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Tectoniks pioneers inflatable technology in developing high-value asset protection for Lockheed Martin U.K.
To help provide environmental protection to its high-value assets, aerospace and defense contractor Lockheed Martin U.K. needed a robust, portable and retractable structure that met specific and rigorous functional and technical requirements—and everything had to be accomplished in a compressed timeframe.
After short-listing four companies that submitted full technical proposals, Lockheed Martin selected Tectoniks Limited in Nesscliffe, Shropshire, U.K., for the $1.85 million USD (£1.2 million) project because it had prepared the most feasible design and project plan. “The project involved the design, manufacture, test and delivery of the most technically complex structure Tectoniks had ever produced, from scratch in just seven months,” says David Kelsall, the company’s technical director. With no time for second thoughts, Tectoniks dove head first into the unique project. The shelter needed to be easy to transport and quick to erect. In creating the 14 m long × 14 m wide × 20 m high portable building, Tectoniks developed technology that mounts inflatable walls onto two arched aluminum truss frames.
The project also called for an unobstructed opening/closing door that would not exceed the dimensional limits for the overall structure. To minimize the weight and maximize the portability of the drive system for the 7 m wide × 17.5 m tall door, Tectoniks quickly dismissed the idea of conventional roller doors. Instead, the company devised a design for a hybrid roller door that runs up and over the structure and also acts as the roof, comprised of inflatable elements and rigid aluminum battens. The door is the first of its kind, according to Kelsall.
The resulting structure is strong, lightweight and fits into the specified six 20-ft. shipping containers.
Not only does the system have to travel easily from one destination to the next, it needs to maneuver effortlessly within any given location. To that end, Tectoniks fit four rail-mounted motorized carriages to the base, which conceals 70 water-filled ballast tanks designed to help the structure withstand 70 mph wind speeds as required by Lockheed Martin. The motorized carriage set-up enables the entire 40-ton structure to move 50 meters from its home position at speeds of up to 10 meters per minute.
Strength and durability
In addition to high winds, the Lockheed Martin shelter needed to withstand other extreme environmental conditions. Tectoniks selected materials accordingly, using Serge Ferrari’s Stamoid 5005 fabric for all of the inflatable elements because of its light weight and strength. Serge Ferrari also applied an antistatic coating to the fabric to make it usable in hazardous atmospheres, Kelsall adds.
As it did with all of the components comprising the structure, Tectoniks electrically grounded the fabric by running an earth cable to a ground spike via a flexible cable raceway.
Tectoniks witnessed the system’s resilience first-hand when conducting the test assembly outside the company’s facility in February 2013. “During this period, the U.K. experienced the worst recorded weather for 100 years,” Kelsall recalls. “The structure was subjected to 67 mph winds, freezing temperatures and over a foot of snow accumulation.” The shelter came away unscathed.
The test assembly was only one part of Tectoniks’ thorough testing process for the structure. Modeled using advanced 3-D computer-aided design (CAD) software, the system underwent rigorous structural evaluation, including finite element analysis (FEA). The computerized method predicts how a product will react to physical effects such as mechanical stress and vibration, heat transfer, fatigue and electrostatics. Tectoniks’ FEA simulated all conceived loads to which the structure might be subjected, including self-weight, wind loads and ballast weight.
Beyond the composition of the unit itself, Lockheed Martin required the integration of all operational functions and systems to allow local and remote monitoring. Engineers and operators control the structure locally through a control panel and human-machine interface (HMI) screen located inside the building. Remote control is handled through an Ethernet link to a remote station with duplicate controls and displays.
Monitored parameters include motorized locomotion and door drives, internal and external lighting, air conditioning, position sensors, CCTV, wind speed measurement, temperature and humidity measurement, and parking brake control. Since the structure reaches 20 meters in height, Tectoniks equipped it with aircraft warning lights and lightning conductors.
After Tectoniks completed the project on time and on budget, Lockheed Martin U.K. put the structure to work in its own rigorous testing acceptance process. Says Kelsall, “It passed with flying colors before being dismantled, packed and readied for shipping.” The structure performed perfectly at its first deployment in 2014.
New ideas, new opportunities
Tectoniks gained a variety of insights while working on the one-of-a-kind project. “The main difference from other structures we have produced was the incorporation of the aluminum truss framework into the overall design,” says Kelsall. “This wasn’t simply a rigid framework covered with fabric—the frame and the inflatable elements work together, and both contribute to the overall structural strength.”
He also calls the inflatable roller door “an entirely new concept [that] greatly reduces weight, making it possible for such a large door to be installed and operated.”
According to Kelsall, the technology Tectoniks developed during the design and manufacture of the project, along with the type of structure itself, could serve many prospective markets. “The military is perhaps the most obvious, but the technology is suitable for any application that requires an opening/closing/moving structure that can withstand extreme weather,” he says.
Some possible applications include enclosures for astronomical telescopes, satellite dishes and radar installations.
Good relationships with clients are essential to success in this type of project; Kelsall emphasizes the importance of a close partnership to ensure a successful outcome for everyone involved, particularly when entering uncharted territory. “Despite the huge technical and logistical challenges faced during the project, we were always assured of Lockheed Martin U.K.’s full support, and motivated by a common goal,” he says.
Holly O’Dell is a freelance writer and editor based in Pine City, Minn.