Guidelines for

ETPM~ BERVIC OC'tll.:VME

32, AVENUE P/\BLO TSA "f0001

92754 NANTERRE

Marine Operations

Front Cover Picture: The Seaway Heavy Lifting crane vessel 'Stanislav Yudin' equipped with a 2500 mT revolving crane inshore at Nigg. The vessel is taking onboard, the Mobil Galahad jacket, deck and piles for transportation and associated installation at the UK Sector of the North Sea

By London Offshore Consultants Limited

Copyright

Guidelines for Marine Operations, is the exclusive copyright of the publishers and may not be reproduced in whole or part without the written pennission of Oilfield Publications Limited.

Re-ordering

Additional copies of this book may be obtained by contacting OPL direct at the address, telephone and fax numbers given at the foot of this page.

This book has been carefully prepared from the best existing sources of information available at the time of preparation but OPL do not guarantee the accuracy of the book nor of the text, diagrams or photographic reproductions portrayed thereon nor do OPL assume any responsibility or liability for any reliance thereon.

a member of the OPS Holding Group

Homend House, PO Box 11, ledbury, Herefordshire HR8 1 BN, England Tel: +44 (0) 1531 634563 Fax: +44 (0) 1531 634239

Email: opl@dial.pipex.com ISBN 1 870945

INTRODUCTION

These Guidelines for Marine Operations have been written by London Offshore Consultants (LOC), one of the world's h;;ading warranty surveyors and marine consultants. Until now they have only been available to LOC's own staff and clients.

Due to interest in the Guidelines, principally from design engineers and mariners engaged in project development and wishing to establish the warranty surveyors requirements, LOC decided to make them generally available, this OPL publication is the result.

It is emphasised that these are guidelines, not Rules. Also they are constantly being updated, as industry practice changes. Thus, project-specific guidelines are often prepared by LOC based on the information in this book.

LOC have a permanent technical staff of over fifty (50) personnel, including master mariners, naval architects and structural engineers, based in offices in London, Houston, Singapore, Stavanger, Dubai and Abu Dhabi.

The services offered by LOC and the addresses of LOC offices are given overleaf and on the inside back cover.

LOC look forward to hearing from readers about any clarifications which they may require to the Guidelines or about ways in which LOC may be of service to them and hope that you will find this new book interesting and useful in your day to day work.

London Offshore Consultants April 1997

London Offshore Consultants has established a reputation as one of the leading offshore marine and shipping consultancies. The consultancy team comprises of qualified and experienced Master Mariners, Naval Architects, Marine, Civil and Structu:al Engineers, providing the Company with a powerful combination of professional expertise. The LOC Head Office is located in London with overseas offices in Houston, Singapore, Stavanger, Dubai, Abu Dhabi and Perth, LOC's work includes the following:

Shipping Offshore

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Salvage and wreck removal consultancy 0 Marine insurance warranty surveying Total loss and seaworthiness investigations 0 Marine consultancy Hull and machinery surveys 0 Feasibility studies Towage studies 0 Rig moving approval Damage survey of port and offshore installations 0 Mooring design for floating production systems Unsafe port investigations 0 Analyses of pipelines Port design and operational studies 0 Motion response analyses Risk assessment and loss prevention 0 Stability calculations Marine superintending 0 Structural analyses Oil shortage claims investigations 0 Design of sea fastenings Slow steaming investigations 0 Towage studies and approvals Pollution investigations 0 Heavy lift evaluations Vessel sale and purchase surveys 0 Crane suitability studies Marine personal injury investigations 0 Barge and tug surveys Hydrographic surveys 0 On and offhire surveys and vessel condition Cargo surveys and investigations surveys

Structural analyses 0 Technical bid evaluations Mooring analyses 0 Risk analyses Meteorological studies 0 Jacket analyses Vessel condition surveys 0 Damage surveys Management and operation audits 0 Failure mode analyses Stability investigations 0 Safety case studies Manoeuvring analyses 0 Preparation of marine and engineering manuals

and Codes of Practice

For details of worldwide office locations, telephone, telefax and telex numbers,

see the inside back cover

The c ic~ I Solution

!if Platform Transport and Installation

lif Platform Removal

lif Inshore and Offshore Heavy Lifting

If Subsea Structure Transport and Installation

[I( Complete Project Management

lif Engineering

Seaway Heavy Lifting Seaway Heavy Lifting Engineering B.V. Wiltonstraat 11-13,2722 NG Zoetermeer, The Netherlands, Tel: +31 (0)79 3417114 Fax: +31 (0)79 3428404

CONTENTS

CHAPTER 1 : LOADOUT ........................................................................................ ~ ........................... 1-14 1. Introduction ..................................................................................................................................... 3-4 1.1 Scope of Guidelines ............................................................................................................................. 3 1.2 Definitions ............................................................................................................................................ 3 1.3 Reference Documents ........................................................................................................................... 4 1.4 Certificates of Approval ....................................................................................................................... 4

2. Planning of OperatiOns ................................................................................................................... 5-7 2.1 General ................................................................................................................................................. 5 2.2 Loadout Manual ................................................................................................................................... 5 2.3 Safety Procedures and Contingency Plans ........................................................................................... 6 2.4 Site Surveys .......................................................................................................................................... 6 2.5 Anchoring, Mooring and Fendering ..................................................................................................... 6 2.6 Environmental Criteria ......................................................................................................................... ? 2. 7 Weather Forecasting and Environmental Monitoring .......................................................................... 7

3. Loads and Analysis ......................................................................................................................... 8-9 3.1 General ................................................................................................................................................. 8 3.2 Weight and Weight Distribution ........................................................................................................... 8 3.3 Stability Requirements ......................................................................................................................... 8 3.4 Skidding Loads ..................................................................................................................................... 8 3.5 Skew and Deformation Loads .............................................................................................................. 8 3.6 Load Factors ......................................................................................................................................... 9

4. Systems and Equipment ............................................................................................................. 10-12 4.1 General ............................................................................................................................................... 10 4.2 Jacking Systems and Winches ............................................................................................................ tO 4.3 Multi-Wheel Trailers .......................................................................................................................... 1 0 4.4 Lifted Load-Outs ................................................................................................................................ 11 4.5 Barge and Ballast System .................................................. : ................................................................ 11 4.6 Power Supply ...................................................................................................................................... 11 4.7 Grillage and Seafastenings ................................................................................................................. 12

