Hatchway is the hole through which the cargo is loaded into the ship. Traditionally this hole has been a source of weakness in the structure, but modern technology has provided large steel hatch covers that can slide back into place at the flick of a lever. Ships with these are allowed to load deeper than the older types covered only by wooden boards and canvas. There are many different types and designs of steel hatch covers. The first seems to have appeared around 1937, and 1949 saw the introduction of the ‘single pull’ hatch cover which by 1955 had established itself as the standard hatchway for most new general-cargo tonnage. The year 1952 saw the introduction of flush-fitting hatchways in between decks, and in 1959 side-rolling covers were introduced for bulk carriers. Because of these developments the hatchway can be made much larger and this means the cargo can be dropped into position. If the hatchway is small the cargo has to be carried or dragged into position at the sides of the ship. This takes time and costs money. It could be argued that the large ‘open’ hatchway is the basis of virtually all the major developments in improving ship productivity since the Second World War. Some modern ships have large hydraulically operated doors in the side of the ship through which the forklift truck can drive and stow the cargo directly.