Barnes Willis was one of those eccentric geniuses who pop up during any conflict and refuse to understand that there are certain ways in which wars are fought, in World War II this consisted of bombers flying over to enemy territory and dropping thousands of tons of bombs on a target – but containing those thousands of tons of bombs into individual small bomb packages. The bombers would then drop many small packages on an area and pelt it with damage, because that was how one bombed targets. Willis in 1941 argued in an academic paper that this was an incredibly foolish was to bomb a target and a more efficient method was to build on massive bomb capable of penetrating the earth and exploding underground. The ensuing shock wave would then cause a miniature earthquake doing extensive damage to the desired target and concentrating most of the explosive force into the ground, rather than up into the air. Best of all the bomb didn’t even have to hit the actual target, you just had to land it near the target. But 1942 Britain was not interested in such wacky ideas and politely ignored this proposal, and Willis in general.
That was until 1942 when a different paper written by Willis came to the attention of the British military, Willis had proposed the idea of building a bouncing spherical bomb that would skip along the surface of the water, but with a backspin on the bomb. The idea was it would bounce along the waters surface till it came into contact with a hard flat surface, spin backwards down the surface, and detonate underwater, concentrating its explosive power against the surface it had bumped up against. That surface, by the way, was any sort of German dam, and in 1942 the British had been having a devil of a time knocking out a series of dams in the Ruhr Valley. At this point the British had reached the “what the hell” stage so they decided to develop this crazy idea and give it a try. It was used in 1943 and worked, amazingly well, popping a series of German dams in a single raid. At that point the British military politely decided that the older wacky Willis idea of a “super bomb” might be worth another look.
Meet Tall Boy, a 12,000 pound bomb that was built in 1944 for use on Germany. Tall Boy stands at 21 feet in length and 38 inches in diameter, it had three fuses within it to ensure detonation and was made with a hardened high-grade steel casing to allow it to survive its descent into the earth. The bomb carried over 5,000 pounds of explosive and had to be carried by a specially modified bomber to actually arrive at its target. In its first two operations the Tall Boy smashed a hard to destroy buried railway tunnel and also took out a heavily re-enforced submarine pen in occupied France. The submarine pen was a particular point of pride for the Tall Boy, the concrete was so massive even this behemoth of a bomb couldn’t get through, but the force of the explosion was enough to collapse part of the pen’s inner ceiling down and cause a mini-tidal wave within the pen, smashing up submarine and rendering the facility unusable. The British military was very pleased with the success of its new weapon so when Willis said his plan would only really work with an even bigger bomb, they were willing to listen.
This is Grand Slam, an appropriately name for a bomb of this size. Grand Slam weighed in at 22,000 pounds and stood at 26 feet 6 inches in height and 3 feet 10 inches in diameter. Within it was packed over 9,000 pounds of high explosive. It was so large it couldn’t properly sit inside the bomber though…
That is a full-sized, four engine Lancaster bomber and that little thing below it is one Grand Slam. The Grand Slam was first used in 1945 to destroy a German aqueduct that had been impossible for the British to destroy from the air, despite many attempts. They dropped the Grand Slam though and toppled the aqueduct due to the massive earthquake effects. The Grand Slam was used several more times in 1945 as the war wound down to further smash many German targets to rubble.
Both bombs in the end were overshadowed by the far more massive destructive power of the U.S. atomic bombs, however in their own sphere of operations they were an incredibly impressive pair of unique weapons, that did an incredible job of destruction, and all thanks to one oddball who refused to believe there was only one way to wage war.