Lighter aboard ship

The lighter aboard ship (LASH) system refers to the practice of loading barges (lighters) aboard a bigger vessel for transport. It was developed in response to a need to transport lighters, a type of unpowered barge, between inland waterways separated by open seas. Lighters are typically towed or pushed around harbors, canals or rivers and cannot be relocated under their own power. The carrier ships are known variously as LASH carriers, barge carriers, kangaroo ships or lighter transport ships.

By the 1950s, the needs of cargo transport customers were no longer being met by the old system of loading individual cargo pieces into a ship's hold. The dimensions and shapes of cargo pieces varied widely, and the ISO standard cargo container had only slowly begun to be adopted during the 1960s. Large container terminals with extensive conveyor systems and storage areas were still only in planning or in the development stages.

The LASH system was developed as an alternative and supplement to the developing container system. The lighters, which may be characterized as floating cargo containers, served dual purposes: transportation over water, and the establishment of a modular, standardized shape for loading and unloading cargo. The lighters, also known as swimming normed cargo containers, are loaded onto a LASH carrier at the port of embarkation and unloaded from the ship at the port of destination.

The system was developed during the 1960s by the American shipbuilding engineer Jerome Goldman. Acadia Forest, commissioned in September 1969, was the first LASH carrier - the ship could take up 75 standardized lighters, with about 376 metric tons of total loading capacity. At the time, it was a novel kind of ship, the first vessel designed primarily to transport other, smaller ships.

In the late 1980s the Soviet Union built Sevmorput, a nuclear-powered LASH carrier ; Sevmorput was one of only four nuclear powered cargo vessels ever built.

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