General Dynamics Electric Boat (EB) is a primary builder of submarines for the US Navy. For our client Midwest Steel, Degenkolb’s team was asked to provide erection engineering, crane logistics and truss rigging for three new EB hull fabrication and outfitting facilities totaling 350,000 square feet.
Two three-bay facilities include 18 massive 12’ X 2’6”, 175,000 lb built-up columns in each, and a third facility, the Virginia Payload Module (VPM) building is a 30,000 SF 1-bay facility. The buildings include overhead cranes, offices and maintenance areas beyond the large fabrication bays.
Degenkolb’s charge included reviewing the EOR’s details to ensure erectability. Degenkolb’s erection plan identified the number of sway frames necessary to laterally brace the huge 227-foot trusses, weighing up to 192,000 lbs. The team was challenged with setting the first truss in each bay without sway frames at the top chord, and maintaining stability during erection.
Because the facilities are located on a windy bay on the East coast, lifting was a challenge for the two cranes on-site. Degenkolb advised that vertical brace frames were placed ahead of time so the team had proper stability from start to finish.
