The Problem: Already hounded by U-Boat submarines during World War I, the British military became extremely concerned when intelligence reports suggested that the Germans were developing an even faster version of their deadly subs.
The Solution: Outfit the British Navy with a better ship. In 1915, engineers
designed the K-Boat, a well-armed hybrid between a submarine and a warship.
The Problem with the Solution: The British Navy made the mistake of using engineers actually from Britain.
Look, we love "Doctor Who," and everybody knows shepherd's pie is the world's most undervalued casserole, but there's a reason we buy German cars—and the K-Boat is a perfect example why. Weighing nearly 2,000 tons, the beast was clumsy on the surface and took five minutes to dive (not great when you're trying to escape enemy bombers). Once below water, the K-Boat often had trouble resurfacing (again, not something you want to hear as a sailor).
After testing began in 1916, the boats started displaying even more worrisome tendencies. Model K13 sank during initial trials, killing all on board. Later, K4 collided with K1. Then, in 1918, a flotilla of K-Boats and other ships were on a practice run when K14 collided with K22, setting off a chain reaction of crashes during which a cruiser rammed and sank K17, and K6 slammed into K4, cutting it in half. In fact, K-Boats managed to claim the lives of 250 British soldiers (and not a single German) before they were finally sent to the scrap heap.
---This summer, mental_floss is re-running parts of "The 20 Greatest Mistaikes in History," Maggie Koerth-Baker's cover story from March-April 2007. To order the back issue, click here. To see other installments in this series, click here.