AMSJ » Continuous miner driver knocked unconscious by rib bolt plate
Incident Prevention/Mitigation Latest News

Continuous miner driver knocked unconscious by rib bolt plate

continuous miner
A continuous miner was injured when a rib bolt plate was ejected.

Back in July this year, a 46 year old continuous miner driver at Springvale Coal was knocked unconscious and required more than 50 stitches to his face when a rib bolt plate got ejected from the rear of the continuous miner following a conveyor jam. Reports indicate that the picks on the continuous miner were in direct contact with rib bolts and rib mesh resulting in entanglement of mesh around the cutting head of the continuous miner at the time.

continuous miner in incident
Continuous miner in heading

According to the the NSW Resources Regulator (NSWRR), the incident occurred at 4.50 pm on Thursday 5 July 2018. The flying object struck a worker when it was ejected from the rear conveyor of a continuous miner. The object struck the continuous miner driver in the face, rendered him momentarily unconscious and knocked him over with his head hitting the mine floor.

The worker was transported by ambulance to Orange Hospital for treatment. The worker received more than 50 stitches for a facial wound and one stitch to a small laceration near the corner of his left eye. He was released from hospital on Friday 6 July 2018.

Continuous miners and the steel picks on the cutter heads are not designed to mine through steel strata supports, such as steel rib bolts and rib mesh.

The worker was part of the development team that was breaking away to the left in B-heading of the 426 development panel to mine the seven cut-through to form the gate roads. The worker had pulled the continuous miner back to trim the intersection when the centre conveyor chain jammed. The worker was standing on the operator platform on the continuous miner and had angled the conveyor in line with his position so he could see down the conveyor chain.

The worker reversed the conveyor to free the chain. An object was ejected from the centre conveyor chain of the continuous miner, hitting the worker. The seven cut-through breakaway was moved 30 metres inbye (closer to the mining face) of the planned position due to adverse strata conditions. The change in breakaway position resulted in the continuous miner cutting through steel rib mesh and steel rib bolts.

The investigation

NSWRR inspectors and investigators responded and began an investigation to determine the cause and circumstances of the incident.

The mine operator is cooperating with the investigation. The NSWRR Preliminary enquiries indicate that the object that hit the worker may have been the plate from a rib bolt.

A final report has not been issued at this stage.

What are the learnings?

The NSWRR has advised mines that a risk assessment must be conducted whenever a change to the mining sequence, such as pillar size and breakaway distances, is considered.

Continuous miners and the steel picks on the cutter heads are not designed to mine through steel strata supports, such as steel rib bolts and rib mesh.

Using the continuous miner to cut steel increases the risk of mesh and other materials getting caught around and entangling the cutter heads and spark generation with potential frictional ignition of flammable materials on the continuous miner and methane gas if it is present in the workings.

Supervisors and workers must recognise hazards and foreseeable risks associated with unblocking conveyors of continuous miners and other plant. Appropriate control measures must be in place before any work is undertaken. There must be sufficient safeguards to prevent a worker being at risk and in the line of fire of objects or component that may be ejected from the cutter head or conveyor chain either while it is operating or under repair.

A full copy of the incident report IIR18-06 is available here. Image: NSWRR Investigators. Image shows continuous miner with cutter heads and entangled rib mesh and bolts.

Read more Mining Safety News

 

Add Comment

Click here to post a comment

AMSJ Spring 2018