The RMS Titanic was considered cutting-edge for its time, built with a double bottom and 15 watertight compartments controlled by electric doors. This design led many—including Shipbuilder magazine—to call it “practically unsinkable.”

However, there was a critical flaw: the bulkheads didn’t extend high enough. Once water began spilling over from one compartment to the next—especially as the ship tilted—the system that was meant to protect it ultimately contributed to its sinking.