Section 2 Definition

201. Application

The definitions of terms and symbols which appear in the Guidance are to be as specified in this Section, unless otherwise specified, and definitions of terms and symbols not specified in the Guidance are to be as specified in Rules for the Classification of Steel Ships and Rules for the Classification of Mobile Offshore Drilling Units.

202. Definition

1. Production systems are systems for processing (separation of contaminants such as water, sand, etc., and degassing) crude oils, etc. drawn up from the seabed, which generally consists of process- ing systems, safety/control systems and process support systems.

2. Process systems are systems for the separation of contaminants such as water, sand, etc., the separation of salt content, sulphur compounds, etc. of the crude oils, etc. drawn up from the sea- bed, and the removal of water from separated gases, which generally consist of crude oil process- ing systems, water processing systems and gas processing systems.

3. Process support systems are systems to support the drawing up and processing of crude oils, etc., which includes power generation and distribution systems, instrument and service air systems, potable water systems, fuel oil systems, instrument systems, communication systems, fire fighting systems, etc.

4. Positioning systems are such systems to keep the unit at a specific position of designated serv- ice area permanently or for long periods of time, which are specified in the followings

(1) Spread mooring systems consist of mooring lines connected to piles, sinkers, etc., which are firmly embedded into the seabed, the other end of which is individually connected to winches, or stoppers which are installed on a unit, the definitions of each category being as given in the followings.

(A) Catenary Mooring(CM) is defined as mooring forces obtained mainly from the net weight of spreaded catenary mooring lines.

(B) Taut Mooring(TM) is defined as mooring lines arranged straight and adjusted by high ini-

tial mooring forces, and the mooring forces obtained from the elastic elongation of these lines.

(2) Single point mooring system (SPM) is a system that allows a unit to weathervane so that the unit changes its heading corresponding to wind and wave directions. Typical SPM systems are as shown below:

(A) Catenary Anchor Leg Mooring (CALM) consists of a large buoy connected to mooring

points at the seabed by catenary mooring lines or a rigid yoke structure.

(B) Single Anchor Leg Mooring (SALM)

which is positioned at or near the water

lines. The unit is moored to the buoy by mooring

consists of the mooring structure with buoyancy surface, and is connected to the seabed. The unit

is moored to the buoy by mooring lines or a rigid yoke structure.

(C) Turret mooring allows only unit's angular movement relative to the turret so that it may be weathervane. The turret may be fitted internally within the unit, or externally at the stern/bow of the unit. The turret is generally connected to the seabed using a spread moor- ing system.

5. Crude Oil Spaces mean spaces used for the storage of crude oil (including crude oil tanks), and the trunks leading to such spaces.

6. Crude Oil Areas mean crude oil tanks, slop tanks, crude oil pump rooms, and adjacent pump rooms, cofferdams, ballast space or void spaces to crude oil tanks as well as the deck areas above these spaces covering all of the length and breadth of the unit.

7. Production Areas mean the areas where production systems are installed.

2 Guidance for Floating Production Units 2015

Ch 2 Classification and Surveys Ch 2