5. Operational Requirements ......................................................................................................... 13-14 5.1 General ............................................................................................................................................... 13 5.2 Operational Recording ....................................................................................................................... 13 5.3 Barge or Vessel Handling ................................................................................................................... 13 5.4 Testing & Measuring .......................................................................................................................... 14

CHAPTER 2 : BARGE TRANSPORTATION .................................................................................. 15-37 1. Introduction ~17 -18 1.1 Scope of Guidelines ........................................................................................................................... 17 1.2 Definitions .......................................................................................................................................... 17 1.3 Safety Procedures and Contingency Plans ......................................................................................... 18 1.4 Reference Documents ......................................................................................................................... l8 1.5 Certificates of Approval ..................................................................................................................... 18

CONTENTS

2. Planning of Marine Operations ................................................................................................. 19-21 2.1 General ............................................................................................................................................... 19 2.2 Transportation Manual ....................................................................................................................... 19 2.3 Documents and Records ..................................................................................................................... 20 2.4 Weather Forecasting ........................................................................................................................... 20 2.5 Environmental Criteria for Towing .................................................................................................... 20 2.6 Wind ................................................................................................................................................... 21 2.7 Waves ......................................................................................................................................... ~ ........ 21 2.8 Ice ....................................................................................................................................................... 21 2.9 Departure Criteria ............................................................................................................................... 21

3. Determination of Loads and Motions ....................................................................................... 22-24 3.1 General ............................................................................................................................................... 22 3.2 Motion Response ................................................................................................................................ 22 3.3 Standard Criteria ................................................................................................................................. 22 3.4 Intact Stability .................................................................................................................................... 23 3.5 Dynamical Stability ............................................................................................................................ 24 3.6 Damaged Stability .............................................................................................................................. 24 3.7 In-harbour Moves ............................................................................................................................... 24

4. Grillage, Seafastenings and Cargo Design ................................................................................ 25-27 4.1 General ............................................................................................................................................... 25 4.2 Loads during Transportation .............................................................................................................. 25 4.3 Method of Structural Analysis ........................................................................................................... 26 4.4 Strength ............................................................................................................................................... 26 4.5 Barge Strength .................................................................................................................................... 26 4.6 Internal Seafastenings ......................................................................................................................... 26 4.7 Fatigue ................................................................................................................................................ 26

5. Operational Aspects .................................................................................................................... 28-29 5.1 General ............................................................................................................................................... 28 5.2 Draught and Trim .... ; .......................................................................................................................... 28 5.3 Pre-sailaway Checks ........................................................................................................................... 28 5.4 Towing Routes .................................................................................................................................... 28 5.5 Communication and Reporting .................................................................. : ....................................... 29

6. _ Requirements for Barges ............................................................................................................ 30-32 6.1 General ............................................................................................................................................... 30 6.2 Certification ......................................................................................................................................... 30 6.3 Technical Information ........................................................................................................................ 30 6.4 Ballast and Pumping Systems ............................................................................................................ 30 6.5 Watertight Integrity ............................................................................................................................ 31 6.6 Barge Deck Openings ......................................................... : ........................................... 31 6.7 Anchoring and Mooring System ......................................................................................................... 31 6.8 Navigation Lights and Shapes ............................................................................................................. 32 6.9 Access ........... ...................................................................................................................................... 32

ii

CONTENTS

7. Towing Arrangements ................................................................................................................. 33-34 7.1 General ............................................................................................................................................... 33 7.2 Tow Connections ................................................................................................................................ 33 7.3 Fairleads ............................................................................................................................................. 33 7.4 Towing Bridle ..................................................................................................................................... 33 7.5 Intermediate Tow Pennant .................................................................................................................. 34 7.6 Shackles .............................................................................................................................................. 34 7.7 Retrieving Arrangements ................................................................................................................... 34 7.8 Emergency Towing Arrangements ..................................................................................................... 34

8. Requirements for Towing Vessels (Th.gs) .................................................................................. 35-37 8.1 General ............................................................................................................................................... 35 8.2 Bollard Pull Requirements .................................................................................................................. 35 8.3 Towing Winches ................................................................................................................................. 35 8.4 Towline Control .................................................................................................................................. 35 8.5 Towing Wire ....................................................................................................................................... 36 8.6 Synthetic Ropes .................................................................................................................................. 36 8.7 Tailgates/Stem Rails ........................................................................................................................... 36 8.8 Additional Equipment ........................................................................................................................ 36 8.9 Bunkers ............................................................................................................................................... 37 8.10 Manning .............................................................................................................................................. 37

CHAPTER 3 : LIFTING ..................................................................................................................... 39-60 1. Introduction ................................................................................................................................. 41-42 1.1 Scope of Guidelines ........................................................................................................................... 41 1.2 Definitions .......................................................................................................................................... 41 1.3 Reference Documents ......................................................................................................................... 42 1.4 Certificates of Approval ..................................................................................................................... 42

2. Planning of Marine Lifts ............................................................................................................ 43-44 2.1 General ............................................................................................................................................... 43 2.2 Site Survey ......................................................................................................................................... 43 2.3 Lifting Manual .................................................................................................................................... 43 2.4 Documentation ................................................................................................................................... 44 2.5 Design Calculations ............................................................................................................................ 44 2.6 Operational Aspects ........................................................................................................................... 44

3. Loads and Analysis ..................................................................................................................... 45-50 3.1 General ............................................................................................................................................... 45 3.2 Module Design Weight ....................................................................................................................... 45 3.3 Rigging Weight. .................................................................................................................................. 45 3.4 Centre of Gravity and Tilt of Module- Single Crane ...................................................................... .46 3.5 Static Hook Load- Single Crane Lift. ............................................................................................... 47 3.6 Static Hook Load- Dual Crane Lift .................................................................................................. 47 3.7 Dynamic Hook Load .......................................................................................................................... 47 3.8 Derivation of Lifting Point Loads- Using a Single Crane .............................................................. .48 3.9 Derivation of Lifting Point Loads- Using Two Cranes ................................................................... .49 3.10 Lifting Through Water ........................................................................................................................ 49

iii

CONTENTS

4. Structures ..................................................................................................................................... 51-54 4.1 General ............................................................................................................................................... 51 4.2 LRFD and Consequence Factors ........................................................................................................ 51 4.3 Method of Analysis of Module .......................................................................................................... 51 4.4 Strength of Module ............................................................................................................................. 52 4.5 Padeye Design .................................................................................................................................... 52 4.6 Padears and Trunnions ....................................................................................................................... 52 4.7 Cast Lifting Points .............................................................................................................................. 53 4.8 Fabrication and Installation of Lifting Points ....................................................................... ., .......... .53 4.9 Seafastening ........................................................................................................................................ 53 4.10 Bumpers and Guides .......................................................................................................................... 53

