|A ball joint secured and ready for transport.|
Next week, the first of two massive ball joints will be delivered from storage in Livermore to our construction site in Fremont, where it will be included in the Seismic Upgrade of Bay Division Pipelines Nos. 3&4.
The two identical joints were fabricated specifically for the project. The inner dimension of the ball joints measures 72 inches (6 feet) in diameter. The joint itself measures more than 8 feet in diameter at its widest point. The ball joints are the largest such joints to be used in the Hetch Hetchy Regional Water System, and at the time of fabrication were the largest ball joints in the world.
The joints are made of ductile iron and are part of a system designed to absorb up to 6.5 feet of horizontal displacement if a major earthquake were to take place on the Hayward Fault.
|A depiction of the ball joint installed in the BDPL3&4 system (courtesy of URS Corp.)|