Liberty ships and the *SS Schenectady* / *Esso* fracture

The anchoring case for the entire bulking-up arc. 4,700 ships built in WWII; 970 (22%) had major fracture casualties; 24 sustained complete strength-deck fracture. All low-toughness plates: Charpy < 10 ft-lb.

The bulking up of safety factors is another matter. The classic example is the Liberty ships. [Tom puts up a slide of the SS Schenectady, fractured in port — rotated upside down on the screen.] There's the classic picture of the Schenectady. It was brand new, sitting in port. They used to build these things in less than two weeks from laying the keel to floating them out. In World War II — this is actually a T1 tanker rather than a true Liberty ship, but the T1 tankers and Liberty ships had basically the same construction, except some carried oil. It had a crack all the way through. There's another picture of the Esso where the same thing happened, except the Esso was sitting out in the middle of the ocean when it happened. It's a lot safer to have it happen in dry dock.