The steel saddle system is designed to provide the clamping force needed to hold down seismic devices during an earthquake. 

An interim fix involving bearing shims had enabled the bridge to be opened to traffic in September ahead of completion of the saddle solution.

The problems centred on broken anchor rods on the self-anchored suspension span (SAS) bridge, which was built as part of the new East Span of the San Francisco-Oakland Bay Bridge.

Hydrogen embrittlement caused widespread failures in a batch of 96 high-strength steel rods anchoring two shear keys directly over the support columns at the east pier. The rods were embedded in concrete, which precluded straightforward replacement and so the steel saddle system was devised to replace the lost clamping force.