How do i contact international union of operating engineers local 99? International Union of Operating Engineers, Local 99 9315 Largo Drive West, Suite 200 Upper Marlboro, MD 20774 Phone: (202) 337-0099 Fax: (240) 716-3956How many members does the international union of operating engineers have? Our more than 3,000 members are part of the International Union of Operating Engineers, comprising a workforce of 400,000 throughout the United States and Canada. My name is Garry Gyenizs and as of November 2020, I am the new Business Manager for Local 478.What is the international union of operating engineers local 478? Welcome to the International Union of Operating Engineers Local 478 website. Local 478 covers all of Connecticut.How do i contact the iuoe? Contact IUOE. Please direct all official correspondence in letter form and addressed to: General President James T. Callahan, International Union of Operating Engineers, 1125 17th St., NW, Washington, DC 20036. Questions about work issues, dues, pensions, complaints, grievances and the like must be directed to the member's local union.