NCR using ‘Head on Generation’ in LHB rakes to save HSD

‘Test Switch’ for HOG – Innovation by Kanpur Electric Loco Shed for reliability improvement of HOG system in locomotives

Pryagraj : Conventional trains with LHB coaches have two generator cars at both ends of the rake to meet power demand of coaches for lighting, fans, air conditioning and other on-board equipment. However, these HSD based DG sets consume substantial diesel besides occupying large space and operation is not eco-friendly and generates noise at platform.

To overcome this limitation of LHB design coach, power supply arrangement to coaches through locomotives has been made, called ‘Head on Generation’ (HOG). Under this arrangement part of traction energy from 25000 Volts overhead wire(OHE) is stepped down using transformer and converter at 750 volts to meet power needs of LHB coaches.

Power couplers connecting each coach are also connected to locomotives and ensure electricity supply to run fans, lights, ACs and other on-board equipment without need of running diesel generators. With reduced requirement of on-board DG 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.

North Central is leading Railway in use of HOG technology and 16 out of total 17 primary LHB rakes are HOG compliant and saving 75000 liters diesel annually through reduced running of DG sets. Similarly, 41 locomotives of North Central railway are fitted with HOG converters to cater all HOG rakes in different primary trains on NCR including Prayagraj, Shramshakti, Humsafar, Shatabdi, Chambal, etc.

With power supply arrangement in HOG rake from locomotive it is of 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 the locomotive is attached to the rake and in case of any defect chances of train getting late increases.

To overcome this constraint an innovative solution has been found by Electric locomotive shed Kanpur through provision of “test switch” in HOG circuitry which bypasses the need of rake being attached to loco to test functioning of HOG converter. Through this innovative arrangement now the locomotive HOG system can be tested independently thus any possible defect can be rectified in time.

This innovation by maintenance engineers of NCR is part of the coveted 20 items list of ‘Good Work’ issued by the Railway Board selected from 2645 entries. NCR is leading Zonal Railway with 8 items in total 20 Good works identified by Railway Board for wider implementation.