PRT300 Portable Rail Tribometer

A new friction inspection tool for more informed, data-driven decisions on friction management.

Applications

Wheel/rail friction is difficult to measure directly. A tribometer creates a model wheel/rail system and measures the friction of this system.

The accuracy of the measurement is determined by how close the model system is to the real system of interest, how well the model system can be controlled and how accurately the force measurement can be taken.

With results validated against full scale test facilities, the Rivelin Rail PRT300 is designed to produce the most accurate measurement possible in a lightweight device.

Michael Watson Rivelin Rail co-founder uses a portable rail tribometer for friction inspection on track

Trial and error or visual inspections don’t cut it elsewhere in the industry, yet they are used far too often in friction management. Our portable tribometer provides immediate and comprehensible data for more informed decision making:

  • Identify friction irregularities, for example low adhesion “hotspots”

  • Inspect rail after safety incidents

  • Determine and compare performance criteria of friction management products such as rail cleaning, traction enhancers and lubricants

  • Optimise friction management strategies

Design principals

How does it work?

The Rivelin Rail PRT300 portable tribometer magnetically clamps to the top of the rail to provide point measurements. A freely rotating measurement ball is used, creep is generated by skewing the axis of rotation of the ball relative to the direction of motion at a set angle. This generates lateral creep in the contact, the tangent of the angle gives the effective linear creep.

Diagram showing operating mechanism of portable rail tribometer forces

Results

Displayed on screen and saved to micro-SD card

close up of Rivelin rail tribometer on track, showing friction force and temperature and humidity results

Friction Coefficient

Boxplot comparing friction coefficient under three rail conditions: dry, wet, and leaf layer (wetted).

Environmental conditions; Rail temperature, air temperature, relative humidity

Map of the United Kingdom showing data points in various colors representing different values, with a color scale from 10 to 90.

GPS co-ordinates

Result validation and comparison

The compact design means that our tribometer can be used in the lab as well as the field. Results are validated against The University of Sheffield’s full scale wheel and rail test facility under dry, wet and lubricated conditions with excellent comparability between results.

Comparison between lab results (under controlled conditions) and field results (under representative usage) has previously been difficult. Our tribometer provides a “common denominator”, when used in the lab and field.

Portable rail tribometer validation with full scale wheel and rail test rig at the university of sheffield

Back-to-back testing, also useful for lab to field scaling

Box plot comparing friction coefficients of Rivelin Rail and full scale rail under dry, wet, and leaf layer (wetted) conditions, showing that friction decreases from dry to wet to leaf layer for both measures.

Comparability between tribometer and full scale test facility, over 500 measurements with a range of rail conditions