Glossary of Marine Terms
T
tandem mill
arrangement of rolling mills, in direct line, allowing the metal to pass from one set of rolls to the next for the reduction of steel.
tank
an enclosed space used for holding liquids.
tank vessel
as defined by section 1001 of OPA means a vessel that is constructed or adapted to carry, or that carries, oil or hazardous material in bulk as cargo or cargo residue, and that: (1) is a vessel of the United States; (2) operates on the navigable waters; or (3) transfers oil or hazardous material in a place subject to the jurisdiction of the United States.
temper
the state of or condition of a metal as to its hardness or toughness produced by either thermal or heat treatment and quench or cold working or a combination of same in order to bring the metal to its specified consistency.
tensile strength
the maximum load in pounds per square inch that the sample will carry before breaking under a slowly applied gradually increasing load during a tensile test.
thetankmsd
a marine sanitation device. See TheTankMSD.com.
time charter
a contract for the services of a vessel for a specified period of time during which the primary control and management of the vessel remain with the owner.
tolerance
the specified permissible deviation from a specified nominal dimension, the permissible variation in the size of the part or the allowable variation in chemistry.
tool steel
actually, any grade of steel that can be used for a tool. generally the term tool steel as applied in the steel industry is a grade of steel characterized by high hardness and resistance to abrasion coupled in many instances with resistance to softening at elevated temperatures. these properties are attained with high carbon and high alloy contents and the steel is usually melted in electric furnaces to assure cleanliness and homogeneity of the product.
toughness
the ability of a metal to absorb energy and deform plastically before fracturing. it is usually measured by the energy absorbed in a notch impact test such as the charpy or izod impact test. the area under the stress-strain curve in tensile testing is also a measure of toughness.
tow
to push or pull vessels on a waterway; also refers to the unit comprised of the towing vessel and the vessels being towed or only the vessels being towed.
towboat
any powered vessel which is used for towing.
“ tramp” tow
movement of barge(s) between two points by including it/them in a tow of a boat and other barges going in the same direction (contrast with “dedicated” tow). It is sometimes necessary to transfer barges being “tramped” from one boat to another to achieve the desired route and destination. Cost is generally less than the use of a “dedicated” boat, but control of the timing of barge movements is also less.
transom
the hull plate and its framing that form the vertical end of a box-shaped barge; also, the frame plate forming the stern of a square-ended boat.
truss
a rigid framework of horizontal, vertical, and diagonal structural members designed to support loads and reinforce a vessel’s hull.
trustee
means an official of a federal natural resources management agency designated in subpart G of the NCP or a designated state official or Indian tribe or, in the case of discharges covered by the OPA, a foreign government official, who may pursue claims for damages under 1006 of the OPA.
tugboat
a model hull towboat of relatively deep draft used primarily for pull towing and designed for navigation in open or unprotected waters.
tumbling
cleaning articles by rotating them in a cylinder with cleaning materials.
turnbuckle
a connecting device usually used with cable or chain and which takes up slack by rotating on its screw threads.
