Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
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The crew works a 12-hour on/12-hour off shift, and is rotated out every 28 days. The Debmar Pacific follows a precise drill plan drawn up and based on the result of earlier research conducted by the explo- ration vessel, which drills holes in a wide pattern in a potential mining area. The sam- pling is used to plot a grid of tightly placed holes that pack together like a large block of Swiss cheese. Each is precisely plotted according to GPS coordinates so that when the Debmar Pacific drops her drill, it touch- es down on the seabed on an exact pre- planned drill location. Over a year, she will mine around 5 km 2 of seabed. Four anchors—two each located port and starboard of the bow and stern—keep the ship in place while drilling is under way. "Each hole is drilled for about six or seven minutes before the drill comes back up," Koa said. "We work 24 hours a day in all weather, but when swells start hitting 5 m, that's when we think about shutting down." The pace is intensive, and it has to be. Pinned to the notice board on the bridge of the vessel is a simple number: N$155,000 ($14,000). "This is what it costs the com- pany each hour the ship is not working. Everyone on board is aware of this number at all times." To put that in perspective, the daily rate to hire an entire Capespan ore carrier begins at around $20,000 a day. An idle Debmar Pacific clocks in at nearly $300,000 per day in lost production—an eye-watering sum for Namdeb's bean coun- ters to digest. This call to port was unscheduled but that does not mean it will be entirely wast- ed. A crew of technical experts was pulled together to carry out all the maintenance tasks that would have been done in her later scheduled stop. When she departed port in late February, the Debmar Pacific was ready for another 30-month cruise. "I got the call a day after Christmas," said Eddie Bruwer, shutdown coordinator, whose job it is to manage the maintenance project. "It took us a week to get everyone together and we are doing everything that needs to be done in the shortest time possible." Anything up to 800 men at a time were toiling on the ship as she rested at a Cape Town dock. That's an awful lot of people crowded onto a space designed to house no more than 60. Advancing Crawler Technology The revamp of the ship goes further than routine repairs; it also allows for newer technology to replace existing systems. "Our exploration process means we identi- fy possible sites to mine, but because of technical challenges it may not be possible to do so profitably," said Valbom. "As our technology develops we can then consider mining areas that we have previously passed by. Calls to port are part of our upgrading process and allow us to keep advancing our onboard technology." Technology is advancing in other spheres as well. Not far from where the Debmar Pacific was laid up, at a research facility about two miles away, is De Beers' latest project—a 300-ton monster of a crawler. This is the third generation of a tech- nology that the company hopes will eventu- ally be the future of undersea mining. The crawler will be based on the newly renamed Mafuta, which in Namibia's Oshiwambo language means "oceans." In an earlier life, the ship could claim to have been the MAY 2014 • E&MJ; 43 www.e-mj.com D E E P S E A D I A M O N D S Drilling tower on the Debmar Pacific. Debmar Pacific docked in Cape Town. EMJ_pg42-45_EMJ_pg42-45 5/6/14 12:46 PM Page 43