Retrofit and refurbishment

We analyse your ventilation system and provides a new ventilation design for safe and economic operation considering the current guidelines and requirements. For the refurbishment or optimisation of an existing ventilation system, HBI provides knowledge of specialists in various disciplines such as tunnel construction, control system, simulation, fire protection, mechanical equipment etc. We provide the adequate approach meeting the requirements of your tunnel project.

Retrofit and refurbishment of ventilation systems

Reference list

HBI Haerter Consulting Engineers conduct detailed analysis of aerodynamic coefficients of a tunnel, the ventilation system and the sensing elements. This is the foundation of the control and monitoring concept. The control usually includes following conditions:
Normal operation, for example unidirectional traffic, special case, for example oncoming traffic, event of fire and evacuation, event of fire and firefighting.

Ventilation control


Brussels Airport - Diabolo Project

Ventilation of station and tunnels

Engelberg railway tunnel

Smoke extraction and smoke control


Metro Panama Line 1

Tunnel ventilation

Pump storage station Linth-Limmern

Site ventilation



Tunnel ventilation

Cross City Tunnel Sydney

Tunnel ventilation

Tunnel Branisko

Tunnel ventilation

Tunnel Richard-Strauss Munich

Tunnel ventilation


Flüelen tunnel

Tunnel ventilation


Balmenrain and Uznaberg tunnels

Tunnel ventilation

Tunnel Wimpasing, bypass Ampfing

Detailed design, functional tests and fire tests


Bypass Meran

Tunnel ventilation


New construction enclosure Schwamendingen

Traffic area ventilation


Kö-Bogen Tunnel, Düsseldorf

Services related to the tunnel ventilation


Tunnel Agnesburg, Aalen-Westhausen

Tunnel ventilation

New or adapted norms and guidelines lead to changing requirements for tunnel constructions. Changes of the usage requirements can lead to new performance requirements. With the check of the functional and safety requirements of existing tunnels by HBI, the safety level is determined and the need for action and the measures to be realized are demonstrated.

Safety check​​​​​​

Lötschberg base tunnel

Ventilation and safety concept

Young Dong railway tunnel

Ventilation and risk control

Tunnel Groene Hart, Dordtsche Kil and Rotterdam Noordrand

Efficiency of the emergency ventilation

Stuttgart city railway: U12 Hallschlag-Münster

Safety and ventilation concept

Augsburg mobility hub

Safety and ventilation concept

Tunnel Rheinufer Düsseldorf

Smoke extraction and keeping smoke-free


City Tunnel Freiburg

Technical safety risk analysis


Tunnel Böhämmer

Safety analysis


Kiesberg tunnel Wuppertal

Tunnel ventilation retrofit


Arlberg Street Tunnel

Expert opinion on tunnel safety


Gallery of Dormagen-Horrem

Risk-based safety evaluation

HBI has the high level of competence and broad experience required to serve as an independent inspection entity. The service that includes assessment of the safety and scrutiny of the safety documentation is targeted to assist in particular the administrative authority. The EU-Directive 2004/54/EC dated 29 April 2004 on minimum safety requirements for tunnels in the trans-European road network prescribes that a safety documentation has to exits. Moreover, the organization shall persist of various entities with clearly defined roles and responsibilities: administrative authority, tunnel manager, inspections entity and safety officer.

Investigating body 2004/54/EC