• Grove GMK6350L

Converting an office complex into a biomedical facility requires many changes; one critical change is ensuring adequate AC and ventilation. For the contractor working on a Seattle, WA building conversion, this meant removing the rooftop HVAC unit and replacing it with a more powerful system. Numerous heavy loads and accessories would need to be lifted on and off the multi-story roof, requiring expert heavy lift capabilities.

The mechanical contractor on the project knew that, based on the building positioning and steep slope, the project needed a specific crane and a team that could handle the challenges and the multi-mobilizations required. That’s why they contracted Omega Morgan’s Seattle crane services team. With permits to apply for and a plan to develop, our crews got right to work on a world-class solution.


Planning began with site visits where the team measured the steep road grade and discovered a large tree and underground utilities, requiring exact crane placement to avoid. Then the crew applied for permitting from the Seattle Department of Transportation, which took eight weeks to receive. We also created a traffic control plan and, once the permit came through, worked with the King County Metro Department to plan around the bus line. 

As our crane team developed a plan, the Grove GMK6350L crane was an obvious choice: it could handle the tight space and hillside set up, as well as having the necessary boom length and capacity. We also discussed and planned for the rigging needed based on the variety of sizes, weights, and types of equipment to be lifted. 

One of the largest lifts would be done on the first day of the project—an HVAC component weighing 18,400 pounds and measuring 11 by 30 feet. We focused on this piece, knowing that once we had the crane in the correct position and had successfully lifted and landed this component, the other lifts would follow in the same pattern and take less time.


When we received the go-ahead from the contractor, our team mobilized the crane and crew. There were eight crew members in total, including three truck drivers, three for crane and mat placement, an operator, and an oiler. Due to the exact placement requirements and placing over four feet of crane matting to create a level platform, our initial mobilization and set up took four and a half hours. Once complete, we began by removing several HVAC units and equipment from the roof.

Over the next four days, our crews made more than 40 lifts from the ground to the roof—including the initial 18,400-pound unit—changing out rigging as needed. Trucks continually arrived on site to deliver components and accessories for rooftop placement. Some of the equipment had been stored by Omega Morgan until the heavy lift project began.

Our crane services team completed four separate mobilizations with three to four weeks in between them. Set up time reduced drastically in later mobilizations as we marked our crane positioning the first time. In the second mobilization, we lifted a 7,700-pound unit and multiple 22,000-pound components—our largest of the project. The third trip to the site included an 18,400-pound lift, among other smaller lifts. And finally, in the fourth mobilization, our largest placement was a 20,000-pound piece, again with numerous smaller loads. In all, we made upwards of 80 lifts and safely placed over one million dollars worth of equipment.

Both the mechanical contractor—our client—and the general contractor were very pleased with our effective crane services. The GC also had us handle a few lifts for them while our crane was onsite. This project spanned several weeks and our teams worked together seamlessly through each lift and mobilization to get the job done safely and efficiently.