Q. Why
Coromandel Express crashed in Odisha?
ยท The tragic death of nearly 300 passengers in a train accident has drawn attention to the safety preparedness of the Indian Railways.
ยท Minister for Railways
has said that interference with the โconfigurationโ of the track led the
Coromandel Express to smash into the stationary goods train from behind at
Bahanaga Bazar in Odishaโs Balasore.
ยท The electric โpoint machineโ is a vital
device in the railway signalling system for quick operation and โlockingโ of
point switches. It plays a key role in the safe running of trains. Failure of
these machines will severely affect train movement, and any deficiencies that
are created or left unaddressed at the time of installation or maintenance of
the system can result in unsafe conditions.
Q. What is meant
by โinterlockingโ in railways?
ยท Interlocking in
railway signalling systems is a crucial safety mechanism that ensures train
movements continue without any conflicts, thus preventing accidents.
ยท There are three main components of the interlocking
system: point, track occupancy sensing devices, and signal. The
interlocking system coordinates the functions of these three components to
control train movements.
ยท The digital interface
of this system is a computer screen (or multiple screens) that shows the full
view of the station layout, the real-time movement of trains, the signals, and
the position of the points. This computer interface is called a data logger.
Q. What is the
function of each of these three main components?
ยท Signals
(which are lights of green, red, and yellow colour) are installed along the
tracks to indicate the status of the track ahead.
ยท Track circuits are electrical circuits (also known as track-occupancy sensing devices)
that detect the presence of trains.
ยท Points allow trains to change tracks. The Coromandel was supposed to go through Bahanaga Bazar on the โUpโ main line, but the point just before the station switched the express on to the loop line that was occupied by the stationary goods train.
Q. How do the points work?
ยท The points, also
called switch rails, are movable rails that are typically placed at the point
of divergence of two tracks going to different directions. Once the direction
of a train is determined, the point gets locked at a particular position, and
cannot be budged until the train has passed. The driver, or loco pilot, has no
say in this matter.
Q. How does the
system sense whether a track is occupied?
ยท There are various kinds of track-occupancy sensing devices. Generally, sensors are installed on the tracks that detect the passage of wheels on the rails. These are called axle counters. They count how many sets of wheels or axles have passed over them in order to determine whether the entire train has passed through.
Q. How is this
whole system configured?
ยท A โsound logicโ of
what is safe train operation is fed into the interlocking system, which is
controlled remotely from the station.
ยท Earlier, when
technology was more basic, this job would be done manually, wherein a pointsman
would physically operate the point to change its direction for an incoming
train, and to lock it. Someone would then physically show a green flag or
signal to the train after checking that the track was clear of obstacles. The
driver would see the flag/ signal and proceed.
ยท Today, out of the
7,000-odd stations in the Indian Railways network, only around 100 small
stations still have manual levers to control these points. The rest operate
electronically, even though the basic principles of the logic are taken from
the old and time-tested standard operating procedure for safety.
Q. How safe is
this system?
ยท If any of the three
components (signals, points, and track occupancy sensors) does not correspond
to the overall โsafeโ logic fed into the computer, the system will work to stop
the oncoming train. This means if the point is not locked, or not set to the
desired direction, and/ or if the sensing device detects that the track is not
clear, the signal will automatically turn red โ indicating to the oncoming
train that something is wrong and that it should stop.
ยท This is called a
โfail safeโ system โ one that errs on the side of safety.
Q.Who operates
and monitors the interlocking signalling system?
ยท The interlocking
system is usually operated and monitored by trained personnel from the
signalling and telecommunications department in Railways, often known as
โsignallersโ or signal operators. They are responsible for setting the signals,
monitoring track circuits, and ensuring the safe movement of trains.
Q. Are
interlocking signalling systems used worldwide?
ยท Yes, interlocking
systems are used in railway networks worldwide. Countries may have variations
in their signalling practices and technologies, but the underlying principle of
preventing conflicting train movements remains the same.
Q. How are these
systems secured against interference?
