Ludwigshafen to Bexbach, the railway engineer Paul Camille von Denis considered the plans and concluded that a line from Homburg to Zweibrücken would be profitable. Construction work began the line to Zweibrücken via Schwarzenacker on 1 June 1856 and the line was opened on 7 May 1857. The Ludwig Railway was extended during 1866 and 1867 from Schwarzenacker to St. Ingbert via Bierbach. Landau–Zweibrücken section Early efforts were made to promote the building of a line from Zweibrücken to Landau; there was support for this especially in the towns in the Queich valley. The Palatinate Railway (Pfalzbahn) at first rejected this proposal because it opposed competition with the Palatine Ludwig Railway and it considered the construction of the section through the Palatinate Forest would be very costly. However, the Queich valley communities did not give up and continued to campaign for the construction of such a link. It would especially benefit Annweiler, which had growing industries, but the towns and villages between Landau and Annweiler would also benefit from a rail link. Against this background, the planning committee initially considered, as an alternative solution, the establishment of a branch line from Landau to Annweiler. Then, however, the committee acceded to pressure from the city of Landau and also strongly supported the construction of a line from Landau to Zweibrücken. This time its efforts were successful: the committee was authorised to prepare a suitable design, but it had to finance this work itself. The necessary concession was issued on 1 April 1865. There were disagreements over the route between Pirmasens and Zweibrucken, which were eventually reflected in two different designs. The first draft favoured a new line directly via Hengsberg, while the second option was an alignment through Walshausen and along the Trualbe through Hornbach and Ixheim. More detailed studies, however, led to the conclusion that it would be difficult to build a direct southern Palatinate line via Pirmasens on either route due to the difficult topography. Therefore, a new approach was developed, with the line running a few kilometres north of the city. It would, coming from the east, initially run through the valley of the Rodalb and then follow the Schwarzbach. This route had the advantage of only having a slight slope to overcome and only requiring one tunnel, the Neuhof Tunnel near Rodalben. First, the Landau–Annweiler section was built, partly over sections of the Albersweiler Canal, which had