Head on Generation (HOG) technology

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Head on Generation (HOG) technology
 
What to study?
For Prelims and mains: Features and significance of HOG and EOG technologies.
 
Context: Railway Ministry is upgrading all existing Linke Hofmann Busch (LHB)  coaches with the Head
on Generation (HOG) technology.
Significance: This would cause the trains to become more cost-efficient and less polluting.
 
What is Head on Generation (HOG) technology?

1. The system runs the train’s ‘hotel load’ (the load of air conditioning, lights, fans, and
pantry, etc.)  by drawing electricity from the overhead electric lines through the pantograph .
2. The power supply from the overhead cable is 750 volts at single-phase, and a transformer with a
winding of 945 kVA converts it to a 750 Volts 50 Hz output at 3-phase. This energy is then
provided to the compartments.

 
How is it different from the present EOG technology?
Under the End on Generation (EOG)  system, the train’s ‘hotel load’ (the load of air conditioning, lights,
fans, and pantry, etc.) is provided with electricity from two large diesel generator sets, which supply 3-
phase power at 750 Volts 50 Hz to the entire length of the train.
Each coach then picks up the power supply through a 60 KVA transformer, bringing down the voltage to
110 volts at which level the equipment in the compartment is run. The generator cars are attached to
either end of the train, giving the system its name.
 
Benefits of HOG over EOG:

1. Since the HOG-fitted trains do not require power from diesel generators at all,  they only have
one emergency generator car attached, instead of two regular generator cars.
2. The extra space  created would now be used for an LSLRD (LHB Second Luggage, Guard &
Divyaang Compartment)– meaning more passengers can be accommodated.
3. Cost savings would be significant: Once all LHB trains get the new system, NR 1390 crores
would be saved every year.
4. HOG system is free of air and noise pollution: It would bring down yearly CO2 and NOx
emissions, which are currently at 1724.6 tonnes/annum and 7.48 tonnes/annum respectively, to
zero.
5. The reduction in emissions could also help the Railways accrue carbon credits , and trade
them on the international market.
6. With the noise-emitting generator sets gone,  noise pollution would also drop.

 
Sources: Indian Express.
Indian Railways Fixes Major Constraint in
using HOG technology

Indian Railways in a bid to reduce its dependency on fossil fuel has started to equip its Linke Hofmann Busch(LHB) coaches
with ‘Head on Generation’ (HOG) system.
Under the HOG system electricity supply to run fans, lights, ACs and other on-board equipment on coaches are powered by
electric locomotive without need of running diesel generator.

With reduced requirement of on-board diesel generat set, released space in power car cum guard van can be used for making
compartment for differently abled person and additional space for parcel. Such coaches are already under manufacture by
railway coach factories and expected in service very soon.

However for power supply arrangement in HOG rake from locomotive it is utmost important that HOG system of rake and
locomotive are fully functional and free from defect to avoid any detention and inconvenience to passengers.

Since locomotive and coaching rakes are maintained at different locations hence combined testing of HOG system is
possible only when locomotive is attached to rake and in case of any defect chances of train getting late increases.

Indian Railways’ Electric locomotive shed Kanpur has now come up with an innovative solution to overcome this constraint.
In a statment issued by the North Central Railway zone of Indian Railways it said,” The Electric locomotive shed Kanpur
through provision of “test switch” in HOG circuitry which bypasses need of rake being attached to loco to test functioning of
HOG convertor. “

Through this innovative arrangement now locomotive HOG system can be tested independently thus any possible defect can
be rectified in time,”it further added.

North Central Railway zone is using HOG technology in 16 out of total 17 primary LHB rakes and saving 75,000 liters
diesel annually through reduced running of diesel generator sets.

Similarly,41 locomotives of North Central railway are fitted with HOG convertor to cater all HOG rakes in different primary
train on NCR including Prayagraj Express, Shramshakti Express, Humsafar Express, Shatabdi Express, Chambal
Express,etc.




