For a site that has not sustained a lost time injury in the eight years since operations started, Glencore’s Mangoola CHPP in the Hunter Valley has developed one safety innovation that stands out above all.
Glencore’s team at the Mangoola CHPP (coal handling preparation plant) in New South Wales has demonstrated how safety improvements can be effectively introduced in response to a tragic incident.
Mangoola CHPP’s asset management team developed a carefully-engineered solution to the difficult task of replacing the belly plates on an ABON chain feeder after a worker at another Glencore site was fatally injured while performing the task in 2016 .
The now-proven safety initiative at the Hunter Valley site was rewarded at the 2019 Australian Mining Prospect Awards with the Flexco Excellence in Mine Safety, OH&S award.
Typically, working space is restricted beneath the chain feeder, and ABON’s standard replacement instructions involve dismantling of the machine from the top down.
The lengthy task requires the removal of the upper floor plates, the chain and flight assembly and then removing the belly plates once each of the former components have been removed.
It also involves multiple crane lifts and the associated interaction of personnel in that environment.
There is also the risk of the belly plates binding within the frame, making it difficult to dislodge them and inviting excessive lifting equipment loads as a result.
During the 2016 incident, the work group was slinging the belly plates from the top side of the machine using manual rigging equipment.
Glencore believes the group was planning the execution of the task as they went to a certain extent and it appears that the injured worker entered the area beneath the load.
With all of the bolts removed and due to the angle of the rigging, it dropped and swung rearward, crushing the worker.
The Glencore CHPP asset management team was faced with the prospect of conducting the same task two years later.
However, the team was instructed to “devise a method to remove and replace these components with the absolute certainty that no person would be injured,” according to Mangoola CHPP manager Chris March.
Led by Mangoola CHPP maintenance supervisor Scott Bannerman, the team spent nine months devising a method based around a hydraulic trolley mounted lifting table.
The trolley travels on a rail system that allows the plates to be removed and railed out. The new plates are then railed in and lifted squarely into position without any personnel being exposed to suspended loads.
Mangoola CHPP completed the task without injury or incident in October 2018, but continued to add improvements to make the task safer.
With the design assistance of FLSmidth ABON, the Mangoola CHPP team improved the process further by manufacturing the replacement plates at a slightly narrower profile by adding ‘shim packs’ to eliminate the prospect of binding when the next change is required.
This method also enabled work to continue above the top deck as it remained in place as a hard barrier between the workers below. It meant that critical bin liner work could proceed with nil risk or impact to the involved work party.
Mangoola Coal operations manager Nick Slater is delighted that the CHPP asset management team’s work has been acknowledged at the Prospect Awards.
“The health and safety of our workforce is our number one priority and our CHPP team has done an excellent job in designing a rail and hydraulic system for one of the higher risk maintenance tasks at the plant – replacing chain feeder plates,” Slater says.
Furthermore, the hot works that were initially required in preparation for the task are no longer needed for the next changeover.
In total, the job took 36 hours to complete from start to finish. However, it is expected that this time will be reduced to 24 hours with the elimination of the hot works.
March believes what sets the initiative apart is the diligent application of engineering in the hierarchy of controls to deliver not only a method that eliminates the risk of serious injury, but also adds productivity benefits.
“By using a combination of rail and hydraulics, we’ve been able to take our people away from areas of higher risk, as well as significantly reducing the time needed to replace the plates,” March says.
Glencore has also conducted the task using the Mangoola CHPP methodology at another of its operations in the Hunter Valley with the same results.
The award-winning initiative reinforces why Mangoola CHPP is recognised as an industry-leading operation in terms of safety, productivity and environment excellence.
“We have maintained a strong focus on safety at Mangoola. In fact, our CHPP team has not sustained a single lost time injury since we started operating in 2011,” March says.
“These types of innovations are designed to help us maintain that record.”