On 7 November 1889, after an agreement was reached between the governments of Natal and the Orange Free State, construction began on the line from Ladysmith to Harrismith. The line reached Van Reenen's Pass in 1891, and on 13 July 1892, service from Ladysmith to Harrismith was formally opened by the Governor of Natal and the State President of the Orange Free State. Although it stretched into the Orange River Colony, the entire length of the line () was the property of the NGR. The Free State portion was largely flat (between Van Reenen and Harrismith the line drops ), but in Natal the line climbed over the course of . Three zig zags were made to overcome the harsh terrain of the Drakensberg. Harrismith remained the terminus of the railway until after the Second Boer War. Between 1903 and 1906, the link between Harrismith and Kroonstad was opened in several stages.
