The T 7 was developed in order to have a small tank locomotive for heavy shunting services and for use in front of freight trains on short branch lines, which is slightly more powerful than the T 3. From 1881, over 400 engines were built over a period of 22 years, of which more than every tenth was delivered to a private railway and the rest to the Prussian State Railways.
“Ruhr variant”, built by Hanomag
Die Lokomotive, September 1921
In principle, these had the same design as the T 3, i.e. three coupled axles, no carrying axles, a simple construction in general and a two-cylinder saturated engine with external Allan controls. Overall, however, the T 7 was larger, with a service weight increased by more than ten tonnes, larger cylinders and a larger wheel diameter. The supplies have also been expanded in line with the higher output.
The former TKh2-12 of the PKP is now in the original KPEV livery as “Breslau 1836” in the museum in Jaworzyna Slaska
The procurements of the state railways were completed in 1893, when 371 locomotives had been delivered. The number of examples that went to various private railways by 1903 was between 37 and 65, depending on the source. The private operators included small, industrial and port railways.
Of the 137 locomotives included in the 1923 renumbering plan, 68 were actually taken over, which were given the numbers 89 7801 to 89 7869 by the Reichsbahn. Almost all of these engines were retired or resold in the 1930s. The last example used was the SEG 372 used by the Süddeutsche Eisenbahn-Gesellschaft between Arnstadt and Ichtershausen in Thuringia, which had been taken over by the Reichsbahn of the GDR in 1949. It remained in service as 89 6401 until 1967.