Reasonable Weather

Reasonable Weather

Definition(s)

Reasonable Weather

Wind strengths of force six or less in the Beaufort scale, associated with sea states sufficiently moderate to ensure that green water is taken on board the unit’s weather deck at infrequent intervals only, or not at all. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Positional Mooring

Positional Mooring

Definition(s)

Positional Mooring

Anchoring system for position keeping at the unit's working location prompt and thorough repair a permanent repair completed at the time of survey to the satisfaction of the surveyor, therein removing the need for the imposition of any associated condition of class. Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards

Positional Mooring

Station-keeping by means of multi-leg mooring systems with or without thruster assistance. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards  

Positional Mooring

Station-keeping by means of multi-leg mooring system with or without thruster-assist. The positional mooring system will consist of the following components, as relevant:
  1. Anchor points:

• Drag embedment anchors.

• Anchor piles.

• Suction anchor piles.

• Gravity anchors.

• Plate anchors.

2.  Anchor lines. 3.  Anchor line fittings:

• Shackles.

• Connecting links/plates.

• Wire rope terminations.

• Clump weights.

• Quick release devices, etc.

4. Fairleads/bending shoes. 5. Chain or wire rope stoppers. 6. Winches or windlasses. Where applicable, the structural or mechanical connection of these items to the unit is also considered to be part of the positional mooring system. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 3, Functional Unit Types and Special Features, June 2013, Lloyd’s Register, Global Standards
Modes of Operation

Modes of Operation

Definition(s)

Modes of Operation

Modes of operation A mode of operation is a condition or manner in which a unit may operate or function while on location or in transit. From the classification aspect, the modes of operation of a unit should include the following: 1. Operating condition The condition when a unit is on location, for the purpose of carrying out its primary design operations, and the combined environmental and operational loadings are within the appropriate design limits established for such operations. The unit may be either afloat or supported on the sea bed, as applicable. 2. Survival condition A severe storm condition during which a unit may be subjected to the most severe environmental loadings for which the unit is designed. Drilling or similar operations may have been discontinued due to the severity of the environmental loadings. The unit may be either afloat or supported on the sea bed, as applicable. 3.Transit condition All unit movements from one geographical location to another. NOTE: For surface type units, the mode of operation will be defined by the loading conditions stated in the approved loading manual. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Linked

Linked

Definition(s)

Linked

Linked means connected while operating to a single point mooring facility, fixed structure or otherwise attached or resting on the sea bed. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Fetch

Fetch

Definition(s)

Fetch

The extent of clear water across which a wind has blown before reaching the unit. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Clear Water

Clear Water

Definition(s)

Clear Water

Water having sufficient depth to permit the normal development of wind generated waves. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Operating Limits Notation

Operating Limits Notation

Definition(s)

Operating Limits Notation

A notation indicating the significant design criteria on which approval of the unit is based, e.g.: • Maximum operating environmental design limits for semi-submersible units and self-elevating units. • Limiting sea state and/or wind speed during which a unit may remain moored to a single point mooring. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Service Restriction Notation

Service Restriction Notation

Definition(s)

Service Restriction Notation

A notation indicating that the unit has been classed on the understanding that it will be operated only in suitable areas or conditions which have been agreed by the Classification Committee, e.g., protected waters service. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Protected Waters Service

Protected Waters Service

Definition(s)

Protected Waters Service

Service in sheltered water adjacent to sand banks, reefs, breakwaters or other coastal features. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Specified Operating Area Service

Specified Operating Area Service

Definition(s)

Specified Operating Area Service

Service within a defined geographical area which will be indicated on the ClassDirect Live website, e.g., Black Sea service. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
ES

ES

Definition(s)

ES

Enhanced Scantlings. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
SEA (HSS-n)

SEA (HSS-n)

Definition(s)

SEA (HSS-n)

Ship Event Analysis (Hull Surveillance Systems). Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
SERS

SERS

Definition(s)

SERS

Ship Emergency Response Service. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
MCM

MCM

Definition(s)

MCM

Machinery Condition Monitoring. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
MCBM

MCBM

Definition(s)

MCBM

Machinery Condition Based Maintenance. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
MPMS

MPMS

Definition(s)

MPMS

Machinery Planned Maintenance Scheme. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
BWMP

