Main Project

Automatic Railway gate control and parameter monitoring

ABSTRACT

The main purpose of this project is to provide cost effective safety measures at level

crossings in railways. This project is a part of a complete system for monitoring the

operation of an LC gate without manning it. It basically collects data and performs

actions (i.e opening and closing of gate) on the basis of certain parameters which are

monitored using electronic equipments fitted at the unmanned LC gate. Manning an

LC gate is a really costly affair as it not only involves the salary for the employee but

also future benefits like PF etc, while in the case of such efficient methods the only

costs involved are maintenance costs. It works on the data provided by the GPS

system on the loco, which sends out latitude and longitudinal coordinates which are

compared at the LC gate and the necessary warnings are given out and after ensuring

that no vehicle is obstructing the path the gate is closed and the driver on the loco is

informed. In this way the LC gate is closed before the train arrives and safety of

vehicular traffic is ensured.

The fundamental process in our system is obtaining train location using GPS

technology and transmitting the data to the control unit for data processing and

information analysis. Real- time positioning information received by the server is

made meaningful and extremely useful for the end user. The availability of this

information allows the Train Controller to take accurate decisions as for the train

location. Positioning data along with train speed helps the administration to identify

the possible safety issues and react to them effectively using the communication

methods provided by the system.

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Automatic Railway gate control and parameter monitoring

SL NO TOPIC PAGE NO

1 INTRODUCTION 3

2 CASE STUDY – INDIAN RAILWAYS 6

3 FACTORS RESPONSIBLE FOR ACCIDENTS 8

3.1 TYPES OF LEVEL CROSSING 9

3.2 CURRENTLY AVAILABLE LC PROTECTION SYSTEMS 10

3.2.1 CROSSING WARNING SIGNAL 10

3.2.2 MECHANICAL CROSSING BARRIER 11

4 GENERAL DESCRIPTION OF SYSTEM 12

4.1 BLOCK DIAGRAM 14

4.2 MAIN COMPONENTS OF THE SYSTEM

4.2.1 RF TRANSCEIVER

4.2.2 PIR SENSORS 19

5 FUTURE TRENDS 20

6 RECOMMENDATION 22

7 CONCLUSION 23

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Automatic Railway gate control and parameter monitoring

CHAPTER 1

INTRODUCTION

Indian Railways has more than 64015 km of track and 6909 stations. It has the

world's 4th largest railway network. The railway traverse the length and breadth of

the country carry over 20 million passengers and 2 million tons of freight daily. It is

one of the world's largest commercial utility employer with more than 1.6 million

employees. Given the size of operation, eliminating accidents is an unrealistic goal

and at best they can only minimize the accident rate. Human error is the primary

cause leading to 83pc of all train accidents in India. While accident rates are low-0.55

accidents per km, the absolute no. of people killed is high because of the large no. of

people making use of the network.

While strengthening and modernization of railways infrastructure is in progress much

of the network still uses old signaling methods. Lack of funds is a major constraint for

speedy modernization of the network. Now India also has the 3rd largest road

network in the world as a result there are a lot of places where the rail track comes in

the way of road traffic. In these places we use level crossings. A level crossing is a

crossing on one level without recourse to a bridge or tunnel of a railway line by a

road or path. There is a risk of serious collisions at level crossings and may result in

multiple fatalities.

A clear example of the line of fatalities that can occur in a level crossing mishap is

given by the Nagpur Level crossing disaster which was an accident that occured on 3

Feb 2005 where 55 people died. The accident happened on an isolated, unmanned

level crossing, when a wedding party of 70 people was being transported to the

ceremony on a trailer being towed by a tractor. The crossing had no attendant or

barriers. The locomotive struck the trailer and stopped just after the crossing, the

crumpled trailer still underneath it.

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Automatic Railway gate control and parameter monitoring

Taking such incidents into account it is extremely important to introduce safety

measures in unmanned level crossings. The problems faced in installing safety

measures are:

*cost involved in manning an unmanned LC gate.

*eliminating human error which are major cause of accidents.

*providing efficient interlocking methods which are foolproof and cost effective as

the present interlocking methods are quite costly.

