Single-Day Bridge Installation

Skybridge in Clayton

This newly installed bridge across Hanley Road in Clayton, Missouri, connects the level 2 cafeteria of the 7700 Forsyth Building to level 2 of the new 7676 Forsyth Building.

Construction began on the bridge in October 2018 at a staging area 1/4 mile from the installation site. The bridge is a steel structure with a concrete floor slab on metal deck. The walls are high performance curtain wall with a laminated blue glass and composite metal panel roof and soffits.

Conventional erection of this sort of construction would have resulted in numerous road closures to a major thoroughfare. By building the bridge off-site and transporting it for single-day installation, Clayco saved local residents and businesses an estimated 5 months of impact to traffic.

Heavy Lifting

In order for Clayco to be able to build the bridge offsite, our team had to rely on the heavy-duty, carrying power of a Goldhofer trailer. The trailer model used in the installation had 160 wheels divided among 40 axles, each with the ability to be independently operated via remote. With a carrying capacity of over 1.5 million pounds, this trailer easy managed and maneuvered the 250,000 pound bridge and the other equipment into place. Once positioned between the two buildings, the bridge was lifted by two HWP gantry cranes. The cranes operate with synchronized lifting to ensure no load shifting and can hold up to 600 tons.

All In A Day’s Work

The skybridge bridge began its 1/4 mile journey down Forsyth Boulevard to its final destination on Hanley Road at 7 a.m. At a painstaking pace, the crew maneuvered the trailer and bridge into place by 9 a.m. Using gantry cranes, the bridge was rotated on a 10-foot turntable and hoisted 33 feet above street level and positioned between the two entry ways. With only a 3-inch margin of error for the bridge’s rotation between the two buildings, positioning needed to be exact. Crews began welding the skybridge into place at 4 p.m. The bridge was securely welded and released from the cranes and trailer by 9 p.m. Hanley Road was reopened to traffic the next day.