Phased plant modernization during on-going operation at HH-Basalt
How do you modernize a decades-old processing plant without interrupting production? At the Oberscheld diabase plant in Germany, operated by HH-Basalt- und Diabaswerk GmbH, this was the challenge.
With infrastructure that had evolved over several decades and a continued need to reliably supply the regional construction industry with high-quality aggregates, any upgrade had to be carefully planned and executed during live operation. Together, HH-Basalt and Sandvik developed a phased modernization approach that combined equipment upgrades, process optimization, and practical innovation, all while keeping the plant running.
The challenge: ageing equipment and zero downtime tolerance
In recent years, the need to modernize the processing section at Oberscheld had become increasingly evident. A key turning point came early in 2023, when spare parts availability for the site’s central secondary crusher – an Aubema gyratory crusher – became increasingly limited. At the same time, uninterrupted operation was non-negotiable. Any solution would need to improve long-term reliability and maintenance efficiency without disrupting production or compromising safety.
Early involvement and phased implementation
Sandvik was involved at an early stage to assess the existing installation and define a modernization concept tailored to the site’s technical and operational constraints. Rather than replacing the plant in one step, the project was structured as a phased upgrade, allowing improvements to be introduced gradually while maintaining full production.
“We chose Sandvik because of the reliability of the technology and the consistently high screening efficiency. The CS430 particularly stood out in this regard,” says Felix Hofmann, Deputy Plant Manager at HH-Basalt und Diabaswerk GmbH.
The solution: modernizing the plant as an integrated system
The first phase focused on replacing the central secondary crusher with a Sandvik CS430 cone crusher. The installation included adaptations to the existing steel structure as well as the addition of a new crane runway to support safer and more efficient maintenance, with Sandvik responsible for both the engineering and implementation of the retrofit, including a process performance guarantee. Since autumn 2023, the CS430 has formed the backbone of the modernized plant section, supporting stable production and laying the foundation for further upgrades.
Building on this, the next phase expanded the focus from individual machines to the performance of the entire material flow. In 2024 and early 2025, two Sandvik circular motion screening units were installed, along with an upgraded hydraulic drive concept for the push feeder feeding the primary crusher. By treating crushing, screening, and material flow as a connected system, the site achieved higher operational reliability and a more predictable maintenance regime – both critical factors in continuous operations.
The screening units were equipped with lightweight GRP dust covers developed by Sandvik in cooperation with engineering partner LSE GmbH. Unlike conventional steel covers, the GRP design allows single-person handling and can be installed or removed within a short maintenance window of approximately one hour. In addition to improving maintenance efficiency, the covers reduce noise and reliably contain dust emissions, enhancing both occupational safety and environmental performance.
Reliable production and a future-ready plant
Today, the modernized plant section at Oberscheld demonstrates what can be achieved when technology, engineering, and operational practice are closely aligned. The phased approach has delivered high production reliability during and after modernization, improved maintenance access and predictability, enhanced occupational safety with reduced noise and dust emissions, and a plant concept designed for long-term continuity rather than short-term fixes.
Sandvik stands out in particular for the quality of its technical consulting, engineering, and the development of innovative, practical solutions, says Felix Hofmann.
The partnership between HH-Basalt and Sandvik continues. Another screening unit is currently in the engineering phase and scheduled for integration and commissioning in 2026, marking the next step in the site’s long-term modernization roadmap.
For more information, please contact
Sandra Pietsch
Marketing Professional
Office Phone: +49 (0) 201 1785-352
Mobile: +49 (0) 173 9000457
sandra.pietsch@sandvik.com