Taking all these factors into consideration this project aims at introducing an efficient

system which controls the operation of the LC gate without human involvement and

thereby reducing the chance of accidents due to human error and providing a cost

effective method to provide safety at unmanned level crossings.

Global Positioning System 

A GPS tracking unit is a device that uses the Global Positioning System to

determine the precise location of a vehicle, person, or other asset to which it is

attached and to record the position of the asset at regular intervals. The recorded

location data can be stored within the tracking unit, or it may be transmitted to a

central location data base, or internet-connected computer, using

a cellular (GPRS or SMS), radio, or satellite modem embedded in the unit. This

allows the asset's location to be displayed against a map backdrop either in real time

or when analyzing the track later, using GPS tracking software. Global Positioning

Satellite (GPS) communications systems are now in common use for sea, air and land

transport navigation applications. GPS uses communications links with number of

satellites to establish the navigation coordinates of aircraft or surface transport

receivers. GPS systems are on the whole very inexpensive. The BART system,

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Automatic Railway gate control and parameter monitoring

known as an AATCS (Advanced Automatic Train Control system) was developed by

Nippon Signal in conjunction with Hughes and Harmon of the United States. As

compared with ATCS, the advantage of using GPS for train control functions it is

more economical. However, the system does have some shortcomings, the most

significant of which is that for certain applications it contributes error certainly

excessive for locating trains in relation to level crossings.

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Automatic Railway gate control and parameter monitoring

CHAPTER 2

A CASE STUDY -INDIAN RAILWAYS.

Indian Railways is massive and has approximately 63,000 route kilometers of

track with 8500 stations, 17,550 manned level crossings, 21,880 unmanned level

crossings with an average of one at every 1.5 kilometers. These are various types of

level crossings such as, some are equipped with barriers, some are open crossings,

some abetting canals. Though the total number of accidents taking place on Indian

railways is on the decline, the accidents at level crossings (LCs) are also

comparatively low when compared to advanced railway systems (0.1 per million train

kilometers). However, there is a concern due to the raising trend and associated

severity of LC accidents.

Year

Passengers

Rly. Staff

Killed

Rly.

Staff

Others Passengers Total Injured

railway

staff

Others Passengers total

2004-2005 50 5 181 236 191 12 209 412

2005-2006 168 9 138 315 483 31 113 627

2006-2007 38 6 164 208 227 24 151 402

2007-2008 9 10 172 191 246 31 135 412

2008-2009 52 12 145 209 257 22 165 444

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Automatic Railway gate control and parameter monitoring

The number of casualties in train accidents is essentially fortuitous and not

strictly susceptible to comparison. The position of casualties in train accidents during

the last 5 years has been as under:-

The term ‘accident’ envelopes a wide spectrum of occurrences with or without

significant impact on the system. Consequential train accidents include mishaps with

serious repercussion in terms of loss of human life or injury, damage to railway

property or interruption to rail traffic of laid down threshold levels and values. These

consequential train accidents include collisions, derailments, fire in trains, road

vehicles colliding with trains at level crossings, and certain specified types of

‘miscellaneous’ train mishaps.

The number of consequential train accidents decreased from 193 (excluding

one train accident on Konkan Railway) during 2007-2008 to 177 during 2008-2009.

The number of train accidents per million train kilometers, which is the universally

accepted safety index, also dropped from 0.22 in 2007-08 to 0.20 in 2008-2009. The

continuous reduction in the number of train accidents per million train kilometers

which has fallen from 5.5 in 1960-61 to 0.20 in 2008-09, is indicative of sustained

improvement in safety performance.

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Automatic Railway gate control and parameter monitoring

CHAPTER 3

FACTORS RESPONSIBLE FOR ACCIDENTS

Level crossings are certainly not homogeneous in terms of accident risk

probabilities. Some have a much greater propensity for accidents than others.

Quantified Risk Analysis (QRA) provides a suitable basis for establishing level

crossing improvement priorities. This is done by allowing a ranking of level crossings

in terms of their accident risk probability. Those crossings with high accident

probabilities would normally qualify for funding allocations, while those with low

accident probabilities would be assigned a low priority for improvement funding.

QRA results should be linked to the Level Crossing Inventory Recording System

which provides for the reporting of hazard probabilities against each level crossing.

