The “OF Tunnel” system defines the optimal configuration for monitoring the quantities necessary to characterise the tensional state of a tunnel, its deformations in space and in the plane:  its deterioration over time. The high degree of flexibility and scalability of the “OF Tunnel” System allows application on all types of tunnels, on structural or non-structural elements, providing additional and continuously developing services.


  • Along the tunnel and cross sections;
  • Along the perimeter/containment walls;
  • At all critical points of the structure.


  • Convergence measurement for tunnel sections;
  • Monitoring of longitudinal deformations in the tunnel;
  • Measurement of bending and reinforcement loads;
  • Monitoring of cracks and interstitial seepage;
  • Calibrations and measurements are stable over time (no drift effect)
  • No hindrance during routine tunnel maintenance.

NTSG has developed a mathematical model for the interpretation of the measurements made by the “OF Tunnel” system and the calculation of engineering quantities derived from them. The model is implemented in the proprietary software “Edgegateway” which acquires the above measurements in real time, uses them to derive the engineering quantities described in the Properties section and manages alerts and alarms in the presence of anomalies.



  • Along the tunnel canopy.


  • Real-time monitoring of the temperature inside the tunnel;
  • Application of a specific fibre optic cable for high temperatures, up to 800°C.


The “OF Fan” system has been developed and certified for vibration monitoring, control of out-of-place movements of the fan, the behaviour of the anchoring elements, to monitor the thrust and power absorption performance of the fan. The “OF Fan” system returns the vibration spectrum of the machine from which it is possible to discriminate the cause of anomalies, when they occur. The high degree of flexibility and scalability of the “OF Fan” system allows application on all types of fans, on structural or non-structural elements, and the integration of this monitoring system with the “OF Tunnel” system.


  • On the fan power cables;
  • On the motor and vibrating body;
  • On the fan’s anchoring structure.


  • Dynamic monitoring of the power absorption of the fan and consequent definition of its state;
  • Monitoring of vibrations, deformations, displacements and degradation of the fan.
  • Monitoring of the system for anchoring the machine to the canopy;
  • Real-time monitoring of fan performance;
  • Spectral analysis of fan vibrations and definition of the cause of failure.