Marine Occurrence report 232 - Australian Transport Safety Bureau

CONTENTS
DOCUMENT RETRIEVAL INFORMATION .................................................... v
THE AUSTRALIAN TRANSPORT SAFETY BUREAU ................................. vii
ATSB INVESTIGATION REPORT TERMINOLOGY .................................... ix
EXECUTIVE SUMMARY .................................................................................... xi
1 FACTUAL INFORMATION ......................................................................... 1
1.1 Creciente................................................................................................ 1
1.1.1 Mooring winches ................................................................. 2
1.2 Port Hedland .......................................................................................... 4
1.2.1 Tidal flow............................................................................. 5
1.2.2 Finucane Island berth D mooring arrangements.................. 6
1.3 The incident ........................................................................................... 7
2 ANALYSIS ..................................................................................................... 13
2.1 Evidence .............................................................................................. 13
2.2 Breakaway ........................................................................................... 13
2.2.1 Mooring arrangements....................................................... 13
2.2.2 Winch brakes ..................................................................... 13
2.2.3 Winch drums...................................................................... 15
2.2.4 Tending mooring lines....................................................... 17
2.2.5 Brake tightness................................................................... 18
2.2.6 Combination of brake factors ............................................ 19
2.2.7 Environmental forces......................................................... 20
2.3 Grounding............................................................................................ 22
2.4 Risk Management ................................................................................ 23
3 FINDINGS...................................................................................................... 27
3.1 Context................................................................................................. 27
3.2 Contributing safety factors .................................................................. 27
3.3 Other safety factors.............................................................................. 28
3.4 Other key findings ............................................................................... 28
4 SAFETY ACTIONS ...................................................................................... 29
4.1 Safety action by the Port Hedland Port Authority ............................... 29
4.2 ATSB recommendations...................................................................... 29
4.3 ATSB safety advisory notices ............................................................. 30
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