Factors influencing the probability of accident occurrence at level crossings include:

1. Rail traffic density (measured in terms of the maximum number of trains passing

the crossing within a 24 hour period);

2. Road traffic density (measured in terms of the maximum number of motor vehicles

of all types passing the crossing within a 24 hour period);

3. Presence of physical obstructions restricting the visibility of the track, warning

signs or signals to road users;

4. Absence of full width barrier protection at level crossings;

5. Absence of flashing lights and audible warning devices at level crossings;

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Automatic Railway gate control and parameter monitoring

6. Poor road surface condition at level crossings (leading to the grounding of low

slung road vehicles);

7. Poor alignment and elevation of the road crossing the track (the road may cross the

track at an oblique angle or may approach the crossing on a steeply rising grade).

It is strongly recommended that accident probabilities should be calculated

for all official level crossings on the railway system (and possibly for the more

critical of the unofficial crossings) and that these calculations should be updated to

continuously to cater to the changes to any of the factors listed above. In addition to

accident probabilities, it would also be highly desirable to calculate the probability of

multiple fatalities and injuries resulting from accidents at individual crossings. The

probability of such outcomes is influenced by all of the above factors and also by the

level of usage of crossings by crowded road and rail passenger vehicles.

3.1. TYPES OF LEVEL CROSSING

Barriers which are operated manually tend to be closed for longer periods than

barriers which may be remotely controlled by crossing staff using electrical actuation

systems, simply because the physical act of closing barriers will require more

time than if the barriers can be activated remotely by mechanical or electrical

means. Typically, if barriers remain closed for excessive periods on crossings carrying a

high volume of road and rail traffic, the build-up of road traffic will exceed the capacity of

the crossing to safely discharge this build-up before the next train arrival at the crossing.

Road traffic build-up in this situation obeys the rules of Queuing Theory: the longer the

barrier closure, the greater the build-up and the slower the passage of motor vehicles over

the crossing once the barriers have been raised. Queuing theory is seldom followed in Asian

regions. The current norm for grade separation is as under:

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Automatic Railway gate control and parameter monitoring

Item Daily traffic density /

traffic movement

Type of crossing

indicated

1 TVU < 6,000 Unmanned Level crossing

2 6,000 less than or

= TVU < 10,000

All unmanned level

crossings to be manned on

programmed basis

3 10,000 less than or = TVU

<100,00

Manned Level Crossings

4 TVU greater than or

= 100,000

Road flyover / overpass

3.2. CURRENTLY AVAILABLE LEVEL CROSSING PROTECTION

SYSTEMS

3.2.1 Crossing Warning Signals:

In general, these are of two types: automatic and manually operated signals.

Manually activated signals are operated by level crossing staff, on instructions

transmitted by telephone or telegraph signal from the nearest station. Automatic

warning signals need short track circuits or markers which detect trains and activate

warning indications at level crossings. These warning indications are usually flashing

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Automatic Railway gate control and parameter monitoring

lights, or sounds emitted by bells or claxons (horns), or a combination of these two. If

visibility at a crossing is a problem, then flashing lights may be increased in intensity

and may be installed so as to suit the layout of the surrounding land and buildings.

Similarly, audible-warning devices may be increased in frequency and amplitude, to

compensate for the sound absorption qualities of the physical environments of level

crossings. From experience, the level of safety afforded by these devices on their own

is insufficient. This is particularly true in the case of level crossings accommodating

two or more tracks. If unmanned level crossings are to be contemplated in these

situations, then some form of train approach indication becomes very essential.

3.2.2. Mechanical Crossing Barriers:

Mechanical crossing barriers are operated by level crossing staff using hand

or electrically powered levers, winches or windlasses. In addition, mechanical

barriers providing complete protection of level crossings are connected to manually

operated warning signals. Combination systems of this type are widely used within

the developing countries of Asia since they may be manufactured inexpensively

within the region. By contrast ,automatic electronic crossing devices are wholly

manufactured within developed countries and must be imported at substantial

cost for installation within the developing countries of the region.

