Read about this tragic fatality involving a pipe wrench.Read More
Two identical accidents, one resulting in a fatality and another resulting in permanent disabilities to two people. The second accident should have been prevented!Read More
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.
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.
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.
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.
- 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.
On 27th August 2011, a stable 3 metre rod exploded while the driller was pumping water into the drill hole before commencement of drilling. The exploded rod scattered around the drill site (15m away from the rig).
After pre-start checks were done, the driller connected a 3 metre rod to the head to commence drilling. In the process of pumping water into the hole, a 3 metre rod on top of the head exploded throwing its debris around. All vehicles at post were not affected since the instruction was given not for vehicles to park close to the rig. Nobody has been injured.
Read more about the causes of this incident and the recommendations in this report compiled by the Boart Longyear.
The rod clamps on an exploration drill rig closed down onto the foot of a driller’s off-sider. Fortunately the off-sider did not sustain serious injuries as he was wearing steel capped boots.
The driller released the foot clamp around the drill rods to raise them towards the top of the mast. The off-sider braced himself by placing his foot on the rod clamp guard to begin the removal of rods. When the rod clamp was closed the off-sider’s right foot was dragged down by the closing action of the rod clamps. This resulted in a tear behind the steel cap of the boot which nearly removed his big toenail.
Read more about the causes of this incident and the recommendations to prevent the hazard in this report compiled by the NSW Department of Primary Industries.
A driller had his feet crushed when drill rig foot clamps unexpectedly closed.
The operator was standing at the bottom of the mast attaching the cyclone pipe. Both of his feet were under the open foot clamps. The driller's offsider accidentally knocked a set of Allen keys off the control console. The keys hit the control lever operating the foot clamps closing both on to the opener's feet.
Read more about the causes of this incident and the recommendations to prevent the hazard in this report compiled by the Queensland Department of Mines and Energy.
A high-pressure air hose burst on a surface exploration drill rig while the driller was attempting to clear a blockage in the hose. The burst hose propelled the sample collection cyclone towards the driller who was operating the drill rig. The cyclone struck the driller with force. The driller sustained severe bruising to his body and back and could have been seriously injured or killed.
Read more about the causes of this incident and the recommendations for prevention in this report compiled by Mineral Resources, New South Wales.
Description of the accident
A Driller was fatally injured on a drill site in the Rustenburg area when he was struck on the head by a drill rod that had failed whilst drilling.
While commissioning a top-drive exploration drill, a joint on a B size wireline drill rod failed which resulted in the top-most drill rod striking the drill rig assistant on the head.
The driller had previously pulled the inner-tube due to a core blockage but elected to add a new 3-meter rod below the drill head rather than drill the short remaining portion of the previous corebarrel. This resulted in a joint in the “quill” section high above the rod clamp.
It is suspected that the fast feed lever was activated instead of the fine feed lever while rotating which placed a very large down-thrust on the quillrod. This very significant downthrust caused the quillrod to bend and deform to such an extent that the exposed connection failed.
The severely deformed drill rod then struck the assistant on the back of his head causing a fatal injury.
Although full details of the accident are not yet available it seems likely that several factors caused this tragic accident.
At the time of the accident, the deceased was standing on the Driller’s platform behind the chair in which a trainee driller was sitting, the deceased was instructing the trainee on the operation of the drill rig. It seems likely that the trainee activated the incorrect control lever due to a lack of familiarity with the control panel.
The control panel of the drill rig was poorly labelled which contributed to the trainee selecting the wrong lever
The Driller elected to add a new 3-meter drill rod instead of completing the previously incomplete core run. This meant that there was an exposed drill rod connection approximately 1,2 meters above the rod clamp. When the very large downthrust was applied, the quillrod bent at the connection and then failed.
Although it is possible that the drill rod connection suffered a normal fatigue failure due to cyclic loading, it is highly unlikely given the significant deformation in both the upper and the lower drill rods.
It is essential that every lever, gauge, and control knob on a drill rig is clearly labelled, either in a language understood by the Driller or with a symbol.
It is essential also to remember that every joint in the drillstring is subject to cyclic loading and is therefore a potential point of failure. If the failure takes place below ground level then it is unlikely that the failure will result in an injury. Failure of any joint above ground level is potentially dangerous and the chances of a serious injury resulting are very great indeed.
All drilling contractors and Safety Officers should ensure that procedures are in place to ensure that exposed joints between the rotation head and the rod clamp are no more than 500 mm above the rod clamp. Drillers must be made aware of the extreme hazard that this situation presents.
Procedures should also be in place to ensure that quillrods are inspected on a daily basis to check for any signs of abnormal wear, notching due to the chuck slipping or any other sign of potential failure.
The following recommendations may assist in eliminating the hazard:
1. Reduce the number of threaded connections in the quillrod – if possible use a 6 meter drill rod in preference to 2 x 3 meter drill rods.
