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
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.
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.

trailer suction hopper dredger


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.


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.