Indian Railways SCR zone saves crore on

energy bills by introducing new HOG
technology in LHB coaches; details
By: Nikita Prasad | 

Updated: Nov 18, 2019 1:58 PM

The South Central Railway (SCR) zone has introduced the HOG (Head-on-Generation) technology in 11 trains
on its network having LHB coaches, hauled by electric traction.

In the first phase, 11 trains have been converted into HOG technology having LHB coaches and running end-to-end with electric
traction facility.

In a new environmentally-friendly initiative, Indian Railways has cut down on its energy bills and saved big bucks!
The South Central Railway (SCR) zone has introduced the HOG (Head-on-Generation) technology in 11 trains
on its network having LHB coaches, hauled by electric traction. With this, the SCR zone is saving an estimated
sum of Rs 29.3 crore per annum in the first phase of conversion. CH Rakesh, Chief Public Relation Officer
(CPRO), SCR zone has said that the fuel consumption for the 11 trains per annum was 49.7 lakh litres, which
resulted in a cost of more than Rs 35 crore. Under the new HOG system, the electrical energy consumption cost
for the trains is only Rs 5.7 crore per annum. Hence, the estimated savings for the railway zone after the
introduction of HOG technology in all the 11 trains comes to be Rs 29.3 crore.
In the first phase, 11 trains have been converted into HOG technology having LHB coaches and running end-to-
end with electric traction facility. The list of trains which have been converted to HOB technology in the SCR zone
are as follows:
 Train number 12759/12760 Charminar Express
 Train number 12744/12743 Vikrama Simhapuri Amaravati Express
 Train number 12723/12724 Telangana Express
 Train number 22705/22706 Tirupati – JammuTawi Humsafar Express
 Train number 22708/22707 Double Decker Express
 Train number 12733/12734 Narayanadri Express
 Train number 12771/12772 Secunderabad – Nagpur Express
 Train number 12757/12758 Secunderabad – Sirpur Khagaznagar Express
 Train number 12705/12706 Secunderabad – Guntur
 Train number 12795/12796 Lingampalli – Vijayawada Intercity Express
 Train number 12793/12794 Rayalaseema Express
The HOG technology can be implemented in trains running with LHB coaches and caters to the power needs of
coaches such as air-conditioning and lighting, by substituting the previous system of attaching two power cars in
the trains, known as end on generators (EOG). The new HOG system works by distributing the power to trailing
coaches by tapping the overhead power lines. The HOG technology does not require any diesel oil consumption,
hence reducing air and noise pollution. The technology will also provide uninterrupted illumination in the coaches.

Indian Railways takes giant leap with eco-

friendly step; saves crores with new
technology for passenger trains
By: Devanjana Nag | 

December 6, 2019 3:26 PM

In a bid to control the pollution, Indian Railways has developed an improvised converter, Head on Generation
(HOG), in electric locomotives.

For HOG system, locomotives and coaches are required to be modified.

