Glossary of Terms, Acronyms and Abbreviations
AHTS - Anchor Handling Tug Supply Vessel
Anchor Handling Tug Supply (AHTS) vessels are mainly built to handle anchors for oil rigs, tow them to location, and use them to secure the rigs in place. AHTS vessels sometimes also serve as Emergency Response and Rescue Vessels (ERRVs) and as supply transports. [Wikipedia]
ASR - Air-Sea Rescue
BHP - Brake Horsepower [Wikipedia]
Canada - The Great White North [Wikipedia]
DOI - Department of Interior
The United States Department of the Interior (DOI) is an executive department of the U.S. federal government responsible for the management and conservation of most federal lands and natural resources. It also administers programs relating to Native Americans, Alaska Natives, Native Hawaiians, territorial affairs, and insular areas of the United States, as well as programs related to historic preservation. [Wikipedia]
DPC - Defense Plant Corporation
The Defense Plant Corporation (DPC) was subsidiary of the Reconstruction Finance Corporation, a government corporation run by the United States federal government between 1940 and 1945. To win World War II the United States and its Allied Nations needed massive war production. Many private companies did not have the capital funds to meet the wartime demand for buildings and equipment. Defense Plant Corporation provided financial support to state and local governments, banks, railroads, mortgage associations, and other businesses supporting the war efforts. With the end of the war, the DPC ceased operations on July 1, 1945. [Wikipedia]
DWT - Deadweight Tonnage
Deadweight tonnage (also known as deadweight; abbreviated to DWT) or tons deadweight (DWT) is a measure of how much weight a ship can carry. It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew. Note that this is not the weight of the vessel. [Wikipedia]
EFC - Emergency Fleet Corporation
The Emergency Fleet Corporation (EFC) was established by the United States Shipping Board, sometimes referred to as the War Shipping Board, on 16 April 1917 pursuant to the Shipping Act (39 Stat. 729) to acquire, maintain, and operate merchant ships to meet national defense, foreign and domestic commerce during World War I. The EFC was renamed the U.S. Shipping Board Merchant Fleet Corporation in February 1927, then abolished entirely in October 1936. Its functions were transferred to the United States Maritime Commission. [Wikipedia]
FLC - Foreign Liquidation Commission
The U.S. government agency responsible for disposal of all surplus property located in foreign areas after World War II. Also: Army-Navy Liquidation Commission. In September 1945 the Commission, with its records and personnel, was transferred to the Office of Foreign Liquidation in the State Department. Ceased operations June 30, 1949.
GT - Gross Tonnage
Gross tonnage (GT) is a measure of a ship's overall internal volume. Note that this is not the weight of the vessel. Gross tonnage is different from gross register tonnage. Neither gross tonnage nor gross register tonnage should be confused with measures of mass or weight such as deadweight tonnage or displacement. Displacement tonnage is typically used for military vessels, while Gross tonnage is used for commercial vessels and transports. Where military and commercial vessels are mixed together in the lists and it is not otherwise specified, the military vessels will use GT, while commercial vessels use LDT. [Wikipedia]
Note:
In this website, a tonnage figure with a small "d" after it is Light Displacement Tonnage (LDT), regardless of the column header. A tonnage figure with a small "g" after it is Gross Tonnage regardless of the column header.
HDML - Harbor Defense Motor Launch
IMO – International Maritime Organization Identification Number
The IMO Ship Identification Number is a unique seven-digit number assigned to propelled, seagoing vessels of 100 gross tons and above. It consists of the three letters IMO followed by seven digits. See more details below. [Wikipedia]
IMR - Inspection, Maintenance and Repair
jumboisation
Jumboization is a technique in shipbuilding consisting of enlarging a ship by adding an entire section to it. Enlarging a ship by jumboization allows an increase in its capacity and revenue potential without needing to purchase or build an entirely new ship. This technique has been used on cruise ships and tankers, as well as smaller vessels like sailing or fishing ships. [Wikipedia]
K to D - Keel-laying to Delivery (days)
Also:
C to D - Contract to Delivery
K to L - Keel-laying to Launch
L to D - Launch to Delivery
KD - "Knock-Down" - a disassembled vessel in kit form
LDT - Light Displacement Tonnage
The displacement or displacement tonnage of a ship is its actual weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Light displacement tonnage is the weight of the vessel with all necessary fuel, water, supplies, crew, etc, but no cargo or other payload. Displacement tonnage is typically used for military vessels, while gross tonnage (GT,) is used for commercial vessels and transports. Where military and commercial vessels are mixed together in the lists and it is not otherwise specified, the military vessels will use GT, while commercial vessels use LDT. [Wikipedia]
LOA - Length, overall
LWL - Length at waterline
units are feet unless otherwise specified
MARAD - United States Maritime Administration
The United States Maritime Administration (MARAD) is an agency of the United States Department of Transportation. MARAD administers financial programs to develop, promote, and operate the U.S. Maritime Service and the U.S. Merchant Marine. In addition it conducts research and development activities in the maritime field; regulates the transfer of U.S. documented vessels to foreign registries; maintains equipment, shipyard facilities, and reserve fleets of Government-owned ships essential for national defense. [Wikipedia]
MARCOM - United States Maritime Commission
The United States Maritime Commission (MARCOM) was an independent executive agency of the U.S. federal government that was created by the Merchant Marine Act of 1936, which was passed by Congress on June 29, 1936, and was abolished on May 24, 1950. The commission replaced the United States Shipping Board which had existed since World War I. It was intended to formulate a merchant shipbuilding program to design and build five hundred modern merchant cargo ships to replace the World War I vintage vessels that comprised the bulk of the United States Merchant Marine, and to administer a subsidy system authorized by the Act to offset the cost differential between building in the U.S. and operating ships under the American flag. It also formed the United States Maritime Service for the training of seagoing ship's officers to man the new fleet. [Wikipedia]
MODU - Mobile Offshore Drilling Unit
An oil platform (also called an oil rig, offshore platform, oil production platform, etc.) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. [Wikipedia]
MPSV - Multi-Purpose Supply Vessel
NDRF - National Defense Reserve Fleet
The National Defense Reserve Fleet (NDRF) consists of ships of the United States, mostly merchant vessels, that have been mothballed but can be activated within 20 to 120 days to provide shipping during national military emergencies, or non-military emergencies such as commercial shipping crises. The NDRF is managed by the U.S. Department of Transportation's Maritime Administration (MARAD). It is distinct from the United States Navy reserve fleets, which consist largely of naval vessels. [Wikipedia]
NLD - No Longer Documented
In this website, NLD indicates that a vessel is no longer in U.S. registry, although it may still be registered and in service somewhere else. The terms suspended and closed have the same meaning in Canadian records.
