One of the amazing aspects about construction on large projects is the amount of careful preparation and safety precautions required to ensure that a crane lift that takes only a few minutes happens without a hitch. Such was the case on the west tower Thursday, when the channel-side derrick crane was raised into place to build one half of the main span. The west tower crew spent more than four weeks building the crane, planning the lift, then carrying it out, as you’ll see in the timelapse video above.
If you have driven over the current bridge in recent days, you may have noticed that derrick cranes have been built on both sides of the pier table on the east side, and they will begin building the main span and back span from that tower in the coming weeks. Using lessons learned from the placement of those cranes, the west tower crews determined a safe path to lift fully built cranes, thereby saving time and enabling them to start main span and back span construction a little sooner.
This time-saving is especially important because, using the balanced-cantilever construction approach, bridge segments from both the east and west towers ideally will meet over the water as close to the same time as possible. In the coming days, a second derrick crane will be lifted for the back-span construction on the west tower, then the new bridge segments will follow.
