The ships were built with square hatch corners. In strength theory, a sharp corner acts as a "stress riser." While the average stress on the hull was low, the localized stress at those 90-degree corners was high enough to initiate cracks.

The disaster was a masterclass in three core principles of Applied Strength of Materials:

This shift transformed naval architecture and remains a foundational lesson in why calculating isn't enough; you have to understand how geometry and environment change how a material behaves.