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The UK’s largest double console hangar was built for Bombardier Aerospace at Biggin Hill Airport.
Known as one of the main Royal Air Force bases during the Battle of Britain, London’s Biggin Hill is today one of the UK’s fastest growing commercial airports.
In addition to some of the recent investments made at the airport, a new double outrigger maintenance, repair and overhaul (MRO) hangar was recently completed for Bombardier.
Architect: Civil Contract Structural Engineer: REIDsteel Steel Contractor: REIDsteel Main Contractor: Civil Contract Employer: Biggin Hill Airport Construction
The hangar has two entrances with a span of 160 m, internal aircraft maintenance cranes, offices and a VIP lounge.
The project team stated that REIDsteel’s early involvement as a steel fabricator and fabricator, hangar door manufacturer and cladding company contributed greatly to the successful completion of the program.
The company’s input was critical as the steel elements had to be installed and leveled on the 45m cantilever trusses that needed to accommodate the complex hangar door fittings and overhead cranes.
After examining traditional hangar solutions, a more economical design was proposed which included a cantilevered truss hangar structure, a traditional office structure and an elegant glass living room, thanks to the transverse baffles in the roof structure with minimal support.
The clever cantilever design, together with the load distribution elements, has made it possible to significantly reduce the use of materials, producing a much lower tonnage of steel (1600 tons) compared to more traditional designs.
The design also allows the hangar roof to be safely roofed without internal column support, fulfilling the client’s desire for two expansive, unobstructed 7,200 square meter hangar spaces.
Because of the nature of the tension connections in the top chord, long-span cantilevers are said to be inherently prone to disproportionate collapse. To alleviate this and help meet stringent deflection standards, load-sharing trusses were used to ensure that each frame could be supported by its neighbors.
“The central core of the building anchors the cantilever and houses the functional spaces of the building. The design provides a very good carbon footprint of concrete, which corresponds to the ideal values ​​of LETI-2030.”
This creates a new problem, as manufacturing tolerances can cause the frame to be taller than its neighbors, resulting in unacceptably high loads. The solution is to let the load distribution trusses “relax” until all permanent loads are applied, and only then preload the slotted bolts.
The design allows for 100% coverage of two hangars with internal overhead cranes instead of 50% of one hangar, as previously proposed, which makes the project promising.
The double cantilever design also means the hangar can be expanded to meet changing needs over a 50 year design life.
Sustainability was a key consideration, and valuable engineering practices ensured the efficient use of steel in the final design while reducing environmental impact.
The resulting reduction in steel weight is key to minimizing embodied carbon and reducing CO2 emissions by 850 tons. The roof is designed to house solar panels, which could potentially reduce carbon emissions by 300 tons per year, assuming customers provide 50 percent coverage.
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