The Brünig railway line () is a Swiss narrow gauge railway line that links Lucerne, in central Switzerland, with Interlaken, in the Bernese Oberland. The line runs via Alpnachstad, Giswil, Meiringen and Brienz, and passes over the Brünig Pass, using sections of rack railway to overcome the gradients, but with most of the line operated by normal adhesion methods.
The line is long. It opened in stages between 1888 and 1916, and was, between 1903 and 2004, the only narrow gauge line of the Swiss Federal Railways. Today the line forms part, along with the Luzern–Stans–Engelberg line, of the Zentralbahn company. The line is served by Panorama Express trains that operate the full length of the line, with regular (non-rack) Regio trains between Interlaken and Meiringen, and Lucerne S-Bahn trains between Lucerne and Giswil. The section between Hergiswil and Lucerne is shared with the Luzern–Stans–Engelberg line.
History
thumb|right|An early train on the climb from Meiringen to the Brünig pass
thumb|right|A train near Meiringen, under Swiss Federal Railways ownership.
The line was constructed by the Jura–Bern–Lucerne Railway (JBL), which opened the section between Brienz over the Brünig Pass to Alpnachstad in 1888. Initially, the line connected to steamships on Lake Brienz and Lake Lucerne, but was extended in 1889 from Alpnachstad to Lucerne, giving connections to the rest of the Swiss railway network. In 1891, JBL became part of the Jura–Simplon Railway (JS).
In 1903, the JS became part of the Swiss Federal Railways (SBB). Only in 1916 did the last section of the current line, between Brienz and Interlaken, open. This allowed through trains to operate from Lucerne to Interlaken, and provided an easy interchange with trains to Bern and beyond.
The line was electrified in 1941 and 1942, using the standard Swiss main line system of supplied by overhead line. The electrification led to a significant acceleration of services, with typical through journey times reduced from over 3 hours to 2 hours.
In late 2012, a new tunnel route was opened between Kriens Mattenhof station and the approaches to Lucerne station. The tunnel replaces a less direct surface alignment, allowing the abolition of several congested level crossings and the provision of double track. A new station, Lucerne Allmend/Messe, built within the tunnel, serves the Swissporarena.
Operation
Route
thumb|right|Gradient profile of the line
thumb|right|Start of the line; the Brünig line terminal platforms in Lucerne station.
thumb|right|Giswil station is the terminus of the S-Bahn service from Lucerne.
thumb|right|A [[GoldenPass Line liveried train descending the rack section from the Brünig Pass towards Giswil.]]
thumb|right|Brünig-Hasliberg station is the summit of the line, in the Brünig Pass.
thumb|right|A train climbing the rack section from Meiringen to the Brünig Pass.
thumb|right|Regio trains, made up of Stadler SPATZ units, passing at Brienz.
thumb|right|Bridge carrying the line over the Aare into Interlaken Ost.
The line begins at Lucerne station, one of Switzerland's principal railway stations and which is shared with the standard gauge lines of the Swiss Federal Railways. The metre gauge terminal platforms, and the first section of the line, are shared with trains of the Luzern–Stans–Engelberg line. Shortly after leaving the station, the line enters a tunnel under Lucerne's southern suburbs as far as Kriens Mattenhof station. From here the line runs on the surface to Hergiswil, where the Luzern–Stans–Engelberg line diverges. Similarly, the historic turntable in Giswil was moved to another location in the course of the renewal of the station in 2013.
Services
The line is served by hourly InterRegio trains that operate the full length of the line, taking just under two hours for the journey. These through trains stop at all stations between Meiringen and Giswil, where they provide the only service, but only at a selected stations between Interlaken and Meiringen, and between Lucerne and Giswil.
The through trains are supplemented by local trains at each end of the route. An hourly Regio train operates between Interlaken and Meiringen, stopping at all stations. Between Lucerne and Giswil, twice-hourly trains of the Lucerne S-Bahn line S5 provide a stopping service. The section of line between Hergiswil and Lucerne is shared with trains on the Luzern–Stans–Engelberg line, including a further InterRegio train per hour, and the twice-hourly Lucerne S-Bahn line S4.