ABS revises Guide for Building and Classing Liftboats

The American Bureau of Shipping has revised its Guide for Building and Classing Liftboats.

This revised Guide has been published on January 1st, 2023, and became effective on the same date.

This Guide was developed for the Classification of Liftboats and specifies the requirements for design, construction and survey after construction of the Liftboat (including hull structure, equipment and machinery systems) for use by designers, builders, owners and operators in the offshore industry.

Changes to Conditions of Classification (1 January 2008)

For the 2008 edition, Part 1, Chapter 1, “Scope and Conditions of Classification” was consolidated into a generic booklet, entitled Rules for Conditions of Classification – Offshore Units and Structures (Part 1) for all units, installations, vessels or systems in offshore service.

The purpose of this consolidation was to emphasize the common applicability of the classification requirements in “Part 1, Chapter 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.

Thus, Part 1, Chapter 1 of this Guide specifies only the unique requirements applicable to liftboats.

These supplemental requirements are always to be used with the aforementioned Rules for Conditions of Classification – Offshore Units and Structures (Part 1).

In accordance with Section 1-1-2 of this Supplement to the ABS Rules for Conditions of Classification Offshore Units and Structures (Part 1), the classification ✠ A1 Liftboat ✠ AMS is to be assigned to liftboats meeting the requirements of this Guide.

A liftboat is a self-propelled, self-elevating vessel with a relatively large open deck capable of carrying equipment and supplies in support of various offshore mineral exploration and production or offshore construction activities.

A liftboat also has the capability of rapidly raising its hull clear of the water on its own legs so as to provide a stable platform from which maintenance and construction work may be conducted.

Liftboats with an overall hull length of 61 meters (200 feet) and above or with leg length greater than 91.44 meters (300 feet) are to comply with the ABS Rules for Building and Classing Mobile Offshore Units.

The requirements for conditions of classification are contained in the separate, generic ABS Rules for Conditions of Classification – Offshore Units and Structures (Part 1).

If you need more information, please visit the ABS Rules and Guides page, where the document is available FOR FREE.