5. Requirements for Lifting Equipment ........................................................................................ SS-57 5.1 General .......................................................................................................................... , .................... 55 5.2 Sling Force Distribution .......................................... , .......................................................................... 55 5.3 Shackles ................................................................................. , ............................................................ 56 5.4 Spreader Beams ......................................................... , ........................................................................ 56 5.5 Hydraulic Lifting Devices .............. , ................................................................................................... 56

6. Crane and Crane Vessels ................................................................................................................. 58 6.1 General ............................................................................................................................................... 58 6.2 Allowable Load .................................................................................................................... , ............. 58 6.3 Crane Radius Curve ........................................................................................................................... 58 6.4 Minimum Clearances .............................................................................................................. , .......... 58 6.5 Crane Vessel Stability ......................................................................................................................... 58

Appendices ............................................................................................................................................ 59-60 Appendix A 1: Summary of Stages in Design/ Analysis of Lift Using Single Crane .................................. 59 Appendix A2: Summary of Stages in Design/Analysis of Lift Using Two Cranes .................................... 60

CHAPTER 4 : STEEL JACKETS ...................................................................................................... 61-78 1. Introduction ................................................................................................................................. 63-64 1.1 Scope of Guidelines ........................................................................................................................... 63 1.2 Definitions .......................................................................................................................................... 63 1.3 Reference Documents ......................................................................................................................... 63 1.4 Certificates of Approval ..................................................................................................................... 64

2. Environmental Considerations .................................................................................................. 65-66 2.1 Definition of Environmental Conditions ............................................................................................ 65 2.2 Load-Out. ............................................................................................................................................ 65 2.3 Towing ................................................................................................................................................ 65 2.4 Installation .......................................................................................................................................... 66 2.5 Stability During Tow .......................................................................................................................... 66

3. Strength ................................................................................................................................... ~ .... 67 -69 3.1 General ......... ; ..................................................................................................................................... 67 3.2 Load-Out ............................................................................................................................................. 67 3.3 Transportation ..................................................................................................................................... 67

iv

CONTENTS

3.4 Lifting ................................................................................................................................................. 68 3.5 Launching ........................................................................................................................................... 68 3.6 Upending and Positioning .................................................................................................................. 69

4. Launch .......................................................................................................................................... 70-72 4.1 General ............................................................................................................................................... 70 4.2 Weight, Buoyancy and Centre of Gravity .......................................................................................... 70 4.3 Launch Analysis ................................................................................................................................. 71 4.4 Launching System and Equipment. .................................................................................................... 71 4.5 Preparations for Launch ..................................................................................................................... 71 4.6 Seafastening Removal/Barge Ballasting ............................................................................................. 72 4. 7 Launch Operation ............................................................................................................................... 72

5. Upending and Positioning .......................................................................................................... 73-76 5.1 Environmental Conditions .................................................................................................................. 73 5.2 Tolerances and Clearances ................................................................................................................. 73 5.3 Systems and Equipment ..................................................................................................................... 73 5.4 Tug Configuration ...................................................... : ....................................................................... 74 5.5 Surveys/Water Depth .......................................................................................................................... 74 5.6 Monitoring of Position ....................................................................................................................... 74 5.7 Preparation for Upending ................................................................................................................... 75 5.8 Control During Upending ................................................................................................................... 75 5.9 Hook Assisted Upending Operations ................................................................................................. 75 5.10 Docking with a Template ................................................................................................................... 76 5.11 Damaged Jacket .................................................................................................................................. 76

6. On Bottom Stability ......................................................................................................................... 77

7. Other Considerations ....................................................................................................................... 78

CHAPTER 5 : GRAVITY BASE STRUCTURES .......................................................................... 79-100 1. Introduction ................................................................................................................................. 81-82 1.1 Scope of Guidelines ........................................................................................................................... 81 1.2 Object of the Guidelines ............................. ~ ....................................................................................... 8l 1.3 Contents of the Guidelines ................................................................................................................. 81 1.4 Other Standards .................................................................................................................................. 81 1.5 Definitions .......................................................................................................................................... 81

2. Stability and Motion Response .................................................................................................. 83-85 2.1 Intact Stability .................................................................................................................................... 83 2.2 Damage Stability ................................................................................................................................ 84 2.3 Motion Response ................................................................................................................................ 85

3. Strength ........................................................................................................................................ 86-88 3.1 Structural Design Specification .......................................................................................................... 86 3.2 Construction Afloat ............................................................................................................................ 86 3.3 Inclination During Towage ................................................................................................................. 87 3.4 Falling Objects ................................................................................................................................... 88

v

CONTENTS

4. GBS Mooring Criteria ................................................................................................................ 89-91 4.1 Environmental Criteria ....................................................................................................................... 89 4.2 Method of Analysis ............................................................................................................................ 89 4.3 Criteria for Intact Case ....................................................................................................................... 89 4.4 Criteria for 'Line Broken' Case ......................................................................................................... 90 4.5 Certification of Equipment ................................................................................................................. 90 4.6 Connection Points to the GBS and Shore .......................................................................................... 90 4.7 Seabed Anchors .................................................................................................................................. 91 4.8 Mooring Pontoons .............................................................................................................................. 91

5. Float Out of Base Structure ....................................................................................................... 92-93 5.1 General ............................................................................................................................................... 92 5.2 Environmental Criteria ....................................................................................................................... 92 5.3 Watertight Integrity ............................................................................................................................ 92 5.4 Underkeel Clearances ......................................................................................................................... 92 5.5 Side Clearances .................................................................................................................................. 92 5.6 Air Cushion ........................................................................................................................................ 92 5.7 Tugs, Towing Points and Pennants .................................................................................................... 93 5.8 Surveys and Control ........................................................................................................................... 93

