Track Machine Targets

Special targets to surveying the absolute track geometry with the TMC stereo camera system

The Reference Point Measurement (RPM) system is a high speed measuring system for track geometry. The resulting track geometry is the fundamental data basis for the tamping machine to maintain perfect track position.

Reference points with known coordinates are used to determine the absolute position of the rail track at speeds up to 100 km/h. A stereo-camera measures the distance between the wheel flange point of the rail and the reference point with a ±2 mm accuracy. Combined with the relative track geometry of the inertial measurement system the result is a high precision 3D trajectory in geo-coordinates. 

The RPM system uses two stereo-cameras mounted on each side of the vehicle for measuring the distance between the wheel flange point and the reference point. Dedicated flashlights ensure reliable  operation at day and night time. The dedicated measuring target is installed on either existing reference points (metallic bolts) or a new reference geometry is established with an initial measuring run.

The measurement values of the RPM system The measuring target mounted on a side post (left) and the RPM stereo-camera system (right) RPM system installed on the 08-275 Unimat Combi (RFI Italia) tamping machine

TMT10 Starlock round marker and accessories

The round marker is the best marker for RPM high speed measuring. It is the recommended solution for existing bolts with a 50mm clearance radius around the bolt. 

TMT10 round marker Starlock disc (11 mm / 12 mm) Assembly aid for starlock disc


For installation a 12mm or 11mm cylindrical bolt is required.

  • Deutsche Bahn (DB) bolts 12x30mm
  • Deutsche Bahn (DB) bolts 11x30mm (additional 11mm Starlock required!)
  • Italy bolts (RFI Italia)
  • UK (Leica standard stub fitting)


  • Uses same geo-coordinate as the existing reference point (constant offset to bolt tip).
  • Fast & easy installation procedure (less than 10 seconds).
  • Does not interfere with conventional measuring prisms.
  • Cutting hole for pliers to dismount or exchange the disc marker.
  • Long lifetime in outdoor conditions

Additional supported Measuring Systems

The round marker does not interfere with conventional prism and robotic total station (RTS) measurement processes. The extra slim profile design (<5mm) makes it possible to mount measuring prisms (Goecke, Bohnenstingl) on bolts equipped with the disc marker.

The following accessories are offered for this product 

  • Starlock disc 11 mm for TMT10 (TMT-STL11)
  • Starlock disc 12 mm for TMT10 (TMT-STL12)
  • TMT10 assembly aid for starlock disc

TMT20 Tunnel-Marker

The tunnel-marker is an alternative solution for the disc marker. Whenever the reference bolt is mounted near blocking obstacles or on curved tunnel walls, the tunnel-marker provides enough clearance for proper installation.
TMT20 Tunnel-Marker   
TMT20 Tunnel-Marker    


The disc marker fits any 12mm cylindrical bolt.

  • Deutsche Bahn (DB) bolts 12x30 mm
  • Deutsche Bahn (DB) bolts 11x30mm
  • Italy bolts (RFI Italia)
  • UK (Leica standard stub fitting)


  • Easy installation procedure using 4mm Allen key.
  • Non-destructive removal mechanism.
  • Reflective center point for direct measurement when using a robotic total station.
  • Long lifetime in outdoor conditions.

Additional supported Measuring Systems

The tunnel markers center location can be directly measured using a robotic total station (RTS). The reflective surface pattern features a center dot marked with a crosshair.


TMT30 ALU-Marker

The ALU-Marker is intended to be used when no existing reference points are present. The design of the base plate makes it possible to use various measurement systems, not only the RPM system. Measuring targets can be easily switched and retain the same reference point.
TMT30 ALU-Marker
TMT30 ALU-Marker


Dimensioning file TMT10, TMT20, TMT25 and TMT30.pdf for download.
Here you find a dimensioning file for each RS product