Crane Accidents study

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Crane Accidents and EmergenciesCauses, Repairs and Prevention

Presented by

Larry Lam Chairman

Soon Chong Tok Technical Director

Portek International Limited15 March 2007

For enquiries, please email: [email protected] contents of this document are copyrighted and proprietary, and may not be reproduced without the permission of Portek International Limited


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Definitions A Crane Accident is an unplanned and unintentionalevent involving a crane or cranes, or other objects that

result in damage or injury of some kind and normallyinvolves a strong human element in its causation.

A Crane Emergency situation is an unexpected andsudden event in which the crane is subject to damage,and where the cause is not immediately linked to theoperator.

A Crane Incident is a general term for either a craneaccident or emergency


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Crane Accidentscan happen in the following ways:

when a ship contacts a cranewhen a crane contacts a ship

when cranes contact each other due to strongwind gusts during operation, often resulting ina multiple chain collisionwhen a crane contacts another crane or anobject during operation


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Right seaside leg hitdiagonally by ship'sbow

(ship contacts crane)

Crane Accidents


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Crane boom struck ships funnel (crane contacts ship)

Crane Accidents


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Crane (blown by wind gusts) collapsed after collision

Crane Accidents


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Exceptional situation such as typhoons, hurricanes,

earthquakes resulting in crane collapse, derailment orsevere damageCrane failure as in

electrical fires in diesel generator or electrical roomcrane drive faults leading to free fall of loadmechanical faults as in brake failure, twist-locks

failures, etc resulting in uncontrolled fall of loadstructural damage as in fatigue failure, poor

workmanship or design.Heavy weather or inadequate lashing during ocean

transportation of cranes

Crane emergency situations can arise from


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Structural failure - A-frame pylon bent and tipped forward

Crane emergency situations


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Right tension rod broke from fatigue

Crane emergency situations


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Frequency of Crane IncidentsCrane Incidents are happening with increasingfrequencies, due to:

rapidly increasing population of cranesincreasing crane dimensions, hence decreasing visibilityand control

insufficient distance between fender face and seasiderail, and increasing flare of ships bow, as ships getbigger standards of crane maintenance not keeping up

standards of safety in crane operation and terminaloperation failing to keep upinsufficient understanding of risks involved, and lack ofprecautions takenadverse and unpredictable weather


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Typical Processes in a CraneIncident

Recovery phase comprising Survey andSalvage and StabilizationRepairs and Re-commissioning


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Typical damage

bending and buckling of the legs, sill beamsand portal beamsderailment seaside and landside bogiestearing apart of joints between equalizerbeam and sill beam


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Ship contacting

Crane boom

Typical damage


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Damage from Ship contacting crane


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Derailment at seaside

Typical damage


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No derailment landside,but severe damage toleg

Typical damage


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Severe bending oflandside leg

Typical damage


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Buckling of sill beam landside

Typical damage


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Joint at equalizer beam separated and twisted

Typical damage


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Total destruction of boom snagged by a departing ship

Typical damage


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Entire portal and boom twisted by ship pulling on boom

Typical damage


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Wind gusts causing crane collisions

Typical damage


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Damage from Collisions


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RepairsDesign and Analysis

Fatigue failure of an unloader & computer modeling of crane structure


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Simulation of failure & Redesign and Repairs

Repairs


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Crane Supports for Repairs

Computer simulation of crane support


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Crane Supports for Repairs

Robust support in place before cutting


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Repair Methodology

Damaged plate removed and replaced


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Repair Methodology

Replaced with new sill beam


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Repair Methodology

Heavy damage due to constraints to side way displacement


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Repair Methodology

Derailment allows displacement, therefore little or no damage


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Repair Methodology

Floating crane removing boom for repairs


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Repair Methodology

Re-installing repaired boom


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Repair Methodology

Boom hinge inspection and NDT checks


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Repair Methodology

Line boring of boom hinge


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Repair Methodology

Dimensional checksusing theodoliteequipment


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PreventionPrevention of crane incidents at

different levels:at crane design and engineering level,at crane operating level,at terminal operation level


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Double brake

machinery

Prevention at crane design level


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Caliper brakes on flanges of boom hoist drums

Prevention at crane design level


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Prevention at the terminal

operating levelBerthing and un-berthing - Vessels should comealongside quay as parallel as possible.Equipment maintenance not to be compromised infavour of operational expediency


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Risk Management Plan

Terminate the risk s not likely. Inherently

risky. Transfer the risks - InsurancePolicy. Consequential losses not covered

Tolerate the risks Accepting the risks. Selfinsurance

Treating the risks involves prevention, reducingthe likelihood of occurrence and severity of loss


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ConclusionRisks associated with container cranes willincrease, due to

Increasing probability of occurrenceGreater severity of loss.

Modern container quay cranes quantumleap in size, and complexity, not yet fullyunderstood as to risk factors


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Thank You

Crane Accidents study

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