PKP Class ST40 is a new class of cargo diesel-electric locomotives used by the PKP LHS broad-gauge division and various Polish private operators, designated 311D or 311Da by its manufacturer, Newag. The class is a heavily reconstructed Soviet M62, using only the underframe. The body is new, the main engine is a General Electric GE 7FDL12. Original engines were also modernised, as ED118 A GE. The class is much more economical and modern than a basic M62. The body has external walkways instead of an internal passage connecting the cabs. The first locomotive was modernised in 2007. As of April 2025, there were 48 class 311D completed, of which 27 are broad gauge 311Da units for PKP LHS, where they are designated ST40s.