The navigation module automatically keeps track of the TBM’s position in real time with respect to the theoretical axis.

A motorized total station fixed on the tunnel lining determines the coordinates of two prisms on the TBM, using a reference prism whose coordinates are known. The coordinates of these two prisms are then used to calculate the TBM’s position.

A bi-axis inclinometer determines the roll and pitch of the TBM. These data are used to determine the front position of the TBM and to check the accuracy of measurements from the theodolite on the two navigation prisms. The data are transmitted to the system’s computer to display the front and rear position of the machine on a screen in the control cabin.

Navigation system schematic


  • Constant control of TBM’s position
  • Accuracy and display of axis
  • Simple and reliable.
  • Semi-assisted station displacement.
  • Generation of station displacement report.
Screen in control cabin


  • Ring sequences calculation software

This software pre-calculates the ring sequences according to the trajectory and generates a daily laying plan with the characteristics of the adopted catching curve, ring positions and associated steering orders for the pilot.

The advantage of this piloting solution is that it enables a new catch-up curve to be regularly recomputed according to the TBM’s position and thus to remain as close as possible to the excavation axis.

The steering principle entails five steps.

Example laying plan
Principe de fonctionnement du programme anneau
Piloting assistance display
  • Piloting assistance

This module lets pilots follow the steering orders from the ring sequence pre-calculation software, which set the change in the horizontal and vertical stroke difference between the thrust cylinders.

The piloting assistance interface constantly indicates on screen to the pilot a point representing the drift between the desired position (target) and the current position of the TBM.

The highly sensitive sensors ensure fine control of piloting and a very regular and precise curve.

  • Automatic steering option

The automatic steering option enables precise and accurate distribution of thrust in the different groups of cylinders in line with the steering orders.

Automatic skirt clearance measurement screen
  • Steering analysis

A report dedicated to the steering analysis is made available to the pilot and surveyors to facilitate decision-making at the end of each excavation.

  • Automatic tailskin clearance measurement system

This tool replaces manual measurement by the operator. Manual measurement is unsafe and often inaccurate because it is difficult to reach and located over the empty space. The proposed system determines the exact values of the clearances and ensures the safety of employees.

Moreover, the measurements are continuously recorded, which makes it possible to observe their evolution during excavation.

Ultrasonic sensors are installed in the tailskin and measure continuously the gap all around the ring. The data is processed to determine the exact shape of the complete ring and its position relative to tailskin axis. The results are transmitted to the piloting computer, which is then able to calculate the new guidance instructions.


The monitoring module is a data acquisition system that records all the parameters from the sensors installed on the TBM. It is also possible to acquire parameters from other automation systems, such as a mortar plant, conveyors or a slurry plant.

Dedicated to the animation of synoptics in real time, this tool allows to supervise effectively all the tasks carried out during the excavation phases, with the possibility of saving and printing graphs, creating daily reports, exporting and recording data to Excel format and set alarms with sending emails or sms.

All the synoptics and reports are accessible via the Internet.

The calculation and display of the following indicators are also integrated into the supervision on dedicated synoptics:

Chamber filling rate for an EPB tunnel boring machine

Clogging indicator for all types of tunnel boring machines

Example of synopses and reports


This tool collects and stores the information from the acquisition system so that, in addition to real-time visualisation, it can also analyse the information in depth afterwards.

An interface specially created for this purpose allows data to be used over long periods in the form of graphs or summary tables.

It is possible to set up tables or synthetic graphs on well-defined subjects such as production parameters, consumables, topographical data, number of rings made per day over the period, digging times, installation, etc…

The benefits

  • Centralization of information,
  • Quality assurance,
  • Real-time and slightly delayed analysis,
  • Post analysis,
  • Facilitates feedback,
  • Facilitates the production of end-of-site reports.
Example of graphs


Other tools are also available in order to exploit all the information related to the tunneling of the tunnel boring machine:

  • Traceability and scanning of segments using a reader connected to the base

The segment scan tool allows you to scan tags containing information on the segments. These tags can be RFID chips, barcodes or QR codes. The scan is used to manage the reception, stock, and quarantine of segments in a quality control process. This management can be carried out as soon as the segments leave the manufacturing plant, but also at various segment storage sites before their delivery to the construction site. The module allows the data of a scanned segment to be recorded in the database and be associated with a tunnel ring number. The aim is to follow the life of each segment from reception to laying with the various manufacturing data and the various damages and repairs they may have received.

QR code and bar code
RFID chip
QR code et code bar
  • Survey and analysis of tunnel cracks using a tablet connected to the base

The module for recording anomalies allows the defects and anomalies detected on the segments to be identified and reported in the form of drawings, using a tablet. All the defects found are recorded in the database and can be consulted and exploited from there.

