Information Technology Reference
In-Depth Information
Roles and responsibilities of these agents are generally shared between
railway managers and infrastructure managers. We distinguish two types of
protection systems:
technical systems
and
non-technical systems
.
Non-technical systems It means all human procedures available to al-
low tra
c safety throughout the rail network. Three types of people are
distinguished:
-
the train driver
for the safety of its own train. In addition, as he meets
other trains, he can inform tra
c o
cers (dispatchers, controllers ,...) of
damages he might see on these trains.
-
on board train staff
and
on board train passengers
can see anomalies such
as: smokes, oil squirts, abnormal vibrations of the train, ...
-
on track staff
can also see anomalies such as: smokes, oil squirts, burning
smell, ...
Technical systems It means all technical equipments that can detect a
hot box. Technical equipments are called as
Hot Box Detectors
(HBD). There
are two types of HBD: on board and on track detectors.
-
On board HBD
only concerns new trains. They directly inform the train
driver when a hot box has been detected. These systems will be managed
in Europe by the EN15437-2 standard
Railway applications - Monitoring
the state of the axle boxes
which is being drafted.
-
On track HBD
. In Europe, HBD are placed along the railway. They re-
spect the EN15437-1 standard [7]: two thermal infrared detectors at either
side of the railway measure the thermal radiation of axle. Temperature
readings are compared to three types of alarms as defined in [7].
3
Hot box protection system modeling
Based on the description of protection systems previously made, a SADT
model of the protection system in two independent sub-systems is proposed
[8]:
-
To monitor trains against hot box danger
: this function allows the detec-
tion of a hot box,
-
To manage a hot box alarm
: this function ensures the safety of train
trac after a hot box alarm.
This function is divided into four independent sub-functions:
To monitor axle
boxes by train staff
,
To monitor axle boxes by STEM agents
,
To monitor axle
boxes by on track HBD
and
To monitor axle boxes by on board HBD
.Dueto
page limitations, only the function
To monitor trains against hot box danger
and the first three sub-functions will be presented. The complete SADT model
is represented by figure 1. For each sub-function, a train fitted for transport is
applied in input and there is two output data: an alarm on the crossed train
and then the train became unfit for transport. The control data corresponds
to a visible axle box anomaly.
