Kate Bachman
Contributing Editor

The Woman Who Changed Welding

In 1943, Henry Kaiser initiated the mass production of U.S. warships by employing prefabrication and the welding of steel plates instead of riveting. Ships were finished in weeks instead of the usual 8 mo., meeting the dire need to complete ships quickly for the war effort. But welding produced new kinds of stress that didn’t occur during riveting, according to the YouTube video “WW2 Memoirs: How One Welder’s ’Ridiculous’ Idea Saved 2,500 Ships From Splitting in Half at Sea.”

The prescribed process had been to start welding at the edges and work in toward the center, and to run long seams continuously. Welders were instructed to weld rapidly, under pressure to meet quotas for quick production.

Without apparent cause, once out to sea in much colder temperatures, deck plates began to split open, costing lives and millions of dollars in destroyed ships. The steel that held intact in warm California bays lost its ductility and ability to flex in the freezing ocean temperatures.

Investigations were launched. Metallurgists, engineers and naval architects studied, inspected and audited the failed ships. Testimony was given before Congress. Blame was assigned to “bad metal” and “bad welding.” 

Under Her Torch

A woman working the graveyard shift as a welder noticed something that the experts had missed. Under her torch, Bessie Hamill felt the metal move, and saw the seams warp and the plates twist. Each cooling weld contracted the surrounding metal, locking tension into the structure. She observed how the metal behaved, marking her observations in a notebook kept in her lunchpail, and sketched crude diagrams of the plates. 

Hamill relayed her suspicion to her supervisor that it was the sequence, the direction and the rushing of the welding process that caused the weld defects, but he dismissed her theory.

Seeing the welds continue to fail in service and more sailors lose their lives, Hamill persisted. She ran her own experiments on her own time, reversing the weld sequence from outside-in to inside-out and alternating the sequence in a way that gave the welds a chance to cool rather than lock the tension in place. She recorded the temperature drops and changes when she altered the sequence and direction. She measured and compared the distortion. As a result of her changes, the plates remained flat. It became apparent that neither bad steel nor bad welders caused the problems; it was the weld direction and sequence. 

In November 1943, Hamill again requested a meeting—this time with several supervisors—and challenged the official procedure. In doing so, she violated the chain of command. She contended that improper weld sequence caused the weld failures. Most of her supervisors rebuffed her, but one of them paid heed. He asked her to demonstrate her theory. 

Hamill showed him how heat moving through steel created tension and how the direction outward to inward created warping. Conversely, by starting the welds from the center, the steel could release its stresses gradually toward the edges, and by alternating sides to allow the welds to cool and relax before proceeding to attach all the sides, the welded plates would remain flat.