The construction was developed by the Union Giesserei company in Königsberg. It was an adaptation of T9³, which consisted in the application of wheel sets of larger diameter, enlargement of the surface area of the grate and a boiler heating surface area and also enlargement of engine cylinders diameter. Serial production of a new type 3/4 P.T.L. dr.kr., later designated as T11 between 1903-1910 was undertaken by the following companies : Union Giesserei, Vulcan, A. Borsig and Hohenzollern. In the interwar period those companies have used 52 locomotives designated as OKi1, 4 others were assigned to the port of the Free City of Danzig. Between 1945-46 the Polish State Railways qualified 52 locomotives to the OKi1 series. The last four locomotives of OKi1 series were deleted from the Polish State Railways inventory in 1966. Among them was a museum copy of OKi1-28 (pre-war designation OKi1-14 PKP, DRG 74 104 II), whose known service record begins in January 1948 in Malbork, and ends with the deletion from the Polish State Railways inventory on 19 December 1966 in Zajączkowo Tczewskie.