Fort Bragg constructs building using shipping containers
Fort Bragg, N.C., recently marked completion of its first steel shipping container building.
The two-story, 4,322-square-foot container building is the 249th Engineers Company operations building and houses two company detachments, reports Public Works Digest.
The U.S. Army Corps of Engineers began construction last July, and the building was completed in November — a total construction time of only 110 days. The building was the first multi-story commercial structure of its kind in the United States.
Greg Bean, the post’s director of public works, attributed the project’s success to a combination of hard work, extensive collaboration and a willingness to consider innovative — perhaps even radical — solutions for Fort Bragg’s needs.
The project encountered complications early. The original contractor had difficulties creating a design that met the necessary specifications, according to Nathaniel Hermann, the Corps’ resident engineer and the project champion,
“Their proposed standard construction solution was going to be a single-story well under the requested 5,000 square feet, so our field office began attempting to help them locate a good solution,” he said.
Then, Ken Gray, the Fort Bragg area engineer, urged Hermann and Jim Gehle,
a fellow resident engineer, to consider a modular alternative. Typical modular construction is built at an off-site factory and later relocated to the build site to minimize construction time and maximize site space and efficiency. The basic structure, which often consists of sections, or “modules,” arrives complete with pre-installed mechanical, electrical and plumbing systems, thus saving significant time and labor costs.
SG Blocks, a Missouri firm, was chosen as one of the principal subcontractors to the Clement Group of Montgomery, Ala., for the turnkey project.
Built to last
The new facility is constructed of 12 used, 14-gauge steel shipping containers commonly called “40-foot Hi-Cubes.” Each of the durable containers measures 9 feet 6 inches high, 8 feet wide and 40 feet long. Each module weighs about 8,500 pounds, is built to hold 50,000 pounds and is capable of withstanding the weight of eight like-sized containers stacked on top of it.
Its durable design characteristics do not end there. The container floors are sup- ported by a grid of C-shaped steel channels spaced 12 inches apart and covered by a 1 1/8-inch layer of marine-grade plywood. The joints and foundation are welded together to further reinforce the container’s structural durability.
“It’s highly unlikely that the structure of these buildings will rot or get moisture damage, and they’re less likely to grow mold or mildew,” Hermann said. “They’re stronger, longer-lasting buildings that are substantially less susceptible to moisture, wind and other elements.”
Modular design offers a number of advantages from a construction standpoint as well. In the face of upcoming expansion initiatives, modular construction could offer some relief as Fort Bragg strives to meet its rapidly expanding infrastructure needs.
While its structure differs from standard military construction in many aspects, Fort Bragg’s newest building conforms where it counts. With an exterior appearance designed to meet the installation’s specifications, the building blends with its surroundings.
The building also boasts the longevity necessary to meet the Army’s 50-year structural life-cycle requirement for all standard construction.
In addition, at under $750,000, the building has a price tag comparable to that of standard construction on Fort Bragg. Materials costs are minimized by purchasing used containers.
About 250,000 containers used to bring foreign goods into U.S. seaports are left there as surplus as a result of trade imbalances. New containers typically cost about $4,500, but used ones can be bought at less than half the price.
The building cost is about $150 per square foot. However, officials predict this cost will decrease as contractors become more familiar with constructing container buildings.
Model of sustainability
Apart from being a sound economic investment, shipping container construction offers a number of advantages from an environmental standpoint. Converting used shipping containers into buildings may present much-needed solutions to the growing national problems of rising construction and materials costs, diminishing virgin steel resources, widespread deforestation of timber for construction purposes and the growing excess of abandoned shipping containers at U.S. seaports.
The process also uses steel in its most conversion-efficient form and preserves energy that would’ve otherwise been expended in the construction of new materials.
SG Blocks calls this practice “value-cycling,” which it defines as finding an alternate use for an end-of-life product that does not require a significant amount of new energy or resources to convert.
Melting down an 8,000-pound steel shipping container expends 8,000 kilowatt hours of energy, said David Cross, SG Blocks’ business development officer,. However, it takes only 5 percent of that amount, 400 kwh, to modify the container to be used as a building block for construction.
“We did the work here, and the work wasn’t in carbon footprint or electrical energy, it was in human energy, and that means we put people to work,” he said. “We create jobs.”
Building Fort Bragg’s future
A lot of people have experimented with using shipping containers for residential buildings, and the military has used them overseas in downrange tactical situations, such as Iraq and Afghanistan and during the first Gulf War. But nobody in the United States has put brick and an exterior insulated finishing system on the outside and completely finished the inside to effectively use them as an integral building component.
The container building’s innovative intermodal design is one of many currently being proposed for the installation.
“We’re looking at future projects utilizing these technologies, and not necessarily using just containers,” Hermann said. “The British call these innovative techniques ‘modern methods of construction,’ and it could be wood modular, or steel modular or containers. We’re looking at what people are doing in Europe and Japan and trying to bring some of those techniques here.”
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