Cargo ships are generally classified according to their main purpose, but it has been done as well based on their appearance and
construction. The older ones were those of flush-deck type, in which the deck ran uninterruptedly from stern to prow, as in many sailing ships of
the 19th century. The bridge and the paddle wheels amidships were a common type during the mid century, and it is possible that the bridge
connecting both paddle wheel's covers were an important step on the development of later types of cargo vessels.
In a time when the steering wheel was located in the stern end it could happen that the wheel and the helmsman were drawn by the waves, so a small
poop-deck was added to place the steering wheel at a higher and safer level. It was seen as well how practical was to add an anchor deck, which later
was enlarged to form a forecastle. The light bridge was gradually turned into a platform linked to the ship by means of a wide stand which served as
breakwater during bad weather conditions.
As a certain fore pitching was seen on those vessels which transported homogeneous loads, new cargo ships were built fitted with a raised quarter-deck
running from amidships to stern, to allow more cargo to be stowed astern. The officers and some passengers were accommodated amidships while the mariners
occupied the forecastle. In some vessels the quarter-deck was prolonged towards the prow, which created a short well-deck behind the forecastle.
However, the well-deck could be flooded by the waves and retain enough water for putting stability at danger. Because of this the quarter-deck and the
forecastle were linked together to form a single deck known as hurricane deck, completing so the cycle back to the primitive flush-deck ship,
which however was now safer thanks to the taller freeboard.
The poop-deck was linked to the bridge in some vessels known as long poopers, which actually were similar to those which had a well-deck. Different
were those vessels built with a shelter-deck above the main deck. The hatches on the shelter-deck could not be closed and the space between both
decks was considered part of the superstructure and not included in the tonnage. If the shelter-deck was of more robust construction and the hatches
could be closed, the vessel was one of closed shelter-deck type, and the whole space beneath that deck was included in the tonnage. Finally,
those smaller vessels whose engines were placed astern had a long poop-deck and a forecastle upon the main deck.
A cargo ship is called a "tramp" when she is not ascribed to a regular line between certain ports, but instead carries her load to wherever she has
been chartered. This irregular form of navigation became less profitable after the Second World War by the fact that the largest part of cargo ships
worldwide were serving in regular lines during the mid 20th century. In that time cargo vessels were typically of the three-isles type, built with
a forecastle, a central quarter-deck and a poop-deck.
French freighter ship MAGELLAN (1958)
Swedish freighter ship RIO DE JANEIRO (1957)