Continuing our nine-part Meet the Bridge Builders video series, this week’s episode looks at the building of the two iconic 515-feet-tall towers. They were built on land, 1,000 feet apart to enable future expansion of the Back Channel should the need arise.
Most cable-stayed bridges use an H, A or inverted-Y-shape frame to add stability to the structure. However, due to the limited space in the Port and the vital need to keep the old bridge open during construction of the new bridge, the design team went with a single-tower approach.
The construction of the towers involved the use of “jump forms” that helped build each tower in 20-foot segments. When a segment was finished, the jump form would detach, elevate to the next 20-foot segment, then close to enable the placement of new rebar and concrete. The process repeated itself more than 25 times until the jump forms reached the top.
The massive tower cranes lifted materials up to the construction crews on both towers. Most of the members of the two crews remained on the job throughout the course of building the towers and took great pride in saying that they built their respective tower. On Dec. 5, 2017, the towers were topped off during a ceremony at the base of the east tower that was attended by Mayor Robert Garcia, government officials and workers to commemorate the completion of the towers.