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Hire fleet plays ongoing role in coal mine rehabilitation

Four years ago, Quarry highlighted Delta Rent’s plant and equipment hire service at the Hazelwood power station and open cut mine in Victoria’s Latrobe Valley. Damian Christie re-examines Delta’s role today as the site undergoes extensive rehabilitation.

On 31 March, 2017, the 1542-megawatt power station at the Hazelwood Mine, which had been supplied with brown coal from the adjacent 1165ha open cut pit, officially closed after 52 continuous years of operation. In our last report on Hazelwood Mine, up to 772 million tonnes of coal had been extracted to fuel the power station, leaving three million cubic metres of overburden – clay, gravel and top soil.

At the time, the mine utilised four bucket wheel excavators and giant conveyors to extract and transport the coal from the pit to the bunker to the boiler. The eight conveyor belts combined would transport about 2000 tonnes of coal per hour and the three 8500-tonne slot bunkers would provide reserve coal storage of 18,000 tonnes for about six hours at a time. This meant it was necessary to continually feed the coal directly into the boilers to generate electricity.

As a result, there was constant pressure to extract as much coal as the power plant was burning – and this in turn required considerable earthworks around the mine to construct and maintain 142km of roads and create drainage.

Hazelwood Mine turned to Delta Rent, one of Australia’s largest suppliers of rental fleets of specialised earthmoving plant and equipment, to administer and maintain the civil earthworks fleet.

In 2013, Delta Rent and the mine’s then facilitator GDF SUEZ – today rebranded as ENGIE – agreed that Hazelwood would pay a set monthly fee for each piece of Delta’s plant and equipment, plus an hourly rate for each additional rent beyond the prescribed number of machines. The initial contract was for five years, and Delta Rent would also supply on-site maintenance and servicing of its mobile equipment as part of the contract.

In what would be a productive, longstanding relationship, Delta Rent subsequently supplied Hazelwood with up to 100 earthworks machines at any one time, depending on the season, the weather and the scale of required jobs. That partnership has been renewed since the closure of the plant and mine in the first quarter of 2017, and the two parties have maintained a viable, cost-effective rental arrangement.

Rehabilitation project

Since 1 April, 2017, ENGIE has been engaged in decommissioning the infrastructure of the 3550ha power plant and mine site as part of the Hazelwood Rehabilitation Project. The company retains an on-site workforce of 130 (directly employed) and can call on up to 200 more contractors (as required). Its decommissioning activities are being managed in three phases. Phase 1, which involved the de-energising of major plant and equipment and clean-up of pollutants, was completed in June 2017.

Phase 2, which has seen the disconnection of all electrical supplies within the site, has occurred since August 2017. Most impressively, part of the decommissioning included the dismantling of the eight conveyors (including the removal of rubber belting a metre wide and 450m long) and the washing down and removal of residual coal from the inert slot bunkers and crushing houses.

This means the power station and the site’s other facilities, including its signature 137m tall chimneys, are awaiting Phase 3 – demolition. In April this year, Delta Group (Delta Rent’s parent company) was awarded the contract for the demolition of the power station. Planning is currently underway for demolition, which will begin in 2020.

Having one eye on the demolition stage has not fazed ENGIE from its work on the rehabilitation project. It is, with community consultation, proposing to convert the 16km mine perimeter into a full pit lake from 2021. The end use of the land external to the mine remediation (eg potentially as parkland) will be decided by state and local government authorities.

There is about another two years of work required to rehabilitate the mine and up to four years of work to remediate the adjacent land, such as the external overburden dump, ash landfills and the Hazelwood cooling pond.

To date, 10ha along Hazelwood’s Eastfield eastern batters have been refurbished by excavating the coal batters back to a slope of three to one, then spreading topsoil over the clay and seeding the entire area. Batters in the site’s Knuckle area were also excavated to realign up to 1000m of pipeline and to install a new fire services pipe, using clay from the northern batters (which were rehabilitated before the closure).

In 2018, work was also conducted along the eastern batters to join up with the Eastfield northern batters. Rehabilitation will subsequently progress around the perimeter of the South Westfield northern batters and into the Westfield, and then down to the full pit lake level by the start of fill for 2021.

The closure of Hazelwood, therefore, means work there is ongoing – and ENGIE continues to employ Delta Rent and contracting service Foundation Civil & Mining to provide the plant and equipment and the operators respectively to achieve the ambitious goals of leaving behind a repurposed space that will benefit the Morwell community in future generations.

‘Dry’ and ‘Wet’ hire

Jessica Murty is Delta Rent’s site supervisor for its mobile plant and maintenance division at Hazelwood and oversees 12 other Delta personnel with prior experience in logging, agriculture, and open cut and underground mining operations. She oversees the “dry” side of the hire arrangement with ENGIE, supplying and maintaining mobile plant fit for project purposes.

There has been as much as 104 plant on-site for the truck and shovel rehabilitation operation in peak periods, comprising primarily earthmoving vehicles. Murty, who has worked in the extractive industry for 11 years, told Quarry that she can source other equipment that ENGIE requires where necessary. “The majority of the plant is used for bulk material haulage to assist ENGIE with their desired end outcome of a successful, world leading, professionally rehabilitated site,” she said.

Delta Rent’s hire machines either come new from the top industry OEMs, such as Caterpillar, Komatsu and Hitachi, or at low hour usage (eg up to 3000 hours). All parts of its fleet, depending on the specific type of machine and application, have an average service life of 12,000 hours.

Machines can also be repurposed for less impact work, eg a dump truck can be converted to a water truck. In the past, the most popular vehicles with quarry operators have been 5.5m3 wheel loaders, articulated dump trucks in the 40- to 50-tonne range and larger excavators from 45 tonnes through to 90 tonnes.

