DELIVERABLE 2.8 - urban track

2.10. CONCLUSIONS
2.10.1. Conclusion about the practice at STIB
D0208_STIB_M24.doc
TIP5-CT-2006-031312 Page 22 of 44
URBAN TRACK Issued: August 13, 2008
Quality checked and approved by project co-ordinator André Van Leuven
The build-up welding practice at STIB is the current state of the art. The rails quality is Q700 and the
welding materials are also the same.
The differences can be summarised as follows:
STIB is the only one present that is until doing the pre-emptive welding on the new rails in order to
prevent squeal noise. Other operators do not face this problem since they have vehicles equipped
with wheel lubricators.
STIB uses the lip to guide the wheel and thus experiences wheel wear on the lip as well.
STIB uses rails with a narrower groove.
2.10.2. General conclusion about track maintenance
Flange lubrication is beneficial in reducing wear on wheels and rails.
Vignol rails of Q900 are recommended in non-embedded curves (they have a lower wear rate) where
exchanging the rail is easy.
Grooved rails of Q700 are recommended on embedded curves (it is possible to build them up 8 times
and to bend them without special difficulties) where exchanging the rail is difficult and expensive).
This restriction is possible with some special heat treatment on site. The first treatment can be done
in the workshop before installation in order to reduce squeal noise in the curve, or it can be done after
the first wear cycle (up to 16 mm wear is accepted in practice). After treatment, the rails of Q700 have
the same hardness as Q900 rails. Grooved rails of Q900 are recommended on tangent track.
New developments proposed by the rail manufacturers such a use of head rail in curves with a
specific wear restoration procedure are still in prototype development phase.
Specific track designs, such as the Viennese curve, are promising for wear reduction but not
applicable for embedded tram applications.
2.10.3. Conclusion for this task
No further research or validation is required concerning this topic.