There’s an adage that says the two happiest days of owning a boat are the day you buy it and the day you sell it. I imagine the same can often be said for airplanes. Maintaining and storing expensive aircraft comes with a lot of headaches. Aerospace engineering is about harnessing physics to slip the surly bonds of earth but it’s also about what all engineering is about: simply solving problems.
Near the turn of the century, aviation engineers began dealing with a new set of problems. Airships, hailed as a revolutionary new form of air transportation, have certain limitations. Their vast size and delicate skin make them challenging to house. As a result, airship hangars are among the most impressive clear-span buildings. Ranging from massive barns to arched tunnel-like structures, the hangars which house zeppelins, blimps and airships are enormous and expensive. In fact, some of the world’s largest buildings are airship hangars.
Quick-Turn, Cost-Effective Building and Storage Solutions
Reasonably, most aerospace companies aren’t looking to break world records. In fact, most companies in the market for an aircraft hangar or other large outsized structure are looking for something they can construct quickly and cost-effectively, due to, for example, a new business development that has expanded their operational needs beyond their current resources.
Tesla’s Fabric Structure
An example of one such company is Tesla. The company’s Howard Hughes-esque CEO, Elon Musk, recently announced that a new Model 3 assembly line was built in two weeks and at much lower cost than the Fremont facility’s other structures.
Armchair critics were skeptical of the fabric structure, while others praised Musk for what they saw as a groundbreaking innovation. Don’t get me wrong; Musk is no fool, but his use of a fabric structure wasn’t a stroke of disruptive genius—it was just good business.
Fabric Hangar and Manufacturing Facility at Solar Ship Inc.
Musk isn’t the first to find that fabric structures can be a low-cost, quick-turn solution to a facility’s expansion headaches. With the sturdy construction of a fabric building, constructing a clear span wide enough to accommodate aircraft for storage, maintenance or even assembly is possible. Tesla’s factory is constructed of aluminum arches, designed to be easily dismantled and relocated elsewhere. For more robust or permanent building needs, fabric buildings with steel structural members and concrete foundations are preferable.
Legacy Building Solutions, a USA-based custom fabric building manufacturing firm, recently completed construction of a building for a Canadian aerospace company called Solar Ship, Inc. Solar Ship’s fabric building is designed for off-grid manufacturing and maintenance of large aircraft.
Solar Ship is in the airship business, building specialty hybrid aircraft to service remote areas with no roads. The wing-shaped design combines the lift of buoyant gas with aerodynamic lift, allowing extremely short takeoff and landing. Solarships are designed to carry cargo to places cut off from the infrastructure of the modern world, including applications such as providing disaster relief, shipping to Canada’s remote north, and connecting remote areas in Australia and China.
The ships’ large surface area allows for solar electric power, which extends the ships’ effective range. While today’s solarships use combustion engines, one of the company’s goals is to eventually abandon fossil fuels in favor of solar electricity.
In keeping with this philosophy, the company wanted their hangar structures to be similarly self-sufficient.
Their fabric structure, measuring 176 x 230 feet, is 60 feet high at the eaves and soars to 82 feet at the peak. As the name suggests, Solar Ship is interested in solar power. The building’s steel skeleton supports twin solar panel banks on the roof, which power the building’s interior lighting and massive doors completely off the grid.
The hangar’s door opens to a maximum width of 164 feet and is 59 feet high. Vents in the fabric sheathing at the peak and soffits allow for good ventilation.
The building’s steel frame sits on an existing concrete pad. Most custom-built fabric buildings, including ones built by Legacy and the one at Telsa’s Fremont facility, are built on a concrete foundation. Customers often intend their fabric buildings to be non-permanent. In these cases, the building can be removed, and the concrete foundation reused.
Why Use Fabric Buildings?
Legacy’s fabric buildings use a proprietary material called ExxoTec PVC fabric. This material is a composite comprised of six layers of primers, top coats and lacquers surrounding a base fabric.
The material is designed for high tensile strength and works with the steel structure to withstand heavy snow and strong wind loads, up to 150 mph wind and up to 256lbs per square foot. The fabric is also translucent, which lets in enough light that most Legacy buildings do not need additional electric light during daylight hours. ExxoTec is also self-cleaning and flame retardant. The material is exceedingly tough and difficult to puncture or tear, and the ripstop fabric prevents small tears from propagating.
The steel members, which can be treated for corrosion or rust, form the same framing structure used in traditionally clad buildings. One advantage of this heavy-duty structure is that additional loads, such as gantry systems, conveyors, or large door systems can be supported. This is especially useful in aerospace manufacturing and maintenance applications.
The fabric cladding has a life expectancy of 20 to 30 years. According to the company, this is comparable to what you’d expect from a typical steel-clad building. The key to the fabric’s longevity is proper biaxial tensioning of the fabric. Correct attachment between the fabric and the metal frame is essential to achieving this proper tension, avoiding sagging and wear. The steel frame has a much longer lifespan, exceeding 50 years.
Fabric buildings offer virtually all the benefits of metal-clad structures, as they are durable, flexible, have a long lifespan and are faster to erect.
(Image courtesy of Legacy Building Solutions.)
Aerospace engineering is full of challenges, not the least of which is building a place to store, maintain and build aircraft. Design constraints of hangars include lofty ceilings, wide clear spans, large doors and accommodation for equipment such as gantry systems, mega doors, or conveyors.
The needs of aircraft hangars align well with the capabilities of fabric buildings, and many aerospace and aviation companies are turning to the innovative building system to reduce costs and obtain a better, optimized building.
For more information about Legacy Building Solutions, visit their website.
Legacy Building Solutions has sponsored this article. Opinions are my own. Isaac Maw