in 1846 the Dundee and Perth Railway agreed to lease the line, probably in order to keep the Scottish Midland Junction Railway out. This was authorised by the Dundee and Perth Railway (Amendment) Act of 27 July 1846: the line was leased to the Dundee and Perth for 999 years for £1,400 per annum. Under the Dundee and Perth The lease was effective from October 1846. The D&PR took some time to assess its new property, but in 1847 it obtained the Dundee and Newtyle Railway (Widening, Altering and Improving) Act on 2 July 1847. This permitted the opening out of the Law Tunnel and the construction of a deviation by-passing Balbeuchly incline. These works were not in fact carried out at this stage, although in 1849 work was undertaken to convert the gauge to standard gauge. The line closed during October 1849 for the work to be carried out. The opportunity was taken to ease the worst sharp curves. The locomotives Earl of Airlie, Lord Wharnclife and Trotter were converted, but John Bull was sold to contractors. The Scottish Midland Junction Railway The Scottish Midland Junction Railway was authorised in 1845 to construct a main line railway from Perth to Forfar, joining Arbroath and Forfar Railway giving ultimate access to Aberdeen. Its intended route through Strathmore meant that the unremunerative Newtyle and Coupar Angus Railway and the Newtyle and Glammiss Railway routes lay directly along a suitable alignment. The SMHR acquired those two small railways, and closed them for upgrading to main line standards, and providing double track. The Eassie to Glamis section closed in July 1846, with the remainder of that line closing in October 1847; the Coupar Angus line closed in November 1847. The SMJR opened from Perth to Forfar on 2 August 1848; a short connecting line was provided at Meigle to join the two routes. By-passing the inclines Returning to the Dundee and Newtyle line, an Act was obtained on 21 July 1859 to build by-pass lines. The Balbeuchly incline was avoided by the construction of a line from Rosemill to Auchterhouse; it had a new station at Dronley and Auchterhouse station was relocated. It opened on 1 November 1860. The Lochee deviation ran from Ninewells Junction to Fairmuir Junction, opening on 10 June 1861. This long westward sweep avoided the Law tunnel and incline, and gave better access to the harbour through the Dundee