Amputation of Part of Left Foot
Description of the accident
The toes of the left foot of the drill rig assistant were amputated by the rotation head of a diamond core drilling machine as it travelled down the feed frame.
Apparent causes
The drill rig assistant ascended the mast in order to align a fishing tool with the rotation head, he pushed the tool into alignment and the Driller lowered the head to engage the fishing tool. The left boot of the drill rig assistant was placed on the feed frame of the drill and as the rotation head travelled down the feed frame it sliced through the boot amputating the toes of the drill rig assistant.
Additional factors
Several other factors contributed to this accident:
1. The fishing job was caused when an HQ quillrod failed. The picture below is a photograph of the failed pin of the quillrod which clearly shows that the pin failed through fatigue, note the rust in the root of the failure.
The failed quill rod
2. There was no quillrod management program in place and site staff indicated that they could not remember when last the quillrod was changed.
3. Proper fishing tools were not available on site, the Supervisor made up a swedge by welding pieces of steel to an NQ drillrod which was in turn welded onto a piece of HQ drill rod. This resulted in a “fishing tool” that was almost 4.5 meters long.
4. The “fishing tool was dropped into the fish but because of its irregular shape it did not sit vertically. The injured man ascended the mast in order to push the homemade fishing tool into vertical alignment.
5. In doing so he climbed up the “wrong” side of the mast, ie. the side without a ladder, he therefore had to stand on one of the cross-members of the feed frame for support.
6. The injured person did not wear a fall arrest device.
Recommendations
It is clear that the injured man did not possess the necessary skills, knowledge or experience to allow him to safely work on an active drill site. It is essential that all operational staff are trained, assessed and found competent before being allowed to work on a drill site.
Appropriate fishing tools must be kept on site or must be readily available from a nearby site.