The line forms a major part of an important international railway link between northern and southern Europe, especially on the Rotterdam-Basel-Genoa corridor.

The main line, second highest standard railway in Switzerland, penetrates the Alps using the Gotthard Tunnel at 1,151 metres (3,776 ft) above sea level.

The line then descends as far as Bellinzona, at 241 metres (791 ft) above sea level, before climbing again to the pass of Monte Ceneri, on the way to Lugano and Chiasso.

An international conference in Bern in 1869 had decided that the best route would be via the valleys of the rivers Reuss and Ticino, linked by a tunnel under the Gotthard Pass.

At the same time, the Aargauische Südbahn completed the section from Rotkreuz to Immensee,[citation needed] which provided a rail link from Aarau.

The track layout of each station shows that in 1899 the Gotthard railway ran on double-tracks from the villages of Flüelen to Giubiasco.

The next picture on the right shows the Pianotondo viaduct and the Pianotono-spiral tunnel's upper gate with its watchman's house, which came into use during the days of the double-track steam service, roughly at the time of the graphic timetable's validity.

At each underpass on the Ceneri section it is clearly visible to this day that these were built at greatly different points in time.

The train with the number 55 is powered by a steam locomotive and, according to the timetable, does not make a scheduled stop at Giubiasco, Rivera-Bironico and Taverne.

The illustrations shows that between Giubiasco and Rivera Bironico trains do not pass each other as in 1899 this was, as mentioned in the paragraph above, a single track line.

Also visible on the graphic timetable is the fact that between Osogna and Biasca, trains however do pass each other along their journeys, it being a double-track line.

What was tapped out on the third telegraph, reached only the railway stations Bellinzona, Faido, Airolo, Göschenen, Wassen and Erstfeld.

The electric signal triggering the alarm operated a relay, activating the bell's hammer through force of the aforementioned weight.

The railway watchman's house number 159 (Casello 159) signal bell on the Monte Ceneri line between Giubiasco and Rivera-Bironico is shown as an example in the timetable's excerpt.

A southbound train departing Giubiasco for Rivera-Bironico would trigger alarms of eleven different signal bells on its 11 kilometres long journey.

Also putting out small shrub fires, caused by the heavily employed brakes of downhill running cargo trains, were part of his duty.

In the worst such incident in recent times, the Gotthard line was closed to all traffic for almost one month following a rockfall near Gurtnellen on 5 June 2012, which killed one rail worker and injured two others.

Steamers operate a shorter, in distance, but longer, in time, service to the city of Lucerne, serving many other towns and villages along the lake shore.

The Gotthard Panorama Express uses this interchange to provide its tourist oriented boat and rail service between Lucerne and Lugano.

The depot at Erstfeld station houses rolling stock needed for the Gotthard route, i.e. for banking service.

[15] After Gurtnellen, at an altitude of 738 metres (2,421 ft), the first of several tunneled railway spirals is encountered; their purpose is mainly to gain height where no space is available.

[15] The line exits the tunnel at Airolo, at an altitude of 1,142 metres (3,747 ft) in the valley of the river Ticino, which it follows as far as Bellinzona.

The valley narrows to the Piotta canyon, and the line passes two spirals ("Piottino-Loops") to lose 200 metres (660 ft) in height before reaching Faido.

[18] At Cadenazzo on the line to Pino, a further branch crosses the Ticino and runs a short distance down the western shore of Lago Maggiore to a terminus at the Swiss resort town of Locarno.

[18] At Giubiasco, the line from Immensee to Chiasso reaches its lowest point of 230 metres (750 ft) above sea level.

Companies that have taken advantage of this include Deutsche Bahn AG, who operate through freight trains from Germany to Italy.

Famous trainsets on the Gotthard route are the Trans Europ Express and the Roter Pfeil, as well as the tilting train, Cisalpino Pendolino.

[1][23] This redundancy helped relieve some of the new tunnel's traffic after a train accident on 10 August 2023 severely reduced capacity.

Now that they have opened, all rail traffic still needs to use the existing route north of Erstfeld, between Biasca and Bellinzona, and south of Lugano.

[25] Operator Sudostbahn has announced, as of 13 December 2020, it will run a new service from Basel and Zurich via the original Gotthard line, using Stadler Flirt units which are also used on the Voralpen express.