14-07-2014, 12:01 PM
INDIAN RAILWAY HISTORY
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SUMMARY OF GROWTH OF ASSETS IN INDIAN RAILWAYS OVER THE YEARS AFTER INDEPENDENCE
The Indian Railways has three gauges: broad gauge (1.676 meter), meters gauge (1 meter) and narrow gauge (0.762 and 0.610 meter). In 1950-51, the combined route kilometers of these gauges were 53,597. In 1995-96 the route length rose to 62,915 km showing a total increase of 9,336 m which represents an increase of 17.42 per cent and an average annual increase of 0.38 percent which was the highest in the Sixth Plan, followed by the First Plan. Electrification in the Indian Railways started in 1925, but remained confined mostly to suburban traffic. Till 1955-56, the electrified route kilometers were just 388 which increased to 748 by 1960-61, registering an increase of 92.7 percent at an average growth of 18.5 per cent per year. The average annual growth rate till 1995-96 was 388. The electrified route length was 0.72 per cent of the total route length in 1950-51 which went up to 19.5 per-cents in 1995-96.In 1950-55, the number of railway stations in the country was 5,976 which gradually rose to 7,068 in 1995-96. In 1950-51, the freight traffic on railways was 93 million tones originating, of which the revenue-earning traffic was 73.2 million tones originating. Since then, both the total traffic and the revenue-earning traffic have been showing an upward trend though not consistently and have increased to 405.5 and 390.7 million tones originating respectively in 1995-96 with an annual average growth rate of 5.38 and 6.39 per cent respectively. The increase in revenue-earning traffic in recent years, particularly during the last five years, has been largely the result of reduction in the volume of non revenue-earning traffic.
GENERAL DESCRIPTION OF LOCOMOTIVE
AC locomotive are designed haul goods and passengers trains.Locomotive are designed operation on 25KV ,50Hz AC single phase overhead lines, locomotive are co-co type consisting two single on 2 bogles ,each having 3 driving axles ,each bogle is equipped with 3 axles hung nose suspended motors to drive the axle through pinion & gear.
Current is collected from overhead line by pantograph & fed to a transformer through vacuum/air blast circuit breaker on roc the transformer steps down v/g from 25KV to 200V. It is then converted to DC through 2 bridge connected silicon rectifiers &fed to traction motors. Speed regulation is obtained by varying the v/g at motor terminals by tap charger, traction motors are permanently in 6 pole connections.
Loco is provided with air brakes and rheostat (dynamic) breaking.The auxiliary machines are fed from ARNO converter which converts the incoming AC single phase to three phase supply at 415 V.
IMPORTANT FUNCTION
Major Inspection: AOH/IOH (18 months for WAG-7 & 12 months for WAP -4 Locos.)
Monthly Schedule Inspection: IA, IB, IC, IO, & ICO (45 days for WAG & 30 days for WAP4 Locos).
Wheel Repair: HITACHI roller bearing wheels.
Accident Repair: 32 locos have been repaired till date.
Drives: Cyclic checks and implementation of various important safety measures to achieve reliability, availability & safety.
Quality Checking: All locos going out of shed is being checked for the quality of work done on major equipments& specifically checked for all safety items.
Special Works: All modifications advised by RDSO & decision taken in shed for reliability is being carried out.
Other Railway: Other railway locomotives are being thoroughly attended.
Locomotive Arrangement: Material Management, Man Management /Inventory Control/Expenditure Control.
ABOUT THE COMPANY
CLW started Traction Motor manufacture from 1969 with Alsthom design of MG-1580 motors and TAO -659 motors and switched over to HS15250, 850HP Traction Motors for which technology was received from HITACHI, Japan. HS 15250A Traction Motor production started in 1988-89.
Now with the advent of three phase technology of locomotives from Bombardier Transportation, Switzerland, CLW has geared up to manufactures 1000HP and 1500HP state-of-the-art-3-phase traction motors for freight (WAG-9) and passenger (WAP-5&WAP-7) locomotives.
