Eppenberg Tunnel

Eppenberg Tunnel
Construction site at Wöschnau portal, August 20
Overview
Official nameGerman: Eppenbergtunnel
LineAarau–Olten line
LocationSolothurn, Switzerland
Coordinates47°22′13″N 8°00′40″E / 47.3704°N 8.0112°E / 47.3704; 8.0112
SystemSwiss Federal Railways (SBB CFF FFS)
StartWöschnau, canton of Solothurn, Switzerland
EndSchönenwerd, canton of Solothurn, Switzerland
Operation
Work begun2 May 2015
Opened12 October 2020
OwnerSBB CFF FFS
OperatorSBB CFF FFS
TrafficRailway
CharacterPassenger, Freight
Technical
Length3.114 km (1.935 mi)
No. of tracksOne double track tube
Track gauge1,435 mm (4 ft 8+12 in) standard gauge
Electrified15 kV 16.7 Hz
Operating speed160 km/h (99 mph)

The Eppenberg Tunnel is a railway tunnel in the Canton of Solothurn, Switzerland. It is part of the 'Future Development of Railway Infrastructure' plan (German: Zukünftige Entwicklung der Bahninfrastruktur or 'ZEB') and increases capacity on the Aarau–Olten line in the Schönenwerd–Däniken section.

A particularly constraining bottleneck in the Swiss rail infrastructure is in the section between Aarau and Olten, which has only two tracks at Eppenberg-Wöschnau, Schönenwerd and Gretzenbach. The route has to be shared by international and national passenger trains as well as freight. Hence quadrupling the complete line between Aarau and Olten had high priority among infrastructure projects.

The main purpose of the tunnel is to increase capacity. The two additional tracks in parallel with the existing double track line effectively create a four track line.

The Federal Assembly adopted the law authoring the 'ZEB' programme in the spring session of 2009, authorising the budget for the Eppenberg tunnel. Due to the large financial requirements for the New Railway Link through the Alps project, construction of the Eppenberg tunnel only began in 2015.