Hastings Deering has helped Sojitz Corporation save thousands of dollars in operating costs at its Gregory coal mine in Queensland’s Bowen Basin.
For more than 40 years, the Gregory mine located 60km northeast of Emerald in Queensland has been known as one of Australia’s premier coking coal operations.
Gregory has a three-million-tonne-per-annum production capacity and a mine life of more than 20 years, and boasts a fleet of 20 mining trucks, 80 per cent of which are Caterpillar (Cat) branded.
The challenge
Since Sojitz Corporation acquired Gregory in 2019, the mine has utilised Cat’s ground engaging tools (GET) on its ancillary fleet, specifically using the EWL (extended wear life) cutting edges on its Cat D11 large track-type tractors (LTTT).
While using this system, Sojitz was flipping cutting edges at an average of 350 hours and changing a new set of cutting edges at approximately 700 hours.
The company manages its D11 tractors on a 500-hour preventive maintenance (PM) interval and wasn’t changing its GET in the field due to safety concerns.
This saw the machines trammed long distances to the workshop to both flip and change the GET, leading to two additional trips to the workshop within a 1000-hour operating period.
This had a ripple effect on Gregory’s operating costs, labour hours and reduction in physical availability.
As a long-standing and loyal customer, Sojitz reached out to Cat’s Queensland dealer Hastings Deering to implement an alternative solution that decreased operating costs and aligned with its 500-hour PM strategy.
The trial
Hastings Deering commenced a trial where three D11s operated under similar conditions.
Each dozer was equipped with different GET systems. The first, DZ38, was fitted with extended wear life (EWL) cutting edges and applied by Hastings Deering.
The second, DZ39, was set with extreme extended wear life (EEWL) middle edges and high abrasion (HA) end bits, while the third dozer, DZ40, was fitted with offset edges.
Image: Hastings Deering
Each system was examined on a regular basis, specifically inspecting the wear trends. To gather the results, Hastings Deering designed an inspection sheet and Microsoft Excel spreadsheet.
The original equipment manufacturer (OEM) also created a ‘Go-No Go’ gauge to analyse the wear on each system.
The outcome
The trial concluded that the DZ40 fitted with offset edges offered the longest wear life, delivering 1385 hours.
Despite this, Sojitz was concerned the solution wouldn’t align with its 500-hour PM strategy due to the offset wear material.
Following further evaluation, the company implemented the EEWL middle edges and HA end bits method to its LTTT fleet, which achieved 1086 hours and was the second best of the three trialled.
This solution is projected to save Sojitz approximately $70,000 per annum in material and labour costs per annum.
According to Sojitz, the EEWL middle edges and HA end bits method was $0.79 per hour cheaper than the EWL cutting edges fitment. This totals $27,650 savings per year in materials across the company’s mining fleet.
Reduced worn undercarriage and labour hours were also estimated to save $200 per hour, or $40,000 per year across the fleet.
Increased productivity was another highlight. By limiting additional travels to the workshop for GET changes, Sojitz’s machinery is estimated to gain an additional 200 operating hours per annum.
A customer-focused approach
Since its inception more than 90 years ago, Hastings Deering has prioritised forming and maintaining long-term relationships with its customers.
This commitment is clearly illustrated in its work at the Gregory coal mine.
By working alongside Sojitz with care, integrity and transparency, Hastings Deering has upheld its reputation as a leading OEM in Queensland that not only provides premier mining equipment but tailored solutions that meet customer specifications.
This feature appeared in the March 2025 issue of Australian Mining.