“We have a good mixture of new and older equipment,” Murty said. “Delta are constantly working to improve their fleet and are currently running a brand new Hitachi EX1200 as part of their heavy haulage project. There are also nine new Volvo A45G articulated trucks that have helped ENGIE achieve a very productive bench cubic metre (bcm) rate.”

Delta Rent has long had a large undercover maintenance workshop and storage area called the “Igloo” at Hazelwood Mine to undertake the maintenance and refuelling of its vehicles. Murty said that with the large amount of equipment on-site, Delta Rent has had to “reconfigure more workshop areas that our team can efficiently work in – rain, hail or shine. Refuelling is now carried out by permanent fuel/lube truck operators and off-road fuel/maintenance trucks. This occurs 22 hours a day in peak season”.

Matt Weddell, the principal and earthworks superintendent for Foundation Civil & Mining (FCM), organises the “wet” side of the arrangement – ie the operators to drive Delta’s mobile equipment. He has had two decades of experience in the extractive and earthworks industry.

“My role here is to co-ordinate and supervise labour and plant resources to ensure the projects are delivered safely, to plan and to budget,” he said. “I am in constant communication with Jess to ensure that the mobile plant is available and fit for purpose when required.”

FCM’s contract workers are recruited from around the Latrobe Valley region and include some former Hazelwood Mine employees. In peak periods (eg summer), the number of operators on-site can be as high as 90.

“We employ people ranging in age from 20 years old to 60 years young,” Weddell said, “with an emphasis on younger people where we can train them and expand their skills base by pairing them where we can with the older and more experienced operators.

“The training is an ongoing practice where we are constantly looking to improve the experience of the workforce,” he added. “It’s about always ensuring all operators are trained and competent on the machinery and that they use the site’s safe operating procedures at all times.”

Assigning the fleet

Together, Murty and Weddell meet daily to collaborate on the assignment of equipment and operators throughout the Hazelwood Mine.

“Peak season sees Matt, myself and our leading hands constantly working closely together,” Murty said. “Meetings to discuss the day’s targets begin around 6.15am. We then return to our teams to organise and prioritise plant repairs. Throughout the day we are in liaison with each other, considering breakdowns and reinstated plant with the day to day and overall success of the project constantly our target.”

She added that the assignment of the rental fleet is determined not just by the quantity of operators on the ground but also the maintenance schedule, safety, weather and other activities within the rehabilitation site.

“We work very closely with Matt, Rob Dugan and their scheduling team to achieve a high rate of utilisation of available plant for the project,” Murty said. “Meetings and communication throughout the day are vital here, especially taking safety and environmental concerns into account. Like any mobile plant supplier there are always days that tasks on-site can change from hour to hour and that really is just the nature of the industry. As part of the greater Delta Group, we can call on other pieces of machinery Australia-wide, should there be a need to specialise.”

Weddell said it was a “critical item” for FCM to have the “equipment availability that Jess and the Delta team work very hard to maintain”.

“We have long-, medium- and short-term planning schedules for all projects on-site which allows the group to forecast the tasks and ensure we have the correct availability of plant from Delta,” he said. “This can change on an hour to hour basis depending on a myriad of things like weather, personal leave, plant, etc. We work as a team to overcome whatever hurdles we encounter to keep the job progressing productively.”

Weddell said that FCM assesses the effectiveness of its contract workers through setting daily key performance indicators (KPIs) to each task. “For example, it could be cubic metres per hour productivity on an excavator, the daily volume shifted. We also monitor Delta on the percentage availability of the mobile plant. These KPIs are used as a monitoring tool to assess the productivity and competency of operators. We have daily meetings to discuss operations and modify them if we believe we can achieve more productive outcomes. We also assist our operators with more specific training where we believe this will be beneficial for productivity and safety.”

Both Murty and Weddell said that the feedback from ENGIE about the performance of their plant and people is encouraging.

“ENGIE have been very supportive of Delta Rent on-site and work with us to achieve the desired outcomes,” Murty said. “Like any contract, there are always challenges but having an understanding of the scope of the work and the required timelines helps both parties work together to achieve the best result.”

“In general, we receive positive feedback as the majority of our operators are conscientious in being safe, productive and caring of the equipment,” Weddell said.

The future

Weddell said that in the wake of the closure of the power station, the Hazelwood Rehabilitation Project had been invaluable to the Latrobe Valley community. “This is a very important project as it has continued to provide employment and in-direct works for local companies, with the view to achieve an asset that the community will enjoy for many years to come,” he said.

He was also optimistic about the future of the local workforce, including his own contract workers. “While the operators may have finished at the Hazelwood Rehabilitation Project, the experience, training and competencies they will have gained in operating this heavy earthmoving equipment in a very regulated project will hold them in high regard for future employment, both here in the Latrobe Valley and on other major extraction projects within Australia.”

Murty said that for her personally, the opportunity to work on “such a significant project” as the Hazelwood Rehabilitation Project proves that “no matter who you are or how you start off, you can always achieve what you want if you work smart and hard for it. It is also very satisfying to be on a project that will ultimately provide a fantastic resource for the local community for many years to come”.

Murty’s advice for quarrying operators that are considering hiring plant and equipment for their operations is to be “sure on what you want to achieve, be conscious of environmental and community concerns and seek advice from your experienced rental representative when it comes to determining required machine types. Technology is changing on a daily basis and rental companies such as Delta Rent can help any clients access the latest gear”.

References & further reading
1 Christie D. Hire fleet helps to keep the midnight oil burning. In: Quarry 23(8), August, 2015: 14-19.
2 ENGIE 2019. Hazelwood: The closure and rehabilitation of the Hazelwood power station and mine.

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