Zbornik radova Koridor 10 - Kirilo Savić

3rd International Scientific and Professional Conference
CORRIDOR 10 - a sustainable way of integrations
Preventive grinding is designed to improve the quality of the running surface of newly-laid rails.
Unfortunately, in Serbia and in Montenegro the rail grinding is still not applied after the laying of new
rails in track before work acceptance, although the experience of others points on necessity of this
measure and confirms its cost effectiveness through extension of rail service life. Besides that, more
often is in use head-hardened rail whose consequence is longer adjustment of rail to the geometry of
wheel. Aim of preventive grinding is to provide optimal conditions in wheel-rail contact at the beginning
of exploitation, and also to remove usual irregularities that appeared during the track laying (for
example, fine unevenness on rail welds).
However, the effect of grinding is not permanent. After a while fissures due to rolling contact fatigue
occurs again and new cycle of rail grinding is necessary. Corrective grinding is designed to remove rail
defects that have already developed by reprofiling the rail to optimize wheel/rail contact.
4. CONCLUSIONS
Rolling Contact Fatigue is a serious hazard to rail traffic across the world and a major problem for
railway infrastructure managers. That hazard is more distinct on railways without adequate
maintenance strategy. Increased traffic density, axle loads and speed as well as lubrication of rails are
contributors to this problem. In contrast to this, correct track geometry, correct wheel/rail contact patch
geometry, improved maintenance (appropriate inspection and rail grinding strategy) can reduce
problems due to rolling contact fatigue.
Appropriate maintenance strategy should provide extra rail service life and should reduce overall rail
maintenance costs. Unfortunately, a visual inspections that are conducted on the Serbian Railway and
the Montenegro Railways present examples of sporadically conducted maintenance and its negative
consequence. Realization of interoperability of European railway network demands from infrastructure
managers in Serbia and Montenegro to have for each conventional line an appropriate maintenance
plan for the infrastructure subsystem in accordance with European technical regulation. Additionally,
the infrastructure managers have to adjust maintenance strategy to local conditions in order to
improve traffic safety. It is clear that this maintenance plan has to include inspection and strategy
against rail defects due to rolling contact fatigue.
This paper emphasizes the importance of grinding strategies against RCF rail defects. It also points on
the importance of preventive activities ("rail care"), removal of more or less severe defects (corrective
activities) and cyclical (controlled) activities during the whole rail service life.
Anyway, the authors recommend combining several non-destructive testing methods for efficient rail
testing: visual inspection, optical inspection by camera, ultrasound testing and eddy current testing.
Realization of the conclusions of this paper requires an urgent harmonization of technical regulations
in the field of railway infrastructure maintenance.
5. ACKNOWLEDGEMENT
This work was supported by the Ministry of Education and Science of the Republic of Serbia through
the research project No. 36012: “Research of technical-technological, staff and organisational capacity
of Serbian Railways, from the viewpoint of current and future European Union requirements”.
Belgrade, 2012 236