Stresses occurring in a ship structure when it is not supported by water, e.g. in a dry or floating dock.

Double bottom tanks are provided with plugs to allow draining prior to examination in a dry dock. Plugs of water tanks shall differ from plugs for oil tanks.

A plan used by the head of a dry dock to determine the blocking required for a vessel prior to entering the dock.

Acceptance tests performed on ship equipment and systems, in the presence of an Owner’s supervisor and/or a class surveyor to demonstrate suitable performance.

1. A place where a ship can be moored. A wet dock is a port area isolated from tidal water movements by a lock gate.

Compressed air or gas mixture saturation system for the conduct of diving operations. Surface compression chamber, diving bell, handling system and fixed gas storage facilities are main components of a saturation diving system.

According to Holland Shipbuilding June 2009 The SEVEN ATLANTIC, delivered by IHC Merwede in 2009 to Subsea 7, is one of the largest and most capable diving support vessels in the world.

A vessel provided with diving equipment and used for underwater work such as the maintenance and inspection of mobile platforms, pipelines and their connections, well-heads, etc.

A manned, non-self-propelled submersible tethered unit consisting of at least one chamber internally pressurized in order to allow a diver to be transported to and from an underwater site.

The offshore industry is heavily dependant on diving operations. Air diving is used for the inspection and repair programmes carried out in shallow waters.

A type of blowout preventer used on an oil rig to divert fluid safely from well under “kick” or rapid pressure rise condition.

A compartment within an underwater system or vehicle provided with internally pressurizing capability to transfer a diver to the work site from the submersible and back.

A person who dives, especially one who works under water using a diving-suit.

Any change inside or outside a control system which disturbs the equilibrum.

Electricity supply to various items of equipment, often at different voltages.

A load that acts over a part or the whole of the surface of the structure.

An urgent signal for help assistance.

A radio signal from a distressed automatically directed to a RCC giving position, identification, course and speed of the vessel as well as the nature of distress.

A term used when a ship requires immediate assistance.

The effects of welding on a metal plate. It may appear as shrinkage or an angular twisting. Distortion of steel structures caused by welding and other thermal processes can be assigned to three main causes.