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Automatic Railway gate control and parameter monitoring

CHAPTER 4

GENERAL DESCRIPTION OF THE SYSTEM

In GPS based wireless protection system both Loco and gate units will be

provided with dual wireless communication system which provides a reliable

communication system. The Loco unit identifies the level crossing zone appropriately

and informs the gate unit (either manned or unmanned), the current status of the train

so that the gate control system can be activated. The gate control system or the data

reception section will go through a series of parameter monitoring procedures. The

major components of the gate controlling system are:

1. R F Transciever

2. Microcontroller (PIC)

3. PIR sensors

4. Alarm circuitry

5. Warning signal circuitry

6. Motor circuitry(server motor or stepper motor)

All the components are connected to the microcontroller. The microcontroller will be

programmed in such a way that when the RF transceiver receives signal, the

microcontroller will perform a certain set of functions. First of all the alarm circuitry

will be activated to give the primary warning to the road vehicles. Then the PIR

sensors will be activated to check whether any vehicles have been trapped in between

the gates. PIR sensors are highly sensitive array of IR LEDs. If any vehicles are

detected in between then certain will be allotted for them before the gate gets closed.

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Automatic Railway gate control and parameter monitoring

Otherwise the motor circuitry will be activated for the gate closure along with the

secondary signal warning system to give the road vehicles the final warning. All these

are timed operations and must be programmed by giving specific delays using the in-

built timers in the microcontroller. When the train gets passed the particular level

cross another signal will be received using RF transceiver and the microcontroller

will again activate the motor circuitry for reverse operation and the gate gets opened

for the road vehicles. All the registers and timers will be reset to the initial condition

after these operations.

The PIR sensors specified above can be replaced by simple IR sensors at 4 corners of

the level cross to reduce the cost factor. It can also be realized using a pair of

ultrasonic sensors. All of these will be having a feedback so that any objection

detected will result in a delay of gate closure and a warning signal to the train through

RF transceiver. This signal will inform the driver of the train to reduce the speed

below 15km/hr.

This automatic controlling system can be implemented in manned level cross also by

expanding it by including gate interlocking and signaling. It will demand more

complexity because of the track circuitry and axle counter circuitry for signaling and

interlocking.

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Automatic Railway gate control and parameter monitoring

4.1. BLOCK DIAGRAM

TRAIN PIR sensors

14

GPS AND RF TRANSCEIVER

Level cross Level cross

Level cross Level crossRF transceiver

RF transceiver

RF TRANCIEVER

MICRO

CONTROLLER

MOTOR CIRCUITRY

PIR SENSORS

ALARM CIRCUITRY

WARNING SIGNAL

Automatic Railway gate control and parameter monitoring

4.2. MAIN COMPONENTS OF THE SYSTEM

4.2.1 RF TRANSCEIVER

RF transceivers are electronic devices that receive and demodulate radio frequency

(RF) signals, and then modulate and transmit new signals. They are used in many

different video, voice and data applications. RF transceivers consist of an antenna to

receive transmitted signals and a tuner to separate a specific signal from all of the

other signals that the antenna receives. Detectors or demodulators extract information

that was encoded before transmission. Radio techniques are used to limit localized

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Automatic Railway gate control and parameter monitoring

interference and noise. To transmit a new signal, oscillators create sine waves which

are encoded and broadcast as radio signals.   

Selecting RF transceivers requires an understanding of modulation methods and radio

techniques. Amplitude modulation (AM) causes the baseband signal to vary the

amplitude or height of the carrier wave to create the desired information content.

Frequency modulation (FM) causes the instantaneous frequency of a sine wave

carrier to depart from the center frequency by an amount proportional to the

instantaneous value of the modulating signal. On-off key (OOK), the simplest form of

modulation, consists of turning the signal on or off. Amplitude shift key (ASK)

transmits data by varying the amplitude of the transmitted signal. Frequency shift key

(FSK) is a digital modulation scheme using two or more output frequencies. Phase

shift key (PSK) is a digital modulation scheme in which the phase of the transmitted

signal is varied in accordance with the baseband data signal. In terms of radio

techniques, some RF transceivers use direct-sequence spread spectrum. Others use

frequency-hopping spread spectrum.

