July 7, 2010

Staging to Start in August/September 2010 for Golden Gate Bridge Main Cable Recoating Project

 

In August/September 2010, Golden Gate Bridge work crews will begin constructing the staging required for work to commence on the Main Cable Recoating project. To preserve the massive main cables for years to come, this critical three-year maintenance project will begin at mid-span on the west side Main Cable, and then move to the east side Main Cable. The first phase of work will include constructing staging (scaffolding) along 300- foot segments of the Bridge sidewalk directly under the main cable at midspan. This staging will provide access to the lower portions of the main cable so that crews can begin cleaning the surface of the main cable, removing deteriorated coatings and roughing the entire surface to be ready to accept the new primer and topcoat, making any needed repairs, and undertaking any needed re-caulking as they go. This first-phase staging work will narrow the west sidewalk to a width of 6 feet, instead of 10 feet, for a distance of about 300 feet at midspan. Signage will alert bicyclists to walk their bikes through this narrow 300-foot section. This staging will be in place for approximately 6 months on the West sidewalk and 6 months on the East sidewalk.

Following this initial phase of work, crews will access the higher portions of the cable via large elevated platforms that are currently being designed.

Main Cable Recoating Project Background

The two massive main cables of the Golden Gate Bridge are scheduled for recoating beginning in late spring/summer 2010. The work that will be performed is an over-coating paint job, so the crews do not have to clean the surfaces down to bare steel; instead the surface preparation will include using hand held vacuum shrouded power tools. Any old paint that is not tightly adhered to the cable will be “sucked” into the hand held vacuum tools. Great care will be taken to preserve the galvanizing on the cable wrapping wires as this coating is critical to preventing corrosion. Then the new paint system will be applied, and the tents repositioned along the main cable.

Crews will start at the roadway level at mid-span, and do the several hundred feet that are accessible at this location using a stationary scaffolding system with a tarp system to catch anything that may possibly get missed by the hand held vacuum tools. Once they move past the mid-span section and start to move higher on the cables, crews will use a powered suspended scaffold system, also with tarps. These sections will be about 60 feet-long as they move along the Main Cable.

The Main Cable Recoating Project includes:

  1. Removal of the original packing from the cable band joints and caulking the grooves with a modern elastomeric sealant.
  2. Reconditioning and/or replacement of specific cable shrouds.
  3. Cleaning and Painting of the main cables, cable bands, and associated cable band bolts.
  4. Painting of the hand rope system.

This project presents some significant day-to-day challenges:

  • Performing work in an environment involving continuous traffic, without closing the Bridge to traffic.
  • Working at a project site within a worldwide tourist attraction that attracts millions of tourists, pedestrians and bicyclists each year and with limited work areas, confined staging areas and restricted ingress and egress.
  • Executing the work safely without affecting use of the Bridge by vehicles on the roadway and pedestrians, bicyclists and Bridge maintenance forces on the sidewalk.
  • Performing work at high elevations and in extreme wind and weather conditions.

 

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