scope:

Foreword

This ABS Guide for Building and Classing Drillships provides criteria that can be applied in the classification of the hull structure of monohull surface-type and ship-shaped drilling units (i.e., drillships).

Requirements for classification of drillships are included in the ABS Rules for Building and Classing Mobile Offshore Drilling Units (MODU Rules). The hull strength criteria contained in this Guide are to be used in conjunction with Part 3, Chapter 2 of the MODU Rules.

The requirements for conditions of classification are contained in the separate, generic ABS Rules for Conditions of Classification - Offshore Units and Structures (Part 1) for all units, installations, vessels or systems in offshore service. The purpose of the Rules for Conditions of Classification "Part 1" is to emphasize the common applicability of the classification requirements in "Part 1" to ABS-classed offshore units, pipelines, risers, and other offshore structures, and thereby make "Conditions of Classification" more readily a common Rule of the various ABS Rules and Guides, as appropriate.

Section 1 of this Guide specifies only the unique supplemental requirements applicable to drillships. These supplemental requirements are always to be used with the aforementioned ABS Rules for Conditions of Classification - Offshore Units and Structures (Part 1).

The effective date of this Guide is 1 August 2011. The application of this Guide is optional, and unless this Guide is specifically requested by an ABS Request For Class (RFC), ABS design review will follow current practice. However, from 1 January 2012, the ABS MODU Rules will require compliance with this Guide.