One of the most visible features of the Bridge Project for the last five years, the 600‑foot-high west tower crane, was lowered to the ground today as part of a weeklong removal process. You may not have noticed its disappearance because it was dismantled incrementally in 40-foot segments, and the jib (the horizontal arm at the top) was lowered little by little until it reached ground level where it will be disassembled.
Starting at the top, construction crews used a 40-foot-tall hydraulic strand‑jack system called the “climbing frame” that wrapped around the tower crane mast (vertical structure of the crane). After the mast was secured, crews began to unbolt the upper segment, moved it laterally, then lowered it to the ground. The climbing frame was then lowered to the next segment, and the process repeated: support, unbolt, move laterally, then lower to the ground, 40 feet at a time.
Upon lowering the tower crane mast to each of the two ties (i.e., connector brackets that attached the towers for support), a secondary hydraulic crane at the deck level was used to disconnect and lower the tie to the deck, where it was disassembled and hauled away. Once the tower crane reached ground level, a crawler crane disassembled the jib, cabin, and counterweights. In the photo above, you can see where the climbing frame reached the first tie.
After the west tower crane is disassembled and removed, the same crew will begin dismantling the east tower crane as the Bridge Project advances toward completion.