Novelty 2025: From 1973, Fablok developed a six-axle machine based on the SM42, which was also planned for export to the CMEA area, but this was ultimately not realized. From 1976, the PKP received 167 of these machines and classified them as SM31 003 - 169. For the needs of the industry, 28 machines followed, which were supplemented by the two prototypes not taken over by the PKP. Contrary to expectations, the CoCo machines were not suitable for the needs of the industry, so that many were soon decommissioned or sold to the PKP. Digital switching of cab lighting and running gear lighting by retrofitting a digital decoder | Freestanding mounted railings and ladders | Rotating fan | Fine, perforated fan grilles