urgency was so great they eventually consented. Lord Moulton was well aware of the danger to civilians, but later explained that the Brunner Mond works were effectively requisitioned because “we could see no other way of obtaining purifying works within the time that they were necessary”.

If the war effort was mainly to blame for the location of the TNT plant, what actually caused the terrible explosion? To help answer this we now have access to the detailed government report, kept secret until 1957, into the likely cause of the disaster which took evidence from 36 experts and witnesses immediately after the disaster.

By this time, the danger of TNT explosion in the purifying process was well known – the inquiry report lists 29 previous fires or cases of accidental TNT detonation. In 1915, a big TNT explosion occurred at the crystallising plant at Ardeer, Scotland causing one death and several injuries. A committee looked into the causes and recommended that TNT should no longer be exempt from the 1875 Explosives Act, but this was ignored by the government. Had they taken this advice, perhaps the Silvertown explosion may never have happened. What caused it was something of a mystery at the time as many Londoners thought it was the result of a Zeppelin raid despite there having been no such raids for several months and indeed no sighting of them that night.

Another line of investigation was that it could have been arson by a German spy, and the inquiry looked into this carefully. They found adequate security and no “alien enemies” working there. There was a 57-year-old German man worked at Brunner Mond, but not in the TNT plant. He also had been living in England since he was ten, had an English wife and 12 children, three of whom were serving in the British Army. Moreover, he had left at 6pm that day and was considered beyond suspicion. However, the inquiry did identify a major security issue that may have been exploited by an enemy.

Raw TNT came to Silvertown from a factory in Huddersfield and took several weeks to arrive via rail, barge and lorry. The inquiry found that barrels and kegs of TNT often arrived broken, and the contents were not checked before melting. The inquiry reported that it would have been quite easy for an enemy agent to add a chemical, like a freely available stick of caustic soda coated in varnish, into a barrel along the route. As caustic soda can ignite molten TNT as temperatures as low as 82C, it could easily cause a fire in the melting pot. No evidence or accounts of sabotage have emerged in the German records, but it remains a possibility.

In the end the inquiry came up with the more mundane if likely cause in that a detonation spark caused by friction or impact.

A government safety inspection, just three weeks before the explosion, revealed some unsafe practices. TNT was left on the floor around a hopper and if degraded, it could have been ignited by a boot nail, grit or something metal. There were no regulations to prevent grit on the floor and, astonishingly, metal tools (which could easily create sparks) were found in the TNT building.

Another possibility was a fire caused by alkali left over from the caustic soda making years before. A century on and its unlikely any new evidence will come to light as to the cause of the explosion but what isn’t in doubt is the massive ramifications it caused.

The hardest hit were the families and friends of the 73 victims, who ranged in age from four-months-old to 76 years. Hundreds more had to cope with injuries. Six hundred families were made homeless and an estimated 70,000 properties were damaged in some way. The government paid compensation to the victims and repaired remaining houses in Silvertown, indeed some of the Victorian houses that were packed up are still visible today.

The inquiry recommended that security of TNT should be improved and it should be stored in magazines away from processing plants. It also called for the inspection system to be strengthened and that TNT should be regulated as an explosive under the 1875 Explosives Act. But it took another explosion at a TNT factory, which killed more than 40 people at Hooley Hill in Manchester, for action finally to be taken on the report findings.

The Special Service Branch of the War Office was put in charge of munitions factories to improve security and in August the Ministry of Munitions finally classed TNT as an explosive under the Explosives Act. All future factories would require a licence following rigorous safety checks and procedures.

A few days ago I decided to go down to Silvertown and see if I could find any memorial to those who died. The whole area has been and still is being transformed and doesn’t resemble in any way what people from overseas might think London to be, such is the legacy of WW2 and the ever-changing face of London.

In the midst of the new developments are several parks and in one I found this simple but beautifully situated memorial just 2 minutes walk from a very expansive River Thames.

Memorial to those that died in the Silvertown disaster

On each side of the memorial are inscriptions to different sad histories including those who died onsite during the production of explosives and also local people who died in WW1 and WW2.

It also gave me the opportunity to take some photos for the new book I am researching and writing.

If big explosions are your thing then check out The Lochnagar Crater and a relic of war from over a century ago or for an impending disaster in the making The ticking timebomb shipwreck that could damage half of London

You might also like my WW1 history book that was published just a few years ago, Lest We Forget.

By Stephen Liddell

I am a writer and traveller with a penchant for history and getting off the beaten track. With several books to my name including several #1 sellers. I also write environmental, travel and history articles for magazines as well as freelance work. I run my private tours company with one tour stated by the leading travel website as being with the #1 authentic London Experience. Recently I've appeared on BBC Radio and Bloomberg TV and am waiting on the filming of a ghost story on British TV. I run my own private UK tours company (Ye Olde England Tours) with small, private and totally customisable guided tours run by myself!

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