Accidents Case Studies

Collapse of crane Crane Operator had hoisted up a bag of sand (780 kg) over the roof . While doing so, the Overload Radius Indicator (ORI) alarm sounded and the cut-off was activated. However, he by-passed the cut-off and continued to lower the boom of the crane The crane suddenly toppled when he started to swing the boom to its left.

Factors Contributing To collapse Site constraints. Front outriggers not fully extended. By-passed of safety devices. Operator at risk behaviors. Safe working load exceeded. Lifting supervisor, rigger and signalman were not appointed No lifting plan. No risk assessment conducted. No Permit-to-work system Implemented.

Analysis – Cause and Root Cause Crane collapse Root cause Analysis – 5 Whys question asking method Q Why the crane collapse? A Due to the crane was overload Why the crane was overload? The outrigger was not fully extended. Why outrigger was not fully extended? Site constraints. (Root Cause)

Analysis – Cause and Root Cause Q Why the operator by-passed safety devices? A If the operator had refused to carry out the lifting work, even when the safety requirements were not in place, he would not be paid. (Root Cause) Q Why lifting supervisor, rigger and signalman were not appointed? A Because there is no lifting plan Why no lifting plan? Company did not have a Safety and Health Management System to manage the lifting operation at site. (Root Cause)

Corrective and Prevent Action Provide every root cause with control measures – Use of Hierarchy of Control to initiate control measures Elimination Substitution Engineering controls Administrative controls Personal protective equipment Gin Wheel Least preferred Most preferred To eliminate the hazard by use of chin wheel or chain block to hoist up the sand in small quantity, since there is a site constraints Chain block

Corrective and Prevent Action Provide every root cause with control measures – Use of Hierarchy of Control to initiate control measures Elimination Substitution Engineering controls Administrative controls Personal protective equipment Least preferred Most preferred Safety and Health Management System Administrative controls To establish Safety and Health Management System and implement to manage the lifting operation issues at site, eg lifting plan, risk assessment and Permit-to-work system

Corrective and Prevent Action Provide every root cause with control measures – Use of Hierarchy of Control to initiate control measures Elimination Substitution Engineering controls Administrative controls Personal protective equipment Least preferred Most preferred The occupier shall implement control the crane supplier to carry out the lifting operation safety or else will not be paid in order to deter the at risk behaviors of the operator

Collapse of crane- Most of the crane collapse over the side Most of the crane topple over the side

Safety awareness for crane operation The load carrying capacity of the crane varies according to the various quadrants Over the front Over the side Operating zone called quadrants Quadrant of operation Over the rear Over the side The operation zone

Safety awareness for crane operation Most of the crane collapse over the side The Stability of crane over the side is always weak as compare to the front or rear The capacity of the crane may change when rotating a load from one quadrant to another.

Safety awareness for crane operation To obtain a safe quadrant is the first consideration for crane operation Instead of the convenience of parking the crane or others

Ensure safe operation Adopted to basic principles of crane operation Stability of Crane (Tipping Stability) Structural Stability Integrity of Lifting Gear/ Safety Devices

Ensure safe operation Stability of Crane (Tipping Stability) - Obtain a safe quadrant - Ensure crane operate on the good footing - Outrigger use correctly - Crane shall on the level footing 45° 400thk hardcore compacted subgrade 25mm thk steel plate (6mx3m) outrigger base plate 25mm thk steel plate (2.4mx4m) 65 ton

Ensure safe operation Structural Stability - Do not overload crane (refer to load chart for capacity) - Ascertain the load weight before lift

Ensure safe operation Integrity of Lifting Gear/ Safety Devices - Wire ropes / Rigging equipment in service condition - eg. Over-hoist / over-loading limit switch in good working order

Have a successful lift!