Isaac Peral Was Too Heavy
In 2013, a new class of diesel-electric submarines was going to be launched, but at a very expensive cost because of a mistake. The Isaac Peral was too heavy! An engineer put a decimal point in the wrong spot, and the submarine was planned with the mistake that added 70 tonnes to its weight! Engineers had to fix it by making the submarine longer, and the mistake cost them $11.4 million.