Indian Railways saves crores, becomes more environment-friendly! Premium passenger trains of Indian Railways
with AC coaches generally run on the End-on-Generation (EOG) system. This adds to both air and noise
pollution. In a bid to control the pollution, Indian Railways has developed an improvised converter, Head on
Generation (HOG), in electric locomotives. This can replace diesel generators. It utilizes power from overhead
catenary in order to feed auxiliaries in the coaches hauled by electric locomotives. According to the Railway
Ministry, it saves up to 1 million litres of diesel per train annually.
For HOG system, locomotives and coaches are required to be modified. Over the years, the locomotives that
have been manufactured by Chittaranjan Locomotive Works (CLW) are HOG compliant. Moreover, from April
2018 onwards, the pace of HOG conversion works for Linke Hofmann Busch (LHB) coaches have been
increased to harness the benefits of this high-end technology. Between the period April 2018 and 5 November
2019, a total of 436 trains (cumulatively more than 500 trains) have been turned into HOG compliant trains. Also,
the national transporter aims to convert the remaining EOG LHB rakes into HOG system on an accelerated pace
in order to harness the benefits of the energy-efficient and eco-friendly technology. Some of the advantages of
the HOG system are as follows:
 With HOG system, the noise level reduces from 100 dB to noiseless
 Till now, there has been a significant reduction of CO2 (over 2500 Ton) as well as NOX (over 10 Ton)
emissions
 The HOG system reduced consumption of diesel, leading to huge savings in operational costs to the
tune of over Rs 1,100 crore per annum
 Compared to EOG Power, which is Rs 22/unit, the HOG Power is economical at Rs 6/unit
The first HOG based electric locomotive, loco number 30277 (WAP7) having 2X500 KVA Hotel Load Converter
was introduced by CLW in 2010. So far, over 550 electric locomotives have been provided with HOG system and
are yielding benefits of savings on fuel bills to Indian Railways.
According to the Railway Ministry, all passenger electric locomotives that are being produced in Indian Railways’
Production Units namely CLW, Diesel Loco Modernization Works (DMW) and Diesel Locomotives Works (DLW)
as well as all passenger coaches that are manufactured in Integral Coach Factory (ICF), Modern Coach Factory
(MCF) and Rail Coach Factory (RCF) are now HOG compliant.
Head on Generation (HOG) – A Giant Leap forward through an environment friendly and energy efficient
technology

Over 500 trains are running with HOG scheme There are savings to the tune of over Rs.1100 crores per annum
with conversion of 500 trains into HOG system

Indian cities are struggling with air and noise pollution. The respiratory diseases are increasing at alarming rates
in cities. Premium passenger trains fitted with Air-Conditioned coaches and running traditionally on the End-on-
Generation (EOG) system are also contributing towards air and noise pollution. These trains are using 2 diesel
power cars for feeding power to air-conditioning and lighting load in the passenger coaches which produce an
unbearable noise of around 100dB. Further, these power cars guzzle on an average 3000 liters of diesel per trip
per train contributing to the pollution in the cities.

Indian Railways have come up with an energy efficient and environment friendly innovative solution to address
the issues of air & noise pollution and energy efficiency in running of passenger trains. An improvised converter
has been developed, which is fitted in Electric locomotives which can replace these diesel generators. It uses
power from overhead catenary to feed auxiliaries in the coaches hauled by Electric locomotives. It saves up to 1
Million liters of diesel per train per annum.

This requires locomotives as well as coaches to be modified for making them suitable for HOG. Locomotives
have been manufactured by Chittaranjan Locomotive Works (CLW), over the years, which are HOG compliant.
To harness the benefits of this high-end technology, pace of HOG conversion works of LHB coaches has been
increased from April 2018 onwards. During April 2018 to 5th November 2019, 436 trains (cumulatively over 500
trains) have been converted into HOG compliant trains. It is planned to convert balance End-On-Generation
(EOG) LHB rakes into HOG system on accelerated pace to harness the benefits of energy efficient and
environment friendly technology. The major advantages of HOG system include:

i. Reduction in noise- from 100dB noise to noise less,

ii. Significant reduction of CO2 (over 2500Ton) & NOX(over 10Ton) emissions till now,

iii. Reduced Diesel Consumption leading to huge savings in operational costs to the tune of over Rs.1100 crores
per annum,

iv. Economical- EOG Power Rs 22/unit, HOG Power Rs 6/unit.

Indian Railways has travelled long way since 2010 when Chittaranjan Locomotive Works (CLW) turned out first
HOG based electric loco No.30277 (WAP7) having 2X500 KVA Hotel Load Converter installed in the
locomotive,which is in regular train service since then. As of now more than 550 Electric locomotives have been
provided with HOG converter technology and are yielding benefits of savings on fuel bills to Indian Railways,
besides being a noise less and emission less solution to the EOG variant.

