Alcatraz Island is a designated National Historic Landmark, which makes construction and renovation challenging, yet rewarding.  The project consisted of structural repairs and retrofitting to the historic Cellhouse (Building 68) and repair of the exterior concrete balconies on the barracks (Building 64) on Alcatraz Island.  The island was open to the public during construction and all operations were conducted in a manner which ensured the least inconvenience to the public and the staff.

The structural stabilization of the Cellhouse building involved the addition of new concrete shear walls, collectors, foundations, and rock anchors, new structural steel bracing, and new composite fiber reinforcing. Repairs were made to the existing concrete and falling hazards removed to increase the safety of the structure.  Piping in the utility corridors were also removed, resupported, and reinstalled. 

The repairs to the balcony of Building 64 involved the application of anti-corrosion treatment as well as traffic coating on the decks. Crews installed chain link fence panels at balcony and stair guardrails and put in exterior floor drains and rain water leaders. The repairs were completed by painting the balcony concrete and metals. As this project was performed within a National Park and on historic buildings, special construction requirements applied.  Several mitigation measures had to be institued in order to comply with the guidelines set forth by the Alcatraz Island Historic Preservation and Safety Construction Environmental Impact Study.  For instance, visual screening and gull exclusion netting was used to address environmental concerns.

Clientele: NPS
Owner: Denver
Specialty: Historic Restoration

Contract Value: $5,778,428.00

Project Recognitions: