Strand Jacks Lift 1.7 Million Pound Box Truss for New UPS Aircraft Hangar

Engineered Rigging once again demonstrated its heavy lift prowess — this time helping to build the largest aircraft hangar under construction in the United States. The 275,000 square foot hangar, part of the new United Parcel Service (UPS) Northwest Aircraft Maintenance Complex in Louisville, KY, will house two Boeing 747-8F aircraft, the largest in its fleet. A key component of the new hangar is a 380-foot long box truss weighing 1.7 million pounds. Engineering Rigging’s strand jacks handily positioned this hefty component.

The box truss is part of the door side of the hangar, and it needed to be raised 80 feet. Its length (longer than a football field) and massive weight required careful planning. Engineered Rigging, which provided equipment rental and onsite support, joined forces with Hensel Phelps, general contractor; Midwest Steel, steel erector; and Ruby and Associates, lift engineer.

“We collaborated closely with lift designer Ruby and Associates to provide drawings of a typical layout that worked with the lift plan,” explained Mike Beres, director of operations for Engineered Rigging. “Later, we helped Midwest Steel to ensure it had the proper equipment and best support possible in the field where we assisted with installation and equipment operation.”

Engineered Rigging provided four 300-ton HSL30006 strand jacks, four SLPP15E hydraulic power units and a unique above jack strand managing recoiler system. After helping to load the strand, a single company operator — on the ground and positioned safely outside the lift zone — used computer controls to execute the 80 foot lift. The lift took 10 hours to complete, in 16-inch increments.

Benefits of Strand Jacks
Using strand jacks to pick and raise the box truss eliminated the dangers associated with the suspended loads of cranes. How? A strand jack is a linear winch in which a bundle of steel strands moves through a main lifting jack. Above and below the cylinder are anchor systems with wedges that grip the strand bundle simultaneously. Lifting and lowering a load is achieved by hydraulically controlling the main jack and two mini jacks (at the top and bottom) alternately. If the system loses pressure, the wedges automatically close, mechanically locking the load in place, thus achieving safety.

Overcoming Challenges
In addition to its sizeable span and incredible weight, the long box truss was also susceptible to thermal expansion, as temperatures fluctuated from morning to evening. This expansion would cause bolt holes to misalign. To solve this problem, Engineered Rigging performed the lift in the evening-to-night time frame.

“Once we lifted the truss, our stand jack system mechanically supported the load overnight to allow the truss to cool,” said Beres. Because the strand jack system supported the load in place, workers could safely wait until temperature conditions were optimal to bolt the box truss into place.  This process took several days to complete. “Our strand jacks provided the ability to safety wait,” added Beres.

In addition to the strand jacks, Engineered Rigging also supplied a split flow pump (SPF) to each temporary tower that had been supporting the incomplete truss. Once the box truss was secured, the SPFs and locking hydraulic cylinders facilitated the removal of the temporary towers. This equipment included the SFP421SJ pumps, hydraulic hoses and eight HCL2006 200-ton cylinders.

“Engineered Rigging is happy to have applied our heavy lifting expertise to the UPS Northwest Aircraft Maintenance Complex,” Beres added. “It is exciting to know that we have been able to help UPS keep its planes in the air as it meets growing global demands for air transport.”

For more information about Engineered Rigging’s equipment rental fleet and capabilities, visit www.EngineeredRigging.com.