An opening in a deck to ensure air and light to the compartment below.

Any tank that is not totally empty or pressed full.

To rotate about a vertical axis in a horizontal plane.

The slewing drive is a gearbox that can safely hold radial and axial loads, as well as transmit a torque for rotating.

A SWATH hull form variant produced by Lockheed Martin from USA. A further development of SWATH technology using four (2x2) torpedo-like submerged hulls instead of two.

A loop of rope or wire which is used for he hoisting of a heavy item. It may also describe a length of wire with a loop at each end.

1.The difference between the actual distance travelled by a ship and the theoretical distance given by the product of the propeller pitch and the number of revolutions. 2. The inclined way upon which a ship is built and then launched.

To separate from by unshackling a link of chain, e.g. slip an anchor.

A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure.

An inclined shipbuilding berth.

A chute for dumping garbage overboard.

Tanks in an oil tanker used to collect drainings, tank washings and other oily mixtures.

Drilling with both oil-based mud and synthetic based mud generates waste streams, often referred to as ‘slop mud’ or ‘slop water’, which are produced when an oil/synthetic/diesel-based drilling fluid becomes contaminated with water.

The operation of a ship at a lower speed than normal one in order to save fuel on ballast voyage or when fuel is expensive.

The residue from any oil separation process which is usually a mixture of water, solid material and high viscosity oil.

Ejection of sludge from the separator bowl.

Sludge oil means sludge from the fuel or lubricating oil separators, waste lubricating oil from the main or auxiliary machinery, or waste oil from bilge water separators, oil filtering equipment or drip trays, (MARPOL).

A tank provided to receive oily residues coming from the oily water filtering or separating equipment and from the purification of fuel and lubricating oils.

A large valve in which a rectangular or circular gate slides across the opening.

Small hydro is the development of hydroelectric power on a scale suitable for local community and industry, or to contribute to distributed generation in a regional electricity grid.