The stability conditions of

watercraft A watercraft or waterborne vessel is any vehicle designed for travel across or through water bodies, such as a boat, ship, hovercraft, submersible or submarine. Types Historically, watercraft have been divided into two main categories. *Raf ...

are the various standard loading configurations to which a

ship A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways s ...

, or

offshore platform An oil platform (also called an oil rig, offshore platform, oil production platform, etc.) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms wi ...

may be subjected. They are recognized by classification societies such as Det Norske Veritas, Lloyd's Register and

American Bureau of Shipping The American Bureau of Shipping (ABS) is an American maritime classification society established in 1862. Its stated mission is to promote the security of life, property, and the natural environment, primarily through the development and verific ...

(ABS). Classification societies follow rules and guidelines laid down by International Convention for the Safety of Life at Sea (SOLAS) conventions, the

International Maritime Organization The International Maritime Organization (IMO; ; ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations responsible for regulating maritime transport. The IMO was established following agreement at a ...

and laws of the country under which the vessel is flagged, such as the

Code of Federal Regulations In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulatory law, regulations promulgated by the executive departments and agencies of the federal government of the ...

. Stability is normally broken into two distinct types: intact and damaged.

Intact stability

The vessel is in normal operational configuration. The hull is not breached in any compartment. The vessel will be expected to meet various stability criteria such as GMt (metacentric height), area under the GZ (righting lever) curve, range of stability, trim, etc.

Intact conditions

Lightship or Light Displacement

The vessel is complete and ready for service in every respect, including permanent ballast, spare parts, lubricating oil, and working stores but is without fuel, cargo, drinking or washing water, officers, crew, passengers, their effects, temporary ballast or any other variable load."Definition of Light Displacement at Naval Vessel Register"
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Full load departure or full displacement

Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 100% capacity. Ammunition and/or cargo is at maximum capacity. The vessel is at its limiting

draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...

or legal load line.

Standard condition

This is only for military vessels. Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 50% capacity. Ammunition and/or cargo is at 100% capacity. This condition is normally used for range and speed calculations.

Light arrival

Along with all the Lightship loads, the vessel has all systems charged meaning that all fresh water, cooling, lubricating, hydraulic and fuel service header tanks, piping and equipment systems are filled with their normal operating fluids. Crew and effects are at their normal values. Consumables (provisions, potable water and fuel) are at 10% full load. Ammunition and/or cargo is at 100% capacity.

Damaged stability

The vessel in the assessed "Worst Intact Condition" is analytically damaged by opening various combinations of watertight compartments to the sea. The number of compartments and their location are dictated by IMO regulations, SOLAS conventions, or other applicable rules. Typically these conditions are identified by the compartment(s) damaged ex: "Hold #3 and Water Ballast Tank 4 Port"

References

{{Reflist

External links

nvr.navy.mil, definitions

Displacement Displacement may refer to: Physical sciences Mathematics and physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

Naval architecture Ship measurements de:Stabilität (Schifffahrt) el:Καμπύλη ευστάθειας nl:Stabiliteit (schip)