Workers at the world’s largest bulk iron ore export operation are downing tools this weekend after negotiations over wages and conditions became gridlocked. High voltage and power workers, who are negotiating a separate agreement with BHP, will down tools for 12 hours on August 9. About eight ships are expected to finish loading from BHP ports over the weekend, a source familiar with the matter said. Western Mine Workers Alliance spokesperson Craig Beveridge said unions had given BHP ample opportunity to respond to workers’ concerns. ‘’Instead of engaging in the bargaining process, BHP continue to delay, distract and waste time,” Mr Beveridge said.