Update for TUNNELLING WORKS – ETZELWERK HYDROPOWER PLANT RENEWAL - Lot 203: Pressure Shaft Renewal

Contract Notice – Open Procedure

Client - Schweizerische Bundesbahnen SBB
Infrastructure – Procurement, Supply Chain and Production Construction Procurement, Bern
Email: hans-juergen.markert@sbb.ch

Project Overview

Swiss Federal Railways (SBB) has launched a major contract as part of the Etzelwerk Hydropower Plant Renewal Project.

The Etzelwerk facility, constructed between 1932 and 1937, utilises the head difference between Lake Sihl and Lake Zurich to generate electricity and currently supplies approximately 10% of Switzerland’s railway power demand.

Following concession renewal in 2023, SBB is undertaking extensive refurbishment and replacement of key components within the pumped storage power plant. A central element of the programme is the replacement of the existing covered pressure pipelines between the surge chamber and the machine hall in Altendorf with a new underground steel-lined pressure shaft.

Scope of Works – Lot 203

This contract covers the excavation and support of the new pressure shaft between:

• The existing surge chamber at Bilsten
• The machine hall at Altendorf

Excavation will commence from a start shaft at the machine hall site in Altendorf, constructed under a separate contract.

Drive Method

The works comprise:

1. Machine-assisted rock excavation (MUF section)

• Length: approx. 85 m
• Gradient: approx. 4%
• Excavation cross-section: 15.26–16.93 m²

2. TBM excavation (subject to sufficient rock quality and cover)

• Length: approx. 2,085 m
• Gradients: approx. 4% to 33%
• Minimum TBM excavation diameter: 3.65 m
• Maximum permissible TBM excavation diameter: 4.2 m

Further details are contained in the tender documentation “B1.1 – Special Provisions”.

Location

Switzerland – Canton Schwyz

• Construction site: Machine Hall, Etzelwerk Power Plant, Altendorf (~410 m above sea level)
• Construction site: Surge Chamber Equipment Cavern (~900 m above sea level)

Participation Requirements

• Participation open to companies from Switzerland, EU, EFTA, or the UK only.
• Award subject to receipt of all required permits and SBB AG budget approval.
• Contract and technical documentation available in German only (translations of general conditions available in DE/FR/IT/partly EN).

SBB General Terms & Conditions and Code of Conduct:
https://company.sbb.ch/de/sbb-als-geschaeftspartner/supply-chain-management/fuer-lieferanten/agb.html

Tender Documentation

Access via SIMAP (restricted access): CLICK HERE

Ad hoc communication platform: Simap.ch

Submission Requirements

• Electronic submission: Not permitted
• Two-envelope system (technical and commercial submissions assessed separately)
• Languages: German, French or Italian
• Variants: Not permitted
• Multiple tenders: Not permitted

Tender deadline:
4 June 2026 – 15:00 (CEST, UTC+02:00)

Tender validity: 365 days

 Contract Conditions

• Electronic invoicing: Required
• Electronic payment: Yes
• Electronic ordering: No

Further contractual and financial details are available in the official publication on simap.ch.

This contract forms a key part of the modernisation of one of Switzerland’s strategically important railway energy assets and represents a significant alpine underground excavation programme combining short MUF works with a 2 km TBM drive under steep gradients. For further information on the tender please visit https://ted.europa.eu/en/notice/-/detail/109071-2026 08/26.