Bight- A loop form by doubling back a rope upon itself.

Bitts - Vertical post or bollards mounted in pairs around which a line can be secured.

Bollard- A vertical post to which the eye of a mooring line can be attached.

Breast lines- Mooring lines leading ashore as nearly perpendicular as possible in a ships fore and daft line.

Chain Stopper- A fitting for securing a chain consisting of two vertical plates mounted on a base wit a pivoting bar or pawl which drops down to bear on a chain link.

Chock-A guide for a mooring line which enables the line to be passed through a ship bulwark or other barrier.

Deadweight- A carrying capacity of a ship including cargo, bunkers, and stores in metric tons that it can be given for any draft and it also used to indicate summer deadweight at summer draft.

Elasticity- The elastic elongation of a unit length of an element caused by a unit load and may refer to a material or a composite structure such as mooring line.

Flake down- Laying a rope in long bights on the deck with each bight clear of the adjacent one so it can be paid out quickly and free from turns.

Fairlead- A guide for mooring line which enables the line to be passed through a ships bulwark or other barrier or to change direction to a congested area without snagging or fouling.

Fleet angle- The angle between the mooring line and a plane perpendicular to the axis of the winch drum.

Fire wire- A wire rigged to the waterline over the off-berth side of a ship to facilitate towing off in an emergency.

First line ashore- A line usually put ashore first to help in hauling the ship into the berth.

Hawser- Synthetic or natural fiber rope used for mooring, warping, and towing.

Head lines- Mooring lines leading ashore from the fore end or fore castle of a ship at an often angle of about 45 degrees to the fore and aft line.

Heaving line- A very light line that is thrown between the ship and the berth that is used to draw the messenger line ashore.

Hockle- A knot-like twisting of individual strand of twisted rope.

Independent wire rope core- A type of construction of a wire rope.

Length between perpendicular- A length of the ship generally between the stern at the design load line and the center of te rudder stock.

Length over all- Is the extreme length of the ship

Lightening or Lightering- The process of transferring cargo from a tanker to another ship.

Loading arms- Oil transfer unit between a ship and shore for discharge and loading may be articulated all metal arms or a combination of metal arms and hoses.

Mandel shackle- a special shackle used to connect a mooring line to a synthetic tail.

Messenger lines- A light line attached to the end of a main mooring line and used to assist in heaving the mooring to the shore or to the ship.

Minimum breaking load- A minimum breaking load of a mooring line as declared by he manufacturer for a new line. It does not include allowance for splicing or for wear and tear.

Mooring restraint- the capability of a mooring system to resist external forces of the ship.

Multi-buoy moorings- A facility whereby a tanker is usually moored by a combination of the ships anchor forward and mooring buoys aft and held on a fixed heading also called conventional buoy mooring.

Panama type fairlead- A no-roller fairlead mounted at the ships side and enclosed so that mooring may be led to ashore with equal facility either above or below the horizontal and strictly pertains only to fairleads complying with panama regulations but often applied to any closed fairlead or chock.

Pedestal roller- a roller fairlead usually operating in a horizontal plane to change the direction of lead or a mooring or other line on a ships deck.

Pre-tension- Additional load applied to a mooring line by a powered winch over and above that required to remove sag from the main run of the line.

Safe working load- A load less than the yield or breaking load by a safety factor defined by a code, standard or good engineering practice.

Sea island- A pier structure with no direct connection to the shore at which tankers can berth and berthing can take place either on one or both sides of the structure.

Seiche- Very long waves of small height generated by resonant oscillation within a partly closed harbour or other body of water. Strong horizontal currents can also be set up which may cause ship surging in adverse circumstances.

Ship to ship transfer- Transfer of crude oil or petroleum product between two ocean going ships made fast alongside at anchor or underway. The transfer of petroleum to barges and estuarial craft is specifically excluded.

Single point mooring- A facility whereby the tanker is secured by the bow to a single buoy or structure and is free to swing with the prevailing wind and current.

Smit bracket- A fitting for securing the end link of a chafing chain consisting of two parallel vertical plates mounted on a base with a sliding bolt passing through the plates.

Spring lines- Mooring lines leading in a nearly fore and aft direction of which to prevent longitudinal movement of the ship while in berth. Headspring prevent forward motion and backsprings is the aft motion.

Stern lines- Mooring lines leading ashore from he after end or poop of a ship often at an angle of 45 degrees to the foe and aft line.

Stopper- A device for securing a mooring line temporarily at the ship whilst the free end is made fast to the ships bitt. A carpenter stopper is a device with opening jaws to receive wire and shaped wedges to hold line when tension is applied.

Summer deadweight- The deadweight of a ship when loaded to summer marks

Summer marks- The summer loadline mark and center of Plimsoll disc on the ships side

Tail- A short length of a synthetic fiber rope attached to the end of a wire mooring line to provide increased elasticity and also ease of handling.