All passenger Electric Locomotives being produced in Production Units of Indian Railways namely CLW, Diesel
Locomotives Works (DLW) & Diesel Loco Modernization Works (DMW) and all passenger coaches manufactured
in Integral Coach Factory (ICF), Rail Coach Factory (RCF) & Modern Coach Factory (MCF) are now HOG
compliant.
Vijayawada railway division saves Rs 4
crore through HOG application 
Power for coaches and traction are drawn from overhead power lines with HOG technology, the latest in
use by the Indian Railways for medium and high-speed trains. 

For representational purposes

VIJAYAWADA: The Vijayawada division of the South Central Railways (SCR), through the
Head on Generation (HOG) technology for some of its train operations, is saving Rs 4.02 crore
every year.

Power for coaches and traction are drawn from overhead power lines with HOG technology,
the latest in use by the Indian Railways for medium and high-speed trains. 

Following the Indian Railways’ decision to save power cost, adoption of HOG has been taken
up on a mission mode.

The work involves modification in the electrical system of power cars and coaches. All new
coaches need to be HOG compliant.
Till date, two rakes for Gudur-Vijayawada Intercity Superfast Express and Vijayawada–
Lingampalli Superfast Express have been converted into HOG. This has resulted in saving of
approximate `4.02 crore per annum. 

The Railways is mainly looking forward to HOG application on its existing fleet of the
locomotive and interconnected rakes where EOG (End on Generation) is functional.

With the new technology, power will be drawn from the overhead cable lines. The power
generator cars, which make noise and emit fumes, will be replaced.

In place of two generator cars, there will be one standby silent generator car only to be used in
emergencies and an LSLRD (LHB Second Luggage, Guard and Divyaang) compartment.

This LSLRD compartment will also be able to use power from the overhead lines. Currently,
the power cost per unit is Rs 36 and, with HOG application, it is available at Rs 6 per unit.

Vijaywada DRM P Srinivas appreciated efforts by senior DEE (maintenance) V Venkataramana

and his team for the works for HOG adoption and opined that the new technology would prove
to be a game-changer for the division.

Indian Railways have come up with an energy-efficient and environment-friendly innovative solution to address
the issues of air & noise pollution and energy efficiency in the running of passenger trains. An improvised
converter has been developed, which is fitted in Electric locomotives which can replace the diesel generators. It uses
power from overhead centenary to feed auxiliaries in the coaches hauled by Electric locomotives. It saves up to 1
Million liters of diesel per train per annum.
Present status of the Rail engines
 Premium passenger trains fitted with Air-Conditioned coaches and running traditionally on the End-on-
Generation (EOG) system are also contributing towards air and noise pollution. 
 These trains are using 2 diesel power cars for feeding power to air-conditioning and lighting load in the
passenger coaches which produce an unbearable noise of around 100dB. 
 Further, these power cars guzzle on an average of 3000 liters of diesel per trip per train contributing to the
pollution in the cities. 
Hence It is planned to convert balance End-On-Generation (EOG) LHB rakes into the HOG system on an accelerated pace
to harness the benefits of energy-efficient and environment-friendly technology.
Brief about Head on Generation system:
 Head on Generation system is an electrical power supply system where electrical power for catering
hotel load of the train, which includes Train Lighting, Air conditioning, Lighting, fannage and other
passenger interface requirement working on the electrical power supply. 
 This scheme is a widely used power supply system by the Railways world over. 
 The power in this system is received from the locomotive. With the introduction of this scheme heavy under-
slung power generating, equipment gets eliminated. 
 Further, it also reduces the use of Diesel sets employed in power cars at the End on Generation system.
Advantages of the HOG system
 Reduction in noise- from 100dB noise to noiseless,
 Significant reduction of CO2 (over 2500Ton) & NOX(over 10Ton) emissions till now, 
 Reduced Diesel Consumption leading to huge savings in operational costs to the tune of over Rs.1100 crores
per annum,
 Economical- EOG Power Rs 22/unit, HOG Power Rs 6/unit.