Important specifications for RF transceivers include data rate, sensitivity, output

power, communication interface, operating frequency, measurement resolution, and

maximum transmission distance. Data rate is the number of bits per second that can

be transmitted. Sensitivity is the minimum input signal required. Communication

interface is the method used to output data to computers. General-purpose interface

bus (GPIB) is the most common parallel interface. Universal serial bus (USB), RS232

and RS485 are common serial interfaces. Operating frequency is the range of signals

that can be broadcast and received. Measurement resolution is the minimum digital

resolution. Maximum transmission distance is the largest distance by which the

transmitter and receiver can be separated. Additional considerations when

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Automatic Railway gate control and parameter monitoring

selecting RF transceivers include power source, supply voltage, supply current,

transmitter inputs, receiver inputs, and RF connector types.

4.2.2 PIR SENSOR

A Passive Infrared sensor (PIR sensor) is an electronic device that measures infrared

(IR) light radiating from objects in its field of view. PIR sensors are often used in the

construction of PIR-based motion detectors. Apparent motion is detected when an

infrared source with one temperature, such as a human, passes in front of an infrared

source with another temperature, such as a wall.

All objects above absolute zero emit energy and is in reference to what is known as

black body radiation. It is usually infrared radiation that is invisible to the human eye

but can be detected by electronic devices designed for such a purpose. The term

passive in this instance means that the PIR device does not emit an infrared beam but

merely passively accepts incoming infrared radiation. “Infra” meaning below our

ability to detect it visually, and “Red” because this color represents the lowest energy

level that our eyes can sense before it becomes invisible. Thus, infrared means below

the energy level of the color red, and applies to many sources of invisible energy.

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Automatic Railway gate control and parameter monitoring

Infrared radiation enters through the front of the sensor, known as the sensor face. At

the core of a PIR sensor is a solid state sensor or set of sensors, made from an

approximately 1/4 inch square of natural or artificial pyroelectric materials, usually in

the form of a thin film, out of gallium nitride (GaN), caesium nitrate (CsNO3),

polyvinyl fluorides, derivatives of phenylpyrazine, and cobalt phthalocyanine. (See

pyroelectric crystals.) Lithium tantalate (LiTaO3) is a crystal exhibiting both

piezoelectric and pyroelectric properties.

The sensor is often manufactured as part of an integrated circuit and may consist of

one (1), two (2) or four (4) 'pixels' of equal areas of the pyroelectric material. Pairs of

the sensor pixels may be wired as opposite inputs to a differential amplifier. In such a

configuration, the PIR measurements cancel each other so that the average

temperature of the field of view is removed from the electrical signal; an increase of

IR energy across the entire sensor is self-cancelling and will not trigger the device.

This allows the device to resist false indications of change in the event of being

exposed to flashes of light or field-wide illumination. (Continuous bright light could

still saturate the sensor materials and render the sensor unable to register further

information.) At the same time, this differential arrangement minimizes common-

mode interference, allowing the device to resist triggering due to nearby electric

fields. However, a differential pair of sensors cannot measure temperature in that

configuration and therefore this configuration is specialized for motion detectors.

In a PIR-based motion detector (usually called a PID, for Passive Infrared Detector),

the PIR sensor is typically mounted on a printed circuit board containing the

necessary electronics required to interpret the signals from the pyroelectric sensor

chip. The complete assembly is contained within a housing mounted in a location

where the sensor can view the area to be monitored. Infrared energy is able to reach

the pyroelectric sensor through the window because the plastic used is transparent to

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Automatic Railway gate control and parameter monitoring

infrared radiation (but only translucent to visible light). This plastic sheet also

prevents the intrusion of dust and/or insects from obscuring the sensor's field of view,

and in the case of insects, from generating false alarms.

The PID can be thought of as a kind of infrared camera that remembers the amount of

infrared energy focused on its surface. Once power is applied to the PID, the

electronics in the PID shortly settle into a quiescent state and energize a small relay.

This relay controls a set of electrical contacts that are usually connected to the

detection input of a burglar alarm control panel. If the amount of infrared energy

focused on the pyroelectric sensor changes within a configured time period, the

device will switch the state of the alarm relay.

PIDs can have more than one internal sensing element so that, with the appropriate

electronics and Fresnel lens, it can detect direction. Left to right, right to left, up or

down and provide an appropriate output signal.

