Measuring and testing equipment

Track gauge and superelevation measuring device

A measuring device that is frequently used in track laying, is the so-called "superelevation measurer". The correct term “track gauge and superelevation measuring device” describes what it does.

Functions: 

  • Track gauge -10 mm to +40 mm.
  • Superelevation -30 mm to +200 mm.
  • Reading accuracy 1 division= 1 mm.

Track gauge and superelevation measuring device
Track gauge and superelevation measuring device
© Robel Bahnbaumaschinen GmbH

Switch gauge and superelevation measuring device

The universal measuring device, which is, in particular, used in turnouts, is the so-called “turnout gauge”. This is used to measure the track gauge, check-rail gauge, check-rail guide face, flange groove and superelevation.

Measuring range:

  • Track gauge 1,435 mm -10 mm up to +40 mm.
  • Check rail gauge 1,394 mm -10 mm to +10 mm.
  • Flangeway (2nd check rail gauge): 1,332 mm to 1,365 mm.
  • Flange groove 31 mm to 60 mm.
  • Measurement accuracy +/- 0.5 mm.

Switch gauge and superelevation measuring device
Switch gauge and superelevation measuring device
© Robel Bahnbaumaschinen GmbH

Digital switch gauge and superelevation measuring device
Digital switch gauge and superelevation measuring device
© Robel Bahnbaumaschinen GmbH

Hand-held measuring device for the determination of level and line faults of the track

Before some devices and methods for the alignment and height measurements are shown, for information purposes, it is important to note an important criterion for the different measuring methods: All these measurements are measurements of the track in an unloaded condition. This is important because in more and more railway administrations measurements are required of the loaded track in accordance with the new and modern technical standards.

Alignment measurements

The alignment of the track is generally determined by a chord measurement. It is necessary to make a distinction between concentric and eccentric measurements.

String chord

Basically, concentric measurements are carried out on 10 or 20 metre long chords, adjusted to the radius of the track.

A variant of the device is the fixed string cord. This was formerly used for eccentric measurements with larger chord lengths (20 to 50 m).

Loading gauge profile measuring device

Since string chord measurement is susceptible to weather conditions, in many railway administrations the optical method of versine measurement is preferred.

Advantage:

  • Independent of weather conditions.
  • More precise measurements by optics compared to string measurement.
  • Suitable for lining measurements in the curve and when leaving tangent track.

 

Optical versine measurement
Optical versine measurement
© Werner Schachner

Height measurement

Height measurement is carried out either by line of sight or by levelling measurements.

In the line of sight measurement both the optical view finder and the graduated ruler are set up on the rail.

For measurements in turnouts, a levelling device is generally used.

Loading gauge profile measuring device

The distance from the centre line of the track to the station platform (ramp) and the height from top of rail to platform edge or loading bay is measured with this device.

Loading gauge profile measuring device
Loading gauge profile measuring device
© Robel Bahnbaumaschinen GmbH Robel Bahnbaumasc

Rail head wear measuring device

This device is used to measure the vertical and lateral rail wear. Measurements can be made at 22.5°, 45° and 67.5° to the rail centre axis.

Rail head wear measuring device
Rail head wear measuring device
© Robel Bahnbaumaschinen GmbH

Measuring point button

Rail crossings must be repaired by welding on a regular basis because of their heavy loading and the associated wear. This so-called "build-up welding" requires accurate measurements on the crossing nose.

Measuring point button
Measuring point button
© Robel Bahnbaumaschinen GmbH

Track fixed point-measuring device

Suitable for the measurement of distances from objects or fixed points such as masts, signal posts, concrete walls, etc. Is used to determine the track geometry as well as for the verification of individual high values with an appropriate yardstick.

Track fixpoint measuring device
Track fixpoint measuring device
© Robel Bahnbaumaschinen GmbH

Rail gap measuring wedge

The gap and thus the distance between the rail ends are measured with this device.

Rail gap measuring wedge (actually, measurement is not made on the rail head but on outer side of the rail head)
Rail gap measuring wedge (actually, measurement is not made on the rail head but on outer side of the rail head)
© Robel Bahnbaumaschinen GmbH

Stock rail and turnout tongue test gauge

With this device worn out places can be measured in the tongue area.

Stock rail and turnout tongue test gauge
Stock rail and turnout tongue test gauge
© Robel Bahnbaumaschinen GmbH

Track angle

For the exact calibration of fixed points and other measurement points that require an accurate, right-angled position.

Track angle
Track angle
© Robel Bahnbaumaschinen GmbH

Rail length measuring wheel

The rail length measuring wheel is suitable for the measurement of lengths. This gives guidance on the rail.

Rail length measuring wheel
Rail length measuring wheel
© Robel Bahnbaumaschinen GmbH

Rail adhesive thermometer

The rail adhesive thermometer is suitable for measuring the rail temperature.

Rail adhesive thermometer
Rail adhesive thermometer
© Robel Bahnbaumaschinen GmbH

You can find suitable specialist literature to the topic here:

The Basic Principles of Mechanised Track Maintenance

The Basic Principles of Mechanised Track Maintenance

This book is dedicated to the many people involved in the day to day planning and performance of track maintenance activities. Providing a practical approach to everyday challenges in mechanised track maintenance, it is not just intended as a theoretical approach to the track system. 
Railways aim at transporting people and freight safely, rapidly, regularly, comfortably and on time from one place to another. This book is directed to track infrastructure departments contributing to the above objective by ensuring the track infrastructure’s reliability, availability, maintainability and safety – denoted by the acronym RAMS. Regular, effective and affordable track maintenance enable RAMS to be achieved.