The lighter aboard ship (LASH) system refers to the practice of loading barges (lighters) aboard a larger 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.
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 by the American shipbuilding engineer Jerome Goldman during the 1960s. The 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.
An important technical problem raised by the invention of the new transport system was the shape of the lighters. Several other designs, differentiated mainly by the shape of the lighters and the loading mechanism, were proposed, but the LASH system found the largest range of applications. In this approach, the lighters were individually lifted onto the carrier ship by a large crane located at the stern of the ship. The crane could move the entire length of the ship and stack the lighters atop each other in the ship's body and on the deck. The cranes had a load-carrying capacity of more than 500 Mp. Loading or unloading a lighter took on average 15 minutes. LASH ships were constructed in Europe, Japan and the USA with almost uniform parameters.
The host vessel is sometimes purpose-built or modified with a door at the waterline, to allow the payloads to be loaded and unloaded without special lifting equipment. An example would be the LASH Turkiye, built at Avondale Shipyard for the Republic of Turkey.
|Type of Carrier||LASH 1||LASH2|
|Type of Lighter|
The first ship of a series of three Sea Bee ships was the MV Doctor Lykes, operated by Lykes Brothers Steamship Company, which had three decks and could transport 38 lighters (12 on the lower decks and 14 on the upper deck). The dual function of the ship is noteworthy, as it had storage tanks with a capacity of nearly 36000 m³ volume built into its sides and unusually large double hull, allowing it to be used also as a product tanker.
|Hight to the first deck||m||9,70|
|Hight to the maindeck||m||16,10|
|Hight to the upperdeck||m||22,80|
|Lighter typ 1||Lighter type 2|
Studies showed that the costs of addressing these issues, along with the costs of operating the carrier ships and her lighters, were much higher the customary freighter ships or the ISO-compliant container ships that were beginning to conquer the transportation market. While barge carriers and lighters are a technologically interesting sea transport system, they are economic only under certain specific conditions of traffic and economy.
The Daily News, Jacksonville, N.C., Carolyn Alford Column: For veteran of three wars, Memorial Day is sacred.
May 28, 2006; Byline: Carolyn Alford May 28--Hello, friends and neighbors. It is good to see you here. "There's more to this life than just a...