---
title: "Innovation Story #2: The Brenner Base Tunnel"
url: "https://www.systra.com/en/innovation-stories/innovation-story-2-the-brenner-base-tunnel/"
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date_published: 2026-01-20
date_modified: 2026-06-11
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language: en-US
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reading_time: 7 min
canonical: "https://www.systra.com/en/innovation-stories/innovation-story-2-the-brenner-base-tunnel/"
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---

# Innovation Story #2: The Brenner Base Tunnel

![Innovation Story #2: The Brenner Base Tunnel](https://www.systra.com/wp-content/uploads/2026/01/innovation_stories1-header2.png)

## a benchmark in terms of safety and sustainability

When it opens in 2032, the Brenner Base Tunnel (BBT), which will link Austria
and Italy, is set to become **the backbone of southern Europe’s rail network**.
Stretching 64 kilometres under the Alps between Innsbruck (Austria) and Fortezza
(Italy), this historic infrastructure project aims to improve passenger and
freight transport while advancing the sustainable mobility objectives of the
Trans-European Transport Network (TEN-T). The latter is a high-speed,
high-capacity network that will transport people and goods across the European
continent.
**SYSTRA has played a leading role in this particularly innovative project for two decades**
. Spotlight on this extraordinary project.

![](https://www.systra.com/wp-content/uploads/2026/01/tunnel-en-1024x666.jpg)

\*MEP (mechanical, electrical and plumbing)

## 2

single-track tunnels

## 55

kilometres of base tunnel

## 64

kilometres including Innsbruck Bypass

## 2025

completion of big infrastructure works

## 2028

expected commissioning

## What is a ‘base’ tunnel?

Base tunnels are constructed at the foot of mountains, allowing the rail line to
remain as direct as possible. This approach minimises gradients and effectively
removes the barrier posed by the mountain, enabling trains to travel as if they
were on flat land.

Nevertheless, tunnelling through the mountain from its base results in a much
longer tunnel compared to building one closer to the summit, where the mountain
is narrower. Reaching higher elevations requires steep ascents, which not only
elevate energy usage but also increase journey duration.

## Key features

### goods trains

320

per day

160

km per hour speed

### Passenger trains

80

per day

250

km per hour speed

- **Passenger and freight** rail tunnel
- Contractor and Client (Lot Mules 2-3): Brennero Tunnel Construction
- Length: **55km **of base tunnel; 64km (incl.Innsbruck Bypass)
- Two single-track tunnels
- ERTMS Level 2 signalling and GSM-R Ridership:
- Completion of mechanised excavation (three TBMs) in May **2025 **(Lot Mules
  2-3)
- **Commissioning of the tunnel expected in 2028**  (Lot Mules 2-3)

## SYSTRA present for two decades

**SYSTRA has been contributing to the BBT project since 2005**, starting with
the preliminary design. Since 2016, the SYSTRA Italy teams have worked on Lot
Mules 2-3 providing a wide range of engineering services demanding a high level
of technical and professional skills including detailed design of civil works,
TBM selection, General Contractor assistance during the tender phase and during
construction, BIM modelling, MEP (mechanical, electrical and plumbing) design
and implementation of value engineering optimisation measures.

In 2024, BBT SE, the contracting authority, awarded **a three-year contract** to
the consortium led by Italferr, with SYSTRA and two Austrian design offices (ILF
Consulting Engineers and EUT Engineering) as co-contractors, for engineering
services and rail equipment for the Brenner Base Tunnel. The consortium is
responsible for the final design of equipment and railway systems for the
tunnel.

Together, we are supporting BBT SE at every stage of the project, with the added
challenge of the **tunnel’s** **cross-border dimension**. Each system of railway
equipment will have to comply with the technical regulations in force in Austria
and Italy and guarantee full interoperability with European standards.

![erica-calatozzo-carre](https://www.systra.com/wp-content/uploads/2026/01/erica-calatozzo-carre-980x1024.jpg)

> “Being part of the joint venture responsible for the detailed design of
> railway equipment in the Brenner Base Tunnel means contributing to one of
> Europe’s most ambitious infrastructure projects. Our combined expertise in
> underground structures and transport systems, driven by ongoing innovation, is
> helping to set new standards for safety and sustainability in European
> mobility.”
> **Erica Calatozzo**, Chief Executive Officer, SYSTRA Italy

## Innovation at the heart of the project

![bbt](https://www.systra.com/wp-content/uploads/2026/01/bbt.jpg)

The Brenner Base Tunnel serves as a prime illustration of modern advances in
infrastructure planning and construction, prioritising **durability**,
**safety**, and **operational performance**.
**Designed with a projected service life of 200 years, the tunnel sets a new standard for sustainability, exceeding what is typically expected from similar large-scale projects**
. The adoption of pioneering methods—such as innovative construction materials,
automated transport technologies, and continuous real-time monitoring—represents
a substantial improvement over conventional construction approaches.

