De Beers Boosts Marine Diamond Recovery with Advanced Subsea Crawler on Benguela Gem
De Beers’ Upstream Technology division in South Africa has developed a new generation of advanced subsea diamond recovery crawlers, marking a major step forward in marine mining technology.
The first unit has been installed on Debmarine Namibia’s flagship vessel, the Benguela Gem, following nearly four years of development.
According to project manager Rudi Agostinho, the crawler represents a carefully engineered blend of automation, precision design, and decades of operational experience.
“We have taken everything we learned from earlier models and engineered a crawler that can operate with significantly enhanced efficiency and greater reliability,” he said.
The new crawler is expected to boost recovery rates by about 20% while adding minimal operating costs, allowing the Benguela Gem to fully utilize the capacity of its onboard treatment plant.
A second crawler is currently being assembled to take over operations during scheduled servicing, ensuring minimal downtime.
Debmarine Namibia, a subsidiary of Namdeb Holdings (a joint venture between De Beers and the Namibian government), commissioned the $486-million Benguela Gem in March 2022 to increase annual diamond output by approximately 500 000 carats.
Agostinho noted that the next-generation crawler will provide a strong platform for the future of marine diamond recovery. “By combining advanced tools, adaptive systems, automation, and predictive maintenance, we have delivered a crawler that can recover more material, more consistently, with less downtime—even in tougher conditions.”
The crawler is substantially larger than earlier models, weighing 370 t and measuring 28 m long, 8 m wide, and 8 m high. Equipped with a sweeping mining arm that covers a 21 m arc in just 25 seconds, it draws seawater, sand, gravel, and diamond-bearing material through an 800-mm-diameter pipeline while operating between 100 m and 135 m below the surface.
Key innovations include a hydraulic track tensioning system that automatically adjusts to changing conditions. This reduces wear, extends the track chain’s life, and improves gearbox torque.
According to mining systems specialist Sebastian (Bas) van der Laer, the goal was to increase engineering availability from 82% to 87%, directly supporting higher production levels.
With its larger scale, advanced systems, and improved reliability, the new crawler underscores De Beers’ commitment to innovation in marine diamond recovery and sets the stage for increased efficiency in subsea mining operations.
