BY MAREX 2018-05-01 21:18:00
Capt. Nick Sloane, the salvage master who worked with the late Capt. Rich Habib to refloat the Costa Concordia, has proposed an audacious solution to Cape Town's severe water shortage: icebergs.
In an interview with Reuters, Sloane said that he is seeking investors for a plan to tow Antarctic icebergs into the Benguela Current, which flows north along the west coast of Africa. According to Sloane, a suitable iceberg could be located within about 1,000 nm of Cape Town, nudged into the right ocean current and slowly floated to a position just offshore. With processing, he suggests, the berg could be melted for drinking water at a rate of up to 150 million liters per day. Assuming a 100-million-ton iceberg, this would satisfy up to a third of the parched city's needs for a year.
The cost - about $130 million - would be more affordable than some of the other water supply alternatives under consideration, Sloane suggests. "I think to tow the iceberg here would be half the cost of desalination . . . ice is pure water and therefore potable," he told Cape Talk in an interview in January.
Sloane's team for the proposal includes glaciologist Dr. Olav Orheim, the former director of the Norwegian Polar Institute. In an interview with local media, Orheim said that the ideal berg would have steep sides, a flat top and a draft of at least 500 feet. Two tugs would pull a giant length of geotextile around the berg to protect it during its journey, then make up a tow to a tanker, which would provide the horsepower needed to move it. Upon arrival about 20 nm off Cape Town, the iceberg would go aground, and the tugs would anchor it in place with the same equipment used for anchoring a MODU. Harvested water would be transferred to shore.
While the idea may seem novel, Cape Town is in need of unusual solutions. A prolonged drought has deeply cut into the city's water supply, and its four million residents face an ever-decreasing daily usage limit. At present, each individual has a quota of 13 gallons per day, less than the average American uses when taking a shower. Car washing is prohibited; toilet flushing is discouraged; restaurants ask customers to use hand sanitizer instead of washing up; and the city's government has warned of an impending "Day Zero," when taps will be shut off and citizens will have to line up at guarded water supply points. Thanks to conservation measures, the date for "Day Zero" has been pushed back until next year, but Sloane and others believe that the risk remains real.