Intermodal container
Invented in the early 20th century, 40-foot intermodal containers proliferated during the 1960s and 1970s under the containerization innovations of the American shipping company SeaLand.
Like cardboard boxes and pallets, these containers are a means to bundle cargo and goods into larger, unitized loads that can be easily handled, moved, and stacked, and that will pack tightly in a ship or yard.
In 1766 James Brindley designed the box boat 'Starvationer' with ten wooden containers, to transport coal from Worsley Delph (quarry) to Manchester by Bridgewater Canal.
Containerization was developed in Europe and the US as a way to revitalize rail companies after the Wall Street crash of 1929, in New York, which resulted in economic collapse and a drop in all modes of transport.
[20] Their invention made a major contribution to the globalization of commerce in the second half of the 20th century, dramatically reducing the cost of transporting goods and hence of long-distance trade.
[29] In 1955, trucking magnate Malcom McLean bought Pan-Atlantic Steamship Company, to form a container shipping enterprise, later known as Sea-Land.
The first containers were supplied by Brown Trailers Inc, where McLean met Keith Tantlinger, and hired him as vice-president of engineering and research.
These standards allow for more consistent loading, transporting, and unloading of goods in ports throughout the world, thus saving time and resources.
[36][37] This holds essential information about the container, including age, registration number, dimensions and weights, as well as its strength and maximum stacking capability.
[32] The reliance on containers exacerbated some of the economic and societal damage from the 2021 global supply chain crisis of 2020 and 2021, and the resulting shortages related to the COVID-19 pandemic.
[6] These typical containers are rectangular, closed box models, with doors fitted at one end, and made of corrugated weathering steel (commonly known as CorTen)[nb 5] with a plywood floor.
ISO containers have castings with openings for twistlock fasteners at each of the eight corners, to allow gripping the box from above, below, or the side, and they can be stacked up to ten units high.
[57] In 2019 it was noted by global logistics data analysis startup Upply[58] that China's role as 'factory of the world' is further incentivizing the use of 40-foot containers, and that the computational standard 1 TEU boxes only make up 20% of units on major east–west liner routes, and demand for shipping them keeps dropping.
Although 20-ft units mostly have heavy cargo, and are useful for stabilizing both ships and revenue,[nb 8] carriers financially penalize 1 TEU boxes by comparison.
Swap body units usually have the same bottom corner fixtures as intermodal containers, and often have folding legs under their frame so that they can be moved between trucks without using a crane.
However they frequently do not have the upper corner fittings of ISO containers, and are not stackable, nor can they be lifted and handled by the usual equipment like reach-stackers or straddle-carriers.
The bottom row in the table gives the legal maximum cargo weights for U.S. highway transport, and those based on use of an industry common tri-axle chassis.
As a result, while being virtually interchangeable:[89] Some pallet-wides are simply manufactured with the same, ISO-standard floor structure, but with the side-panels welded in, such that the ribs/corrugations are embossed outwards, instead of indenting to the inside.
The EU has started a standardization for pallet wide containerization in the European Intermodal Loading Unit (EILU) initiative.
[93] Many sea shipping providers in Europe allow these on board, as their external width overhangs over standard containers are sufficiently minor that they fit in the usual interlock spaces in ship's holds,[91] as long as their corner-castings patterns (both in the floor and the top) still match with regular 40-foot units, for stacking and securing.
The North American market has widely adopted containerization, especially for domestic shipments that need to move between road and rail transport.
[94] The size of the containers matched new federal regulations passed in 1983 which prohibited states from outlawing the operation of single trailers shorter than 48 feet (15 m) long or 102 inches (260 cm) wide.
[96] This size being 8 feet (2.44 m) longer and 6 inches (15 cm) wider has 29% more volume capacity than the standard 40-ft High-Cube,[97] yet costs of moving it by truck or rail are almost the same.
[110] Their length of 8 ft (2.44 m) corresponds to the width of a standard 20-foot container, which is why there are forklift pockets at their ends, as well as in the sides of these boxes, and the doors only have one locking bar each.
Following the extended usage of pallet-wide containers in Europe the EU started the Intermodal Loading Unit (ILU) initiative.
However, transporting containers in this way is typically avoided due to the cost of doing such and the lack of availability of planes which can accommodate such awkwardly sized cargo.
There are many established methods and materials for stabilizing and securing intermodal containers loaded on ships, as well as the internal cargo inside the boxes.
The US military often used its Conex containers as on-site storage, or easily transportable housing for command staff and medical clinics.
Intermodal containers are not strong enough for conversion to underground bunkers without additional bracing, as the walls cannot sustain much lateral pressure and will collapse.
Cleaning or replacing the wood floor can make these used containers habitable, with proper attention to such essential issues as ventilation and insulation.
