Shipping Terms & Abbreviations

Aframax
refers to an oil tanker of 80,000 to 120,000 DWT with a beam greater than 32.31 metres
The term refers to the Average Freight Rate Assessment system used for calculating tanker shipping costs
Beam
is the maximum width of a ship's hull excluding the superstructure
Capesize
refers to ships which are too large to pass through the Panama Canal or Suez Canal and therefore have to sail around either Cape Horn or the Cape of Good Hope to pass between oceans
The term is most commonly used to refer to Bulk Carriers and is defined by Lloyds Register as ships of 100,000 to 180,000 DWT and a draft of about 17 metres
Chinamax
refers specifically to ships with the following maximum dimensions -
LOA
360 metres
Beam
65 metres
Draft
24 metres
The term is applied only to Bulk Carriers and is derived from China's ongoing massive imports of coal and iron ore
Deadweight
please see DWT
Displacement
is the actual weight of a ship, measured in accordance with Archimedes Principle by the weight of water displaced, usually calculated with a full load of fuel and stores
Full Load
is the displacement of a ship floating at its Plimsoll Mark / National Load Line
Deep Load
applies only to warships and is the ship's displacement with a full load of ammunition, stores and fuel
Standard
is a term defined in the Washington Naval Treaty as the displacement of a warship fully manned and loaded, including all armament / ammunition and everything else intended to be carried in war, but excluding fuel and reserve boiler water
Light
is the displacement of a ship excluding cargo, fuel, ballast, stores, and crew / passengers
Warships are always referred to by displacement rather than deadweight
Draft
is the vertical distance from the waterline to the bottom of the hull or keel of a ship
DWT
Deadweight Tonnage / Deadweight is the weight of all of a ships cargo, fuel, ballast, stores, and crew / passengers expressed in metric tonnes (1,000 kg / 2,205 lbs)
The term is frequently used to refer to a ship's maximum carrying capacity when fully loaded to the point that the Plimsoll Mark / National Load Line is at the surface of the water but may also refer to the actual deadweight of the ship as loaded
Deadweight is not a measure of a ship's displacement and is not to be confused with Net Tonnage or Gross Tonnage
Handymax
is a term used to refer to a class of bulk carriers of 40,000 to 50,000 DWT
Modern Handymax ships are usually between 150 - 200 metres LOA, have five cargo holds and are equipped with four cranes each with a lifting capacity of 30 tonnes
Handysize
is a term used to refer to a class of Bulk Carriers of 15,000 to 35,000 DWT and is the most common size of bulk carrier with approximately 2,000 ships in service
Modern Handysize bulkers are typically about 32,000 DWT, have five holds and are equipped with four cranes each with a lifting capacity of 30 tonnes
Handysize bulkers are very flexible ships able to enter smaller ports and load / discharge cargo without the assistance of shore based cargo handling equipment. These ships generally carry a wider range of products than larger bulk carriers including grain, logs, cement, phosphate, coal, and various ores as well as other types of general "break bulk" cargo
Handysize can also refer to a wider class of bulk carriers encompassing three series of ships -
Handy
less than 40,000 DWT
Handymax
40,000 to 50,000 DWT
Supramax
50,000 to 60,000 DWT
LOA
Length Overall - is the maximum length of a ship's hull measured parallel to the waterline
LWL
Loaded Waterline Length - is the length of a ship's hull measured at the point that it sits in the water
Alternatively it is the length of a ships hull measured at the Summer Temperature Seawater Load Line or Plimsoll Mark
Malaccamax
refers to the largest ship capable of navigating the Strait of Malacca which at its shallowest point has a depth of 25 metres
Panamax
refers to the size limits for ships traversing the Panama Canal as determined by the dimensions of the canal locks which are -
Length
1,050 ft (320.04 m)
Width
110 ft (33.53 metres)
Depth
41.2 ft (12.56 metres)
Maximum permitted dimensions for ships using the Panamax Canal are -
LOA
950 ft (289.56 m)
965 ft (294.13 m) for Passenger / Container ships
Beam
106 ft (32.31 metres)
Draft
39.5 ft (12.04 metres)
Air Draft is restricted to 190 ft (57.91 m) from the waterline to the highest point to allow passage under the Bridge of the Americas at Balbao