ยท The relay room โ
which is the place from where the entire interlocking/ signalling apparatus can
be controlled or manipulated โ is locked with double locks. One key is with the
station master; the other is in the custody of the signalling staff.
ยท To open the relay
room for any maintenance the station masterโs approval is required, and every
entry and exit is logged in a register.
ยท As technology
improved over the years, the Indian Railways put in place a system in which the
opening and closing of the relay rooms were connected electronically to the
data loggers. Every such event is not only registered on the servers, but it
also triggers an SMS that goes to the officials concerned.
ยท Since relay rooms (or
huts or cabins) are places from where signals can be manipulated, their access
protocol is strictly codified and guarded.
Railways
orders week-long countrywide safety drive on signalling systems:
ยท The Railways had
ordered a week-long countrywide safety drive on signalling systems with special
emphasis on the existing โdouble lockingโ arrangement of its signalling
apparatus at stations.
ยท This is practised to
ensure checks and balances in handling the crucial signalling apparatus at
every critical point, from the point of view of safety and security.
Observations
from this incident:
1.
Signalling neglected?
ยท The current practice
of a disconnection memo to the station master from the signal maintainer
followed by a connection memo is not strictly followed.
ยท As it now appears in
the case of this accident, a signal maintainer or technician of the signalling
department at the Bahanaga Bazar station did open one of the location boxes at
the station to โloopโ the circuit and achieve a โclear pathโ (or a green
signal) for the Coromandel Express
ยท The Indian Railways
may have missed a key step of giving signalling and telecommunications network
upgrade and human resources development upfront a priority while infusing large
capital into the gigantic network to improve rail infrastructure and introduce
modern and faster trains.
2.Requirement of Ground staff
ยท A shake up in the
recruitment process and at the lower level staff is imperative.
ยท Safety and
punctuality of trains depend on the ground staff โ trackmen, maintenance staff
of telecom and signalling, loco-pilots, guards, station masters and the likes.
3. Need
for highly skilled staff
ยท With technology
upgrade and demand for more as well as faster trains, Railways cannot afford to
have semi-skilled staff at these levels anymore. We need to have highly skilled and motivated personnel
with better pay and training.
ยท These personnel should become part of the working group protocols rather than be looked down, while the signalling and telecommunications wing should be given its due in decision making.
1. Vacancies
ยท Most of the posts at this level are not filled on time, either due to the recruitment process itself or because posts are being done away with due to shift to the automatic-digital system.
2. Outsourcing
ยท The issue of outsourcing certain critical works had also received flak as it is allotted to the lowest bidder resulting in tardy maintenance.
3.
Encroachment:
ยท The idea of enhancing speeds is to run more trains and see to it that the trains are running on time (set timings are good). Yet, we cannot simply increase speeds without ensuring tracks are free of encroachers by fencing or setting up walls in populated areas.
4.
Loop lines :
ยท The South Central Railway (SCR) zone mostly has a single line of about 3,663 km, double line of 2,645 km and a triple line of 165 km, which should explain the congestion and reasons why loop lines near stations play a vital role. These sectional points help the Railway authorities to move the slow moving passenger and freight trains into loop lines to enable faster trains to speed through.
5.
Causes of Derailment:
ยท The major causes of
derailments are rail fractures, weld failures, track defects and rolling stock
defects among others.
Way Forward:
ยท In the 2023-24 Union
Budget, the Railways received a record allocation of โน2.40 lakh crore. However,
when capital expenditure on crucial activities related to safety such as track
renewal and signalling and telecom are considered, their shares dwindled or
stagnated over the last few years. Allocation for track renewal dipped to 7.2%
and expenditure proposed for signalling remained at 1.7% in FY24 when
considered as a share of budgetary support for capital expenditure
ยท Retired as well as
serving officers are suggesting a modern signalling system equivalent to
European Train Control System (ECTS), at least on the new lines under
construction, to begin with, by spending a few crores extra.
ยท With this, we can
have a total tracking of the system, remove the human element, and have a
fail-safe method, along with running more trains at better frequency and
timings