One Rincon Phase II is the second tower of the One Rincon Hill development and will complete this landmark San Francisco project. Webcor performed the concrete on Phase I and was selected to provide general contractor services for the entire Phase II project. The second tower is 52 stories and includes 299 residential units over approximately 505,000 gross square feet. Amenities include a fitness center and a sky lounge on the top floor. The structure consists of a concrete core and large steel reinforced concrete columns called outriggers. The core is attached to the outrigger columns by steel buckling restrained braces (BRB’s) that are designed to transfer loads in a seismic event. The roof levels of the building include tuned mass damper tanks containing 50,000 gallons of water to counter any building movement.