She discovered that the ships in the North Atlantic were exposed to temperatures that could fall below a critical point at which the steel changed from being ductile to becoming brittle, allowing cracks to start easily.
Hun fandt ud af, at skibe i Nordatlanten var udsat for temperaturer som kunne falde under et kritisk punkt, hvor stålet gik fra at være sejt til at være sprødt, og derfor kunne skroget ret let revne.