Lightering
Encyclopedia
Lightering is the process of transferring cargo between vessels of different sizes, usually between a barge and a bulker
or oil tanker
. Lightering is undertaken to reduce a vessel's draft in order to enter port
facilities which cannot accept very large ocean-going vessels. Lightering can also refer to the use of a lighter
barge for any form of short-distance transport, such as to bring railroad car
s across a river.
sufficiently to enter the port. Dredging, advances in dock
construction, and containerization
have reduced the frequency of the practice in dry bulk shipping after the middle of the 20th century. However, the practice remains in common usage in the oil tanking industry ("wet" cargo trade).
, generally between 20 nautical miles (37 km) and 60 nautical miles (111.1 km) from the shore, and can be performed while the ships are at anchor, drifting, or underway. The product is typically transferred using specialized hoses which offload cargo from the larger vessel to the smaller. Fenders
are used to separate the two ships moored to each other and prevent damage while the cargo is being transferred.
In dry bulk, lightering can be undertaken one of two ways. If the vessel to be lightered is geared, then it can discharge cargo to smaller, ungeared vessels (typically barges). If the vessel to be lightered is gearless, then floating cranes are often used to transfer cargo to another vessel or barge.
Also, although not very common, vessels will sometimes lighter before (or even between) berthings
, shifting to shallower berths in order to discharge more quickly and also free up space for larger vessels.
Bulk carrier
A bulk carrier, bulk freighter, or bulker is a merchant ship specially designed to transport unpackaged bulk cargo, such as grains, coal, ore, and cement in its cargo holds. Since the first specialized bulk carrier was built in 1852, economic forces have fueled the development of these ships,...
or oil tanker
Oil tanker
An oil tanker, also known as a petroleum tanker, is a merchant ship designed for the bulk transport of oil. There are two basic types of oil tankers: the crude tanker and the product tanker. Crude tankers move large quantities of unrefined crude oil from its point of extraction to refineries...
. Lightering is undertaken to reduce a vessel's draft in order to enter port
Port
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....
facilities which cannot accept very large ocean-going vessels. Lightering can also refer to the use of a lighter
Lighter (barge)
A lighter is a type of flat-bottomed barge used to transfer goods and passengers to and from moored ships. Lighters were traditionally unpowered and were moved and steered using long oars called "sweeps," with their motive power provided by water currents...
barge for any form of short-distance transport, such as to bring railroad car
Railroad car
A railroad car or railway vehicle , also known as a bogie in Indian English, is a vehicle on a rail transport system that is used for the carrying of cargo or passengers. Cars can be coupled together into a train and hauled by one or more locomotives...
s across a river.
History
Lightering was practiced for all types of cargo for centuries. The practice became more widespread with the 19th century introduction of steamships too large to enter some of ports they intended to serve, in which case lightering became necessary to reduce the vessels' draftDraft (hull)
The draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull , with the thickness of the hull included; in the case of not being included the draft outline would be obtained...
sufficiently to enter the port. Dredging, advances in dock
Dock (maritime)
A dock is a human-made structure or group of structures involved in the handling of boats or ships, usually on or close to a shore.However, the exact meaning varies among different variants of the English language...
construction, and containerization
Containerization
Containerization is a system of freight transport based on a range of steel intermodal containers...
have reduced the frequency of the practice in dry bulk shipping after the middle of the 20th century. However, the practice remains in common usage in the oil tanking industry ("wet" cargo trade).
Wet bulk
Lightering for tankers typically occurs in the EEZExclusive Economic Zone
Under the law of the sea, an exclusive economic zone is a seazone over which a state has special rights over the exploration and use of marine resources, including production of energy from water and wind. It stretches from the seaward edge of the state's territorial sea out to 200 nautical...
, generally between 20 nautical miles (37 km) and 60 nautical miles (111.1 km) from the shore, and can be performed while the ships are at anchor, drifting, or underway. The product is typically transferred using specialized hoses which offload cargo from the larger vessel to the smaller. Fenders
Fender (boating)
In boating, a fender is a bumper used to absorb the kinetic energy of a berthing boat or vessel against a jetty, quay wall or other vessel. Fenders are used to prevent damage to boats, vessels and berthing structures. Fenders are nowadays constructed in several ways, typically of rubber, foam...
are used to separate the two ships moored to each other and prevent damage while the cargo is being transferred.
Dry bulk
In many developing nations, such as China and especially India, dry bulk vessels still often lighter in order to meet draft restrictions at ports that either do not have natural deep water access or whose channels have yet to be dredged to sufficient depth to allow some of the larger-size bulk carriers to safely transit.In dry bulk, lightering can be undertaken one of two ways. If the vessel to be lightered is geared, then it can discharge cargo to smaller, ungeared vessels (typically barges). If the vessel to be lightered is gearless, then floating cranes are often used to transfer cargo to another vessel or barge.
Also, although not very common, vessels will sometimes lighter before (or even between) berthings
Berth (moorings)
A berth is a location in a port or harbour used specifically for mooring vessels while not at sea.-Locations in a port:Berth is the term used in ports and harbors to define a specific location where a vessel may be berthed, usually for the purposes of loading and unloading.Most berths will be...
, shifting to shallower berths in order to discharge more quickly and also free up space for larger vessels.
See also
- Lighter (barge)Lighter (barge)A lighter is a type of flat-bottomed barge used to transfer goods and passengers to and from moored ships. Lighters were traditionally unpowered and were moved and steered using long oars called "sweeps," with their motive power provided by water currents...
- Lighter Aboard ShipLighter Aboard ShipThe lighter aboard ship system refers to the practice of loading barges 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...
- Lighterage clause
- LightermenLightermenLightermen were workers who transferred goods between ships and quays, aboard flat-bottomed barges called lighters in the Port of London.-History:...