A (22) | B (29) | C (39) | D (16) | E (14) | F (27) | G (10) | H (16) | I (18) | J (1) | K (6) | L (26) | M (18) | N (8) | O (5) | P (24) | R (10) | S (45) | T (14) | U (11) | V (9) | W (6)
Glossary term Description

Vessel or shipping that is not on a regular liner trade but picks up cargo at one or more ports, takes it to another port where it is discharged, the voyage completed and the next voyage is then started, possibly from another port. Chartered or hired for a single voyage rather than for a set period of time

tower units Cooling equipment for supplying of cool air to porthole containers in terminals.

Ships' tonnage is a measure of capacity (volume) not weight (mass) and dates back to ancient times when a ship‟s capacity was calculated by the number of tuns (barrels) that it could hold. Gross tonnage, compensated gross tonnage, and net tonnage should therefore be expressed in tons. However, for the actual weight of goods carried by a vessel, the lifting capacity of its cranes, or the steel used in a ship's construction will use tonnes.


Compensated gross tonnage (cgt) A measure (in tons) of the output of a shipyard that takes into account the different levels of work needed to build ships of different types. The ordinary gross tonnage figure is modified accordingly.


Deadweight (dwt) Weight in tonnes of cargo, stores, fuel, passengers and crew carried by a ship when loaded to the maximum summer loadline.


Displacement tonnage Amount of water displaced by the vessel (which will vary depending on whether the vessel is loaded or empty).


Gross registered tonnage (grt) Capacity, in cubic feet, of the spaces within the hull and of the spaces above the deck available for cargo, stores, passengers and crew (with certain exceptions). The figure is divided by 100, hence 1ft³ of capacity = 1 gross ton. This measurement is no longer in common use.

Gross tonnage (gt) The moulded volume of all enclosed spaces of the vessel. A formula is then applied to those measurements, hence no unit of measurement is assigned and the figure is simply referred to as the vessel's “gross tonnage”.


Net tonnage (nt) The volume of a ship‟s payload spaces, taking account of depth, draught, and number of passengers, but never exceeding gt × 0.3. No unit of measurement is assigned and the figure is simply referred to as the vessel's “net tonnage”.


tight fit A method of securing the load by direct or indirect physical contact with load-bearing components of the means of transport or the transport container.

Layer in a container that is numbered from bottom to top


Rise and fall of the water level in a particular place. Tides have an approx cycle of 12 hours and are affected by the Moon's phase and position relative to the Sun and Earth. Certain areas around the world have no appreciable rise and fall of tide, eg Mediterranean Sea. Spring tides bring about the highest high tides and the lowest low tides. Neap tides have smaller high tides and low tides compared with spring tides. All charts are reduced to the chart datum (CD), which is usually the lowest spring tide (LLWS or LAT). Drying heights are the distance an object projects out of the water at CD. Charted vertical clearances are measured from mean high water springs (MHWS) and the height of a light is also measured from this level.


Twenty-foot equivalent unit - the general term used to describe container capacity or traffic figures


(The European Union) Trans-European Network for Transport

tbp Tonnes bollard pull (tugs)
tank container A large container essentially comprising an ISO frame in which liquid containers are mounted. They must meet special requirements with respect to pressure-resistance as a result of the pressures they have to withstand. For this reason, the actual containers are generally cylindrical or spherical in form. Several containers can be mounted either horizontally or vertically in a single frame. Only specific containers must be used for foodstuffs and must be marked "Potable liquids only". Tank containers for hazardous goods must meet the requirements of the IMDG code. Half-height tank containers serve to carry high-density liquids which cannot be carried in normal tank containers because they cannot be filled to a high enough level and are therefore subject to surging.