The longest ship to pass through the Panama Canal was the 973 ft (296.57 m) San Juan Prospector and the widest ships were the US Navy's Iowa Class Battleships with a maximum beam of 109 ft (33.0 m)
In September 2007 work commenced on a project to expand the capacity of the Panama Canal through the construction of new lock complexes at the Atlantic and Pacific entrances
The new lock complexes, scheduled to open in 2015, will have the following dimensions -
Length
1,400 ft (427.0 m)
Width
180.5 ft (55.0 metres)
Depth
60 ft (18.3 metres)
The new maximum permited dimensions for ships using the Canal, referred to as "New Panamax", are expected to be -
LOA
1200 ft (366.0 m)
Beam
160.7 ft (49.0 metres)
Draft
49.9 ft (15.2 metres)
Plimsoll Mark /
National Load Line
the Plimsoll Mark, named after British MP Samuel Plimsoll, is a circle with a horizontal line drawn through it to show the maximum permitted draft of a ship - letters identifying the classification society that certified the load line frequently appear on either side of the mark (eg L R for Lloyds Register)
The 1876 Merchant Shipping Act (UK) made the Plimsoll Mark compulsory for all British shipping and this was extended to all foreign ships calling at British ports in 1906
The first international agreement on universal load line regulations was reached in the Load Line Convention of 1930 - these regulations were reviewed and amended by the Load Line Convention of 1966 with further amendments in 1971, 1975, 1979, 1983, 1995 and 2003
The purpose of a Load Line is to ensure that when a ship is fully loaded it still has enough reserve buoyancy to provide a margin of safety in the event of an accident
As water density and therefore buoyancy varies with temperature and salinity - warm water being less dense than cold water and fresh water being less dense than seawater - modern Load Line marks cater for different water temperatures, water types and expected sea conditions as shown in the following diagram -
TF Tropical Fresh Water *
F Fresh Water *
T Tropical Seawater
S Summer Temperature Seawater
W Winter Temperature Seawater
Summer Temperature Seawater is the primary load line from which all others are derived and is at the same level as the horizontal line through the Plimsoll Mark
The Tropical Seawater and Winter Temperature Seawater load lines are one forty-eighth of the summer load draft above and below the Summer Temperature Seawater Load Line respectively
The Fresh Water load line and Tropical Fresh Water load line are calculated from the displacement in metric tonnes at the Summer Temperature Seawater load line - see Wikipedia for the formula
Supramax
is a term used to refer to a class of bulk carriers of 50,000 to 60,000 DWT
Modern Supramax ships usually have five cargo holds and are equipped with four cranes each with a lifting capacity of 30 tonnes
TEU
Twenty Foot Equivalent Unit - is an inexact unit of cargo measurement, related to the volume of a 20 foot long "intermodal" shipping container, which is commonly used to describe the capacity of a container ship
General dimensions for a standard 20 foot intermodal shipping container are -
Length
20 ft (6.1 m)
Width
8 ft (2.44 metres)
Height
8 ft 6 ins (2.59 metres)
Volume
1,360 cubic feet (39 cubic metres)
However both 9 ft 6 ins (2.9 m) tall "High Cube" containers, with a volume of 1,520 cubic feet (43 cubic metres), and 4 ft 3 ins (1.3 m) tall half height containers, with a volume of 680 cubic feet (19 cubic metres), are also counted as one (1) TEU
To complicate matters further shipping companies calculate the capacity of their vessels in different ways - for example Maersk calculates the capacity of their ships by weight (based on an average 14 tonnes per TEU) while other companies calculate capacity by the number of containers that can actually be fitted on the ship
An example of this difference is the 11,000 TEU "official" capacity of Maersk Lines E Class container ships as stated by Maersk and the 14,770 TEU which coud actually fit on these ships
Waterline
in general terms is the line where the hull of a ship intersects the surface of the water
It can also refer to a mark positioned amidships on a ship's hull, known as the Plimsoll Mark or National Load Line, which indicates the draft of the ship and the legal limit to which it can be loaded for specific water types and temperatures

For further information try searching for the required term on Wikipedia