VESSEL REVIEW | Benguela Gem – Debmarine Namibia’s newest vessel to undertake seabed diamond recovery

A new custom-built diamond recovery vessel has been completed and delivered by Netherlands-based the Damen Shipyards Group via its Damen Shipyards Mangalia division on Romania's Black Sea coast.

Designed by Norwegian naval architecture firm Marin Teknikk, Benguela Gem is owned and operated by Debmarine Namibia, a joint venture between the government of Namibia and UK-based diamond mining and jewelry company the De Beers Group. The newbuild measures 177 by 27 metres, making it the largest purpose-built diamond recovery vessel in the world besides being the new flagship of the De Beers fleet. It is also around 8,000 tonnes heavier than the company's next largest ship, the 174-metre Mafuta.

The 14,700DWT, steel-hulled Benguela Gem was designed and built in Europe whereas the mission equipment was developed in Cape Town, South Africa. The mission equipment was then integrated into the vessel in Cape Town by De Beers Marine. The equipment is contained in modules, which allowed for their complete installation using only a single crane.

The vessel will use subsea crawling extraction techniques to retrieve diamonds from depths of between 90 and 150 metres off the coast of Namibia for later processing using its onboard equipment. The processing equipment then discharges around 99 per cent of any gravel collected during the actual diamond recovery, meaning only diamonds will remain on board.

Benguela Gem combines advanced technology and a fully integrated design to ensure enhanced efficiency, reliability, and accuracy. A DP2 system automatically optimises the vessel's performance in changing weather conditions to minimise energy use. The DP2 system is based on a seven-thruster propulsion system powered by six generators to enable greater flexibility in operations.

The vessel also generates its own fresh water through the use of heat recovery systems and a reverse osmosis treatment plant.

ABB supplied the vessel with an advanced power system for power generation, distribution, and variable speed drive propulsion systems. ABB also provided an integrated power system package that includes a large online double-conversion marine uninterruptible power supply (MUPS) to support the ship's vital control processes, thus significantly reducing the risk of critical power loss and downtime.

Theunissen was responsible for some of the vessel's audio and communications equipment, including an intercom/telephone system, a CCTV camera suite, and an emergency telegraph system. Bakker Sliedrecht completed the electrical engineering, electrical system integration, commissioning, and delivery of more than 150 metres of switchboards.

Accommodations are available for 106 crewmembers and processing technicians. De Beers said that employee well-being features were a priority in the vessel's design, with the occupants having access to entertainment systems, a gym, a hospital, and relaxation facilities on board.

A helicopter deck is also fitted.

Debmarine Namibia expects Benguela Gem to operate for at least 30 years, adding around 500,000 carats of high-value diamonds to its annual production.

Click here for more news stories, feature articles, and vessel reviews as part of this month's focus on offshore vessels.