Section 1 General

1.1 Application

1.1.1 The requirements of this Chapter apply to all drilling units engaged in drilling operations for the exploration and exploitation of petroleum, gas or other resources beneath the sea bed.

1.1.2 Surface type units are to comply with this Chapter, but reference should also be made to Pt 4, Ch 4, 4 Surface type units.

1.1.3 Units engaged in rock drilling or other similar work operations not related to petroleum or gas resources will be specially considered but should comply with the general requirements of this Chapter as applicable to the unit.

1.2 Class notations

1.2.1 The Regulations for classification and the assignment of class notations are given in Pt 1, Ch 2 Classification Regulations, to which reference should be made.

1.2.2 In general, units complying with the requirements of this Chapter and the relevant Parts of the Rules will be eligible for the assignment of one of the following class type notations:

Mobile offshore drilling unit; or
Drill ship.

Other type notations may be assigned when considered appropriate by the Classification Committee.

1.2.3 Drilling units with an installed drilling plant facility which comply with the requirements of Pt 3, Ch 7 Drilling Plant Facility will be eligible for the assignment of the special features class notation DRILL.

1.2.4 When a DRILL notation is not assigned to a unit with a drilling plant facility, classification of the unit will be subject to the drilling plant being certified by LR, or by another acceptable organisation.

1.2.5 When, at the request of an Owner, a unit is to be verified in accordance with the Regulations of a National Administration, a descriptive note will be included in the Class Direct website.

1.3 Scope

1.3.1 The following additional topics applicable to the class type notation are covered by this Chapter:

Structural arrangements of the unit related to drilling operations.
Supporting structures for drilling equipment, bulk storage and raw water towers.
Drill floor and derrick substructure.
Drilling cantilevers.
Structural arrangements in way of drilling wells.
Structural mud tanks or pits.
Deckhouses and modules related to drilling operations.
Pipe racks and supports.
Hazardous areas and ventilation.
Pollution prevention.

1.4 Installation layout and safety

1.4.1 In principle, drilling units are to be divided into main functional areas to ensure that the following areas are separated and protected from each other:

Drilling area:
- Drill floor area
- Mud circulation and treatment area.
Auxiliary equipment area.
Living quarters’ area.

1.4.2 Attention is to be given to the relevant Statutory Regulations for fire safety of the National Administration in the country of registration and the areas of operation as applicable, see Pt 1, Ch 2, 1 Conditions for classification and Pt 7, Ch 3 Fire Safety.

1.4.3 Additional requirements for safety systems and hazardous areas are given in Pt 7 SAFETY SYSTEMS, HAZARDOUS AREAS AND FIRE.

1.4.4 Living quarters, lifeboats and other evacuation equipment are to be located in non-hazardous areas and be protected and separated from the drilling area.

1.5 Plans and data submission

1.5.1 Plans, calculations and data are to be submitted as required by the relevant Parts of the Rules together with the additional plans and information listed in this Chapter.