BWMP

Definition(s)

BWMP

Ballast Water Management Plan. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Critical Areas

Critical Areas

Definition(s)

Critical Areas

Part(s) of a product that require specific operational control in service life; includes sealing surfaces and locations of high stress and strain under static and/or cycling loads. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards

Critical Areas

Critical areas are locations vulnerable to substantial corrosion, buckling and/or fatigue cracking. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Ballast Tank

Ballast Tank

Definition(s)

Ballast Tank

A ballast tank is a tank which is used solely for salt-water ballast. A space which is used for both the storage of liquids and salt-water ballast will be treated as a salt-water ballast tank when substantial corrosion has been found in that space. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Overall Survey

Overall Survey

Definition(s)

Overall Survey

An Overall Survey is a survey intended to report on the overall condition of the hull structure and to determine the extent of additional Close-up Surveys as necessary. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Close-up Survey

Close-up Survey

Definition(s)

Close-up Survey

A Close-up Survey is a survey where the details of structural components are within the close visual inspection range of the Surveyor, i.e., normally within reach of hand. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Representative Spaces

Representative Spaces

Definition(s)

Representative Spaces

Representative spaces are those which are expected to reflect the condition of other spaces of similar type and service and with similar corrosion prevention systems. When selecting representative spaces, account should be taken of the service and repair history on board and identifiable Critical Structural Areas. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Substantial Corrosion

Substantial Corrosion

Definition(s)

Substantial Corrosion

Substantial corrosion is wastage of individual plates and stiffeners in excess of 75 per cent of allowable margins, but within acceptable limits. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards  

Substantial Corrosion

Extent of corrosion such that assessment of corrosion pattern indicates wastage in excess of 75% of allowable margins, but within acceptable limits Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards
Corrosion Preventing System

Corrosion Preventing System

Definition(s)

Corrosion Preventing System

A corrosion preventing system is normally a full hard protective coating. This is usually to be an epoxy coating or equivalent. For other systems, with the exception of soft and semi-hard coatings, see Pt 1, Ch 3,1.5.16 of the Rules for Ships. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Independent Double Bottom Tank

Independent Double Bottom Tank

Definition(s)

Independent Double Bottom Tank

An independent double bottom tank is a double bottom tank which is separate from topside tanks, side tanks or deep tanks. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Prompt and Thorough Repair

Prompt and Thorough Repair

Definition(s)

Prompt and Thorough Repair

A prompt and thorough repair is a permanent repair completed at the time of survey to the satisfaction of the Surveyor, thereby removing the need for the imposition of any associated condition of class or recommendation. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Critical Structural Areas

Critical Structural Areas

Definition(s)

Critical Structural Areas

Critical structural areas are locations which have been identified from calculations to require monitoring or from the service history of the subject unit or from similar units, if applicable, to be sensitive to cracking, buckling or corrosion which would impair the structural integrity of the unit. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards  

Critical Structural Areas

Areas that have been identified from calculations to require monitoring or from the service history of the subject vessel or from similar or sister vessels to be sensitive to cracking, buckling or corrosion which would impair the structural integrity of the vessel. Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards
Accommodation Unit

Accommodation Unit

Definition(s)

Accommodation Unit

Accommodation unit is a support unit whose primary function is to provide accommodation for more than twelve offshore personnel who are not crew members or passengers. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Support Units

Support Units

Definition(s)

Support Units

Support units are units whose primary function is to support offshore installations. They are normally engaged in one or more of the following functions: crane operations, fire-fighting, diving operations, maintenance, construction, pipelaying and accommodation. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Column-stabilised Units

Column-stabilised Units

Definition(s)

Column-stabilised Units

Semi-submersible or column-stabilised units have working platforms supported on widely spaced buoyant columns. The columns are normally attached to buoyant lower hulls or pontoons. These units are normally floating types but can be designed to rest on the sea bed, see also 2.2.3. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards  

Column-stabilised Units

A column-stabilised unit is a unit with a working platform supported on widely spaced buoyant columns. The columns are normally attached to buoyant lower hulls or pontoons. These units are normally floating types but can be designed to rest on the sea bed. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 3, Functional Unit Types and Special Features, June 2013, Lloyd’s Register, Global Standards