In 2013, as the eastern span replacement of the San Francisco-Oakland Bay Bridge was drawing to a close, 277 vertical steel rods to improve the seismic stability of the replacement were tested under tension using three-inch-diameter bolts. Within two weeks, 32 of the steel rods had snapped. 277 of these rods were used in the $6.5 billion construction project, but only 96 were accessible. Metal testing suggested hydrogen embrittlement during the manufacturing of the rods may have caused the failures. Thankfully, this was able to be corrected before the bridge opened, but it was a major setback in the construction.
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