Rudder Actuator

Rudder Actuator

Definition(s)

Rudder Actuator

Rudder actuator means the components which convert directly hydraulic pressure into mechanical action to move the rudder. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 5, Main and Auxiliary Machinery, June 2013, Lloyd’s Register, Global Standards
Maximum Skew Angle

Maximum Skew Angle

Definition(s)

Maximum Skew Angle

The maximum skew angle of a propeller blade is defined as the angle, in projected view of the blade, between a line drawn through the blade tip and the shaft centreline and a second line through the shaft centreline which acts as a tangent to the locus of the mid-points of the helical blade sections, see Fig. 7.1.1. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 5, Main and Auxiliary Machinery, June 2013, Lloyd’s Register, Global Standards
Mass Produced Engines

Mass Produced Engines

Definition(s)

Mass Produced Engines

Mass produced engines, for main and auxiliary purposes, are defined as those which are produced under the following criteria:
  1. In quantity under strict quality control of material and parts, according to a quality assurance scheme acceptable to LR.
  2. By the use of jigs and automatic machine tools designed to machine parts to specified tolerances for interchangeability, and which are verified on a regular inspection basis.
  3. By assembly with parts taken from stock and requiring little or no fitting.
  4. With bench tests carried out on individual assembled engines according to a specified programme.
  5. With appraisal by final examination of engines selected at random after workshop testing.
Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 5, Main and Auxiliary Machinery, June 2013, Lloyd’s Register, Global Standards
Main Propulsion Turbines

Main Propulsion Turbines

Definition(s)

Main Propulsion Turbines

Main propulsion engines and turbines are defined as those which drive main propelling machinery directly or indirectly through mechanical shafting and which may also drive electrical generators to provide power for auxiliary services. Auxiliary engines and turbines are defined as those coupled to electrical generators which provide power for auxiliary services, for electrical main propulsion motors or a combination of both. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 5, Main and Auxiliary Machinery, June 2013, Lloyd’s Register, Global Standards
Main Propulsion Engines

Main Propulsion Engines

Definition(s)

Main Propulsion Engines

Main propulsion engines and turbines are defined as those which drive main propelling machinery directly or indirectly through mechanical shafting and which may also drive electrical generators to provide power for auxiliary services. Auxiliary engines and turbines are defined as those coupled to electrical generators which provide power for auxiliary services, for electrical main propulsion motors or a combination of both. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 5, Main and Auxiliary Machinery, June 2013, Lloyd’s Register, Global Standards
System Monitoring

System Monitoring

Definition(s)

System Monitoring

The act of checking, on a regular basis, the applicable processes, activities and associated documentation that the Fabricator’s quality system continues to operate as defined in the quality programme. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Still Water Condition

Still Water Condition

Definition(s)

Still Water Condition

Still water condition is defined as an ideal condition when no environmental loads are imposed on the structure, e.g., no wind, wave or current, etc. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Quality System

Quality System

Definition(s)

Quality System

The organisation structure, responsibilities, activities, resources and events laid down by Management that together provide organized procedures (from which data and other records are generated) and methods of implementation to ensure the capability of the fabrication yard to meet quality requirements. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Gravity Loads

Gravity Loads

Definition(s)

Gravity Loads

Gravity and functional loads are loads which exist due to the unit’s weight, use and treatment in still water conditions for each design case. All external forces which are responses to functional loads are to be regarded as functional loads, e.g., support reactions and still water buoyancy forces. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Draught TT

Draught TT

Definition(s)

Draught TT

Draught, TT, is the maximum design transit summer draught, in metres, measured from top of keel. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Draught T0

Draught T0

Definition(s)

Draught T0

Draught, T0, is the maximum design operating summer draught, in metres, measured from top of keel. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Depth D

Depth D

Definition(s)

Depth D

Depth, D, is measured, in metres, at the middle of the length, L, from the top of keel to top of the deck beam at side on the uppermost continuous deck. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Breadth (BS)

Breadth (BS)

Definition(s)

Breadth (BS)

“Breadth (BS)” is the greatest moulded breadth of the ship, in metres, at or below the deepest load line draught (dS). <Annex 1, regulation 12A>. Source: Resolution MEPC.141(54), amendments to the Annex of the Protocol of 1978 relating to the International Convention for the Prevention of Pollution from Ships, 1973 (Amendments to regulation 1, addition to regulation 12A, consequential amendments to the IOPP Certificate and amendments to regulation 21 of the revised Annex I of MARPOL 73/78), 24 March 2006, International Maritime Organization. Legislation
Rule Length

Rule Length

Definition(s)

Rule Length

Rule length, L, in metres, for self-elevating units and semi-submersible units with twin lower hulls is to be taken as 97 per cent of the extreme length on the maximum design transit waterline measured on the centreline or on a projection of the centreline, see Fig. 1.5.1. FIG.1.5.1 Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards  

Rule Length

The Rule length, L, for surface type units is the distance, in metres, on the summer load waterline from the forward side of the stem to the after side of the rudder post or to the centre of the rudder stock if there is no rudder post. L is to be not less than 96 per cent, and need not be greater than 97 per cent, of the extreme length on the summer load waterline. In ships with unusual stem or stern arrangements the Rule length, L, will be specially considered. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards
Taut-leg Mooring

Taut-leg Mooring

Definition(s)

