Debmarine Namibia mines for diamonds off the southern coast of Namibia and currently owns, operates and maintains five marine diamond mining vessels. Debmarine Namibia contracts De Beers Marine South Africa (based in Cape Town) to provide specialist technical engineering project support services on the vessels during scheduled vessel maintenance dry docking in the Cape Town harbour.
De Beers Marine South Africa elected to further subcontract the Yokogawa DCS (Distributed Control System) over several competitors’ systems as the core control platform, which communicates to numerous dedicated OEM (Original Equipment Manufacturer) and automation equipment. Their choice was based upon the faultless performance of the system under harsh operating environmental conditions as well as the low cost of ownership to the client who also benefited from Yokogawa’s long-term migration policies.
The DCS is responsible for the control of mining, plant equipment and monitoring of various other equipment. The means of communication is a combination of Hardwire, Modbus and Profibus DP signals. The preferred interface is a distributed Profibus DP digital network with remote nodes to reduce wiring.
The mining control comprises the control of a rotating drill bit 6m in diameter at 120m below the surface connected to a series of pipes known as the string. Once the drill is on the sea bed it drills for approximately five minutes and then is lifted while the vessel moves position. Whilst drilling, the gravel is sent up the string and through a processing plant comprising of scrubbers, screens, ball mills, density change circuit, driers and finally X-ray machines.
The majority of all the electrical motors are controlled and managed with intelligent Profibus DP starters and variable speed drives. A universal control block was developed for the intelligent starters and variable speed drives which is used across the fleet. This involved the interaction of the De Beers’ electrical department to develop a control block which met the requirements set out. Once the control block was developed, thorough verification was done, prior to implementation, on a test phase with all relevant inputs.
Yokogawa performed an upgrade of the current Centum CS3000 and Exaquantum software to the latest CENTUM VP software as well as upgrading VNET network to Vnet/IP. All PC’s are housed in an environmentally controlled and secure location. The challenge faced by Yokogawa was to execute the project during the short dry dock window. With Yokogawa’s excellent project management skills, planning and execution, as well as their continuous communication and liaison with De Beers, Yokogawa achieved on-time execution and completion of the project within budget, and to specification. In the period between June 2013 and December 2014, a total of three Debmarine Namibia Mining Vessels and one De Beers Marine South Africa vessel were upgraded with the remainder to follow.
Established in 2001, Debmarine Namibia prospects for and mines marine diamonds sustainably off the southern coast of Namibia. Debmarine Namibia is the world’s leading offshore marine diamond mining company and is a joint venture company owned in equal shares by the Government of the Republic of Namibia and De Beers. Debmarine Namibia owns, operates, manages and maintains five diamond mining vessels in water depths ranging from 90m to 140m. It is a Namibian based company with its head office based in Windhoek. Debmarine Namibia employs around 800 people.
Established in 1888, De Beers is the world’s leading rough diamond company with unrivalled expertise in the exploration, mining and marketing of diamonds. De Beers, and its joint venture partners, operate in more than 20 countries across five continents employing around 20,000 people. From its mining operations across Botswana, Namibia, South Africa and Canada, De Beers produces and markets approximately 40% of the world’s supply of rough diamonds.
Yokogawa’s global network of 86 companies spans 56 countries. Founded in 1915, the US$4bn company conducts cutting-edge research and innovation. Yokogawa is engaged in the Industrial Automation and Control (IA,) Test and Measurement, and other businesses segments. The IA segment plays a vital role in a wide range of industries including Oil and Gas, Chemical, Food and Beverage, Iron and Steel, LNG Supply Chain, Petrochemical, Oil and Gas, Pharmaceutical, Power, Pulp and Paper, Refining, Renewable Energy and Water and Wastewater.
Yokogawa’s comprehensive solutions range from sensors such as Pressure Transmitters, Temperature, Flow Meters, Level and Liquid and Gas Analyzers and Network Solution Products, to Control and Safety Systems. This includes the software for advanced control that optimises productivity; and services that minimize plant lifecycle costs. Yokogawa South Africa’s Service Training Department is accredited and proficient in theoretical and practical training for Instrumentation and Control systems from first principles. Our Internship Programme contributes to the continued technical skills improvement in South Africa.