Test air leakage rate: With a fully-charged air system (typically 125 psi), turn off the engine, release the service brake, and time the air pressure drop. The loss rate should be less than 2 psi in 1 minute for single vehicles and less than 3 psi in 1 minute for combination vehicles.
Construction on the Coronado Bridge began in 1967. Almost 500 prestressed concrete piles were fastened to the sea floor of the bay to provide the foundations for the bridge. The steel and concrete components were largely built offsite, then assembled together from marine construction barges over the bay.
The dream of spanning the Golden Gate Strait had been around for well over a century before the Golden Gate Bridge opened to traffic on May 28, 1937. Pedestrian Day was held on May 27, 1937. We do not have the exact employment figures. The Bridge was built by 10 different prime contractors and their subcontractors.