15-06-2012, 11:52 AM
AUTOMATION PROCEDURES OF CONTROL OF RAILWAY RAILS
AUTOMATION PROCEDURES OF CONTROL OF RAILWAY RAILS.pdf (Size: 246.4 KB / Downloads: 93)
Abstract
Introducing new inspection techniques into the rail industry is a challenge that involves many aspects of
accreditation and approvals. It is also necessary to consider the skills level of operators and training requirements
specific to that industry. We have done comparison between new SPG 80 and of old handcart NW 60 for
examination of mistakes in rails with new and old ultrasonic machine and tandem ultrasonic probe.
Old and new systems were precise and suitable for search and evaluation of mistakes in steel track, critical point
is thermite weld. This way of examination searches defect in rails, for search tracks between next to joints of
rails.
Introduction
Ultrasonic method has shown by the inspection of the vital element of the railways vehicles as
an applicable and reliable method for detecting initial crack or falsies in the material. In
»Mostovna« in Ljubljana was in year 1959 purchased the first ultrasonic device Krautkrämer
USM 1 for the inspection of the flash-butt welds on the rails. After some years the ultrasonic
devices USIP 9 and USIP 10 for the maintenance workshops in Maribor, Dobova, Nova
Gorica and Ptuj were also purchased. Prior to this USL 32 device was mainly used. The
education of operators was performed in Ravne by Ing. Mitja Špik, where the basic
instructions about the general methods were given.
Ultrasonic rail control on the Slovenian Railways
With the law for the security of the railway traffic [2] it is defined, that the railway track and
their parts must maintained assure safe railway traffic. It must be also regularly supervised
and periodically inspected. In context of regular track maintenance also the ultrasonic
inspection of the rails was included. Regarding to the Regulation for conditions of projecting,
building and maintenance of railways superstructure [3] it is necessary at least once per year
on the entire railway network to execute the »not demolished« ultrasonic inspections of rails.
The evaluation of the faults (defect) is performing accordance to the »339 – Directive for
united criteria for the control of the track condition« and »UIC 712 Kodex [4].
Conclusion:
With the ultrasonic measuring car in average 600 faults are detected, which also includes the
faults which are not critical. There are around 4% of critical faults, which are in the first phase
insured with the joint – plates, later eliminated with the new wide tips of thermit weld, or with
a implantation of the new piece of the rail. Around 55 % of the faults are directly related to
the rail; around 45 % of the faults are related to the rail weld (thermit or flash-butt weld).
Some faults, like the notches on the driving rail edge “Head checks” can with the own growth
enlarge the possibility of the rail brake. The specialty of the surface faults, and the faults close
under the surface is, that they are not able to be detected with the ultrasonic heads which are
installed on the ultrasonic measuring car. For this purpose new not demolished method of
material test with Eddy current is being used abroad.