6. Towing Criteria ........................................................................................................................... 94-97 6.1 General ............................................................................................................................................... 94 6.2 Tugs and Required Bollard Pull ......................................................................................................... 94 6.3 Tow Route, Surveys and Clearances .................................................................................................. 95 6.4 Towing Points ..................................................................................................................................... 96 6.5 Towing Pennants and Shackles .......................................................................................................... 96 6.6 Environmental Criteria for Tow Departures ...................................................................................... 96 6.7 Crewing Requirements ....................................................................................................................... 96

7. Water Ballast System ....................................................................................................................... 98

8. Deck Mating ...................................................................................................................................... 99

9. Installation at Offshore Location .................................................................................................. ! 00 9.1 Underkeel Clearance ........................................................................................................................ 100 9.2 Seabed Survey .................................................................................................................................. 1 00 9.3 Positioning Accuracy ....................................................................................................................... 100 9.4 Environmental Criteria .............................................................................................................. ; ...... 100 9.5 Verticality of Platform after Installation .......................................................................................... 100 9. 6 Reversibility ..................................................................................................................................... 1 00 9. 7 Schedule for Installation ................................................................................................................... 1 00

CHAPTER 6: LIFT-OFF, TRANSPORTATION AND MATING OF TOPSIDES .................. 101-117 1. Introduction ............................................................................................................................. 1 03-107 1.1 Scope of Guidelines ......................................................................................................................... 1 03 1.2 Object of the Guidelines ................................................................................................................... 103 1.3 Contents of the Guidelines ............................................................................................................... 1 03

vi

CONTENTS

1.4 Other Standards ................................................................................................................................ 1 03 1.5 1.6 1.7 1.8

Definitions ........................................................................................................................................ 103 Manuals and Procedures ................................................................................................................... 104 Safety and Contingency Procedures ................................................................................................. 104 Personnel .......................................................................................................................................... 1 04

2. Stability and Motion Response ........................................ : .......................................................... ~. ... l05 2.1 Intact Stability ... J 105 2.2 Damage Stability .............................................................................................................................. 105 2.3 Motion Response .............................................................................................................................. 105

3. Structural Analyses ................................................................................................................. 106-108 3.1 Methods of Analysis ......................................................................................................................... 106 3.2 Static Loads and Eccentricities ........................................................................................................ 1 06 3.3 Design Seastates Windspeeds and Currents ..................................................................................... 106 3.4 Wave Loads :1107 3.5 Collision Loads ................................................................................................................................. 107 3.6 Flooded Compartment ...................................................................................................................... 107 3.7 Load Combinations and Coefficients .................... J 107

4. Equipment ................................................................................................................................ 109-111 4.1 Barges ............................................................................................................................................... 109 4.2 Supports ............................................................................................................................................ 109 4.3 Ballasting/Deballasting System ........................................................................................................ 1 09 4.4 Tank Water level Indicators .............................................................................................................. 11 0 4.5 Ballast Control Rooms and the Command Centre ................... , ....................................................... 110 4.6 Guides and Fenders .................................................................. ; ....................................................... 110 4. 7 Positioning System ........................................................................................................................... 111 4.8 Positioning Marks ............................................................................................................................. 111 4.9 Electrical Supplies and Lighting ...................................................................................................... 111

5. Lift-Off ...................................................................................................................................... 112-114 5.1 Sequence of Operations .................................................................................................................... 112 5.2 Introduction of the Barges Beneath the Topsides ............................................................................ 112 5.3 De ballasting to take Most of the Weight of the Topsides ................................................................ 113 5.4 Approval to Complete the Lift Off ................................................................................................... 113 5.5 Completion of Lift-off ...................................................................................................................... 114 5.6 Moorings at the Pier ......................................................................................................................... 114

6. Towing Criteria ............................................................................................................................... 115 6.1 Towing Configuration and Effectiveness ......................................................................................... 115 6.2 Bollard Pull Requirements ............................................................................................................... 115 6.3 Tow Route, Surveys and Clearances ................................................................................................ 115 6.4 Towing Connections ......................................................................................................................... 115 6.5 Towing Pennants and Shackles ........................................................................................................ 115

7. Deck Mating ............................................................................................................................. 116-117 7.1 Approval to Start the Operation ....................................................................................................... 116

vii

C~NTENTS

7.2 Minimum Clearances During Deck Mating ..................................................................................... 116 7.3 Control and Position on Approaching Shafts ................................................................................... 116 7.4 Control and Monitoring of Final Position ........................................................................................ 116 7.5 Communications with the Substructure ........................................................................................... 116 7.6 Approval of Final Positions .............................................................................................................. 117 7. 7 De ballasting the Substructure ........................................................................................................... 117 7.8 Removal of the Barges ..................................................................................................................... 117 7.9 Deballasting to the Hook-up Draft ................................................................................................... 117

CHAPTER 7 : OFFSHORE PIPELINES ...................................................................................... 119-154 1. Introduction ............................................................................................................................. 121-125 1.1 1.2 1.3

Object of the Guidelines ................................................................................................................... 121 Scope ................................................................................................................................................. 121 Other Standards ................................................................................................................................ 121

1.4 Deviation from the Guidelines ......................................................................................................... 122 1.5 Definitions ........................................................................................................................................ 122

2. Documentation ......................................................................................................................... 126-128 2.1 General ............................................................................................................................................. 126 2.2 Key Documents ................................................................................................................................ 126 2.3 Document Retention ......................................................................................................................... 128

3. Warranty Surveyor Attendance ............................................................................................ 129-130 3.1 General ............................................................................................................................................. 129 3.2 Vessel Audits .................................................................................................................................... 129 3.3 Onshore Activities ............................................................................................................................ 129 3.4 Offshore Activities ........................................................................................................................... 130

4. Environmental Considerations .............................................................................................. 131-132 4.1 Environmental Data .......................................................................................................................... 131 4.2 Limiting Environmental Conditions ................................................................................................. 131 4.3 Environmental_Studies ..................................................................................................................... 131 4.4 Environmental Impact ...................................................................................................................... 132

5. Surveys and Route Preparation ............................................................................................. 133-134 5.1 Route Survey .............................................................................. ...................................................... 133 5.2 Geotechnical Surveys ....................................................................................................................... 133 5.3 Preparatory Works ............................................................................................................................ 133 5.4 Post-Preparation Survey ................................................................................................................... 134 5.5 Post-Lay Survey ............................................................................................................................... 134

