Dundee Tunnel Research


SBB 2000 is a new railway in Switzerland enabling trains to travel at 200 km/h. It opened in December 2004.

The commissioning trials included aerodynamic assessments of trains running overland and through tunnels. One purpose was to assess pressure comfort on board trains passing through tunnels designed to allow the use of unsealed trains.

The tunnels have airshafts to provide pressure relief. SBB decided to assess the effectiveness of the shafts by measuring pressures on board trains during some of the commissioning trials. Only a few measurements were needed for this purpose - i.e. a single pressure sensor inside a train.

The University of Dundee proposed that additional measurements should be taken to enable the tests to advance understanding of the influence of airshafts on tunnel pressures. It was already known that numerical predictions of such influences are not 100% accurate. SBB agreed to allow additional measurements provided that they were funded separately.

In an astonishingly short time:

The purpose of these web pages is to provide the data from the tests in sufficient detail to enable them to be used for academic purposes. This is believed to be the first time that detailed flow measurements have been made in a tunnel shaft so the data may be of value to flow analysts whether or not they are also interested in tunnel pressures.


This test programme was a classical example of a project that could not have been successful without a high degree of cooperation from many people. It is not feasible to thank everyone who contributed, but DTR wishes to place on record its gratitude to everyone who helped. Particular mention should be made of:

SBB - for providing the train set and the tunnel
EPSRC - for providing finance and responding so rapidly and encouragingly
HBI Haerter AG - for professional, technical and logistic support
Vord Consulting Ltd - for professional and technical competence and warm companionship
Silsoe Research Institute - for providing ultrasonic anemometers and friendly assistance far beyond the call of duty
Edinburgh Chamber of Commerce - for turning an import/export nightmare into a seamless dream
Betrib Lehmann - for providing facilities on site and forgiving days of invasion of privacy
Kimo - for inventing Debimo blade flow meters
Sound & Vibration Technolgy - for the free loan of a sound meter
Electro-Mation GmbH - for the free loan of replacement equipment when the original was lost in transit
Arnold Clark Ltd - for greatly discounting the van hire rate for travel between the UK and Switzerland
Alstom (France) - for joining the project team and sharing all data
University of Dundee - for meeting all deadlines with never a hint of complaint
Predicted tunnel pressures and shaft velocities

Predictions made before the test programme