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Rail Infrastructure Clearance Management

European Union
Complete with results
Geo-spatial type
Total project cost
€5 252 000
EU Contribution
€2 600 030
Project Acronym
STRIA Roadmaps
Network and traffic management systems (NTM)
Infrastructure (INF)
Transport mode
Road icon
Transport policies
Societal/Economic issues
Transport sectors
Passenger transport,
Freight transport


Call for proposal
Link to CORDIS
Background & Policy context

In the UK, Laser Rail is in the process of delivering a track clearance measuring system to Network Rail (the national rail infrastructure operator). The National Gauging Project (NGP) aims to upgrade the measuring platform by using modern 'off-the-shelf' equipment like a high-speed rotating laser.

In Germany, the consortium, made up of Metronom Automation, FTI Engineering Network and Fraunhofer Institute Physical Measurement Techniques, has developed a high-speed train-borne measuring system, THELIX, which aims to deliver clearance profiles at cyberspeed.

In France, this train is to be operated by Deutsche Bahn. OBSERVEUR (the last generation of PHOTOPROFIL 1 and 2) is at the acceptance phase from SNCF for operating inspections of civil engineering at between 5 and 120 Km/h.

In Italy, state railway operator FS is currently developing a new measuring vehicle from MERMEC, which aims to deliver clearance measurements.


The current technologies used for infrastructure gauging purposes are very simple:

  • The most common checking system is made of a piece of wood, shaped like a train, which is expected to run through the tunnels, and the gauging process consists of checking the breakage of that piece of wood after it has travelled over several kilometres of track: it is only a go/no-go process, with very poor measurement or location capability.
  • A more recent system is composed of a rotating laser scanner, mounted either on a lorry or a road-railer, and run at just a few kilometres per hour. These systems may provide digital processing of the clearance, but the track must be closed before starting a measuring run.
  • Some countries, like France, are operating a measuring wagon, travelling in the range of 5-10 km/h. Such a low running speed has the same drawback as manual inspection systems: the track has to be closed during the measurement run.

The objective of the research work was to make it possible to run on the track to be inspected at a commercial running speed. This process would allow the clearance to be checked without stopping the commercial trains. The expected gain is very advantageous from a commercial and financial point of view of the global management of the infrastructure.


The INFRACLEAR clearance sensor is based on laser sheet triangulation profiling techniques. It integrates the following technologies:

  • A laser sheet projector, with a fan angle close to 270 perpendicular to the axis of the track. The laser power is an 18 W continuous wave solid-state laser, with specific spreading optics;
  • One set of high-speed and high-resolution cameras, installed separately from the laser, pan for clearance measurement;
  • Geometric stability of this arrangement is ensured by the implementation of a global rigid metallic frame supporting all the cabinets, including the lasers or sensors;
  • A running track reference, based on the inertial principle, is provided by additional cabinets, including lasers, cameras and inertial sensor, which is attached under the main frame and looking closely towards the rail;
  • The whole sensor frame, with all the sensor cabinets and the computers will be installed in a 'comfortable' container, well protected against the outside environment;
  • The measuring container has to be mounted on a classical freight wagon, and fixed on it with the usual locks. This solution makes it possible to put the measuring container on any wagon, so it can be run on a specific track gauge.

This system is composed of three sub-systems namely:

  • A measurement device, including a train-borne sensor and the measuring car;
  • A processing device associated with an expert system to provide conditional maintenance programmes;
  • A simulation tool making it possible to determine clear and safe 'European routes' for a given train gauge over borders.


Parent Programmes
Institution Type
Public institution
Institution Name
European Commission
Type of funding
Public (EU)


INFRACLEAR researchers used operational monitoring technology to optimise the way trains are cleared to go through tunnels. This is essential for ensuring that trains will be able to use the infrastructure to get where they're going safely and that the routes can handle larger trains carrying more cargo.

INFRACLEAR technology makes it possible to check clearance measurements at a normal running speed, without stopping commercial trains. The clearance system comprises sensors and processing computers installed in a protected container, which can be mounted on any classical freight wagon. This makes it possible to use the device on any track gauge. The new, integrated inspection system can perform on highspeed lines (up to 140 km/h), detecting obstacles and measuring for clearance ; two essential aspects of security and safety. The solution is compatible across the European network and offers a simulation tool for determining clear and safe European routes.

INFRACLEAR achievements:

Developed a new, high-speed track clearance monitoring system which:

  • can operate across Europe;
  • operates at commercial speed, keeping tracks open to traffic;
  • ensures that the infrastructure can accept larger, innovative vehicles such as tilting trains.


Lead Organisation
Cybernetix S.a.
Technopole de Chateau-Gombert, Avenue Albert Einstein 306, PO Box 94 MARSEILLE, France
Organisation website
Partner Organisations
Cideon Engineering Gmbh
Tzschirnerstrasse 5a, 1648 BAUTZEN, Germany
EU Contribution
Eurailscout B.v.
Stationplein, 121, AMERSFOORT, Netherlands
Organisation website
EU Contribution
Dma S.r.l.
Via Bottego 8, 10129 TORINO, Italy
Organisation website
EU Contribution
Laser Rail Ltd
Fitology House, Smedley street east, MATLOCK, United Kingdom
EU Contribution
Arbeitsgemeinschaft Paneuropaischer Korridor X Ges.b.r.
Elisabethstrasse 9, VIENNA, Austria
Organisation website
EU Contribution


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