The decision to lay down their tools for four to seven hours per day from Wednesday to Friday came after the labor union's 21st round of wage talks with the company ended without an agreement earlier in the day.
The negotiations began in May, but the two sides have yet to find common ground.
The union has been demanding that Hyundai Heavy raise the basic monthly wage by 123,000 won (US$103), among other proposals.
Observers say the standoff is likely to continue for a while as the shipyard struggles to win more orders.
In the first eight months of the year, Hyundai Heavy secured orders for 17 vessels worth a total of $2.17 billion, or only 27.1 percent of its annual target of $8 billion, industry data showed. (Yonhap)