CLW also has in house manufacturing facilities of other Electric Power and Control equipments i.e. smoothing reactor, Inductive Shunt, Master Controller, Traction Braking Switch, Electro –Pneumatic (EP) Contactors and Reversers
INTRODUCTION
units and electric locomotive, other electric vehicles such as electric milk floats, elevators, conveyers and trolly buses, as well as vehicles with transmission systems such as diesel electric, electric hybrid vehicles and battery electric vehicles. Additionally, electric motors in other product (such as the main motor in washing machine) are described as traction motors.
Traction motors is a 4 pole DC series motor in which field winding is connected with armature. It is forced ventilated machine arranged for axle mounting on sleeve wearing. Transverse movement is limited by the flange so axle supervision bearing. An electric locomotive as well as diesel-electric locomotive in Indian railway contain six de traction motors at once.
A railway electrification system supplies electrical energy to railway locomotives and multiple units so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world. Railway electrification has many advantages but requires heavy capital expenditure for installation.
In India 1,500V DC and 25KV AC, 50 Hz is used for mains lines trains. The 1500V DC overhead system (negative earth, positive centenary) is used around Mumbai. The Mumbai region is the last bastion of 1500V DC electrified lines of Indian railways
POLES OF DC MOTOR
The magnetic poles of DC motor are structures fitted onto the inner wall of the yoke with screws. The construction of magnetic poles basically comprises of two parts namely, the pole core and the pole shoe stacked together under hydraulic pressure and then attached to the yoke. These two structures are assigned for different purposes, the pole core is of small cross sectional area and its function is to just hold the pole shoe over the yoke, whereas the pole shoe having a relatively larger cross-sectional area spreads the flux produced over the air gap between the stator and rotor to reduce the loss due to reluctance. The pole shoe also carries slots for the field windings that produce the field flux
FIELD WINDING OF DC MOTOR
The field winding of dc motor are made with field coils (copper wire) wound over the slots of the pole shoes in such a manner that when field current flows through it, then adjacent poles have opposite polarity are produced. The field windings basically form an electromagnet, that produces field flux within which the rotor armature of the dc motor rotates, and results in the effective flux cutting
BBCR (BURN BEHIND COMMUTATOR RISER)
Whenever the welding of power coil is loose air gap is present between the commutator riser and power coil conductors which offers high resistance .In power coil high current is flow which generate heat in the gap due to present of high resistance .This heat is damage the insulation and burn it.
Power conductors are joint by welding called tig welding .If any welding is loose create BBCR. This welding is firstly checked by DROP TEST. In the drop test the resistance of individual conductor’s resistance is much high shows air resistance means lose welding which is to be tight.
Variation of ±.05 m ohm is allowed in normal class
CONE BURNT
The rotor of traction motor moves very fast due to which heat is generated at the cone. This heat is gradually increase with time .When heat is become high it is damaged or burn the mica insulation, which is used for insulate the cone from commutator. These type of failure is called cone burnt. When insulation damaged commutator become short circuited with cone and shaft. This short circuiting is very dangerous
OVALITY
The shape of the commutator is circular in normal condition. The brushes are placed on the commutator with approximate 3kg tension. Due this high tension the shape of commutator is slightly changes from circular and becomes some ova. This effect is called ovality.Due to ovality brushes loss is increase and connect is not make properly which provide pulsation brushes is also rubbed more.
38WHEEL SPIN
On a steam locomotive, the driver must reduce the steam admission to the cylinders by easing closed (or partially closed) the throttle/regulator when he hears the wheels start to spin. On diesel or electric locomotives, the current drawn by individual or groups of traction motors are compared - the motor (or group) which draws proportionally less amps than the others is deemed to be in a state of slip - and the power is reduced. Some systems - EMD Super Series for one - measure known wheel speed against ground speed as registered on a Doppler Radar. Many locomotives additionally use sand, which is applied to the wheel/rail contact point to improve adhesion - this is either controlled automatically, or manually by the driver (Foamer? No Way, 25 Apr 98). See also Wheel Spin Relay
CONCLUSIONS
By attending the 30 days training in electric traction Ahmedabad division western railway Iconclude that In this overall training of one month I put my greatest effort to understand &explore more & more about the loco and electric traction. But the loco is such a complexmachine which has so many function & components which need so much time to understand.But I try my best to utilize this short span of time to bring out the valuable knowledge about theloco and electric traction.
