long. Work was started in the summer of 1845 but progress was slow and hindered by the collapse of some of the arches of the Ardwick viaduct on 11 March 1848. A single line was opened throughout on 20 November 1848 for goods traffic only, and the line soon formed an important link from the Potteries and the south-west to Hull and the West Riding. Regular passenger trains began at the end of 1852; connections were arranged at Miles Platting and Ardwick for journeys from Rochdale and beyond to London. On 19 April 1865 the order was given for the branch to be doubled, and this second line was ready on 7 August. Formation of Lancashire and Yorkshire Railway The Ashton, Stalybridge and Liverpool Junction Railway had always been closely aligned to the Manchester and Leeds Railway, and in 1846 amalgamation was decided upon, also to include the authorised but unbuilt Wakefield, Pontefract and Goole Railway. The M&LR was vigorously extending its area of influence, and its original name was inappropriate, so as part of the amalgamation, a change of name was made: the combined company was to be the Lancashire and Yorkshire Railway. The amalgamation and the change of name were confirmed by Act of 9 July 1847. Stalybridge to Huddersfield The roundabout route of the Leeds and Manchester Railway, via Normanton, encouraged the development of shorter routes, and an independent Leeds, Dewsbury & Manchester Railway was incorporated by an Act of 30 June 1845 to build a line from Leeds to Cooper Bridge, near Mirfield on the Manchester and Leeds Railway. The next month, on 21 July 1845, the Huddersfield and Manchester Railway and Canal Company was authorised. This was a reorganisation of an existing canal of 1811. The new railway would run from near Cooper Bridge via Huddersfield to the Stalybridge station of the Sheffield, Ashton-under-Lyne and Manchester Railway. In 1847 the SA&MR too reorganised, and was renamed the Manchester, Sheffield and Lincolnshire Railway. Together the two new lines would form a new, shorter, route from Leeds to Manchester, reaching Manchester over the SA&MR line. 1845 was a peak year for railway authorisations: the Manchester and Birmingham Railway was authorised to build a branch from Heaton Norris, on its line just north of Stockport, to Guide Bridge on the Sheffield, Ashton-under-Lyne & Manchester Railway. By Act of 6 July 1846 the Manchester and Birmingham Railway amalgamated with