Construction of Queensland railways
Queensland's railway construction commenced in 1864, with the turning of the first sod of the Main Line by Lady Diamantina Bowen, the wife of Queensland's first governor Sir George Bowen at Ipswich, Queensland, Australia. A narrow gauge of 3 ft 6 in (1,067 mm) was selected due to cost savings in providing a rail link to Toowoomba.
Source: Wikipedia — Construction of Queensland railways (CC BY-SA 4.0)