Major Bridge Improvements Since Opening
Since its completion in 1937, a number of rehabilitation and improvement projects have been completed that have preserved, protected, and extended the life of the world-famous Golden Gate Bridge. The most significant of these improvements are noted below - many of which were the first for a major suspension span.
Lower Lateral Bracing System (1953-1954)
On December 1, 1951, a great windstorm threatened the integrity of the Bridge. A lower lateral bracing system was added to the span to significantly increase the torsional stability of the stiffening truss of the roadway at a cost of $3.5 million.
Comprehensive Inspection (1967-1969)
Consulting Engineers from Amman & Whitney in New York conducted a major inspection that included all bridge structures.
This comprehensive inspection was the first of a major suspension span.
Replacement of Suspender Ropes (1973-1976)
During the 1967-1969 Bridge inspection conducted by Amman & Whitney, advancing corrosion was discovered at the suspension rope connection point at the roadway. Bridge engineers worked with Amman & Whitney to develop the first-ever plans and specifications to replace the suspender ropes, while keeping the span open to traffic.
All 250 pairs of vertical suspender ropes, which are spaced 50 feet apart across both sides of the Bridge, were replaced with the use of unique traveling platforms spanning between the two main cables, suspended above the roadway. Only on the nights of November 8, 1972; July 13, 1975; and May 4 and 23, 1976, was the bridge roadway closed for a few hours to relocate the traveling platforms.
This replacement of the suspender ropes was the first of a major suspension span.
Earthquake Retrofit (1980-1982)
Following the 1971 San Fernando Earthquake, the California Department of Transportation issued new retrofit design standards for existing structures. Both the San Francisco and Marin approaches to the Bridge were retrofitted to increase earthquake resistance. The project was completed in 1982 with 80% of the $2.8 million cost borne by the federal government.
Toll Booth Renovation (1980-1989)
Over the nine-year period, all 11 toll collection booths were renovated to more safely accommodate the flow of traffic at a cost of $1.7 million in District funds.
Bridge Deck Replacement (1982-1986)
Over the years, salt and moisture from fog and from the ocean have penetrated and deteriorated the Bridge's roadway deck. In response, the original concrete deck and its supporting steel stringers were replaced with a lighter, stronger orthotropic deck.
Bridge engineers worked with Amman & Whitney to develop the first-ever new deck design and construction plan. Over 401 nights, without closing the roadway to traffic, the original concrete roadway deck, consisting of 747 sections, was replaced with the lighter, stronger, orthotropic steel deck. The roadway was widened also by two feet resulting in outside curb lane widths of 11 feet, up from 10 feet (the four inside lanes remained at 10 feet wide). Daytime peak traffic was not affected. The final phase was completed in the summer of 1986 when two inches of epoxy asphalt were laid over the surface of the steel deck roadway.
Approximately 80% of the total cost of $68.1 million was borne by the Federal Highway Administration as a result of Congressional legislation recognizing the importance of this project in the protection of interstate commerce. The District paid the balance.
This Bridge deck replacement was the greatest engineering project since the Bridge was built and was the first of a major suspension span.
Decorative Tower Lighting (1986-1987)
The lighting design developed by consulting architect Irving F. Morrow during the original design of the Bridge was included in original construction. The decorative tower lighting cost $1.2 million, with funding provided in part through a donation from Pacific Gas & Electric Company. Abbett Electric Company installed the lighting at cost.
Pedestrian Railing Replacement (1993-1994)
By 1992, after 55 years of constant weather exposure, approximately 6,557 lineal feet of west side pedestrian railing had deteriorated. The District replaced the railing with an exact replica, preserving the historical and architectural character of the Bridge, at a cost of $1.3 million.
Pavement and Drainage Rehabilitation (1996-1997)
In August 1996, pavement and drainage rehabilitation of 1,600 feet of roadway in the Bridge Toll Plaza area commenced. To maintain the smooth flow of traffic during peak periods, work was performed at night. The project was completed in early 1997.
Seismic Retrofit - Phases 1 and 2 (1997-2008)
Phase 1 and Phase 2 of the Golden Gate Bridge Seismic Retrofit Design and Construction Project were completed. From 1997 to 2002, Phase 1 retrofitted the Marin approach structures. From 2002 to 2008, Phase 2 retrofitted the San Francisco approach structures and the Fort Point Arch.
For more information on this project, visit the Seismic Retrofit Design and Construction Project page.
Safety Railing Installation (2001-2003)
A 4-foot, 6-inch high public safety railing was added between the Bridge roadway and each of the two sidewalks.