Everyone knows about the Gotthard, but few have heard of the Hauenstein. Yet without it, the NRLA would not exist. In fact the Hauenstein rail line between Olten and Basel, with its 2,500-metre tunnel opened in 1858, is arguably the most important link in Swiss rail history. One of the earliest mountain railways ever built, it connects the Swiss plateau to the European rail network and is an early pointer towards the Gotthard. Thanks to the Hauenstein line, Basel's Central Railway has at least as much say over the Alpine tunnels as Zurich's North-Eastern Railway. With the opening of the Gotthard rail line in 1882, the Hauenstein becomes part of the interregional transit axis. It is here that the SBB build the first base tunnel - roughly a century before the flat lines through the Alps. Opened in 1916, it is around 8 kilometres in length.
« While the reduced distance between the tracks would still be sufficient to allow rolling stock to cross inside the tunnel, it would nevertheless seem advisable to avoid any crossing of trains in view of the fact that imprudent passengers might come to harm by leaning or stretching their arms out of the carriage. »
Swiss Railways & Commerce Department, Letter dated 12 November 1875