From an article by Lynn Doan and Barbara Powell published on 1 Feb 2015 by Bloomberg under the headline:
“Oil Workers in U.S. Begin First Large-Scale Strike Since 1980”
Shell activated a “contingency plan”
(Bloomberg) — The United Steelworkers union, which represents employees at more than 200 U.S. oil refineries, terminals, pipelines and chemical plants, began a strike at nine sites on Sunday, the biggest walkout called since 1980.
The USW started the work stoppage after failing to reach agreement on a labor contract that expired Sunday, saying in a statement that it “had no choice.” The union rejected five contract offers made by Royal Dutch Shell Plc on behalf of oil companies since negotiations began on Jan. 21.