The Next Generation Crawler (NGC) being hoisted aboard the Benguela Gem, marking the next phase of advanced marine diamond recovery.
8 m in height, with a fully equipped weight of 370 t. Its boom sweeps a 21 m arc in just 25 seconds, powered by an array of high-performance systems - a 3,4 MW dredge pump for material transport, a 600 kW hydraulic system and a jet water system to fluidise the seabed. Rated to operate at depths of up to 200 m, it typically works between 100 m and 135 m below the surface in concessions located as far as 20 km offshore. Track innovation Built as a modular platform, the crawler houses all key recovery systems including the excavation boom, slurry pumping and transport, hydraulics, electrical control and instrumentation and advanced sonar. Sebastian ‘Bas’ van der Laer, Mining System Specialist at Upstream Technology, notes that the track system on this generation has seen major advancements. “The track tensioning system is unique - using hydraulics that can adjust automatically during operation,” he explains. “It responds in real time to operational forces reducing chain wear, extending lifespan and improving gearbox torque - enabling the crawler to overcome larger obstacles.” This adaptive tensioning technology is a first for subsea crawlers, cutting the risk of track derailment and ensuring smoother movement across uneven seabeds. Improved reliability Operational data from the previous generation of crawlers was rigorously analysed to identify and address potential weak points, enabling longer component life, van der Laer says. “Our goal was to raise engineering availability to 87%, up from 82% on the previous generation,” he explains. “That 5% improvement translates into a significant increase in production over the crawler’s three-year lifecycle.” The team prioritised durability and robustness, particularly in the pumps, with a target of increasing service life by 30%. Critical sensing systems now feature built-in redundancy, eliminating single points of failure that could halt operations. Machine-learning algorithms further enhance reliability by analysing sensor data to predict component wear, enabling preventative maintenance and reducing downtime. Further automation Automation has been a key lever in boosting both performance and durability, says Technology Development Manager Imraan Parker. By embedding best operating practices directly into
The Next Generation Crawler (NGC) is a cutting-edge subsea mining unit developed for deployment on the Benguela Gem.
the crawler’s systems, the team has achieved more consistent performance and greater control over the operational forces acting on the machine. “All this translates directly into longer structural life,” Parker explains, highlighting the value of the forward-looking sonar which can map the seabed in real time - even in low-visibility conditions where cameras are ineffective. “Sonar enables more precise recovery allowing the crawler to work right down to the footwall - the boundary between ore- bearing material and the underlying seabed,” he says. “When gullies or variations appear in the footwall, the system can adapt to the terrain and recover more ore-bearing material.” One-person operation Automation also plays a central role in the crawler’s launch and recovery systems. Van der Laer notes that a single operator can control both the crawler and its handling system from the vessel. “The crawler can operate continuously for between 6 and 15 days before planned retrieval,” he says. The vessel automatically tracks the crawler’s movements, maintaining the optimal position for pumping and cable management - a critical factor for stability, efficiency, and safety in offshore operations. Deployment and retrieval are carried out using a single cable and winch. To compensate for the vessel’s vertical movement in ocean swells, a wire line tensioning system (WLTS) keeps the cable under constant tension. An umbilical cable houses all essential
DECEMBER 2025 - JANUARY 2026 | www.modernminingmagazine.co.za MODERN MINING 29
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