As a hydro-mechanical engineer, B. T. A. Sagar (1929-2017) specialized in gates and valves for irrigation and hydropower projects around the world. The collection includes representative projects from across Dr. Sagar's career and a variety of countries in which he worked. The bulk of the collection is documentation for engineering projects where Dr. Sagar either designed, advised, or reviewed the gates and/or valves involved, along with his papers, publications, and presentations.