Safety Incident Topic: Crane Overtuned
Location of Incident: Road Between Tank And Cooling Tower Area
Date of Incident: 15 January, 2007
Brief Account of Incident
A 50 tonnes crane being employed to lift pipes from ground level to a pipe rack 8 meters high located at the west side of the cooling tower. Prior to setting the pipes in place, it was required to blow out (clean) the pipe pieces. There was not enough space on the road between the cooling tower and tank area to extend both sides of the stabilizer fully so one side of crane stabilizer was not fully extended. When the crane operator lifted the pipes and rotated the crane, it overturned in the direction of the shortly extended stabilizer. The crane fell towards the tank area. The crane hook hit the vent pipe on top of the naphtha tank (at a height of 14m) then came to rest on top of the tank. The crane boom was jackknifed and rested on an acetic acid product line which was bent slightly. Fortunately, as the crane overturned slowly, there were no injuries or environmental problems.
- Naptha leak / acid leak- single or multiple leakCritical Factors
- West side of stabilizers to the tank area was not fully extended due to narrow working space.
- Crane rotated in the direction of the not fully extended stabilizers.
Immediate Root Causes
1- Crane stabilizers not fully extended both sides.
2- Crane operator miscalculated weight load on un-extended stabilizer side.
3- Detailed work procedure was not prepared prior to crane operation specifically.
System Root Causes
1- The crane company supplied 50 ton crane where 25 ton crane was requested-Last minute plan change required the crane to reset and change location to blow out the pipes.
2- Crane operator’s decision to continue without change of location; but only adjusting boom angle while rotating the boom
3- Employee observed first movement; boom was raised to a high angle and then rotated to prevent overturn.- Crane operator began to lift and commenced his turn simultaneously on return of pipe.- At this position on return run; crane stabilizers on the west side could not support the load causing the crane to overturn.
4- In summary:
- Work procedures insufficient to task
- Proper precautions had not taken
- The work procedure did not address specific crane issues.
- Lack of employee experience regarding crane operation and safety.
1- Another company contracted to bring 25 ton crane to complete remaining job and new safety procedures utilized during setup and completion of task.
2- Spread the narrow working place to extend all stabilizers fully according to newly revised work procedure
3- Specific safety protocols and procedures drawn up for use of heavy equipment within SSBP
4- All outside contractors to be monitored closely and to follow SSBP safety procedures while working within SSBP
5- Safety training plan for outside contractors to address safety issues while performing tasks for SSBP Lesson Learned
6- This incident is directly related with lack of sufficient safety procedures in place compared with other major big project. Therefore it is required to increase safety standards even if small project.
7- In the event of difference or deviation against original plan, new safety analysis for the situation should be performed within all authorized people.