The International Union of Operating Engineers (IUOE) is a trade union within the United States-based AFL–CIO representing primarily construction workers who work as heavy equipment operators, mechanics, surveyors, and stationary engineers (also called operating engineers or power engineers) who maintain heating and other systems in buildings and industrial complexes, in the United States and Canada. Founded in 1896, it currently represents roughly 400,000 workers in approximately 123 local unions and operates nearly 100 apprenticeship programs.