This locomotive is in fact a SP45 with a modified heating system – a steam boiler was replaced by an electric heating system. During 2010 4 locomotives were rebuilt to class ST45.
Currently, there are three SU45 locomotives in operation. Vehicles number 143 and 194 operate freight depots, and vehicle number 079 was repaired in 2022 and returned to service. It is stationed in Wrocław and runs tourist passenger trains. Currently, it is planned to restore vehicle number 228 purchased by the Association of Railway Enthusiasts in Chojnice from PKP Cargo to traffic. The vehicle is to be renovated and used to operate tourist passenger trains.