BOB Zweilütschinen–Lütschental: Railway Straightening and Section and Construction of New Buechiwald Tunnel (BE)

Client
Berner Oberland-Bahnen AG
Consultant
IUB Engineering Ltd. in consortium
Period
2014-2016
Construction costs
CHF 38 million
Scope of services

General planning for phases 31 to 53 for construction engineering, railway technology and surveying.

Description

The one track narrow-gauge railway between Zweilütschinen and Grindelwald is electrified. The core part of the track straightening is the one track Buechiwald Tunnel which bypasses a section of the line exposed to natural hazards in the form of a leaning tunnel. The tunnel was mined out of moraine and heavily fissured rock under the protection of a piperoof. The bridge has a double shell. Special conditions existed because of the water catchment near the east portal which defined the approval process as well as the constructional engineering and operational boundary conditions. The limited space at both portals and the only access to the construction site being via the tracks meant that special attention had to be paid to railway operation during implementation.

Main Data
  • Straightened section: 1.4 km
  • Length of tunnel: 708 m
  • Of which cut-and-cover: 45 m
  • Excavation profile: max. 70 m2