Guidelines for the Design, Operation and Maintenance of Multi Buoy Moorings (MBM)

While this guidance is most applicable to the initial planning of new facilities, it may also be a useful reference point for upgrading and evaluating existing berths. It includes practical advice on adequate anchor chain lengths, water depth and manoeuvring space. Recommendations are also given on the inspection frequency of pipeline end manifolds (PLEM), in addition to information on relevant ancillary equipment.

Multi buoy moorings (MBM) are common in the oil industry and are generally used in areas where the environmental conditions are moderate.

This publication provides information and guidance to assist with the planning, design, operations, maintenance and inspection of multi buoy moorings. While the information provided is primarily geared towards the initial planning, design and operation of new facilities, it may also be useful for reference when upgrading or evaluating existing berths or when replacing individual components.

The scope of this publication embraces mooring and oil transfer equipment within the multi buoy berth, up to and including the pipeline end manifold (PLEM). Information regarding the subsea pipelines serving the PLEM is considered to be outside the scope of this publication.

The main objective is to provide information and recommendations on good practice to assist with the development of site specific requirements. Terminals, operators and designers are encouraged to provide feedback to OCIMF on the content and on any aspects that are not addressed, for proposed inclusion in subsequent editions.

Section 1 Description of Multi Buoy Moorings

1.1 General

1.2 Design Limitations of MBMs

1.3 Comparisons with Fixed Berths (Piers and Sea Islands)

1.4 Comparisons with SPMs

1.5 Required Support Facilities

Section 2 Design of Multi Buoy Moorings

2.1 Preliminary Design Considerations

2.2 Site Selection, MBM Orientation and Layout

2.3 Mooring Load Analysis

2.4 Mooring Buoy and Hook Design

2.5 Anchor Chain Leg Design

2.6 Anchor Point Design

2.7 Hose System Design

2.8 Pipeline End Manifold (PLEM)

2.9 Ancillary Equipment

2.10 Coating Systems

Section 3 Operation of Multi Buoy Moorings

3.1 Health, Safety and the Environment (HSE)

3.2 Nomination and Vessel Acceptance Criteria

3.3 Pre-Arrival Procedures

3.4 Approach to Berth and Preparations

3.5 Berthing and Mooring Operations

3.6 Safety While in the Berth

3.7 Hose Connection and Disconnection

3.8 Departure from the Berth

Section 4 Inspection and Maintenance of Multi Buoy Moorings
4.1 General

4.2 Methods of Inspection

4.3 Mooring Buoys

4.4 Anchor Chains

4.5 Anchors Points

4.6 Hose Systems

4.7 Pipeline End Manifold (PLEM)

4.8 Ancillary Equipment

4.9 Spare Parts

Appendices

Appendix 1 Example Hose Lifting Method
Appendix 2 Example Hose Lowering Method

OCIMF

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