circumferential wheel irregularity measurement

The Triceratops, or TriTops, from RailMeasurement is a tool that measures irregularities on railway wheels.

The equipment uses different technology from RailMeasurement’s equipment to measure irregularities on rails. TriTops can be taken to site in a handy plastic instrument case and used by one person. It was developed for a major vehicle supplier and is used by them.

Measurements are taken, as with most other equipment for this purpose, by jacking a wheelset off the ground and rotating the wheel by hand while measurements are recorded by the instrument. Typically about 4 wheels can be measured in an hour with two people (one jacks up and turns the wheelset, the other moves the equipment under the train and takes the measurements). Measurements are given at three positions across the wheel tread and at a location from flange-back that can be readily adjusted.

The TriTops software gives the following measurements and shows the following features:

  • Displacement, corrugation, out-of-round, diameter
  • Polar plots
  • Acoustic roughness and one-third octave spectra (according to EN15610)