The comapny Dolata was established in 1998, but it wasn't until 2018 that they expanded to the railway. They started in Dąbrowa (near Poznań) as a gravel/aggregates mine and sorting facility. Now they also do transports and produce concrete. The name comes from the company owner - Agnieszka Dolata.
The expansion to the rails happened (afaik) in 2018 and BR232-789 was the first class 232 locomotive to receive Dolata's black and silver livery. The company currently has a railway operations base in Szamotuły (also near Poznań), where they repair their sizeable fleet, now consisting of a couple of 232 and TEM2 locomotives (additionally - they own an ex-PKP ST44 locomotive, but there are no plans of bringing it back to life).
On a foggy November morning, while visiting my family in Rokietnica, I made my way to the local railway station and snapped this picture of Dolata's first 232 at the aggregate siding near the station. Since then, the station has had a substantial overhaul and the siding has ceased existing.
Photo by Piotrek/Toprus