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Contractor worker struck by drift bar during pin removal of drilling substructure


Location: ONSHORE

Incident Date: 13 January 2023   Time: 13:00

Type of Activity: Lifting, crane, rigging, deck operations

Cause: Struck by

Function: Drilling

What happened?:

The operation at hand was rigging down the substructure of the drilling rig by removing the securing pins and disassembling two parts of the substructure. The crew was waiting on trucks and was in the process of repositioning cranes in preparation to rig up the crane and disassemble the substructure by removing the pins. As the UPPER substructure was still in place, no crane could be hooked up to the support leg to take the weight. The support leg weighs 5 ton. A Drift bar was used to remove one of the pins of the support leg. The Derrickman removed one pin, as instructed by the Driller (not normal procedure on this rig but not detailed in the SOP). This had no effect on the support leg because the pin on the other side was still holding the full weight of the support leg. The IP had watched the Driller and Derrickman knock out the pin. He picked up the Drift bar and went to the other side of the substructure himself he was not instructed to remove this 2nd pin as work was suspended to wait for a crane to come and hook on to the support leg to take the weight before drifting the 2nd pin out. All other workers stood down on pin removal operations at this time. He started striking the pin. When the pin was knocked all the way through the pivot point of the support leg, the weight of the leg dropped onto the bar and caused it to deflect. Hitting the IP in the chin. Travel of the bar when it was deflected: approximately 20cm from a horizontal position upwards and to the left, striking the IP on the side of his jaw. Due to the 5-ton weight and the force applied to the bar, this short travel distance was enough to fracture his jaw.

What Went Wrong?:

Operating procedures and control of risks: The SOP does not clearly state that the leg should be supported before removing the pins. There needs to be cohesion between the SOP, JSA and Lifting plan regarding the sequence of works. Written procedures are vital in maintaining consistency and in ensuring that everyone has the same basic level of information. Equally essential is the requirement to implement processes for communicating job related risks, hazards and control measures to employees and contractors as detailed within Permits, Risk Assessments and Job Safety Analysis.

Corrective Actions and Recommendations:

  1. The substructure SOPs are to be reviewed and relevant to the contractor crew of the rig, and clearly state that pins shall only be removed on the lower substructure with the cranes in place.
  2. The lifting plan for the lower substructure should also clearly cover supporting the load before removing pins.
  3. The incident was communicated in weekly safety meetings, emphasizing the importance of following instructions and checking with supervisors before starting any new tasks.
  4. A line of fire safety campaign covering a line of fire and heavy impact tools utilized during rig site operations implemented.

Figure 1: Pin removal
figure 1

Figure 2: X-ray of the injury
figure 2

Figure 3: Upper substructure before removal
figure 3

Figure 4: The pin that holds the support leg
figure 4

Figure 5: The pin post removal of the support leg
figure 5

Safety Alert number: 364
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