This glossary of maritime terms is offered as an aid to better understanding what is meant by those who make their living from ports and ships.
JACKUP – A deck with legs that can be jacked up or down. During operations, the legs rest on the seabed. When the rig is moved, the legs are retracted, leaving the rig floating. A jackup has Normally no propulsion machinery of its own.
JONES ACT – Contentious US Merchant Marine Act of 1920, Section 27, requiring that all U.S. domestic waterborne trade be carried by U.S.-flag, U.S.-built, and U.S.-manned vessels.
KEEL – The lowest longitudinal timber of a vessel, on which framework of the whole is built up; combination of iron plates serving same purpose in iron vessel.
KNOT – Unit of speed in navigation, which is the rate of nautical mile (1,852 metres or 6,080 feet) per hour. i.e. 1.852 km/h.
LAID-UP – Ships not in active service; a ship which is out of commission for fitting out, awaiting better markets, needing work for classification, etc.
LAKER – Type of ship that trades only in the Great Lakes of North America. They carry predominantly grain and ore cargoes.
LASH – Lighter aboard ship: A barge carrier designed to act as a shuttle between ports, taking on and discharging barges.
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LASH SHIPS – LASH stand for Lighter Aboard Ship. It is a specialized container ship carrying very large floating containers, or ‘lighters’. The ship carries its own heavy-duty crane for loading and discharging the lighters over the stern. The lighters each have a capacity of about 400 tons and are stowed in the holds and on deck. While, the ship is at sea with one set of lighters, further sets can be made ready. Loading and discharge are rapid at about 15 minutes per lighter, no port or dock facilities are needed, and the lighters can be grouped for pushing by towboats along inland waterways.
LAY-BY – ships that are laid up usually waiting for cargo or a charter, often outside a port.
LAY-UP – Temporary cessation of trading of a ship by a shipowner during a period when there is a surplus of ships in relation to the level of available cargoes. This surplus, known as over-tonnaging, has the effect of depressing freight rates to the extent that some shipowners no longer find it economical to trade their ship, preferring to lay them up until there is a reversal in the trend.
L/C – Letter of credit
LCL – LESS THAN CONTAINER LOAD – A consignment of cargo which is insufficient to fill a shipping container. It is grouped with other consignments for the same destination in a container at a container freight station.
LIFEBOAT – A specially constructed (often double-ended) boat, which can withstand heavy, rough seas.
LIFEBOAT DRILL – An exercise conducted on board every ship to familiarise crew and any passengers with how to evacuate the ship in an emergency. The master of every vessel is bound by international law to make the officers, crew and passengers adequately acquainted with the procedures of lowering and the use of lifeboats in case of emergency.
LIGHT DISPLACEMENT TONNAGE – The weight of a ship’s hull, machinery, equipment and spares. This is often the basis on which ships are paid for when purchased for scrapping. The difference between the loaded displacement and light displacement is the ship’s deadweight.
LIGHTER – General name for a broad, flat-bottomed boat used in transporting cargo between a vessel and the shore. The distinction between a lighter and a barge is more in the manner of use than in equipment. The term ‘lighter’ refers to a short haul, generally in connection with loading and unloading operations of vessels in harbour, while the term ‘barge’ is more often used when the cargo is being carried to its destination over a long distance.
LIGHTER ABOARD SHIP – An ocean ship which carries barges. These barges are loaded with cargo, often at a variety of locations, towed to the ocean ship, sometimes referred to as the mother ship, and lifted or, in some cases, floated on board. After the ocean crossing, the barges are off-loaded and towed to their various destinations. The ocean ship then receives a further set of barges, which have been assembled in readiness. This concept was designed to eliminate the need for specialized port equipment and to avoid transhipment with its consequent extra cost.
LIGHTERAGE – Charge for conveying cargo by lighters or barges.
LIGHTERING – Conveying cargo with another vessel known as a lighter from ship to shore, or vice versa.
LIEN – Retention of property until outstanding dept is paid.
LINER – A cargo or passenger-carrying ship which is operated between scheduled, advertised ports of loading and discharge on a regular basis.
LINER SERVICE – Vessels operating on fixed itineraries or regular schedules and established rates available to all shippers. The freight rates which are charged are based on the shipping company’s tariff or if the company is a member of a liner conference, the tariff of that conference. An agent once compared a Liner Service with a bus service travelling to regular stops at regular times and on a regular turnaround route. See also Non-Liner Service.
LINER SHIP OPERATORS – Operators who trade ships regularly from one port to another.