Anchoring Systems and Procedures

Following an increase in the number of incidents involving anchor losses, windlass motor failures and associated personnel injuries, OCIMF revised and updated the original 1982 publication to highlight the lessons learnt from incidents, provide improved information on anchoring practices and recognise advances made in anchor systems. The publication assesses the design capabilities and limitations of anchoring systems and equipment with the aim of enhancing the safety of operations.

This publication, which supersedes the 1st edition of ‘Anchoring Systems and Procedures for Large Tankers’, published in 1982, has been prepared by OCIMF to provide recommendations and guidance with the aim of promoting the safe operation and satisfactory performance of anchoring systems.

As background to the development of this revised publication; concerns had been expressed, by OCIMF member companies and others, about an increase in the number of incidents involving anchor losses, windlass motor failures and associated personnel injuries. A review of third party anchoring incidents by an OCIMF member highlighted the following particular issues:

• A number of incidents involving personnel injury and exposure of personnel to hazards during anchoring operations
• the loss of anchors and cables in relatively benign environmental conditions
• anchoring systems suffering significant damage in harsh environmental conditions
• incidents involving anchors dragging, with an associated risk of damage to third parties and the involved vessel
• inability to recover an anchor using the ship’s equipment
• reports of windlasses and drive motors being damaged due to excessive loads
• maintenance-related failures, i.e. failures caused by the lack of, or improper, maintenance.

Common factors were identified that contributed to these operational incidents and equipment failures, which included the following:

• Poor seamanship and a general lack of appreciation of the impact of deteriorating environmental conditions on anchoring system loads while remaining anchored or attempting to recover anchors
• improper operational procedures leading to excessive loads being placed on windlasses while in gear
• failure of anchor and chain components including flukes, shanks, shackles, swivels and common links.

As a result of the review, it was agreed to revise and update the information contained in the original 1982 publication to assist in promulgating the lessons learnt from incidents, to provide improved information on anchoring practices and to recognise advances made in anchor systems in the intervening years. In particular, this publication highlights the design capabilities and limitations of anchoring systems and equipment with the aim of enhancing the safety of operations.

The scope of this publication addresses anchoring systems and procedures that are applicable to all vessel types, irrespective of their size.

Section 1
Purpose and Scope

Section 2
Issues Associated with Anchoring Systems and Procedures

Section 3
General Description of Anchoring Systems
3.1 Anchoring System
3.2 Anchors
3.3 Chain Cable
3.4 Hawse Pipe
3.5 Anchor Lashing
3.6 Chain Stopper
3.7 Windlass
3.8 Drive Units
3.9 Windlass Control Systems
3.10 Spurling Pipe and Chain Locker

Section 4
Design Considerations
4.1 Design Standard
4.2 Design Philosophy of Anchoring Equipment
4.3 Environmental Forces Acting on a Ship at Anchor
4.4 Anchors
4.5 Chain Cable
4.6 Chain Stopper
4.7 Windlass
4.8 Testing of Anchor Equipment and Systems
4.9 Interface Between Ship Structure and Anchoring Equipment
4.10 Arrangement of Equipment
4.11 Additional Equipment

Section 5
Operational Procedures
5.1 Anchoring Procedures
5.2 Maintaining an Anchor Watch
5.3 Getting Underway
5.4 Use of Anchors in an Emergency

Section 6
Maintenance Issues
6.1 Routine Maintenance
6.2 Surveys and Inspections During Refit

Appendices
A An Example of Typical Planned Maintenance Activities
B An Example of Typical Refit Inspection, Survey and Maintenance Activities
C Example Certification for Anchor Chain Cable and Chain Cable Fittings

The Oil Companies International Marine Forum (OCIMF) is a voluntary association of oil companies with an interest in the shipment and terminalling of crude oil, oil products, petrochemicals and gas. OCIMF focuses exclusively on preventing harm to people and the environment by promoting best practice in the design, construction and operation of tankers, barges and offshore vessels and their interfaces with terminals. Learn more at www.ocimf.org