In 2023, Winstone Aggregates began a major upgrade of its Whitehall Quarry to meet growing demand across the Waikato and Bay of Plenty regions. Rocktec led the project’s design, engineering, and integration of a new tertiary crushing plant. This development marked a significant leap in capacity, efficiency, and environmental performance.
From Legacy Quarry Site to Leading-Edge Operation
Whitehall Quarry has been operating since the 1940s. By 2022, it had reached the limits of its production capacity. To future-proof the site, Winstone Aggregates launched an extensive plant expansion. This included installing new tertiary equipment, replacing outdated secondary systems, and introducing advanced automation.
The results were clear: a four-stage crushing circuit, optimised material flow, and noticeable improvements in safety, energy use, and product consistency.
Key Enhancements
Upgraded Equipment: The site now includes a Terex Cedarapids MVP450X cone crusher, a Rocktec BTM-96R VSI crusher, and both Terex LJ-TSV and Rocktec Avalanche screens.
Streamlined Conveyance: Rocktec designed and installed twelve conveyors spanning 368 metres. This reduced transfer points, cutting down wear, energy use, and dust generation.
Civil Construction: Over 490m³ of concrete foundations and bunker walls were completed in partnership with Brian Perry Civil.
Smart Automation: Rocktec also over saw the delivery of a centralised PLC and SCADA system, providing real-time plant control and improved responsiveness.
Running Strong in 2025
Today, the upgraded plant operates with high reliability. It can produce five grades of sealing chip, two concrete aggregates, and PAP—simultaneously. As a result, Whitehall Quarry consistently meets regional supply demands with fewer delays and increased control.
Operational Gains Realised
Production Efficiency: Automation and better workflows have significantly improved plant responsiveness.
Environmental Impact: Conveyor-fed systems, dust suppression, and efficient motors have reduced diesel usage and cut emissions.
Safety Enhancement: Enhanced accessways, fewer vehicle movements, and better guarding have created a much safer work environment.
“When it came to designing our new plant, Rocktec took the time to truly understand our specific needs and operational challenges. Their depth of experience in delivering projects of this scale was evident throughout—from concept to commissioning.”
2 Years on and Project Teams from Winstone Aggregates Whitehall Quarry and Rocktec Engineering reflect on a successful project.
Built for the Future
The Whitehall Quarry upgrade wasn’t just about adding capacity. It was a strategic move toward smarter, safer, and more sustainable aggregate processing. Thanks to Rocktec’s engineering leadership, the site has become one of the region’s most advanced quarrying operations.
Importantly, this investment supports Whitehall Quarry’s goal: to lead the Waikato as the top aggregate supplier. With improved output, better quality control, and upgraded systems, the quarry is ready to meet the infrastructure needs of New Zealand—now and well into the future.