by Stephanie CrosbySome 600 workers at the Jeffboat shipyard in southern Indiana remain on strike. The workers, represented by Teamsters Local 89, walked off the job Friday and voted Sunday to extend their strike.Union President Fred Zuckerman says the one sticking point is health care in the barge maker’s contract proposal. He says costs to employees have gone up too much.The company contends the union workers are being offered the same health care package as non-union workers, but Zuckerman says that isn’t an arguing point.“Actually, we have a better health insurance plan and have had it for quite some time," says Zuckerman. "So actually they have lowered, in their proposal, our health insurance plan to where it’s going to cost us more money for the health insurance for less benefits.”Zuckerman says they’re in agreement with the company on everything else in the contract, and was surprised when American Commercial Lines presented them with a ‘last, best and final offer’ on Thursday.