The Tall Boy

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Yesterday I did a post on La Coupolle which was a V2 rocket base in Northern France. Nearby is a huge bunker called Blockhaus d'Éperlecques which was going to be the original V2 rocket base. The Germans called it Kraftwerk Nord West or translated as Power Plant North West and was meant to house a liquid oxygen factory as well as storing up to 100 missiles with the capability of firing 36 per day.

The Allies were trying to stop the V1 and V2 rockets from bombing their cities so they had constant bombing raids named under Operation Crossbow. Normal bombs would bounce off this structure and were a nuisance, but caused little or no damage. The walls of the bunker were 7 m thick or 23 ft and made of reinforced concrete. Now you can understand why a new bomb had to be developed as nothing up until now had worked.

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The Tall Boy bomb was the biggest bomb developed at the time.

Sir Barnes Wallis from the bouncing bomb fame (Dam Busters) developed a special bomb for this place though. It was called the "Tall Boy". The aim was to drop the bomb from a set height and it would gather up speed and reach around 700 mph and bury itself in the ground up to 40 m deep and only then detonate causing an earthquake effect.

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The RAF dropped 17 tall boys on the bunker on the 19h June 1944 and bought down part of the roof. Up until this point the bombing raids had destroyed everything around it and hadn't dented the bunker itself. The Germans realised the Allies had a new weapon now after they were hit with a seismic wave that was caused by a bomb landing nearby and creating a crater 30 m in diameter. After this raid the Germans abandoned the idea and luckily had La Coupolle to fall back on just up the road.

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This shows the results of what seismic action can do. These walls are 7 m thick and were thought to be indestructible.

The advancement in weaponry during the war had advanced so much and this was just a prime example. The need for bigger and better things to outfox the enemy was required. The Tall boy had a bigger brother after this called the "grand slam which was used to destroy the battleship Tirpitz. Sir Barnes Wallis was instrumental in how his work helped speed up the end of the war.