The 20ft shipping containers were available more than 50 years ago. The first containers were used to send goods in metal boxes that could be loaded and unloaded by crane. The first businessman to load a ship with several dozens of 35ft shipping containers was Malcolm Mclean, a North Carolina resident.
His route was Newark, New Jersey to Houston, Texas. A shipping container is made up of a body with bottom, top, and side walls having upper and lower horizontal hollow chords. Each of these chords has an opening at the bottom and top. To allow runoff of dirt and water, it has interior baffles sloped downward.
Generally, the cargo container is made with closed-top dry vessels from aluminum, plastic, plywood, fiberglass, steel or a combination of these materials. The hinged rear door allows for stowing and unstowing of cargo.
Todays shipping containers are made in many ways. Some are made from 14 gauge steel with an exterior dimension of 20×8.5×8, which makes them an ideal onsite storage unit. Containers are made in several sizes like 20, 30, or 40 feet long with a height of 8, 8.5, and 9 feet.
A 20ft shipping container is designed to store and carry anything. It is ideal for short or long-term choice of storage units for building supplies, commercial use, and home use. A 40-ft shipping container does not have pockets. All containers bottoms walls have u-shaped horizontal beams found midway along the length of the wall and extending downward.
The walls have a top with one aperture and many baffles are seen along the beam. These baffles extend outward from the side toward the opposite sidewall, and stop at spaced intervals from the wall.
Shipping containers made from steel have corrugated walls welded to the top, end frames, and bottom side rails. Found on the containers 8 corners are steel castings served as the end frames and welded to 4 corner posts. Their roofs may be made of corrugated sheet steel or flat sheet steel.
Supporting the roof structure are the interior bows. The plymetal doors are fitted with anti-rack and locking hardware and weatherproof seals. The floor is made of wood laminate, plywood or planking screwed to the cross pieces.
Containers made from aluminum are fitted with steel. The parts of the containers with steel materials are the end frames and side rails. The interior and exterior posts with sheet aluminum make up its walls which are riveted to the posts. Plywood lined the internal walls and roof bows which are welded to the top rails, bolted, or riveted, are made of aluminum.
Fiber-reinforced polymer, FRP, is another material used in making shipping containers. In this material, the container is framed in steel with FRP panels fitted on the wall sides, roof, and front-end wall. There are no roof bows to support the roof structure. However to make them waterproof, it is coated in mastic.
20 ft shipping containers are known for their strength and durability, modular elements, transportability, availability, and cost-efficiency. Today, they are used to construct apartments, studio rooms, school campus apartment, offices, classrooms, and villages.