Tower Crane Boom Bent
Conditon of the tower crane’s boom.
A dangerous occurrence involving a hammerhead crane had happened, whereby its boom was bent and twisted during lifting down a shear wall formwork from level 20 of a building under construction to the ground. This event caused severe boom damaged, but no injuries reported.
Investigation and inspection of the crane components was carried out and the main focus is given to the components that have failed, which is the connection between the sections of boom and also the joint between the boom and its pendant.
Tower crane installation and maintenance is highly critical and required an experience and competent parties to do it. Owner/user of the crane are responsible to carry out thorough inspection on every component of the crane, with the control and supervision of Registered Competent Person registered with DOSH. Below are few matters that requires most attention during the installation and maintenance work:
- Periodic inspection by owner/user should focus more on the connection/joint of every boom section, especially the means used for connection like pin and cotter pin.
- Components that are damaged, defective or not comply with the manufacturer’s specification cannot be used, until rectification action taken.
- Pin used at every connection between boom sections must be secured with cotter pin to ensure pin is mounted and not easily uprooted.
- Cotter pin used must be in good condition and does not rust, so it can lock pin perfectly and not loose.
- Integrity of the coupler on boom section must be ensured in good condition, and follow the manufacturer’s design specification. This is to ensure that it can hold the pin and cotter pin strongly and safe.
- Method of joining the coupler at boom section (welding) should be examined to be in good condition, according to the manufacturer's specifications.
