The Arch Types of Aluminum Interlocking Buildings

hangar image by F/32 from

Aluminium buildings with interlocking arches have a unique place in American history. Arched metal buildings are also known as Quonset huts. These multipurpose structures were developed during World War II as kits that soldiers could easily transport and assemble for shelter.

Variations of the original design include changes in arch types and building materials. After the war, these prefabricated building kits were sold for business and home use in the states. The unique Quonset hut design is used for storage and aeroplane hangars, churches, restaurants, retail stores and even homes.


hangar image by J-F Perigois from

Quonset huts are assembled with a series of interlocking arches that create curved walls. Full-arch Quonset huts form a semicircle that can bear more weight than the mailbox arch type. Mailbox arches have straighter walls and a curved roof that bears less weight but is more pleasing to the eye.

The lightweight design is made of corrugated steel, interlocking metal arches, and plywood for the door and window openings at both ends of the building. These metal buildings are durable and weatherproof.

The T-Rib Arch

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The first Quonset huts were based on the World War I Nissen hut. The Nissen hut was less durable and much less weatherproof than the Quonset hut. Steel arch frames, metal panels, Masonite wallboards and paper insulation went into the 12 crates that made up the Quonset hut kit. It could be constructed in just one day by ten men, and the construction required no special skills or equipment. The Quonset hut was also known at the T-Rib for its arch type.

Modified T-Rib Arch

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The original Quonset hut design was modified by changing the interlocking arches so that there was four feet of vertical wall on either side. This allowed the soldiers to move beds, sinks and washing machines flush against the walls, creating more space within the structure. The modified arches were assembled in two sections instead of three and were much lighter than the originals.

Return to the Full Arch

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In 1943, Great Lakes Steel Corporation's Stran-Steel Division took over the Quonset hut contract. The Stran-Steel Quonset hut brought back the full arch and increased the size of the metal building. Although the constructed shelter was larger than older versions of the Quonset hut; it was much lighter.

Wooden Arches

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Wooden arches were an arch type used in a variety of Quonset huts created during the war. The James Manufacturing Company used wooden ribs and insulated fabric covering in their kits. These huts were designed for arctic conditions. The fabric used was fireproof, pest-proof and waterproof. Connecting bars, fasteners and nails were the only metal components of these buildings, and the packing crates they came in became the floors.

Steel was in high demand during the war, and it wasn't a weather-hardy choice for shelter. It rusted in tropical conditions and conducted the cold in the Arctic. Frank Hobbs designed the Pacific hut in 1942. This all-wooden hut is covered by a waterproof form of Masonite.

The Emkay hut was created by the Morrison-Knudsen company. It had a two-centered pointed arch, wooden ribs, wallboard and was an all-weather choice. The Emkay hut could be constructed to any length in multiples of 12 feet and was used for large military outposts.

The Portaseal hut is a wooden structure with tarpaper covering and plywood walls. These huts were often used along the Alaska Highway and Canol pipeline.

Utility and Interlocking Huts

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Large metal buildings were used as warehouses and shelters during World War II. The Armco hut was a heavy iron building without ribs, but it was curved and corrugated like the Quonset hut. This building could withstand six feet of soil on its roof. Cowin steel buildings were designed to withstand the weight of snow, but these "Steeldromes" could not handle Alaskan snow loads. The elephant hut or utility building is a large version of the Quonset hut. It took ten men 300 hours to construct these metal buildings. The multiple building uses interlocking arches and can expand in both directions. National Steel Products built their 5-acre Houston headquarters with multiple building units.

The Quonset Hut Today

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Prefabricated metal buildings are still used today, but few employ the arches used in the original Quonset huts. Aluminium arched warehouses are descendants of the Quonset hut, and arched metal buildings are often used as residential storage sheds today.

In the book "Quonset: Metal Living for the Modern Age" the Quonset hut is described as an American icon and a feat of American architecture and ingenuity.