6. Pipeline Construction ............................................................................................................. 135-141 6.1 Pipe lay Spread and Equipment ........................................................................................................ 135 6.2 Pipe, Materials and Equipment Control ........................................................................................... 135 6.3 Control and Monitoring of Position ................................................................................................. 135 6.4 Anchor Handling .............................................................................................................................. 136 6.5 Dynamic Positioning ........................................................................................................................ 137 6.6 Pipelay Start-Up ............................................................................................................................... 138

viii

CONTENTS

6.7 Pipelay .............................................................................................................................................. 138 6.8 Pipeline Laydown ............................................................................................................................. 139 6.9 Pipeline Abandonment & Recovery ................................................................................................. 140 6.10 Contingencies ................................................................................................................................... 140 6.11 Welding and NDT ............................................................................................................................ 140 6.12 Field Joint Coating ........................................................................................................................... 141

7. Towed Pipeline Installation .................................................................................................... 142-144 7.1 General ............................................................................................................................................. 142 7.2 Surface and Near-Surface Tow ......................................................................................................... 142 7.3 Mid-Depth Tow ................................................................................................................................ 142 7.4 Off-Bottom Tow ............................................................................................................................... 143 7.5 On-Bottom Tow/Pull ........................................................................................................................ 143

8. Pipeline Crossings ................................................................................................................... 145-146 8.1 General ............................................................................................................................................. 145 8.2 Design of Crossings ......................................................................................................................... 145 8.3 Pipeline Installation .......................................................................................................................... 145

9. Freespan Rectification .................................................................................................................... 147 9.1 Span Survey ...................................................................................................................................... 147 9.2 Span Criteria and Analysis ............................................................................................................... 147 9.3 Correction ......................................................................................................................................... 147

10. Trenching and Backfilling ............................................................................................................. 148 10.1 General ............................................................................................................................................. 148 10.2 Trenching Tools ................................................................................................................................ 148 10.3 Procedures ........................................................................................................................................ 148

11. Tie-Ins ....................................................................................................................................... lS0-151 11.1 General ............................................................................................................................................. 150 11.2 Above Water Tie-In .......................................................................................................................... 150 11.3 Subsea Tie-In .................................................................................................................................... 150 11.4 Tie-In Procedures ............................ , ................................................................................................ 151

12. Shore Approach and Landfal1 ....................................................................................................... 152 12.1 General ............................................................................................................................................. 152 12.2 Procedures ........................................................................................................................................ 152 12.3 Design Requirements ....................................................................................................................... 152

13. Testing and Commissioning ................................................................................................... 153-154 13.1 Flooding and Cleaning ..................................................................................................................... 153 13.2 Gauging ............................................................................................................................................ 153 13.3 Pressure Testing ................................................................................................................................ 153 13.4 Leak Testing ..................................................................................................................................... 153 13.5 Pipeline Commissioning ................................................................................................................... 154

ix

CHAPTER 1 : LOADOUT

1. INTRODUCTION 1.1 SCOPE OF GUIDELINES

These guidelines are a basis for the planning, design and operational aspects of load-outs which are subject to approval by a Marine Warranty Surveyor. The purpose of them is to specify appropriate standards, based on sound engineering and good marine practice, in order to ensure that the load-out procedure at all times meets an acceptable level of safety.

The guidelines are based on experience over a large number of previous projects. However, as knowledge advances in specific ~eas, it is recognised that these guidelines may need to be modified to meet alternative or new proposed methods of operation. The general criteria is that the overall level of safety should not be reduced by the introduction of novel or alternative proposals.

The Marine Warranty Surveyor will review and comment on all relevant specifications, proposed load-out and load-off reports and procedures, choice of systems and equipment. Information shall be made available to the MWS in sufficient time to enable completion of these reviews well before the planned operations.

1.2 DEFINITIONS Load-out Contractor: The company which is responsible for a load-out of a cargo onto a barge or vessel, or a load-off of a cargo from a barge or vessel.

MWS: Marine Warranty Surveyor and/or Marine Warranty Survey Company.

Module: A unit of cargo such as a jacket, integrated deck, topside components, pre-assembled units, items of equipment or parts thereof.

Contingency plan: Preconsidered response to a deviation from an intended course of action.

Grillage: The temporary structural members that support the module and distribute the vertical static and dynamic loads over the barge or vessel framing.

Sea fastenings: Shall in general mean the temporary structures or tie-downs that secure the module for transportation and berthing forces.

Skidded load-out: The module is pushed (by jacks) or pulled (by winches) onto the barge or vessel, supported on a skidway.

Trailer load-out: The module is supported on multi-wheel trailers for the movement onto the barge. The trailers may be self propelled or may be pushed or pulled onto the barge.

3

CHAPTER 1 : LOADOUT

Lifted load-out: The module is lifted onto the barge.

1.3 REFERENCE DOCUMENTS The MWS review of technical documents will include checks to current editions of relevant national standards or codes.

1.4 CERTIFICATES OF APPROVAL A Certificate of Approval will be issued on site, immediately prior to the operation, by the attending representative of the MWS when he is satisfied that the preparations for load-out are complete and that the weather forecast is satisfactory.

As a pre-requisite to the issue of a Certificate of Approval the associated calculations and operations manuals are to be reviewed and approved by the MWS well before the planned start of operations.

4

CHAPTER 1 : LOADOUT

2. PLANNING OF OPERATIONS 2.1 GENERAL

A comprehensive load-out manual shall be prepared by the Load-out Contractor and issued for review and approval by the MWS. This shall be submitted in sufficient time for MWS to comment on it and for any resulting amendments to be incorporated in the manual and put into effect prior to the loadout operation itself. An engineering manual which covers the structural analysis of the module and the load-out supporting system shall also be prepared.

All planning shall be based, where possible, on the assumption that it may be necessary to interrupt or reverse the operation.

The planning shall be based on the use of well proven principles, techniques, systems and equipment, to ensure acceptable health and safety levels and to prevent loss of human lives and major economic losses.

2.2 LOADOUT MANUAL The load-out manual shall include a description of the procedure to be adopted and details of the equipment to be used for the operation.