Notable features like **prefabricated segmental linings **and an
**advanced monitoring system** not only increase the tunnel’s resilience but
also provide accurate, ongoing oversight of its structural health.

In addition, innovations such as
**the integrated drainage pipe cleaning system** and
**the carefully considered layout of the exploratory tunnel **simplify routine
maintenance activities, allowing these to be performed without interrupting rail
movements; this ensures optimal long-term operation.

The extensive use of **Building Information Modelling (BIM)** across all project
stages provides a robust management framework and maximises operational
transparency, giving all parties direct access to critical information from
initial planning through to maintenance. Altogether, this comprehensive strategy
highlights the crucial role of well-conceived infrastructure in driving economic
growth and improving international links.

Detailed analyses allowed the selection of the most suitable TBM machines,
considering the severe Alpine conditions.

![Bild-3_Baulos-Tulfes-Pfons_Verbindungstunnel_©BBT-SE](https://www.systra.com/wp-content/uploads/2026/01/bild-3_baulos-tulfes-pfons_verbindungstunnel_bbt-se-1024x682.jpg)

![](https://www.systra.com/wp-content/uploads/2026/01/mfw012-tun-18-1024x731.jpg)

**Advanced numerical analyses **(2D and 3D models) led to improvements in both
design and construction allowing us to consider the big challenges that a long
and deep tunnel like BBT poses. Specifically, The Trens Emergency Stop (one of
three emergency stops foreseen for safety reasons and the only one located on
the Italian side) posed a challenge due
**to the very complex lay-out of several interconnected tunnels**.

**The integration of innovative solutions is being made at every stage of the project:**

- **Enhanced safety:** new evacuation standards, emergency air overpressure
  systems, advanced monitoring, and cross-border interoperability,
- **Inter-European engineering: **cross-border adaptation and full
  interoperability with all European control and signalling systems,
- **Collaborative process:** an international engineering joint venture that
  brings together French, Italian, and Austrian expertise for a robust yet
  flexible design.

## Focus on Innovative Solutions

![](https://www.systra.com/wp-content/uploads/2026/01/zoom-3-1024x752.jpg)

### Tunnel

To address the challenge of selecting tunnel boring machines (TBMs) suitable for
extremely variable Alpine rock conditions, SYSTRA developed the
**Digital Project Hard Rock Tool**. This digital solution utilises Monte Carlo
algorithms\* for advanced statistical risk evaluation, ensuring the most
reliable tunnelling methods are chosen.

\*A Monte Carlo algorithm is a method that uses randomness to solve problems
that might be too complicated to handle directly in a deterministic way.

### Innovative materials research

A major challenge was the development of collapsible backfilling\*.
**Expanded clay** was identified as the most promising solution, even though its
mechanical characteristics were insufficiently explored at the time. SYSTRA led
a research project to develop, validate, and implement this innovative approach
tailored for the tunnel’s demanding environment.

\*Collapsible backfilling is a tunnel construction practice involving highly
flowable, easily compacted material used to fill voids behind linings or
supports, ensuring safety in the lining under high rock pressure together no
future settlement and structural stability.

![](https://www.systra.com/wp-content/uploads/2026/01/zoom-4-1024x752.jpg)

![](https://www.systra.com/wp-content/uploads/2026/01/zoom-1-1-1024x752.jpg)

### MEP and safety systems

The tunnel’s electrical, ventilation, fire detection, and access control systems
combine the latest technologies, are **modelled in BIM**, and designed to meet
Austrian, Italian, and European requirements for interoperability, safety, and
resilience.

## A BENCHMARK FOR FUTURE INFRASTRUCTURE

The Brenner Base Tunnel is considered one of the most important infrastructure
projects of the century. Advances are incorporated into every stage of the
project, from planning to operation, enabling the project team to meet
constantly evolving modern requirements even during the construction process.
The focus is on cutting-edge technologies that improve the tunnel’s efficiency,
safety, sustainability and maintainability. As a result, the Brenner Base Tunnel
is not only an iconic engineering feat, but also a benchmark for future
infrastructure developments, demonstrating a commitment to long-term
sustainability.

## See Also other Innovation stories

### Innovation Story #1: the T10 tramway in Lyon

Backed by SYSTRA’s expertise, the new T10 tramway links Vénissieux, Saint-Fons
and Lyon, providing a sustainable and inclusive transport solution for the Lyon
metropolitan area. Find out how this emblematic project illustrates SYSTRA’s
commitment to efficient, environmentally-friendly urban mobility.

![header_t10_inno_sories](https://www.systra.com/wp-content/uploads/2025/03/header_t10_inno_sories-1024x645.png)

_Innovation Story #1: the T10 tramway in Lyon Read more sur Innovation Story #1: the T10 tramway in Lyon_