A containership (often spelled as two words: container ship) is a ship
that carries large containers (often called Connex boxes, or Sea-Trains) of goods
. The use of containers, or containerization, has become the most popular method of transporting
non-bulk cargo (bulk cargo being oil, liquids, grain, or any other cargo that can be densely packed/poured) by sea
since its inception in 1956.
Malcolm McLean, a former truck driver who diversified into the shipping industry, is credited with being the "father" of containerization.
Historically, one of the biggest challenges associated with the transportation of goods is packaging. Where t-shirts and Tupperware fit well inside cardboard boxes, pineapple and furniture can be a tad more difficult. What results, of course, is a variety of shapes and sizes to be loaded into a ship's cargo hold. Finding ways to safely stow and stack such different shapes was difficult...but it also required a tremendous number of crane lifts to bring each package aboard individually.
Containerization takes products of different shapes, sizes, and suppliers, and secures them inside containers; the containers are then loaded, and stacked into the ship. Such simplification greatly reduces turnaround time while in port, and allows for greater cargo density (goods / cubic foot).
A separate, but equally beneficial characteristic of containers is their climate control options. Whereas previous methods required the refrigeration or heating of complete cargo holds or compartments, containerization now permits climate control on a micro level.
Today, the use of containers has become so popular that a series of standards have been developed on their size, shape and construction. Containers were originally designed to be 20' long (they've since doubled in size, to 40'); in order to evaluate the container capacity of a ship, the TEU (twenty-foot equivalent unit) was created as a unit of measurement, describing how many 20' containers a particular ship could carry at full capacity.
Lastly, containers are designed to be quickly loaded and offloaded between truck and ship by pierside gantry cranes. Shipping companies are able to eliminate the need for terminal storage by publishing sailing schedules, and offloading cargo from the ship directly to the chassis of a truck.