De Beers Group’s Upstream Technology business has launched a next generation subsea crawler, more than two decades after developing its first underwater mining system for diamond recovery. The new crawler, designed for Debmarine Namibia’s flagship vessel Benguela Gem, marks a significant advancement in marine diamond recovery technology.
Rudi Agostinho, Next Generation Crawler (NGC) Project Manager at Upstream Technology in Cape Town, explains that the crawler is the result of almost four years of development and is now fully operational off the coast of Namibia. A second identical unit is being assembled to ensure continuous operations during scheduled servicing of the first, minimizing downtime.
“We have engineered a crawler that operates with significantly enhanced efficiency and reliability,” says Agostinho. “The upgrade allows the Benguela Gem to boost effective recovery rates by approximately 20%, with minimal increase to operating cost, enabling the vessel to fully utilize its onboard treatment plant capacity.”
Advanced Engineering and Automation
The next generation crawler is larger and more capable than its predecessors, weighing 370 tonnes and measuring 28 metres long by 8 metres wide and high. Its sweeping mining arm covers a 21-metre arc in just 25 seconds, handling a combination of seawater, sand, gravel, and diamond-bearing material drawn through an 800 mm pipeline.
Sebastian “Bas” van der Laer, Mining System Specialist, highlights the crawler’s new track tensioning system, which automatically adjusts hydraulically to reduce wear, extend track chain life, and improve gearbox torque. The technology aims to increase engineering availability from 82% to 87%, supporting higher production rates.
Imraan Parker, Technology Development Manager, adds that automation underpins the crawler’s performance, allowing consistent best-practice operations, reducing structural stress, and extending the machine’s service life. Automation also aids deployment from the vessel and integrates advanced systems, including forward-looking sonar, enabling operators to recover diamonds down to the seabed footwall.
Innovative Build and Deployment
At Upstream Technology’s Cape Town facility, the crawler’s assembly introduced several engineering innovations. Abdul-Gameed Davids, Senior Workshop Engineering Officer, notes the use of two synchronized overhead cranes to lift the 47-tonne dredge motor into the crawler frame—a method now formalized for future builds.
Transporting the completed crawler to the harbour required precise planning. Steven Smith, Senior Project Engineer, details that a 750-tonne crane hoisted the crawler onto the quay. Before deployment, the crawler underwent full-scale land-based simulations, testing over 2.2 km of cabling and 10,000 connections, all verified before sea trials. Close collaboration with Debmarine Namibia’s operational team allowed feedback from the vessel’s crew to be incorporated into the final system.
The next generation sub-sea crawler represents a major leap in marine diamond recovery, combining automation, precision engineering, and decades of operational experience to deliver higher efficiency, reliability, and production rates in offshore diamond mining.
