Strikes now in their fourth week impact 12 U.S. refineries and have closed in on-fifth of the production. 6,550 members of the United Steelworkers union are on strike. No date for starting negotiations has been announced. The strike began on Feb 1 when wage talks between steelworkers and Shell Oil Company brokedown. The strike has spread to the largest U. S. refinery at Port Arthur, TX.