After a new contract is rejected, labor leaders work on a walkout strategy, the biggest union at the shipyard declares its support and a federal mediator is helping both sides negotiate.

But members of the Bath Marine Draftsmen’s Association Local 3999 have agreed to work until the end of the week while negotiations continue.

Four incidents in the past year, including two that killed at least 17 seamen, suggest a problem with training that could extend beyond the Pacific Fleet, say several analysts and former naval officers.