Posted February 23, 2011

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ASSEMBLY OF MAIN CABLE PAINTING PROJECT SCAFFOLDING UNDERWAY

 

On the evening of February 22, 2011, scaffolding required for Golden Gate Bridge crews to begin the renovation of the span’s massive main cables was delivered to midspan (midpoint of the Bridge) and unloaded onto the west sidewalk.

Beginning on February 23, 2011 on the WEST SIDE main cable, fixed scaffolding will be assembled over the next few weeks, along the 400-foot-long segment from midspan south towards the San Francisco side of the span. The scaffolding and a tent-like containment structure will entirely surround or envelop the main cable in 60-foot-long segments. The containment structures will be moved along the 400-foot-segment of the main cable as each 60-foot-long segment is completed. The scaffolding will extend from the sidewalk level to about 3 ft. above the main cable, which translates to it being up to 25 ft. tall at its maximum and 6 ft. wide.

Then, workers will spend up to six months renovate this portion of the main cable. Following the completion of this section of work, the scaffolding will be disassembled and reassembled along a 400-foot-long segment heading north from midspan toward the Marin side. Workers will then renovate this segment of the WEST SIDE main cable over the next 6 months. This 800-foot section alone is anticipated to take about 1 year to complete.

Once work is completed on the WEST SIDE main cable, the work effort will shift to the EAST SIDE main cable. The same system will be used on the EAST SIDE main cable. Also, the higher portions of both of the main cable will be recoated using elevated platforms beginning this summer. As the renovation progresses, updates will be provided.

WHAT WILL BE THE IMPACT ON THE WEST SIDEWALK?

While this work is underway on the WEST SIDE main cable, the fixed scaffolding will reduce the west sidewalk width from 10 feet to 7 feet for a distance of 400 ft. Depending on the adjustment to the 7 foot-wide segment, if safety needs warrant it, bicyclists may be asked to walk their bikes through the work area.

WHAT DOES “MAIN CABLE RENOVATION” MEAN?

Golden Gate Bridge work crews will undertake the following during the three-year renovation of both of the main cables: Inside the tent-like containment areas, they will clean the surface of the main cable; rough the surface of the main cable to be ready to accept new paint; make any additional required repairs; re-caulk the main cable bands; apply new paint system.

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 while working inside the tents. 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 containment tents repositioned along the main cable.

WHAT DAY-TO-DAY CHALLENGES DOES THIS PROJECT PRESENT?

  1. Performing work in an environment involving continuous traffic, without closing the Bridge to traffic.
  2. Project site within a worldwide tourist attraction that attracts millions of tourists, pedestrians and bicyclists each year.
  3. Project site with limited work areas, confined staging areas and restricted ingress and egress.
  4. Variable and unpredictable Bay Area climate that can have a substantial impact on production.

 

cable worker bridge
sketch containment area bridge
main cable mid span golden gate bridge

 

 

 

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