Track Monitoring System


The Track Monitoring System helps maintain the safety of railroad tracks by monitoring settlement and twist. The track monitoring systems are installed when nearby construction activities, such as tunneling or excavation, may affect the safety of the tracks. The systems are also installed on tracks that pass through areas endangered by landslides or washouts.

Track Monitoring System

Settlement of the track is monitored by linked track-settlement sensors that are mounted directly on the ties (sleepers). With continuous track, the track settlement sensors are anchored in the ballast instead. The twist in the track is monitored by track twist sensors mounted on the long-axis of the ties.

All sensors are connected to an automatic data acquisition system. The data acquisition system can be programmed to provide local alarms. When external communications links are possible, data are

transmitted to a data center where the Atlas web-based monitoring system is installed. Atlas processes the data, checks for alarms, and provides plots of settlement and twist. If movement exceeds safe limits, Atlas can notify safety officials via email or text messages sent to mobile phones.


  • Heavy duty, stainless steel construction, made to withstand vibration and reballasting activities.
  • Continuous, unattended monitoring, with local alarms possible.
  • Trend graphs, profile plots, and alarms can be made available on the internet via the Atlas server.
  • Proven in installations in the US, UK, Canada, Switzerland, and Australia.
Track Monitoring System

For more information

Please download the Track Monitoring System datasheet. It can be viewed and printed with Adobe Acrobat Reader.

Drawing of Track Monitoring System in Use

Track Monitoring System Specifications

A track monitoring system consists of settlement sensors and twist sensors. Settlement sensors are mounted parallel to the rails and typically linked together. Twist sensors are mounted parallel to the ties.
Settlement SensorSensors can be placed up to 3m apart. Each sensor includes a signal cable to connect to the next sensor. Settlement sensors require a mounting bracket and gauge tubing
Mounting BracketBracket includes a swivel for the settlement sensor and a telescoping socket for the gauge tube. Order one mounting bracket for each settlement sensor
Gauge TubingGauge tubing defines the gauge length of the settlement sensor. Order one gauge tube for each settlement sensor
Twist SensorTwist sensors can be placed within 3m of any settlement sensor. Each sensor includes a signal cable to connect to a settlement sensor. Twist sensors are supplied with a mounting bracket and do not need gauge tubing
Jumper CableThe jumper cable connects the sensor bus to a data logger. Order one jumper cable per installation.
End PlugThe end plug terminates one end of the sensor bus. Order one end plug per installation.
OtherScrews or anchor bolts are required to fasten mounting brackets to rail ties. These are best sourced by the user
Part Numbers
Track Settlement Sensor97806550
Gauge Tubing, 3m / 10 ft97806558
Mounting Bracket97806555
Track Twist Sensor97806570
Bottom Plug57804510
Jumper Cable, 25 m57804525
Sensor TypeMEMS tilt sensor . Thermistor for temperature readings
RequirementsAccepts power input between 8 to 15 Vdc. Outputs ±2.5 volt differential signal. The biaxial version contains two tilt sensors.
Calibrated Range±10 degrees
Resolution9 arc seconds or 0.04 mm/m using the CR1000 data logger.
Sensor Repeatability±22 arc seconds or ±0.1 mm/m, subject to site conditions
Calibration11-point calibration taken at three temperatures from -8 to 40 °C
Signal CableCable for 3m gauge length supplied with each sensor. The connectors are fully waterproof.
Data Loggers
M-LoggerThe M-Logger is specifically designed to read MEMS sensors. It can operate a single chain of up to 16 sensors. The M-Logger can also be used to verify the operation of the sensors at installation time.
Campbell Scientific CR1000The Campbell Scientific CR1000 data logger can operate up to 6 chains of serial sensors. The CR800 logger can operate 3 chains of serial sensors.
Atlas Web-Based Monitoring
Readings retrieved from the data logger can be processed manually by spreadsheet or automatically by the Atlas web-based monitoring system. See separate data sheet for details.