NSY - Naval Shipyard
O/N - Official Number
The Official Number (O/N) is the 6 or 7 digit number awarded to a vessel at the time it is first documented with the US Coast Guard. This number remains with the vessel for its existence. By international aggreement, numbers starting with 1, 2, 5, 6, or 9 are reserved for the U.S., while those starting with 3, 4, 7, or 8 are reserved for British/Commonwealth countries. Other countries may use their own schemes. U.S. numbers presently being issued are above 133000, so could be confused with IMO numbers. The IMO system has largely supplanted the O/N system. The USCG maintains a searchable database of O/Ns here. [Wikipedia]
OSRV - Oil Spill Response Vessel
OSV - Offshore Support Vessel
PSV - Platform Supply Vessel
A platform supply vessel (PSV) is a ship specially designed to supply offshore oil and gas platforms and other offshore installations. They typically range from 160 to 330 ft in length and are distinguished by the large open deck area used to store supplies and house equipment and to allow for efficient loading and offloading. The primary function for most of these vessels is logistic support and transportation of goods, tools, equipment, and personnel to and from their destination. [Wikipedia]
RCN - Royal Navy (Canada)
RN - Royal Navy (Great Britain)
RAN - Royal Navy (Australia)
RNZN - Royal Navy (New Zealand)
SY - Shipyard
towboat - barge-pushing tugboat
A towboat is a specialized type of tugboat that is built, ironically, to push its load. [Wikipedia]
tractor - tractor tugboat
Any time you find a reference to a "tractor" in this website, it is referring to a very specific type of tugboat - one with a special drive that can rotate and thrust in any direction. Thus the boat can push or pull equally well in any direction without reorienting the hull. These are generally employed for docking large vessels in harbor. [Wikipedia]
USACE - United States Army Corps of Engineers (USACE)
The United States Army Corps of Engineers (USACE) is a direct reporting unit and engineer formation of the United States Army that has three primary mission areas: Engineer Regiment, military construction, and civil works. For the military construction mission, the chief of engineers is directed and supervised by the Assistant Secretary of the Army for installations, environment, and energy, whom the President appoints and the Senate confirms. Military construction relates to construction on military bases and worldwide installations. [Wikipedia]
USCG - United States Coast Guard [Wikipedia]
USN - United States Navy [Wikipedia]
USSB - United States Shipping Board
The United States Shipping Board (USSB) was established as an emergency agency by the 1916 Shipping Act (39 Stat. 729), on September 7, 1916. The United States Shipping Board's task was to increase the number of US ships supporting the World War I efforts. The program ended on March 2, 1934. [Wikipedia]
USSR - Union of Soviet Socialist Republics [Wikipedia]
WSA - War Shipping Administration
The War Shipping Administration (WSA) was a World War II emergency war agency of the US government, tasked to purchase and operate the civilian shipping tonnage the United States needed for fighting the war. Both shipbuilding under the Maritime Commission and ship allocation under the WSA to Army, Navy or civilian needs were closely coordinated though Vice Admiral Emory S. Land who continued as head of the Maritime Commission while also heading the WSA. [Wikipedia]
see also: USCG Common Terms (pdf)
Vessel Identification Numbers
In this website, you will often see "ID" numbers. These may be official USCG hull identification numbers and/or callsigns. Hull identification numbers are typically 6-8 numerical digits. These are assigned when the vessel is constructed, and never change. They can therefore be a useful way to track the history of a vessel through changes in name and ownership.
IMO Ship Identification Number Scheme
(Circular letter No.1886/Rev.5)
The IMO ship identification number scheme was introduced in 1987 through adoption of resolution A.600(15), as a measure aimed at enhancing "maritime safety, and pollution prevention and to facilitate the prevention of maritime fraud". It aimed at assigning a permanent number to each ship for identification purposes. That number would remain unchanged upon transfer of the ship to other flag(s) and would be inserted in the ship's certificates. When made mandatory, through SOLAS regulation XI/3 (adopted in 1994), specific criteria of passenger ships of 100 gross tonnage and upwards and all cargo ships of 300 gross tonnage and upwards were agreed.
The implementation of the scheme became mandatory as of 1 January 1996. In 2013, IMO adopted resolution A.1078(28) in order to allow the voluntary application of the IMO Ship Identification Number Scheme to fishing vessels of 100 gross tons and above.
SOLAS regulation XI-1/3 requires ships' identification numbers to be permanently marked in a visible place either on the ship's hull or superstructure. Passenger ships should carry the marking on a horizontal surface visible from the air. Ships should also be marked with their ID numbers internally.