If an ice cream sundae isn’t complete without the cherry on top, then an airport control tower is downright naked without its observation deck. ALL Crane Rental of Georgia, a member of the ALL Family of Companies, set the observation deck for a new control tower at Auburn University Regional Airport—and got to take a brand-new Liebherr LTM 1400-6.1 for a spin in the process.
“The 1400 was perfect for this job,” said Gage Norris, sales representative with ALL Crane Rental of Georgia. Nicknamed the “Silver Bullet” for its silver-and-red paint scheme coordinated by Liebherr and ALL, the new 500-ton all-terrain crane joined ALL’s fleet in June. It is touted as the world’s strongest six-axle mobile crane.
“If we didn’t have it, we would have had to go to a 550- or 600-ton crane,” said Norris. “But those would have required launching the boom, and we didn’t have anywhere nearby with enough room to do that.” Launching involves reinstalling a separately transported boom using a specialized boom-launch trailer. The Liebherr LTM 1400-6.1, meanwhile, uses a boom dolly to support its attached boom during highway travel, eliminating the need to reinstall it at the site.
Construction of the airport’s new control tower began last year, with ALL customer Stone Building Company serving as general contractor. The tower support reaches nearly 100 feet into the air.
The observation deck was built on the ground, with ALL’s Liebherr LTM 1400-6.1 brought in to lift it into place. The deck measures 34 feet in diameter and stands 30 feet high. “Lifting something that size, at that height, you lose headroom between the boom and the load as you hoist,” said Norris. “A lift radius of 55 feet enabled the operator to maintain 6.5 feet of clearance between the observation deck and the crane’s cab.”
To lift the 94,000-pound observation deck, the crane was configured with 181 feet of main boom, Liebherr’s Y-guy superlift attachment to add capacity, and 308,647 pounds of counterweight. All four outriggers were fully extended.
Norris credits the ironworkers with executing the unusual rigging arrangement used to lift the observation deck. “There’s a steel cradle under the entire structure,” said Norris. “The observation deck was actually built on top of it. Four small openings in the roof and four matching openings in the floor allowed the rigging to pass through the structure and connect directly to the cradle below.”
Once ALL’s crane operator positioned the observation deck, the ironworkers carefully worked the cradle free.
The crane held the observation deck in place for five hours while the team of eight ironworkers secured it to the tower.
Before the lift, Norris used Liebherr’s Crane Planner 2.0 software to plan the crane’s configuration and movements. “It works seamlessly with the LICCON [Liebherr Computed Control] system, which is on the 1400 and all Liebherr cranes in our fleet.” The plan actually identifies a lift chart by number that our operator can refer to in his preparation for the lift.”
Norris credited the coordination among Stone Building Company, the ironworkers, and ALL’s Georgia and Mobile, Alabama, teams. ALL’s Mobile branch delivered the Liebherr LTM 1400-6.1 from its yard for the project.
