A Marvelous Engineer Mistake

Humans have been building submarines for many decades now. You would think after designing so many functional submarines most manufacturers would be able to get the basics right. As it turns out, not so much:

According to El Pais, the S-81 Isaac Peral — the first of four state-of-the-art new submarines commissioned for the Spanish Navy — is 75 to 100 tons overweight. That may not seem like a lot, considering the submarine’s full weight when submerged is 2,430 tons, but according to engineers at Navantia, the Spanish shipbuilding company responsible for its design, that excess bulk is enough to prevent the Isaac Peral from successfully resurfacing once submerged.

Emphasis mine. On the upside it does 50 percent of what is expected of a submarine!