Information and details of the following items shall be included:

Loadout procedure Schedule Description of the module including weight and centre of gravity Organization and communication Site information Environmental criteria and weather forecasting procedure Water depth, tide tables and current speed data Load-out equipment, such as:

trailer type, number, capacity and ground bearing load pulling and retrieval winch systems hydraulic push/pull systems crane type, crane radius curve lift rigging details and certification ballast pump type, number, capacity and arrangement linkspans/bridging ramp

Description of barge/vessel, grillage and seafastenings Barge/vessel movements and procedures Mooring arrangements before, during and after loadout Fender details Recording and monitoring procedures including monitoring of barge heel and trim during

loadout Ballast procedures Module set down and shimming requirements Barge ballast and trim for welding of seafastenings Check lists Contingency plans Safety procedures Calculations for relevant items, such as:

Strength of skidway on land

5

CHAPTER 1 : LOADOUT

Pulling winch arrangement capacity and anchor point capacity Trailer axle and wheel loading and ground capacity Quay strength Linkspanlbridging ramp Barge/vessel deck and strength of skidway on barge Ballasting of barge Mooring capacity and limiting environmental criteria Structural strength of module and any temporary loadout beams Lifting point and lift rigging design

Associated drawings

The schedule which is included in the load-out manual shall clearly show the timing of the load-out and ballasting operations, related to tidal variations, including identification of points which may be critical in event of a late start or delays during load-out.

The schedule shall also include reference to the time taken to secure the seafastenings on completion of load-out and to the actions to be taken thereafter.

2.3 SAFETY PROCEDURES AND CONTINGENCY PLANS Safety procedures shall be developed and included in the load-out manual. The manual shall also address any possible need to deviate from the established procedures. Contingency plans shall be included in the manual, detailing the actions to be taken in the event of equipment failure, deterioration in weather conditions and any other unforeseen delays and relevant considerations.

The organogram shall clearly show the line of communications between the parties involved in the loadout. The personnel responsible for deciding to commence or halt the loadout shall be clearly shown.

2.4 SITE SURVEYS The load-out route at the fabrication site shall be documented by drawings, civil engineering data and calculations to verify that the capacity along the route is sufficient to resist the anticipated loads.

The seabed at the load-out quay shall be surveyed prior to load-out to ensure that sufficient under keel clearance exists, both during and after load-out, and that no obstructions exist which will interfere with the operations. A minimum underkeel clearance of O.Sm shall be maintained at all times. The effects of silting shall be considered and the sounding charts shall be clearly marked with the date when the survey was undertaken. The number of sounding points shall be sufficient to give

adequate definition and to ensure that any high spots have been identified. The effects of abnormally low tides, swell and barometric pressure shall be taken into account.

All elevations shall refer to Lowest Astronomical Tide (LAT) as well as any local datum. I

2.5 ANCHORING, MOORING AND FENDERING During load-out, the barge or vessel shall be held in position by moorings which are designed to hold the barge in position in the extreme wind, current and wave conditions anticipated during the operation. A specification of the mooring arrangement and all the equipment shall be included in the load-out manual. Generally, polypropylene or nylon ropes will not be acceptable as part of the mooring system unless used as a contingency.

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CHAPTER 1 : LOADOUT

The calculated maximum loads in the mooring wires, blocks, bollards and other rigging shall not exceed the safe working load (SWL) of any component.

The pulling and holding capacities of any mooring winches shall be clearly stated; the holding capacities must be at least 10% greater than the calculated maximum applied loads. The strength of the foundations of the winches shall also be documented.

In general, the use of anchors should be avoided. However, if anchors are necessary in the mooring arrangement, they shall be set and tested prior to load-out. The test load shall be at least 1.25 times the calculated maximum applied load for that particular mooring line, in both the intact and one line broken case. Procedures for testing shall be proposed by the Load-out Contractor for approval by the MWS.

A sufficient number of fenders in good condition shall be provided to prevent damage arising from contact between the barge or vessel and the quay side.

The barge or vessel shall not be moved from the load-out position after load-out until sufficient seafastenings have been installed. See also Section 4.7.

After the load-out has been completed and initial seafastenings have been installed, the barge or vessel shall be moored safely until sailaway. The moorings in the post-loadout position shall be designed to withstand the 10-year return period extreme environmental conditions with any one line broken.

2.6 ENVIRONMENTAL CRITERIA Limiting wind speeds and wave heights for the load-out operation shall be defined and agreed in order to ensure the safety of the proposed operation. The choice of limiting conditions will depend on several parameters, such as the site, the duration of the operation, tidal range and the type of load-out being performed. If the load-out quay is sheltered the effect of waves may be considered to be negligible The possible exposure of the load-out quay to long period swell waves should be considered.

Generally, for trailer or skidded loadouts the limiting forecasted wind speed shall be Beaufort Force 5 (equivalent to 10 m/s). The forecast shall be of a duration which is equal to the planned length of the operation plus allowances for contingencies and, if applicable, moving the barge to a safe mooring after load-out.

For lifted load-outs other values may be appropriate, depending on the equipment to be used.

2.7 WEATHER FORECASTING AND ENVIRONMENTAL MONITORING Prior to commencement of load-out, a favourable weather forecast shall be obtained from a recognised meteorological agency. The forecast shall be of sufficient duration to cover the load-out, installation of initial seafastenings and, if applicable, movement of the barge to a safe mooring.

Weather forecasts shall be obtained at 12 hour intervals for the duration of all of the operations.

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CHAPTER 1 : LOADOUT

3. LOADS AND ANALYSIS 3.1 GENERAL

The stresses and deformations of the module and any temporary supporting structure during load-out shall be shown to be in accordance with appropriate Standards or Codes of Practice such as those given in section 1.3. Wherever possible, the design shall be carried out to the requirements of one code only.

Calculations demonstrating the integrity of the barge or vessel shall be prepared for each critical stage of the load-out of the module.

For grounded or skidded load-outs the strength of the barge or vessel, in particular the longitudinal bulkheads, shall be documented.

The grillage design and layout shall take account of any limitations imposed by the load-out method.

3.2 WEIGHT AND WEIGHT DISTRIBUTION The load-out arrangement shall be based on the best estimate of weight, derived from the weight control system. Final load distribution into the load-out support structures or hydraulic trailers shall be confirmed after weighing the module, prior to load-out.

