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 original Tappan Zee Bridge is a cantilever bridge built during 1952â55. The bridge is 3 miles (4.8 km) long and spans the Hudson at its second-widest point. The Tappan Zee river crossing was named by 17th century Dutch settlers.