2. If using standard wireline drill rods:
a. Only new drill rods should be used to make up a quillrod and a protocol to replace the quillrod at regular intervals should be introduced.
b. Threaded connections should be correctly pre-torqued as per the drill rod manufacturers’ specifications.
c. A saver sub should be used on the bottom-most connection to protect the pin thread on the bottom-most quillrod.
d. Avoid slipping of chuck jaws and if circumferential grooves are noticed in the quill rod then it should be changed out with a new quill rod made up of brand new drill rods.
3. If available, use a heavy-duty wireline drill rod in preference to standard wireline drill rod.
There have been several related incidents of diesel fuel fires occurring on mobile plant while they were being refuelled.
The fires initiated from escaping diesel fuel coming into contact with hot engine components including turbo chargers. In each case the operator filling the mobile plant was in close proximity to the fire and a ‘quick-fill – dry break’ type refuelling system was being used.
This hazard alert was prepared by the New South Wales Government Read the full details of this hazard by downloading the report below.
A blast hole drill rig mast was being lowered from the vertical to horizontal position. Its top end was about 1 metre from its horizontal resting position when a bearing block capping bolt failed. This caused more bolts to fail and the mast then fell close to its intended horizontal resting place, but causing considerable damage. Nobody was injured.
The mast pivot shaft was being held in position by a bearing block at each end. The removable half of each of the blocks was held in position by two capping bolts.
Read more about the causes of this incident and the recommendations to prevent the hazard in this report compiled by the Queensland Department of Natural Resources and Mines.
This alert has been extracted from a report published by an Australian mining company
Description of the accident
A drill rig assistant suffered a blow to the head and an injured knee when the drill rod he was helping to support suddenly fell to the ground.
A dual tube reverse circulation (RC) drill rig was tripping drill rods using the main winch and hoist cable attached to a ‘clamshell’ or sliding saddle from which a wire rope is run to a hook. Both the clamshell and the hook have handles for manually controlling the apparatus. This system (or variations of it) is standard practice in the industry.
The incident occurred when the wire rope attaching the clamshell to the hook broke causing the drill rod to slide through the clamshell and fall to the ground. The drill rig assistant had hold of the handle on the hook which dragged him down as the rod fell causing him to strike his head against the drill rod. As he collapsed, he also knocked his right knee on a metal guard on the ground.
The drill rod came to rest against the mast having fallen onto and through the steel working platform– Figures 1 & 2.
The wire rope used was an 8mm, 6x6 rope (6 strands each made up of 6 wires), with a mean breaking load of 4 600kg Figure 3. This cable is intended for use as wireline rope on diamond drill rigs and not as a lifting cable although the practice of using the readily available wire line rope on multipurpose rigs is common.
The wire rope was fitted with swivels at both ends and the rope was terminated with Crosby clamps. The drill rod was a 4” diameter x 6 meter long and had a mass of approximately 160kg. The main winch of the drill had a single line capacity of 10MT and no load limiter was fitted to the winch.
It seems likely that the wire rope had been overstressed at some time possibly due to the hook or clamshell being caught on a part of the drill rig. Since the main winch is capable of exceeding the rating of the wire rope and no load limiting device was installed on the drill, it is possible that the overstress could have caused even by a relatively small overload.
Almost all rotary percussion and reverse circulation drill rigs use a clamshell arrangement to trip drill rods and so the potential for this accident to be repeated is very great indeed. It is therefore recommended that 10mm or 12mm wire ropes only are used.
The main winch should not be used for rod tripping – instead the auxiliary winch should be used.
All elements of the clamshell, wire rope, swivels, shackles and the winch must be fully inspected on a daily basis.
All elements of the rod tripping equipment must be manufactured to an acceptable technical standard and must be permanently stamped with the safe working load of the piece of equipment.
Hydraulic fluid burst through the wear spot on the hose and injected through the double gloves into the fitter’s index finger. Major surgery was required to track and remove the injected hydraulic fluid from the fitter’s finger and hand.Read More
While pulling drill rods the “D” Shackle used to connect the hoist rope to the hoist plug failed catastrophically.Read More
The injured man inserted his arm into the cyclone to clear the blockage and while his arm was still in the cyclone, the Driller closed the cover plate. The injured man’s forearm was trapped in the opening by the cover plate and he sustained a compound fracture of the left lower arm.Read More
As the pedal depressed it opened the foot clamp and released the drillstring which fell into the hole causing the hoisting plug to hit the top of the clamp. The force with which the hoisting plug hit the foot clamp caused the foot clamp pedal to lift very abruptly. The force of the upward moving pedal sliced through the injured man’s safety boot causing a deep laceration in the sole of the man’s foot and severe contusion of his ankle.Read More
Just as the injured man was about to loosen the drill rod the chuck and therefore the drill rod rotated unexpectedly pulling the drill rig assistant towards the drill rig, jamming his right hand between the spanner and the substructure of the drill rig. This resulted in the traumatic amputation of his right middle finger.Read More