IMPROVEMENT OF THE REALIGNMENT PERFORMANCE FOR SHORT WAVELENGTH TRACK IRREGULARITY ON A TAMPING MACHINE

ABSTRACT Track maintenance work is essential to maintaining the safe and stable operation of a railway system. In recent years, the realignment of track irregularity with wavelengths of approximately 5 m is required in order to reduce the Q-force and the track irregularity growth on the Tokaido Shinkansen. Tamping machines are generally used to realign track irregularities. But, the newest Type-09 tamping machine has a lower realignment performance for track irregularities of around 5 m in wavelength due to its capabilities when it comes to measuring chord length. Therefore, a new measuring system has been attached in the tamping machine in order to measure 3.6 m versine at the longitudinal level. Since a high-precision gyroscope is used, the measuring system is not influenced by the vibration of the tamping machine when in operation. Through repeatability testing it was confirmed that short wavelength track irregularities could be measured with high accuracy. The data measured by Dr Yellow (a track inspection car) was combined with the data taken from the gyroscope to propose a new algorithm for correcting 5 m chord versine track irregularities with better accuracy. Maintenance tests will be conducted to verify the results.