Taut-leg Mooring

A system that relies principally for its compliance on the axial extensibility of the mooring line rather than the catenary profile. Such moorings provide a significant upward load on the seabed connection. Source: API RP 2SM Design, Manufacture, Installation, and Maintenance of Synthetic Fiber Ropes for Offshore Mooring, Second Edition, July 2014. Global Standards Source: API RP 2SM, Design, Manufacture, Installation, and Maintenance of Synthetic Fiber Ropes for Offshore Mooring, First Edition, July 2014. Global Standards

Taut-leg Mooring

A mooring system based on light-weight anchor lines pre-tensioned to a taut configuration with no significant catenary shape at any unit offset, and applying vertical and horizontal loads at the anchor points. With this type of system, compliancy is derived from the inherent axial elastic stretch properties of the anchor line. 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
Thruster-assist

Thruster-assist

Definition(s)

Thruster-assist

The use of thrusters, inclusive of their associated equipment, to supplement the unit’s 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
Surface Type Jack-up Unit

Surface Type Jack-up Unit

Definition(s)

Surface Type Jack-up Unit

A surface type self-elevating (or jack-up) unit is a floating unit, which is designed to operate as a sea bed stabilized unit in an elevated mode. These units have a ship type displacement hull of single or multiple hull construction fitted with moveable legs capable of raising the hull above the surface of the sea. The legs may be designed to penetrate the sea bed, or be attached to a mat or individual footings which rest on the sea bed. In general, installation and maintenance activities would be undertaken in the jacked-up condition. These unit types are generally self-propelled. 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
Surface Type Self-elevating (or jack-up) Unit

Surface Type Self-elevating (or jack-up) Unit

Definition(s)

Surface Type Self-elevating (or jack-up) Unit

A surface type self-elevating (or jack-up) unit is a floating unit, which is designed to operate as a sea bed stabilized unit in an elevated mode. These units have a ship type displacement hull of single or multiple hull construction fitted with moveable legs capable of raising the hull above the surface of the sea. The legs may be designed to penetrate the sea bed, or be attached to a mat or individual footings which rest on the sea bed. In general, installation and maintenance activities would be undertaken in the jacked-up condition. These unit types are generally self-propelled. 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
Surface Type Floating Unit

Surface Type Floating Unit

Definition(s)

Surface Type Floating Unit

A surface type floating unit is a unit with a ship or barge type displacement hull of single or multiple hull construction intended for operation in the floating condition. 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
Self-elevating or (Jack-up) Unit

Self-elevating or (Jack-up) Unit

Definition(s)

Self-elevating or (Jack-up) Unit

A self-elevating (or jack-up) unit is a floating unit which is designed to operate as a sea bed-stabilised unit in an elevated mode. These units have a buoyant hull (generally either triangular or pontoon shaped) with movable legs capable of raising its hull above the surface of the sea. The legs may be designed to penetrate the sea bed, or be  attached to a mat or individual footings which rest on the sea bed. These unit types are generally not fitted with a propulsion 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
Riser Components

Riser Components

Definition(s)

Riser Components

Valves, connections, etc., andsimilar apparatus incorporated in the riser 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
Riser Support

Riser Support

Definition(s)

Riser Support

Any structural item used for connecting a part of the riser system to the unit. 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
Liftboat

Liftboat

Definition(s)

Liftboat

A liftboat is a unit with a buoyant hull (generally either triangular or pontoon shaped) with moveable legs capable of raising the hull above the surface of the sea and designed to operate as a sea bed-stabilised unit in an elevated mode. The legs may be designed to penetrate the sea bed, or be attached to a mat or individual footings which rest on the sea bed. In general, installation and maintenance activities would be undertaken in the jacked-up condition. These unit types are generally self-propelled. 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
Jack-up Unit

Jack-up Unit

Definition(s)

Jack-up Unit

A self-elevating (or jack-up) unit is a floating unit which is designed to operate as a sea bed-stabilised unit in an elevated mode. These units have a buoyant hull (generally either triangular or pontoon shaped) with movable legs capable of raising its hull above the surface of the sea. The legs may be designed to penetrate the sea bed, or be  attached to a mat or individual footings which rest on the sea bed. These unit types are generally not fitted with a propulsion 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
Floating Pipe

Floating Pipe

Definition(s)

Floating Pipe

A surface pipe between the singlepoint mooring or buoy and the ship manifold. The floating pipe is normally permanently attached to the single-point mooring. 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
Type Notation

Type Notation

Definition(s)

Type Notation

A notation indicating that the unit has been arranged and constructed in compliance with the particular Rules intended to apply to that type of unit, e.g., Mobile drilling unit. Typical type notations are defined in Part 3. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Special Features Notation

Special Features Notation

Definition(s)

Special Features Notation

A notation indicating that the unit incorporates special features which significantly affect the design, e.g., DRILL. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Support Vessel

Support Vessel

Definition(s)

Support Vessel

Alternative name for a support unit as defined in 2.1.13. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Special Duties Notation

Special Duties Notation

Definition(s)

Special Duties Notation

A notation indicating that the unit has been designed, modified or arranged for special duties other than those implied by the type notation, e.g., oil exploration. Units with special duties notations are not thereby prevented from performing any other duties for which they may be suitable. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Sheltered Water

Sheltered Water

Definition(s)

Sheltered Water

Water where the fetch is six nautical miles or less. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards