The Boeing Company, the aerospace industry’s global giant, recently expanded its St. Louis, MO manufacturing complex with the help of Condaire Inc., an industrial mechanical contractor.

Boeing added a 90,000-sq-ft aircraft hangar that houses the production of F/A 18 fighter jets, which Boeing acquired along with a fleet of other military aircraft when it merged with McDonnell Douglas in 1997.

Condaire, which has earned the globally recognized ISO 9001 certification for quality assurance, installed the hangar’s hvac and plumbing systems on an incredibly tight construction schedule.

Boeing wanted the hangar finished and ready for production in time to honor a commitment to its union employees so they could begin work. The compressed schedule allowed Condaire a scant three-month window to complete work that ordinarily would take nearly a year.

Prefabrication helps time frame

One of the keys to the Condaire team’s ability to meet such a fast pace — and to do so safely — was that it prefabricated the piping in-house and then shipped it, ready to install, to the jobsite.

Although prefabrication is not a new concept here, it has been used primarily by contractors in the industrial market, according to Greg Harrop, Condaire’s vice president of operations. Companies like this one are borrowing from that industrial experience and increasingly using prefabrication in their hvac and commercial work.

“We see prefabrication as the way all business has to go because it’s going to make you more cost-effective,” says Keith Myers, vice president of business development at Condaire.

“You’re in control of the atmosphere, you have lifting equipment and automatic welding equipment all around you, and you’re in a safe atmosphere. It makes your cost of installation — your actual field hours — less.

“As long as things are field-measured and drawn properly, they’ll be fabricated according to the drawings,” he continues. “As long as that’s done, you’re going to have a more cost-effective job than if you were to build it at the site.

“Imagine trying to weld or groove something 70 feet in the air. It’s rather dangerous and time-consuming.”

The contractor estimates that prefabrication of the piping reduced the installation time in the Boeing hangar by 25%.

That time savings became even more critical when six York air-handling units arrived at the jobsite one month late, compounding the already tight schedule.

“That put everybody in a little bit of a bind,” says Harrop. “So we prefabricated the piping and got it up into the rack above the air-handling units and got all of that work pulled ahead.

“When it came time for us to set the air-handling units up there, we had as much pre-measured, -cut, and -grooved as possible. Then we were able to erect the six units in about three days and get them piped up.”

High up with no scaffolding

A tight construction schedule was not the job’s only challenge. Installing an hvac system in an aircraft hangar, in which plenty of clearance height is a given, also poses logistical problems: How does one safely install piping and other pieces of equipment 60 ft off of the ground without any scaffolding?

“You’re talking about being close to 60 feet in the air without anything underneath you,” Harrop says. “There was no platform underneath us and no way to build any sort of scaffolding to get up there, so it was all done out of basket lifts and by rigging it.

“We put up as much of [the piping] in 40-foot lengths as we could. It was difficult to rig the air-handling units, because we had to boom them up through some steel and set them into place.”

The contractor’s four-man crew also worked from narrow catwalks that allowed little room for equipment and even less room for mistakes. Other contractors on the job had to share the same space, so cooperation was critical.

The challenges, however, didn’t end there.

The Condaire team connected the utilities in the new facility to those in an adjacent hangar over a jet that was under construction. One mistake on the crew’s part (such as dropping a piece of equipment on the aircraft) could have easily cost millions of dollars to repair.

Coordination breeds success

Ultimately, Condaire and its subcontractors completed their work successfully without any recordable accidents. Harrop and Myers attribute much of that success to the continuous coordination meetings that started immediately after the contract was awarded and continued for the project’s duration.

“The general contractor [J.S. Alberici Construction] really worked well with its subcontractors. Instead of working against them, they worked with them.

“They had an excellent project manager who was concerned about his subcontractors getting done, not just about doing his own work and leaving us in the lurch. There was a good team all the way around,” says Harrop.

Lockwood Greene, the engineering firm that designed the hvac system, also cooperated and allowed Condaire to make adjustments to the design so that the system could be installed properly, according to Harrop.

Bob Duckworth, senior estimator at Condaire, also credits that type of cooperation for the project’s success.

“We completed the job as partners rather than as separate entities. If it weren’t for that partnering outlook on the job, it wouldn’t have gotten done.”