The Second Great Fire of London

Today marks the 76th Anniversary of the Second Great Fire of London.

On 29 December 1940 around 100,000 bombs fell in just a few hours, causing a firestorm across most of the City’s square mile up to Islington.

14 fire fighters were to lose their lives that night, with over 250 injured.

The largest continuous area of Blitz destruction anywhere in Britain occurred on this night, stretching south from Islington to the very edge of St Paul’s Churchyard. The area destroyed was greater than that of the Great Fire of London in 1666.

The raid was timed to coincide with a particularly low tide on the River Thames, making water difficult to obtain for fire fighting. Over 1,500 fires were started, with many joining up to form three major conflagrations which in turn caused a firestorm that spread the flames further, towards St Paul’s Cathedral.

As the fires raged, Prime Minister Winston Churchill insisted that St Paul’s Cathedral be saved at all costs. The struggle involved fire crews and local volunteers.

The German raid planned for the night of the 29th December was to feature an initial attack led by a specialist Pathfinder Squadron, followed by the first wave of bombers with mainly  incendiary bombs and some high explosives to set the City alight, followed much later in the evening by the second wave of bombers with high explosive bombs. The clear intention was to destroy the City with key strategic targets being the bridges over the river, train stations and tracks and communications centres such as the Faraday building on Queen Victoria Street which was a centre for the London Telephony system and also for international telephony circuits.

The role of the Pathfinder squadron was to locate the target using a beam radio system where radio signals transmitted from the Continent would direct a plane to its target with a change in the signal where beams crossed indicating a key geographic point to commence the attack.

The planes of the Pathfinder Squadron flew over the countryside between the coast and south London and on approaching Mitcham the signal changed indicating the point from where a carefully planned course and time would lead the planes directly to the centre of London.

This approach allowed for accurate bombing despite the heavy layers of cloud below. The Pathfinders aimed to start fires which the main bomber force could then follow.

At the planned time the bombers released canisters containing the incendiary bombs. On the drop-down, the canisters then broke open to shower individual bombs over a wide radius.

The waves of the main bomber force then started to arrive, each loaded with canisters of incendiary bombs and the occasional high-explosive bomb.

These were relatively small devices and could be easy to deal with, however, when dropped in such large numbers, it only took a few to start fires in hard-to-reach locations that could very quickly get out of control.

The 1KG incendiary was 34.5cm long and 5cm in diameter. The body was of magnesium alloy with a filling of an incendiary compound (thermite). On hitting the ground, a needle was driven into a percussion cap which ignited the thermite. The heat from this also ignited the magnesium casing causing an intense heat which would ignite any flammable material that the bomb was in contact.

More than 160 civilians died during that night, with many more dying of their injuries sustained in this raid in the days that followed; 14 firemen died fighting the fires and 250 were injured. Buildings destroyed in the firestorm included 19 churches, 31 guild halls and all of Paternoster Row. Paternoster Row was the centre of the London publishing trade and an estimated five million books were lost in the fire.