At the planning stage suitable contingencies shall be added to allow for changes to the weight and centre of gravity position. The following values may be used:

Weight contingency: 10% Shift of centre of gravity: longitudinal: l.Om, transverse: 0.5m

3.3 STABILITY REQUIREMENTS During load-out the barge or vessel onto which the module is loaded out shall have a minimum value of metacentric height (GM) of LOrn.

The barge or vessel shall have a minimum freeboard of 0.5 metres. Where there is a risk of waves coming on deck, open manholes shall be protected by upstands ('tophats') or other means to prevent the possibility of down flooding

3.4 SKIDDING LOADS Skidding loads are the loads required to move the module, and may result from friction, inertia and the slope of the skidding or rolling surface.

The values used for friction coefficients shall be proposed by the Load-out Contractor and documented where necessary by test results or previous experience.

3.5 SKEW AND DEFORMATION LOADS If the module is supported at more than three points without any load equalization system, the module may be skewed (i.e. deformed).

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CHAPTER 1 : LOADOUT

The resulting vertical skew or deformation loads shall be computed taking account of the following items as appropriate:

The stiffness of the module and its supporting structure Skidway tolerances Movements of the barge or vessel (heel and trim) Settlement of the ground

Horizontal skew loads may also be generated if the prime mover loads are applied asymmetrically about the module centreline e.g. where one winch fails during a skidded loadout and the loadout continues with one winch only.

The module structure and temporary loadout beams shall be checked for horizontal skew loads taking account of the following items as appropriate:

The stiffness of the module and its supporting structure Break-out friction forces Rolling friction Drag forces from non-self-propelled trailers Pulling forces from winches

3.6 LOAD FACTORS Where a Load and Resistance Factor Design (LRFD) method is used the following LRFD load factors shall be used for load out:

Gravitational 1.3 Deformation 1.0 Skew 1.0

The use of the above Load Factors of 1.0 for the deformation and skew load cases require that the operational procedures followed during loadout are such as to ensure that the deflections assumed in the structural analysis are not exceeded in practice.

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CHAPTER 1 : LOADOUT

4. SYSTEMS AND EQUIPMENT 4.1 GENERAL

All equipment used shall be in good condition and well maintained. It will be inspected by the MWS representative prior to issue of a Certificate of Approval.

The equipment used shall be in accordance with the manufacturer's operating procedures and specified safe working loads and in compliance with relevant codes and practices.

A braking system, capable of arresting module movement, is required at all stages of the load-out

A pull back system which can retrieve the module in a contingency situation shall be provided unless it can be demonstrated that, with the module partly onboard, the barge can be kept level with the quay through a complete tidal cycle.

4.2 JACKING SYSTEMS AND WINCHES An adverse longitudinal barge or vessel slope of at least 1% shall be considered when assessing required winch, jack and braking capacities.

The computed load on the jacking or winching system shall not exceed the certified safe working load of the system. Both break-out (i.e. start up) and moving conditions shall be assessed. In computing the SWL of winch systems, due allowance shall be made for splices and bending of wire ropes, and friction losses in sheaves.

The arrangement of the winching or jacking system shall permit the entire module to be moved from the quay onto the barge or vessel without re-rigging.

It shall be demonstrated that, in the event of failure of any one component or subsystem, the jacking or winching system shall continue to function effectively.

4.3 MULTI-WHEEL TRAILERS For a trailer load-out the multi-wheel trailers shall be used in accordance with the manufacturer's specification. For the following, the values recommended by the manufacturer shall not be exceeded:

Axle loadings Trailer spine beam shear and bending stresses Trailer deflections

The hydraulic system of the trailers shall generally be connected such that the trailers are in three groups, thereby providing a three point support system. The position of centre of gravity of the module shall be within the triangle defined by the centres of the three groups and shall be at least 1 metre from the sides of this traingle.

The required minimum vertical distance through which each of the trailer's axles is able to move (i.e. the travel) shall be calculated taking account of the following:

Ground level and incline of linkspan/bridging ramp Trailer deflections Module deflections Allowances for barge/vessel heel and trim

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CHAPTER 1 : LOADOUT

It is recommended that when planning the operation, the maximum foreseeable travel shall be at least 1 OOmm less than the value allowed by the manufacturer of the trailers

The module shall be positively restrained to prevent movement relative to the trailers

4.4 LIFTED LOAD-OUTS For lifted load-outs the Load-out Contractor shall make available for inspection and approval by the MWS:

Certificates for the crane Crane radius curve (i.e. crane capacity as a function of outreach Lifting and rigging arrangement Certificates for all equipment in the rigging arrangement including spreader beams, slings,

shackles and padeyes Barge or vessel handling and mooring procedures If the crane is a floating crane then its stability/ballast details during lifting shall be provided NDT records for padeyes/trunnions to be used during loadout

4.5 BARGE AND BALLAST SYSTEM A ballasting schedule shall be prepared, showing that the barge or vessel can be safely deballasted and/or ballasted to receive the module without overstressing the module or barge/vessel. The ballast system shall have sufficient capacity to compensate for the worst combination of change of load and tide rise or fall during the operation.

To ensure adequate contingency in the event that the loadout is halted, the ballast system shall have adequate capacity to compensate for tide changes through a complete tide cycle.

Sufficient spare pumps shall be provided to allow for pump malfunctions and the actions to be taken in the event of pump failures shall be documented. The ballast system shall have a minimum reserve pumping capacity of 50%.

For load-out onto a cargo barge it is recommended that a ballast system, with its own power supply, is installed, this system being independent of the barge's integral ballast system. Normally, the cargo barge's own ballast system shall not be used during a loadout, except as a contingency, nor included in the calculation of reserve capacity. However, some very large barges have sophisticated integral ballast systems, with redundancy of pumps and power supplies. It is generally not necessary to install a separate system when using these barges.

All equipment shall be tested, and shown to be fully operational, prior to the load-out.

4.6 POWER SUPPLY The power supply system shall have adequate capacity to supply all equipment which may be used during the load-out for continuous running at maximum rating.

If the ballast pumps and other equipment share a common power supply, for example the local electricity supply, a back-up power supply shall be provided which can be brought into action quickly in order that the load-out can be completed in a safe manner.