[attachment=65818]
SUMMARY OF GROWTH OF ASSETS IN INDIAN RAILWAYS OVER THE YEARS AFTER INDEPENDENCE
The Indian Railways has three gauges: broad gauge (1.676 meter), meters gauge (1 meter) and narrow gauge (0.762 and 0.610 meter). In 1950-51, the combined route kilometers of these gauges were 53,597. In 1995-96 the route length rose to 62,915 km showing a total increase of 9,336 m which represents an increase of 17.42 per cent and an average annual increase of 0.38 percent which was the highest in the Sixth Plan, followed by the First Plan. Electrification in the Indian Railways started in 1925, but remained confined mostly to suburban traffic. Till 1955-56, the electrified route kilometers were just 388 which increased to 748 by 1960-61, registering an increase of 92.7 percent at an average growth of 18.5 per cent per year. The average annual growth rate till 1995-96 was 388. The electrified route length was 0.72 per cent of the total route length in 1950-51 which went up to 19.5 per-cents in 1995-96.In 1950-55, the number of railway stations in the country was 5,976 which gradually rose to 7,068 in 1995-96. In 1950-51, the freight traffic on railways was 93 million tones originating, of which the revenue-earning traffic was 73.2 million tones originating. Since then, both the total traffic and the revenue-earning traffic have been showing an upward trend though not consistently and have increased to 405.5 and 390.7 million tones originating respectively in 1995-96 with an annual average growth rate of 5.38 and 6.39 per cent respectively. The increase in revenue-earning traffic in recent years, particularly during the last five years, has been largely the result of reduction in the volume of non revenue-earning traffic.
GENERAL DESCRIPTION OF LOCOMOTIVE
AC locomotive are designed haul goods and passengers trains.Locomotive are designed operation on 25KV ,50Hz AC single phase overhead lines, locomotive are co-co type consisting two single on 2 bogles ,each having 3 driving axles ,each bogle is equipped with 3 axles hung nose suspended motors to drive the axle through pinion & gear.
Current is collected from overhead line by pantograph & fed to a transformer through vacuum/air blast circuit breaker on roc the transformer steps down v/g from 25KV to 200V. It is then converted to DC through 2 bridge connected silicon rectifiers &fed to traction motors. Speed regulation is obtained by varying the v/g at motor terminals by tap charger, traction motors are permanently in 6 pole connections.
Loco is provided with air brakes and rheostat (dynamic) breaking.The auxiliary machines are fed from ARNO converter which converts the incoming AC single phase to three phase supply at 415 V.
IMPORTANT FUNCTION
Major Inspection: AOH/IOH (18 months for WAG-7 & 12 months for WAP -4 Locos.)
Monthly Schedule Inspection: IA, IB, IC, IO, & ICO (45 days for WAG & 30 days for WAP4 Locos).
Wheel Repair: HITACHI roller bearing wheels.
Accident Repair: 32 locos have been repaired till date.
Drives: Cyclic checks and implementation of various important safety measures to achieve reliability, availability & safety.
Quality Checking: All locos going out of shed is being checked for the quality of work done on major equipments& specifically checked for all safety items.
Special Works: All modifications advised by RDSO & decision taken in shed for reliability is being carried out.
Other Railway: Other railway locomotives are being thoroughly attended.
Locomotive Arrangement: Material Management, Man Management /Inventory Control/Expenditure Control.
ABOUT THE COMPANY
CLW started Traction Motor manufacture from 1969 with Alsthom design of MG-1580 motors and TAO -659 motors and switched over to HS15250, 850HP Traction Motors for which technology was received from HITACHI, Japan. HS 15250A Traction Motor production started in 1988-89.
Now with the advent of three phase technology of locomotives from Bombardier Transportation, Switzerland, CLW has geared up to manufactures 1000HP and 1500HP state-of-the-art-3-phase traction motors for freight (WAG-9) and passenger (WAP-5&WAP-7) locomotives.