This module is part of a quality approach, with monitoring of the rings after they have been laid in the tunnel. In particular, it guarantees time saving in the process of monitoring damages and repairs, and it allows the conservation and exploitation of the rings’ history.

  • Integration of surface settlement data
  • Integration of surface settlement data

Controlling surface settlements when passing the tunnel boring machine, particularly in urban areas, is a key point in the tunnel boring phases. Thanks to the automation of surface settlement methods, it is now possible to acquire this data.

Thus, with a view to bringing together in the CAP database all the parameters relating to excavation in order to be able to carry out cross-analyzes between the data from the tunnel boring machine and the surface settlement data, CAP offers a new interface integrating analysis of surface settlements.

This tool makes it possible to visualize and analyze in a synthetic way the evolution of surface settlements during the passage of the tunnel boring machine using simple and automatic graphics. It thus makes it possible to carry out cross-analyzes with the data from the tunnel boring machine.

Example of the evolution of settlement data of different points during the passage of the TBM and location in relation to the route
  • Representation of the axis and TBM position on google maps

This tool displays the axis and the position of the tunnel boring machine on a google maps map and thus allows to visualize precisely in real time where the tunnel boring machine is located in relation to the surface frame.

Google maps

Shift reports application

This tool allows the input, recording and use of data for all the tasks performed when using a tunnel boring machine.

1. Features

An input interface
A set of predefined tasks must be entered, timed and commented on as the position progresses by the pilot and / or the station manager.
The set of tasks will be pre-configured on the interface at the start of the construction site. The site will be free to add tasks.

A report creation interface according to configurable frames
All the data entered will be the subject of generation of reports comprising a gantt chart, a summary of information relating to the position, performance indicators, dynamic graphs and progress reports which are updated as and when. as information is entered. Reports from the interface will be downloadable in PDF or printable directly from the interface.

A raw data analysis interface
All the data entered can be extracted and visualized graphically in a simple way over a given time slot.

2. Data recording and storage

The data entered will be recorded and stored in a remote database and available for the duration of the work. The duration of use should be defined at the time of the offer. At the end of the work, the data can be exported.

3. Accessibility and connection

The tool is accessible from a WEB platform. The platform will be hosted on a server, accessible by the site according to secure protocols (identification login / password).
An internet connection will be required to use the tool. An “offline” mode will allow you to continue entering data in the event of a temporary loss of connection.


In order to make the data of the construction site more easily accessible, CAP proposes a 3D module representing the entire project. This extension, distributed under the CAP3D brand, is particularly well suited to urban projects. Indeed, it allows to visualize on the same interface a faithful and real time representation of the crucial elements of a metro site:

  • Tunneler
  • Stations
  • Tunnel
  • Building
  • Geology
  • Auscultation

CAP 3D allows you to navigate the construction site in real time. The main information of the project is accessible via this interface, and in particular the state of activity of the TBM, its positioning, the surrounding geology, possible incidents on the machine and/or its environment, to locate the segments and their characteristics in connection with the tool for the survey of cracks and the scanning of segment chips…
The tool also makes it possible to produce longitudinal and transverse sections of the tunnel at the point chosen by the user, these sections including all the elements useful for understanding the machine’s environment: tunnel, geology, structure, surface settlements.

Innovation / Improvements

CAP continues to be a pioneer in its industry. To always stay on top of and close to the needs of its customers, the internal team of software engineers and developers constantly evolves applications to bring new features and innovative digital solutions.
Here are some examples of current and upcoming developments.

Reduction of TBM downtime

A tool is being developed for troubleshooting and for efficient and user-friendly diagnostics in order to reduce the downtime of the tunnel boring machine. The purpose of this tool is to facilitate diagnosis without having to constantly mobilize an automation engineer and without being directly connected to the PLC.

Reduction of TBM downtime

A tool is being developed for troubleshooting and for efficient and user-friendly diagnostics in order to reduce the downtime of the tunnel boring machine. The purpose of this tool is to facilitate diagnosis without having to constantly mobilize an automation engineer and without being directly connected to the PLC.

Automated control of tailskin and shield deformation

To meet the customers’ need to effectively monitor any deformation of the tailskin and shield that may occur during the excavation phases, work has been launched with one of our sites to set up a tool to automatically control these. deformations using distance connected laser meters.

Proposal for a simplified guidance solution

A new, simplified guidance solution is under study, suitable for projects where the axis to be followed by the tunnel boring machine does not include a complex path.