Why welded submarine hulls demanded caution

The wartime discussion gives complete welding greater military value in submarines than in other warships, while warning that pressure-hull failure makes a major construction change unusually consequential. Moving away from riveted pressure hulls first required steel better suited to welding. A specialist radiography team under Dr. W. R. Harper then made weld quality inspectable rather than assumed. Designers also had to preserve accurate hull circularity and scrutinize openings, discontinuities, and other stress concentrations. A local weakness could compromise the whole pressure hull and cause disaster, a danger linked here to defects in some German designs. Welding's operational promise depended on materials, inspection, production accuracy, and detail design advancing together.