The article is devoted to the scientific and pedagogical activities of B.M. Troyanovskii, Doct. Tech. Sci., Professor of the MPEI Chair of Steam and Gas Turbines named after A.V Shcheglyaev, on the occasion of his 100th anniversary. The article outlines the main results of scientific investigations that determined the development lines of large-capacity steam turbines for thermal and nuclear power plants in Russia and abroad, and the principles of designing the last stages of low-pressure cylinders for large-capacity steam turbines.