International Union of Operating Engineers | 12,984 followers on LinkedIn. International Union of Operating Engineers represents over 400,000 working people across the United States and Canada | The International Union of Operating Engineers (IUOE) represents over 400,000 working people across the United States and Canada. Members of the IUOE are primarily operating engineers, who work as heavy equipment and crane operators, pipeliners, mechanics, and surveyors in the construction industry, and stationary engineers, who work in operations and maintenance in building and industrial complexes, as well as a number of job classifications in the petrochemical industry.