Mechanical Joint Controller

The mechanical integrity of an Insulated Block Joint (GII) can be easily monitored with the CGM, a system patented by Marini Impianti Industriali.

Through a sensor (SEN-CGM) it measures the relative movement between the jointed rails. The aim is to generate an Alarm in case of a relative movement between  the rails. The alarm is sent only if the movement exceeds the preset threshold value.

This alarm allows you to activate procedures for checking/maintenance of the GII as a prevention of a possible mechanical break. To avoid the removal of a possible alarm, the sensor is designed so that once it is activated, it is no longer able to be reset except for its eventual substitution.

If the sensor breaks away from the rail, the Alarm is immediately activated. The CGM system complies with the RFI TCAR SF AR 12 004 A Italian Railway Specification, and it is equipped with different accessories including:

  • Sensor with High Visibility Protective Carter cat/prog 830/500
  • Installation Tool cat/prog 830/503
  • Gluing Kit cat/prog 830/501
  • Wiring Kit

The CGM Sensor is made with a safety architecture that ensures a SIL4 safety integrity level, according to the Cenelec EN 50129 and EN 50126 reguations.


The sensor is equipped with an electrical contact that is: A closed contact for a gap between the rails within the Regular Operating Zone.
An open contact for a gap between the rails within the Alarm Zone. This electrical contact is connected to the Signalling System (IS) and it indicates the alarm state or the normal operation of the GII detected by the sensor.