Safety issue
The ARTC Code of Practice does not clearly address the
possibility that a series of track irregularities, even minor ones
which do not exceed intervention limits, could cause an undesirable
harmonic response in some rail vehicles.
ATSB safety recommendation
The Australian Transport Safety Bureau recommends that the
Australian Rail Track Corporation takes safety action to address
this safety issue.
Australian Rail Track Corporation recognises the issue
identified by the Australian Transport Safety Bureau investigation
and is undertaking research to identify a sustainable and practical
approach to address the issue.
Australian Rail Track Corporation accepts that the track
maintenance standard as currently applied treats each identified
track geometry deficiency as a separate entity and may not fully
recognise that there may be rare but possible combinations of track
geometry deficiencies and rail vehicle ride characteristics that
can unite to initiate a derailment.
The identified deficiency relates more the spacing of
minor track geometry deficiencies in combination with rail vehicle
characteristics including bogie spacing and type, wheel profile and
load placement than the size of the individual geometry
deficiencies.
Australian Rail Track Corporation has a robust electronic
track geometry measuring system in place with significant data
captured and processed to generate a Track Quality Index (TQI) for
any given track section.
Research undertaken to date indicates the problem is not
unique to the NCoP applied by Australian Rail Track Corporation, a
review indicates that other codes applied within Australia and
overseas have yet to define a systemic and sustainable long term
solution to the problem.
Australian Rail Track Corporation considers that the issue
is worthy of further consideration and has established a project
group to review current standards and practices including the
concerns raised by Australian Transport Safety Bureau.
The ATSB is satisfied that the
intended action by the ARTC would adequately address the safety
issue.
