Gwelo_station_20_705. Steam in Southern Africa: Rhodesia 1973. in October 1973 it was common practice for Gwelo to Bulawayo trains to start in the evening and run through the night. The largest and most powerful steam locomotives operated by Rhodesia Railways were the 4-8-2+2-8-4 Beyer Garratts of Class 20. Here 20 705 (BP 7690/1954), waits in the evening sunshine of 27th October 1973, for the signal to depart on its journey to Bulawayo. roger.griffiths@hotmail.com