By David Shepardson WASHINGTON (Reuters) – The Brotherhood of Railroad Signalmen (BRS) union, representing more than 6,000 members, said on Wednesday that workers voted against ratifying a national tentative agreement reached in mid-September, the second union not to approve the deal. Previously six of 12 unions voted to approve the deal. The National Carriers’ Conference Committee (NCCC), which representing freight railroads in labor talks, said Wednesday it was disappointed in the BRS vote, but both sides have agreed to maintain the status quo until early December. The Brotherhood of Mainten…