India made the switch from ICF design to LHB coaches in 2003 when the first such German-technology coaches were imported. Since then it has increasingly indigenized the coaches and now manufactures only LHB passenger coaches apart from train sets.But, recently senior railway engineers have raised concerns over heavy corrosion in the bogies of LHB passenger coaches, despite the use of materials that are designed to resist corrosion and efforts to strengthen cleaning and maintenance practices, according to a PTI report.The issue was discussed at a recent conference of principal chief mechanical engineers (PCMEs), where senior technical officials asked the three railway coach manufacturing units, Integral Coach Factory (ICF) in Chennai, Rail Coach Factory (RCF) in Kapurthala and Modern Coach Factory (MCF) in Rae Bareli, to examine the problem and identify suitable solutions.“Heavy corrosion in LHB bogies is a cause of worry,” the minutes of the conference, prepared by the Railway Board, said according to PTI.
Why are LHB coaches seeing corrosion?
Officials have advised greater attention to the upkeep of both air-conditioned and non-air-conditioned LHB coaches. They said corrosion affecting the bogies could create a potential safety concern for passengers.Eastern Railway had prepared a detailed report in March examining corrosion in LHB AC and non-AC coaches. The report analysed the problem according to both the age of the coaches and the individual components affected.Following this assessment, the Railway Board asked all railway zones to examine the issue and pay particular attention during scheduled maintenance to the components and sub-assemblies identified in the report.Experts examining the matter noted that the shift from indigenous coaches manufactured at ICF, Chennai, to the German-designed Linke Hofmann Busch (LHB) coaches had represented a major advancement for Indian Railways in terms of speed, safety and service life.However, the appearance of corrosion at an early stage in certain parts of the LHB coaches has become a concern. The underframe and lavatory areas have been identified as particular problem areas, raising questions about structural integrity while also adding to maintenance costs.Experts examining the corrosion problem found that the close proximity of structural components to lavatory areas was among the major contributing factors. Water can seep through the flooring of toilets or escape from faulty pipe fittings and eventually reach the underframe, exposing these components to corrosion.“Although bio-toilets are designed to treat waste, any accidental overflow or leakage of effluent – which is acidic and rich in chlorides – causes rapid corrosion of the trough floor, sole bars and headstock,” the Eastern Railway report said according to PTI.The report identified several other factors that can contribute to severe corrosion. These include cleaning methods, dents or damage to the steel surface of coaches and vinyl advertisement wrappers. Such wrappers can allow water to penetrate through their edges, tears, joints or areas where they have not adhered properly to the surface.The experts also highlighted the particular exposure faced by coaches operating in coastal areas.“Coaches running in coastal regions are exposed to saline air. The high salt (NaCl) content acts as a powerful electrolyte, accelerating the electrochemical process of corrosion,” the experts said, recommending a combination of design-related, maintenance and operational precautions.Among the measures suggested are avoiding aggressive chemicals as well as untreated or high-salinity water during coach washing. The experts also recommended thorough rinsing and drying after washing so that corrosive residues do not remain on metallic surfaces.Another precaution is to ensure that drain holes, slots and passages in the underframe and bogie areas remain clear of blockages. This would help prevent water from accumulating and remaining stagnant in these areas. Improvements to existing corrosion-protection systems were also suggested, along with other measures.The railway ministry has directed all zones to examine the critical safety areas and implement the precautionary measures identified by the experts.
