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
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.

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”.


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

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


Taking cargo from one ship and loading it on to another. Often done at a transhipment hub - a port capable of accommodating a large ship, from which it is loaded on to smaller vessels that can access other nearby ports.


trailer suction hopper dredger

Turnbuckle Tightening elements made up of two threaded rods, a threaded barrel and a lever, usually in the form of a ratchet. Turnbuckles are the preferred tensioning method when securing loads with chains.
twist lock A securing mechanism for securing containers in a vertical direction; twist locks are placed between the containers and fastened in the oblong holes on the container corners.

ultra-high frequency. Portable radio sets capable of sending and receiving signals between different areas on board large steel vessels


under-keel clearance. Allowance made to ensure a certain clearance between the ship's bottom and the seabed. See also DUKC.