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CHAPTER 1 : LOADOUT

The power supply system shall be designed to keep the essential equipment running in the event of one of the following:

One power unit breaks down Failure of the common energy supply

4.7 GRILLAGE AND SEAFASTENINGS If the grillage is pre-installed on the barge, dimensional checks shall be carried out prior to load-out to ensure that the module can be set down safely within agreed tolerances.

If the grillage is loaded out with the module the relative alignment of the grillage and barge frames and bulkheads shall be estimated by measurement prior to load-out.

For trailer load-outs, the planned position of the module, and the possible need for shimming shall be checked when the module has been partially set down onto the grillage. Complete set down shall not take place until satisfactory shimming and positioning has been achieved and accepted by the MWS. If there are more than four module support points, shimming shall be carried out with the barge ballasted such that the deflected shape of the barge is the same as the transportation condition.

Prior to load-out, all preparations for installation of seafastenings should be completed. Erection of seafastenings should commence as soon as practicable after the module has been set down and should be installed in such a sequence that the module is fully restrained in minimum time, and that no unnecessary stresses are introduced into the module structure.

During installation of the seafastenings special care shall be taken to prevent damage to the module.

The barge or vessel shall not be moved from the load-out position after load-out until sufficient seafastenings have been installed. These seafastenings should be capable of withstanding horizontal forces equal to 10% of module weight taken in any direction and applied at the centre of gravity of the module.

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CHAPTER 1 : LOADOUT

5. OPERATIONAL REQUIREMENTS 5.1 GENERAL

Prior to the decision to start a Load-out operation a readiness review meeting should take place on site. The purpose of the meeting is to ensure the following:

The load-out equipment is functioning and has been tested The procedure to be followed is confirmed The weather forecast is favourable for the planned duration of the operation including an

allowance for contingencies The results of module weighing are satisfactory and have been accepted by all

parties

Checklists shall be prepared and completed to ensure all preparations have been carried out satisfactorily.

For operations consisting of several predefined stages, a decision based on similar principles to the commencement of the load-out shall be made prior to the commencement of each stage.

5.2 OPERATIONAL RECORDING During the operation a record of events should be kept by the Load-out Contractor. A list of the events and activities which are to be recorded shall be included in the load-out manual.

The log should also record deviations from agreed procedures and breakdowns or other delays to the operation.

5.3 BARGE OR VESSEL HANDLING Movements of the barge or vessel at the fabrication site shall be carried out in accordance with any relevant harbour regulations. Harbour authorities should be notified prior to any moves.

If the barge or vessel is to be operated outside the conditions for which it is approved by the Classification Society, the MWS shall be advised and the Classification Society shall be notified.

After the load-out is completed, a regular watch shall be provided to ensure the following:

Security of moorings Barge draught, heel and trim

In adverse weather conditions the barge or vessel watch shall be continuous. A suitable number of spare mooring lines of adequate size and in good condition shall be available on site.

If sub-zero temperatures are expected, the Load-out Contractor shall take action to avoid freezing of water in the tanks and on deck. Similar precaution should be taken with cooling liquids within barge or vessel machinery.

The barge or vessel shall not be moved from the load-out quay after load-out until sufficient seafastenings have been installed. See Section 4.7.

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CHAPTER 1 : LOADOUT

5.4 TESTING & MEASURING Prior to load-out, all systems and equipment which will be used during the load-out, shall be checked and shown to be in accordance with the approved documentation.

The pull/push system for a skidded load-out shall be commissioned and tested prior to load-out to verify that the system has sufficient capacity.

Equipment shall be provided for monitoring barge or vessel heel and trim. During the load-out, the following parameters shall be monitored:-

Draught of barge or vessel Heel and trim of barge or vessel Ballast tank quantities Tide level Movement of module onto barge or vessel

Where the vessel deflections or alignment to the quay are critical these shall be monitored using surveying equipment and targets on the vessel. The power supply shall be tested with all systems which shall be supplied, running at maximum rating.

Ballast systems shall be function tested immediately prior to loadout. This test shall be witnessed by the attending surveyor.

Loadout paths on the barge or vessel and the final position of the module over the grillage should be clearly marked.

A dimensional survey of pre-installed grillages and seafastening shall be checked against the module as-built dimensions.

Pre-fabricated grillages and seafastening NDT records shall be made available for inspection by the attending surveyor prior to loadout.

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CHAPTER 2 : BARGE TRANSPORTATION

1. INTRODUCTION 1.1 SCOPE OF GUIDELINES

These guidelines cover the marine aspects of module transportations on towed barges.

The purpose of the guidelines is to specify appropriate standards, based on sound engineering and good marine practice, so that the tow, at all times, meets an acceptable level of safety. Guidance on the selection of tugs and barges is included.

The guidelines are intended to cover module transportation operations, in open seas as well as inland waters, which are subject to approval by the Warranty Surveyor.

These guidelines are based on experience over a large number of previous projects. However, as knowledge advances in specific areas, it is recognised that these guidelines may need to be modified to meet alternative or new proposed methods of operation. The general criteria is that the overall level of safety should not be reduced by the introduction of novel or alternative proposals.

The Insurance Warranty Surveyor will review and comment on proposed towing arrangements, seafastening design, choice of tugs and barges and all relevant specifications and procedures. Information shall be made available to the Insurance Warranty Surveyor in sufficient time to enable completion of these reviews well before the commencement of any transportation operation.

1.2 DEFINITIONS Contractor: The Contractor who is responsible for the transportation operations.

Fabricator: The company which is responsible for the construction and installation of the grillage and seafastenings.

MWS: Warranty Surveyor and/or Marine Consultant.

Towmaster: Master of the tug or other person specified in the procedures as having ultimate responsibility for the towing operation.

Bollard Pull: Continuous static bollard pull as defined by the towing vessel's Bollard Pull Certificate.

Cargo: Modules, topsides components, equipment or parts thereof being transported on a barge.

Contingency plan: Preconsidered response to a deviation from an intended course of action.

Grillage: The temporary structural members that support the module and distributes the vertical static and dynamic forces into the barge framing.

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CHAPTER 2 : BARGE TRANSPORTATION

Seafastenings: Shall in general mean the temporary structural members that resist rolling and pitching forces and restrain the module in the global horizontal direction.

Unit: The combination of cargo and barge.

MBL: Minimum Break Load

1.