downtown seattle 2+U office tower frame being set up by cranes and equipment

A recent case study published by Lifting Gear Hire, a lifting equipment rental specialist, featured Omega Morgan Crane Service and showcased their expertise at creating innovative solutions. Apex Steel and Lifting Gear Hire partnered with our Seattle team to set the foundation for an office complex nicknamed the 2+U office tower in downtown Seattle, Washington. The core of the challenge rested with the Y-shaped structural columns supporting the proposed 38-story building. They would need to evenly distribute the weight of every floor above and maintain a 72-degree angle of installation.

With limited space and a strict schedule of road closures, Omega Morgan and Apex Steel utilized their skill and experience, along with a skip-around schedule, to set the supports. The supports were engineered to start on the second floor and pass through the next five stories at a 72-degree angle.

With a total weight of 165,400 pounds for the heaviest support columns and a height of 60 to 70 feet, it was necessary to install them in sections. The rigging itself weighed nearly 4,700 pounds, and accurately lining up the pieces to ensure even weight distribution, with space for only one crane, required precise calculations.

On-site challenges also had to be overcome. The anticipated crane position was changed to avoid having the counterweight contacting and damaging branches of a nearby tree. To eliminate the possibility of damage to the tree, branches were tied back and the crane re-positioned five feet away and set on a wooden ramp to accommodate a slope.

The weight of the columns and the tight space necessitated an innovative rigging situation where a single crane could install the columns. Further, the limited space demanded the single crane’s rigging setup to be as short as possible.

Omega Morgan engineers used a rolling block and hoist system to minimize the headroom once the columns were upright. Because it was impossible to use any tall rigging, a short main boom was used to ensure column placement without interfering with other structural components of the building.

The collaboration of the parties ensured completion of the job safely and on schedule. Having the right equipment and reliable partners is as critical to the successful completion of a job, as is the team’s knowledge and experience. The combined efforts of Omega Morgan, Apex Steel, and Lifting Gear Hire enabled the team to overcome a series of challenges that this project presented.