Proceedings 2002/2003 - IRSE

INTERNATIONAL CONVENTION 85
RIC level crossings are constructed and maintained
to provide the maximum possible reliability
and safety. Nevertheless, reports of failure to
operate correctly are received quite frequently. Any
such report needs to be investigated exhaustively, to
determine what the cause of the reported failure
might be, and to provide urgent repair of any fault
revealed by the inspection. If, as often occurs, no
fault is found, the question remains unresolved
whether the failure report was prompted by an
intermittent fault, or an error of observation by the
person making the report.
Likewise, any accident or incident on a level
crossing calls into question the safety of the system.
Indeed, it is in the interests of a party claiming
damages from the railway, or defending a charge of
failing to obey a signal, to throw as much doubt as
possible on whether the crossing signals were working
correctly at the time of the incident in question.
The subsequent inquiry can benefit greatly from the
availability of a detailed record of the operation of
the crossing equipment at the time of the incident.
There is a clear need for a method of data recording
that will enable the recent operational history of
a level crossing to be ‘read', after the report of that
the level crossing equipment failed to operate
properly. The level crossing monitor must monitor
the status of a level crossing, log events, and report
warning or failure conditions to a central location. On
systems which require a daily test of the crossing,
there is also a need to provide the facility for remotely
testing the level crossing battery supply and the
monitor itself.
From the inception of the ‘Cerberus’ system it was
considered inevitable that, once crossing loggers
were installed, they would eventually be required to
provide data acceptable as legal evidence, for
instance in the event of an inquiry following a level
crossing fatality. For that reason the software design
and testing was based on a stringent process of
specification, documentation and independent
validation, to produce a record that could be
presented unchallenged as legal evidence.
In 1988, the Signals Development Section of what
was then State Rail first began developing a monitoring
and logging system for railway level crossings,
taking advantage of the growing availability of more
powerful and less expensive data acquisition
hardware.
Today, State Rail's 'Cerberus' monitor is a leading
'black box recorder' for railway level crossings. It
logs level crossing events, monitors level crossing
operation, remotely tests the level crossing battery,
and reports level crossing status.
At the time of writing, ‘Cerberus’ Level Crossing
Monitor system is installed on most level crossings
across New South Wales, with more than 100 fully
commissioned with communication links to Control
Centres in Sydney, Orange, Wagga Wagga and
Broadmeadow.
THE ‘CERBERUS’ SYSTEM – MONITOR,
CONTROL CENTRE and SOFTWARE
The ‘Cerberus’ Level Crossing Monitor and
Remote Test System consists of two major components,
the Level Crossing Monitor and the Central
Monitoring and Control Workstation, and a collection
of associated software.
The ‘Cerberus’ Level Crossing Monitor is the
‘black box’ recorder. It can operate as a standalone
unit, independent of any communications with the
world beyond the level crossing, or be linked by
telephone to a Control Centre.
The monitor is based on a standard RIC 64-way
digital/analogue data acquisition board, installed in a
custom-built 19” housing with internal power supply.
The board is fitted with a lithium battery-powered
non-volatile memory, real-time clock and an
8-channel analogue to digital converter. It connects