The bridges of San Mateo County

Due to the need to circumvent the Bay more quickly, the first bridge to span the Bay was the Dumbarton Bridge. A private company, Dumbarton Bridge Company, financed and built the 1.2-mile bridge in 1927 that paralleled an existing railroad bridge built by the Southern Pacific in the early 1900s.

Much concern for a route across the Bay that was closer to the tip of the Peninsula went unheeded until a private concern opted to finance building a bridge between San Mateo and Hayward. (A bridge from Hunters Point to the East Bay had been rejected earlier by state officials and the Navy as being too dangerous). Amid the mud flats at the edge of the Bay, on March 1, 1928, construction of the seven-plus mile, $7.5 million San Mateo-Hayward toll bridge began. Construction was fast and uneventful. The piles and deck slabs were poured with cement made from oyster shells dredged from the Bay’s bottom. The oyster shells had accumulated in the shallow Bay over thousands of years and made a plentiful supply for many years for the Portland Cement Company in Redwood City.

To support the bridge’s deck, 4,854 piles were driven into the bedrock and over 10,350 tons of reinforcing steel and 2,910 tons of structural steel were used. There is a deep channel in the middle of the Bay that allows sea-going ships clearance, and over this a cantilevered span with a 300-foot-wide "gothic” draw section was to be built. It lifted up 32 feet and allowed a 135-foot clearance for the passage of ships. This feature would later be the reason for the redesign and construction of a new bridge to open in 1967. The daily time loss by an average of 2000 motorists waiting for it to open and close before allowing them to proceed in 1929 was not deemed important, but by 1966 about 5,600,000 cars crossed the bridge yearly and this wait became intolerable.

On March 2, 1929 the bridge was opened and, although it was connected to Bayshore Boulevard by way of Third Street instead of 10th Street as many desired, it was declared an instant success. The revenues, however, disputed this optimism. The company lost $ 232,500 the first year and never improved its bottom line. The Depression cut into travel times and the $.40 toll proved too steep. Fewer than 2000 cars daily used the bridge — less than 750,000 per year. It was not until 1947 that the daily use exceeded 2000 cars.

In 1951, the state bought the bridge. By 1955, the daily use exceeded 9,000 vehicles and there was pressure for a new bridge, this time without the draw bridge. This meant the elevation of the center of the new bridge had to have at least a 132 foot clearance. Six lanes were designed for the new bridge and it would be hooked up with the proposed 19th Avenue Freeway, thus avoiding the winding Third Street road.

On July 17, 1961, construction began on the $70 million bridge and it was completed in six years. A section of the original bridge, on the west side of the Bay, was saved to be used as a fishing pier.

Rediscovering the Peninsula appears in the Monday edition of the Daily Journal.