CLW also has in house manufacturing facilities of other Electric Power and Control equipments i.e. smoothing reactor, Inductive Shunt, Master Controller, Traction Braking Switch, Electro –Pneumatic (EP) Contactors and Reversers
INTRODUCTION
units and electric locomotive, other electric vehicles such as electric milk floats, elevators, conveyers and trolly buses, as well as vehicles with transmission systems such as diesel electric, electric hybrid vehicles and battery electric vehicles. Additionally, electric motors in other product (such as the main motor in washing machine) are described as traction motors.
Traction motors is a 4 pole DC series motor in which field winding is connected with armature. It is forced ventilated machine arranged for axle mounting on sleeve wearing. Transverse movement is limited by the flange so axle supervision bearing. An electric locomotive as well as diesel-electric locomotive in Indian railway contain six de traction motors at once.
A railway electrification system supplies electrical energy to railway locomotives and multiple units so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world. Railway electrification has many advantages but requires heavy capital expenditure for installation.
In India 1,500V DC and 25KV AC, 50 Hz is used for mains lines trains. The 1500V DC overhead system (negative earth, positive centenary) is used around Mumbai. The Mumbai region is the last bastion of 1500V DC electrified lines of Indian railways
POLES OF DC MOTOR
The magnetic poles of DC motor are structures fitted onto the inner wall of the yoke with screws. The construction of magnetic poles basically comprises of two parts namely, the pole core and the pole shoe stacked together under hydraulic pressure and then attached to the yoke. These two structures are assigned for different purposes, the pole core is of small cross sectional area and its function is to just hold the pole shoe over the yoke, whereas the pole shoe having a relatively larger cross-sectional area spreads the flux produced over the air gap between the stator and rotor to reduce the loss due to reluctance. The pole shoe also carries slots for the field windings that produce the field flux
FIELD WINDING OF DC MOTOR
The field winding of dc motor are made with field coils (copper wire) wound over the slots of the pole shoes in such a manner that when field current flows through it, then adjacent poles have opposite polarity are produced. The field windings basically form an electromagnet, that produces field flux within which the rotor armature of the dc motor rotates, and results in the effective flux cutting
BBCR (BURN BEHIND COMMUTATOR RISER)
Whenever the welding of power coil is loose air gap is present between the commutator riser and power coil conductors which offers high resistance .In power coil high current is flow which generate heat in the gap due to present of high resistance .This heat is damage the insulation and burn it.
Power conductors are joint by welding called tig welding .If any welding is loose create BBCR. This welding is firstly checked by DROP TEST. In the drop test the resistance of individual conductor’s resistance is much high shows air resistance means lose welding which is to be tight.
Variation of ±.05 m ohm is allowed in normal class
CONE BURNT
The rotor of traction motor moves very fast due to which heat is generated at the cone. This heat is gradually increase with time .When heat is become high it is damaged or burn the mica insulation, which is used for insulate the cone from commutator. These type of failure is called cone burnt. When insulation damaged commutator become short circuited with cone and shaft. This short circuiting is very dangerous
OVALITY
The shape of the commutator is circular in normal condition. The brushes are placed on the commutator with approximate 3kg tension. Due this high tension the shape of commutator is slightly changes from circular and becomes some ova. This effect is called ovality.Due to ovality brushes loss is increase and connect is not make properly which provide pulsation brushes is also rubbed more.
38WHEEL SPIN
On a steam locomotive, the driver must reduce the steam admission to the cylinders by easing closed (or partially closed) the throttle/regulator when he hears the wheels start to spin. On diesel or electric locomotives, the current drawn by individual or groups of traction motors are compared - the motor (or group) which draws proportionally less amps than the others is deemed to be in a state of slip - and the power is reduced. Some systems - EMD Super Series for one - measure known wheel speed against ground speed as registered on a Doppler Radar. Many locomotives additionally use sand, which is applied to the wheel/rail contact point to improve adhesion - this is either controlled automatically, or manually by the driver (Foamer? No Way, 25 Apr 98). See also Wheel Spin Relay
CONCLUSIONS
By attending the 30 days training in electric traction Ahmedabad division western railway Iconclude that In this overall training of one month I put my greatest effort to understand &explore more & more about the loco and electric traction. But the loco is such a complexmachine which has so many function & components which need so much time to understand.But I try my best to utilize this short span of time to bring out the valuable knowledge about theloco and electric traction.