Greek shipowners order construction of iron-ore carriers in the belief that the 5-year charter-rate slump is coming to an end. The companies ordered 12 Capesizes last quarter, the most since the beginning of 2008, according to data from Golden Destiny SA, a shipbroker in Piraeus, Greece, cited by 'Ekathimerini'. Ship prices plunged to the lowest in almost a decade in 2012 and charter rates tumbled 99 percent since 2008. Construction costs are now so low that owners will probably order $250 billion of new vessels by 2016…