The City of Portland is a haven for bicyclists and pedestrians. With over 6% of commuters biking to work daily, Portland easily ranks number one with the highest proportion of any major U.S. city. When the Portland Bureau of Transportation’s studies identified the need for a safe crossing between two of Portland’s fastest-growing neighborhoods–Lloyd and Central Eastside–a plan to build a bridge between the areas began.

Blumenauer Bridge (originally called Sullivan’s Crossing) will provide this vital access between two growing areas of Portland and a connection to the city’s green loop for cyclists and pedestrians alike. Once planning commenced, the contractor awarded the project needed an experienced and safety-first heavy lift and rigging company to install the bridge. Omega Morgan’s Portland heavy lift and rigging team became the natural choice.

ENGINEERING A HEAVY LIFT & RIGGING SOLUTION

Omega Morgan’s engineering department began planning the project at the end of November 2020, with limited information regarding the structure of the modified deck-tied steel arch bridge. In the early stages of plan development, our team identified several challenges, beginning with the bridge’s ability–or lack thereof–to support itself at the designated rigging locations. Together with another engineering firm on the project, the team devised an effective solution to stiffen the bridge in key areas by welding collars to the upper tube, allowing for the structure to be safely rigged and placed. Additionally, the uneven ground and uphill path created the potential for the necessary gantry system to tip at the base.

By installing rotating tilt caps to our attachment points and a turntable to the SPMT, we enabled the bridge to rotate as our heavy rigging crew moved south to north on the fixed gantry system.

After months of planning, when our heavy lift and rigging team learned the final weight of the bridge–560,000 pounds, 13,000 pounds heavier than previously expected–they went back to the drawing board. To accommodate the increased weight, OM engineers added two cranes to the plan–one in the initial phase to move the bridge onto the gantry system, and a 100-ton crane to assist the 550-ton crane for the final set. The engineering team also decided to set the bridge at the north end, which would allow the equipment transport crew to move east and west to ensure final placement.

Developing the final engineering plan continued through the beginning of October 2021, only days before the scheduled installation, and by the end, Omega Morgan’s engineering team had completed more than 885 hours of work. In all, the team fleshed out eight different iterations, ensuring that they left no detail unaccommodated.

COMPLETING THE HEAVY LIFT ON SCHEDULE

The bridge crosses I-84–a major highway through the city–which needed to be cleared and blocked before work could commence, but could only remain closed for the weekend. Therefore, the plan’s entire execution was restricted to a mere 55 hours. Once the highway was clear at 1:00 a.m. on Saturday, OM’s heavy lift and rigging crew, consisting of two groups of 10 riggers per shift and three crane crews working around the clock, got to work.

We started by jacking the bridge to the correct height to install the SPMT at the first location. The next step involved rigging and lifting the 276′ long by 24′ wide bridge with two 550-ton cranes before lifting with a sharing triangle to our first location. Our plan continued by rigging one 550-ton and one 360-ton crane together with the triangle and one 550-ton crane at the other end, with all three cranes moving the bridge together while being propelled with the SPMT out to the 550-ton gantry. Upon completing that phase, the team moved the SPMT to the other end of the bridge before the final push across the highway. The last move required our 550-ton crane to relocate and re-rig with the 100-ton crane to final set the south end of the bridge.

By 4:00 p.m. on Sunday, Omega Morgan successfully installed the main section of the Blumenauer Bridge, and our heavy lift and rigging crews headed out, leaving plenty of time for the contractors to make any necessary repairs to the highway and finish bonding the bridge to the temporary tower. Our client was delighted with the project’s timely completion and Omega Morgan’s highly professional team. We are proud to be a part of installing this exciting addition to Portland’s pedestrian-friendly infrastructure.