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A British engineer attempts to create a weapon for breaching the Atlantic wall. He does not succeed.

Sources:

Brian Johnson. The Secret War.

https://www.wired.com/2015/01/well-didnt-work-rolling-rocket-bomb-designed-kill-nazis-almost-killed-dog-instead/

https://www.military.com/video/operations-and-strategy/second-world-war/the-great-panjandrum-scares-a-dog/1123500263001

https://allthatsinteresting.com/panjandrum