CHAPTER 5

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Automatic Railway gate control and parameter monitoring

FUTURE TRENDS

Our system can be incorporated to design and implement innovative Passenger

Information Systems (PIS) based on real time information of train positions. LED-

Display panels put up at railway stations can display arrival departure time of each

train enabling the public user to make informed decisions on their journeys. Route

number, destination of the arriving vehicle and waiting time can be displayed with

real time information. With accurate forecasting of train arrival-departure at stations,

Railway Department can improve the loyal customer base and also attract new

passengers to railway transport service by winning their trust and reducing user

uncertainty of using public transport facilities. The user experience can be further

enhanced by introducing information Kiosks which can provide information to

travelers in an intuitive and interactive manner to make informed decisions on

selecting train routes and departure time. The interactive kiosk can be used to obtain

travel information such as alternate routes to specified destination, route details on the

railway map and latest information on train schedules etc. As a marketing strategy,

information regarding the particular city, culture and commercial activities can also

be provided to the user through the kiosk. Another extension of the PIS system is

delivering real time train information to handheld devices such as mobile phones and

PDAs. With the increasing interest on mobile applications, access to latest train

schedule information via mobile connection can be influential for improving

customer base of the railway service. Easy to use mobile applications can be designed

and implemented to enable train commuters to easily subscribe to our service and

obtain latest train schedule information via mobile devices.

The use of GSM over RF significantly improves the feasibility and availability of our

system. Despite the high mobile penetration and number of mobile telecom service

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Automatic Railway gate control and parameter monitoring

providers (GSM) covering the island, RF usage and the range is poor in many

available transmitters. Thus, selection of GSM over RF data communication is

feasible and enables island wide service provisioning. A current project of installing

GSM-Railways is on the implementing stage. It is a joint venture done by NOKIA

and INDIAN RAILWAYS. Then the GSM network will be available all over india

wherever there is a railway track. The competition between the GSM service

providers has also lead to high quality GSM services at fair rates. The central control

system includes a server for handling and processing all the position information

received from train locators via the GSM network. It may be used to transmit the

information via massages in mobile phones.

Also a central base station can be implemented so that it can route the data received to

different gates and thereby controlling all the railway stations around a major

junction. It will be working basically as a server to route the data.

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Automatic Railway gate control and parameter monitoring

CHAPTER 6

RECOMMENDATIONS

There is currently considerable research and practical action being taken by the

industry to better safety at level crossings and to implement additional controls and

upgrades to improve level crossing safety performance. The risk at level crossings is

dominated by fatality risk, rather than major or minor injuries. With over 38000 level

crossings and complex nature of road traffic, India ranks better than many advanced

countries in safety at level crossings. The Railways are persistently following the

steps to reduce unmanned level crossing accidents. The safety measures it has been

implemented in manned level cross is almost 100 percent. The only reason of

occurring accidents still are the undisciplined mannerism of people. But in unmanned

level crossings the situation is different. Currently there is no existing system to

provide safety. Even though our proposal is not a full proved system according to the

concern of railways, we will be able to provide safety to a large extent. It has been

experienced that manning of unmanned level crossings is not an ideal solution and a

foolproof arrangement. Because manning a level cross will result in a life long

payment of the employee. Also these level crosses will be having a very less vehicle

traffic to get manned. With proliferation of more manned level crossings in certain

sections, slow down of train operation is also apprehended. The policy of manning

unmanned level crossings is therefore not much enhanced and full proof automatic

management systems will pave the way for a much cheaper and effective way of

ensuring safety.

CHAPTER 7

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Automatic Railway gate control and parameter monitoring

CONCLUSION

The existing signaling and controlling systems of railway gates are dominated by

electrical and mechanical equipments which include large number of relays,axle

counters,track circuits,mechanical levers etc. It has been estimated that the expense of

implementing such a control and signaling network around a railway station is more

than 1crore. The present trend is to replace all these systems by electronic equipments

which are comparatively much cheaper. Our project is also aiding to this present

trend. Although the safety ensured by electronic systems has a lot of loop holes, a

keen and detailed research will revolutionize the field.

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