Nos. 94-1583, 94-1848. Argued November 10, 1994. Decided February 8, 1995. Louis E. Sigman, Dale D. Pierson (argued), Pasquale A. Fioretto, Brian C. Hlavin, Baum, Sigman, Auerbach, Pierson Neuman, Chicago, IL, for International Union of Operating Engineers, Local 150, AFL-CIO. Elizabeth Kinney, Librado Arreola, N.L.R.B., Chicago, IL, Aileen A. Armstrong, Linda J. Dreeben, Deborah E. Shrager (argued), N.L.R.B., Appellate Court, Enforcement Litigation, Ellen A. Farrell, Corinna L. Metcalf, Injunction