head-on-generation-hog

Context:

Railway Ministry has announced that it would be upgrading all existing Linke Hofmann Busch (LHB) coaches with the Head on Generation (HOG) technology, a move that would cause the trains to become more cost-efficient and less polluting.

Background-

  • Linke Hofmann Busch (LHB) coaches were originally designed to operate on the End on Generation (EOG) principle.
  • The generator cars are attached to either end of the train, giving the system End On Generation name.
  • During April 2018 to 5th November 2019, 436 have been converted into HOG compliant trains. 

 

Difference Between HOG technology and EOG Technology

End on Generation (EOG) system

Head on Generation (HOG)

  • 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.
  • The system runs the train’s ‘hotel load’ by drawing electricity from the overhead electric lines through the pantograph.
  • Each coach 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 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.

 

The major advantages of HOG system include:

  • Reduction in noise- With the noise-emitting generator sets gone, noise pollution dropped from 100dB noise to noise less,
  • Free of air pollution- Significant reduction of CO2 (over 2500Ton) & NOX (over 10Ton) emissions till now.
  • They only have one emergency generator car attached, instead of two regular generator cars because the HOG-fitted trains do not require power from diesel generators at all.
  • Reduced Diesel Consumption leading to huge savings in operational costs to the tune of over Rs.1100 crores per annum.Cost savings - EOG Power Rs 22/unit, HOG Power Rs 6/unit.
  • The extra space created is used for an LSLRD (LHB Second Luggage, Guard & Divyaang Compartment) and hence more passengers can be accommodated.
  • According to the Indian Railways, once all LHB trains get the new system, it would be saving INR 1390 crores every year.  The increased cost efficiency, as per the Ministry, is because of the low price per unit of electricity in the HOG system @ INR 6/unit, as compared to the price of INR 22/unit in the EOG system.
  • The reduction in emissions could also help the Railways accrue carbon credits, and trade them on the international market.