In addition to visual inspection, mostly the under load track geometry and vehicle
dynamics measuring systems are used to determine track condition state on the European
rail networks. The under load condition monitoring of tramway tracks is not widespread.
On the one hand, the reason for this may be the prime and operating cost of the above
mentioned measurement systems, on the other hand, up to now the specialists have considered
that condition monitoring based on visual inspections and unloaded track geometry
measurements are sufficient to plan maintenance work.
Budapest has a large tram network, where significant reconstruction and development
works are being made currently. A uniform Track Condition Assessment Model, which
is based on visual inspection and automatic under load track geometry measuring system
too, is absolutely needed to reduce maintenance cost and increase safety and ride
comfort for passengers. For the specialist of Budapest Public Transport Ltd. (BKV)
there is no decision support system, which would facilitate the planning of maintenance
work. The developing methodology will make this work more efficient based on approximate
estimates of track condition.
Information about the condition state of track is given by the in-service vehicle’s
wheel-mounted inertial sensors. These vehicle dynamics measurements enable to determine
the forming additional loads between the wheel and rail, which refer to the faulty
track sections and the main geometric parameters of these track sections can also
be estimated from the measured data. The system is able to identify those places,
where the amount of wear of rail and the track gauge exceed the admissible limits.
Furthermore, the track irregularities (rail shifts, misalignment rails and so on)
in horizontal and transverse plans can also be determined. The measured data are stored
in a database and displayed on map.
The long-term storing of condition state of track ensures a complex analysis and it
is absolutely necessary to optimize maintenance and renewal strategy and control track
geometry degradation.
