Oyster Point Marina Breakwater Modifications

When the old concrete breakwater entrance to Oyster Point Marina was widened to handle new ferry service, wave action increased in the marina. To prevent boat damage, Yerba Buena was charged with installing floating docks and breakwaters at the end of each dock as wave attenuators.

We demolished and reconstructed Docks 11, 12, 13, and 14.

The first project phase was the design and fabrication of the precast concrete floating docks and breakwater floats. Each float consisted of a concrete deck and a polystyrene foam core encased in concrete, with PVC sleeves and pull boxes embedded for electrical and communications systems.

Design, fabrication, and delivery of the floating docks, breakwater floats, precast concrete piles, and ADA-compliant, hinged aluminum tread plates, or transition ramps, took eight months. Yerba Buena mobilized a month ahead of delivery to cut and demolish the existing docks and prepare to receive the new ones.

Crews cut and demoed designated dock section —about 3,500 square feet in all—and used a barge- mounted crawler crane and vibratory hammer to load them out onto a material barge. Workers installed the new breakwaters, temporarily reusing existing 12-inch square concrete piles to stabilize the new floating docks during positioning. At each dock, they disconnected the utilities and removed or relocated storage lockers, fire hose cabinets, and cable TV pedestals.

The same crane and hammer were then used to pull 36 of the existing piles and redrive 11 of them, which were in good enough condition to be reused. A derrick barge with a diesel drop hammer was used to drive 33 new 24-inch square piles for the new breakwater floats and finger piers.

A floating crane was used to lift the dock floats from the transport barges when they were delivered to the site.