The osprey is adapted to a wide variety of habitat, but does have certain standards for nesting. So too the namesake bird, the United States Marine Corps MV-22 Osprey Tiltrotor Aircraft, benefits from specialized facilities for its care and maintenance.

As the MV-22 came online in recent years to become the primary assault support aircraft for the U.S. Marine Corps, leadership at the Marine Corps Air Station (MCAS) Camp Pendleton committed to building a dedicated hangar for the six Osprey now assigned to the base.

Balfour Beatty Construction, which has done a number of design-build contracts with the U.S. military over the years, won the $38 million contract in 2012, based on a package emphasizing safety and sustainability. 

The assignment included demolition of an existing hangar, and design and construction of a new, 123,451-square-foot, two-bay hangar to include state-of-the-art specialty maintenance shops, administration offices and mission planning facilities. KMA Architecture provided design services. 

The greatest engineering challenge, and maneuver evincing the most safety concerns was the placement of two 475,116-pound, 10-foot-tall, 20-foot-wide, and 340-foot-long steel truss sections. As the largest steel erection ever at MCAS, that element of the build got special attention from top officials.

Safety First

It was safety first in the extensive planning for the project, and it was also safety first in the daily routine on site. Each day started with a "stretch and flex" for all workers. The light warmup and stretching has health and safety benefits itself - helping to prevent the soft-tissue and muscle strain injuries that often bother construction workers.

Gathering the entire work crew also gave supervisors a chance to verify that all were fit for work that day.

"It gives us a chance to make sure everyone looks sound," said Balfour Beatty Construction Superintendent Dan Chandler.

After the stretching, a full briefing on the day's activities was given to all hands at once. That practice avoids the risk of errors and omissions that can occur when the word is just passed down from supervisor to foreman to laborer.

Even before anyone entered the site for the first time, noted Quality Control Manager Pat Anderson, they had a full safety orientation, and been shown the logistics and plan layout.

The attention to safety is part of Balfour Beatty's "Zero Harm" culture. It involves meticulous planning and consideration of all possible risks, according to Chandler.

According to Senior Project Manager Mark Chappell, "It's a matter of making safety personal. It's not enough to meet OSHA standards. Our goal is to remove any risk, and to do that we get input from the newest hire to most senior workers."

There is a special focus on newer workers - based on studies showing most injuries occur to first-year workers, they had special stickers on hardhats, so more senior workers could look out for them.

And although meeting OSHA standards is not the be all and end all of safety efforts, it is nice to have validation that the standards are met. So when the project had a surprise visit from OSHA, managers were pleased that after two days on site, the inspectors found no violations at all.

But the most important measure of the project success was that in a 21-month project comprising 200,000 man-hours of work, there was not a single lost-time incident. "We are very proud of that," said Chappell.

Designing for Sustainability

Sustainability was another priority on the project, and the project was designed to meet the requirements for a LEED Silver rating from the United States Green Building Council. Anderson noted that the sustainability efforts began with the demolition of the old hangar.

"All the material was recycled," she said. "There was need for soil stabilization which took the form of 930 stone columns, each about 3-foot-wide, and 45-foot-deep."

Subcontractor Hayward Baker set up a recycling plant to produce 1-1/4-inch rock and used a 900 CFM compressor, BG-24 drilling rig, 900-ton belt crane, and American cranes with five yard rock hoppers to install the columns.

The green features of the building include a photovoltaic parking structure with 20 kW solar photovoltaic array that will provide 30 percent of the energy to the facility. A highly reflective single ply PVC cool roof system, which requires less energy consumption during the summer, and R-30 insulation in the walls serve to reduce the climate control costs.

To make the most of natural lighting, there are 60 skylights in the hangar bays, and there are 58 solar tubes at roof level streaming sunlight to second floor areas. The light from the solar tubes in controlled by dimmers in the ceiling lenses, so that meeting and presentation spaces can be darkened for videoconferencing. Base authorities required that all electric lighting in the office space utilize LEDs. Specialized low-E glazing that reflects away heat and ultraviolet light was used in the windows. An additional requirement was that the glass be blast resistant.

To maintain mission readiness, the building was also outfitted with two generators that can provide 100 percent backup energy in case of an emergency.

Working Around an Active Flight Line

Operating within 50 feet of an active flight line presented special challenges to the construction team, and particularly when it came time to deliver and install those massive steel trusses. Three months of planning went into that operation, with coordination required between the contractor, the military and Caltrans, among others.

The material was delivered from El Cajon, about 7 miles away, in eight sections, each 80-feet-long, 10-feet-high and 20-feet-wide. Working around road construction and base activities, the deliveries were made at midnight. A California Highway Patrol escort accompanied the trucks to the base entry. Since the material had to traverse the actual airstrip, wide gates had been built into the security fencing. The gates were just wide enough, Chandler said, providing about 4 inches of clearance. But drivers and flaggers met the challenge. "We got pretty good at it by the end," said Chandler. The pieces were assembled and lifted by two cranes working in tandem.

Luis Adrianzen, Marine Corps Air Station Public Works Division Project Leader, praised Balfour Beatty for the successful completion of the complex project. Construction was completed in December, and the Marine Corps moved in and began operations in the new hangar facility within a couple of weeks. "Senior leadership was very pleased with the lack of impact on base activities, and the way Balfour Beatty kept everything within the work area." Execution of the project was "flawless," he said.