Inventory Reference 9/2/282/0002 Formal Gradings Grading Grade II GradingComment archiveimport Grading by: South African Heritage Resources Agency Statement of Significance The tunnel was part of the N.Z.A.S.M. railway line built in 1891-1895 between Pretoria and Lourenco Marques. In view of the steep gradient it was fitted with a rack railway.