A few weeks ago, we posted a video of an orange “tripod” from one of the derrick cranes being lifted onto the pier table at the west tower. Now, all four of them have been installed (two at each tower), including the crane boom. Shortly, they will begin the process of building bridge segments in a balanced-cantilever approach. This photo shows to the two cranes on the pier table at the east tower.
The ladder in the foreground leads up to a cab where a crane operator will sit. There is a second cab on the other side of the tower to operate the far crane. The gray apparatus under the cranes is a transport mechanism that will enable each one to move back and forth on the pier table and bridge segments to pick up and move steel beams and concrete panels.
Each crane will move along a track that will be extended as bridge segments are added. That track is visible under the point of the tripod, just behind the construction worker in the photo. A wheel assembly (pictured in lower right) will allow smooth movement along the road deck.
In the coming weeks, the derrick cranes will be used to move and place edge girders, floor beams and concrete panels to construct the first segments that extend from the pier tables.