Innovation on track: Exploring aluminium's role in railways

Improvements in transport infrastructure have increased the need to address pollution and energy efficiency. Today, millions of people and tonnes of goods are transported on trains yearly because they are the most efficient, convenient, and comfortable means of transportation. As the transportation industry advances, the focus on energy conservation and pollution reduction has become paramount. Since their inception during the Industrial Revolution of the 19th century, railways have undergone constant development to increase their efficiency, security, and ability to incorporate new technologies.

On the other hand, aluminium may replace these traditional metals because of its lightweight nature, corrosion resistance, formability, high specific strength, and cost-effectiveness. Aluminium can cut the total weight of a rail car body by half, making it a critical component in the railway industry's shift. This adaptable material is presently used in various components ranging from train flooring and sidewalls to ceilings, sideboards, and floor panels. Aluminium is crucial in modernising trains and boosting energy efficiency.

Using aluminium results in a 50 per cent reduction in the total weight of a rail car body. Aluminium, a prominent construction element used in modern train manufacturing, is currently being utilised to fabricate contrails that connect several components of the train's structure, including the floor, sidewall, ceiling, sideboards, and floor panels.

The first Indian-manufactured aluminium goods train rake commenced its journey from Bhubaneswar in Odisha. Furthermore, in addition to its reduced weight compared to previous models, it has enhanced capacity for transporting cargo. Besco Limited's Waggon Division produced aluminium-bodied waggons in response to an order made in 2021 by Hindalco Industries Limited, a prominent player in the aluminium industry. The project was successfully finished within the designated timeframe of 15 months. The composition comprises a complete set of 61 waggons and one Brake Van.

As per AL Circle's “Global Aluminium Industry Outlook 2023” , the transportation sector accounted for the major share of 27% followed by the building & construction sector at 23% in 2022. Demand for aluminium from the railway sector is increasing across the world given de-carbonization and environmental protection.

These waggons have a greater carrying capacity, need less energy to operate, are corrosion-resistant, and reduce greenhouse gas emissions by 14,500 metric tonnes throughout their lifespan. They may be recycled indefinitely, and their aluminium superstructure will look new even after 30 years. These aluminium waggons are an excellent way for India to achieve its environmental objectives. In addition, there is no need for any outside painting, which reduces waste and pollution.

The rakes are 180 tonnes lighter than conventional steel rakes, allowing them to cover the same distance in the same amount of time while using less energy. Its tare weight is around 3 tonnes less than BOBR waggons and 2 tonnes less than BOBRNHSM1 waggons. The rake's corrosion-resistant construction will cut maintenance expenses and haul 180 more tonnes each trip than standard rakes. Huck bolts are used to secure the complete waggon superstructure instead of welding.

Some approaches to enhance energy efficiency and decrease carbon dioxide emissions include reducing aerodynamic resistance, gearbox loss, tyre rolling resistance, and weight. An effective strategy for increasing the efficiency of railroads is to incorporate a lightweight and robust structure. Historically, metals, specifically stainless steel and cast iron, have been the predominant materials employed in constructing conveyance apparatus, including railroads. Due to its lightweight, resistance to corrosion, malleability, high specific strength, and relatively low cost, aluminium has the potential to supplant conventional metals.

• India has successfully used aluminium for its metro trains and is now interested in extending it to long-distance trains such as the Rajdhani and Shatabdi Express trains. The Government of India has approved the utilisation of aluminium for the upcoming generation of trains that will be integrated into its extensive railway networks, which cover a combined route length of 67,956 km. In contrast, Japan and various European countries have been reaping the advantages of employing aluminium train coaches for over 15 years.
• Also, Hindalco Industries recently unveiled ambitious plans to build an extrusion facility for aluminium trains in India. According to Satish Pai, the Managing Director of Hindalco Industries, the company is strategically considering implementing a significant capital expenditure project to establish a large-scale extrusion facility in India to produce aluminium bogie bodies. The firm intends to finance the project independently, estimating the cost of the extrusion press to be around INR 2,000–2,500 crore. Pai revealed that the company is actively scouting for suitable land to establish the press. He expressed confidence in the company's ability to fund the project through internal accruals, relying on the robust cash flow it generates to handle the undertaking seamlessly.
• Kolkata Railways is replacing its earlier, pure-steel third rail system with a steel-encased aluminium one to mimic the worldwide green efforts of metro networks. This will make the metro system considerably more environmentally friendly by drastically reducing carbon emissions. The development will not only enhance the efficiency of the Metro Railway but is also expected to result in a substantial annual reduction of INR 1 crore in power expenses. Kolkata Railways hopes to provide its customers with more convenient transit alternatives and make significant progress towards promoting sustainability by adopting this cutting-edge strategy.

The accessibility of aluminium for building is related to its simplified structure and strong corrosion resistance. Aluminium has a well-rounded performance owing to its low weight, robust resistance to corrosion, exceptional malleability, elevated specific strength, and favourable cost-efficiency. Aluminium has a weight that is around one-third of that of steel. However, within the transportation sector, although notably lighter, most aluminium components have a weight that is approximately half that of corresponding steel components.

To know more about how aluminium has transformed the industry, read AL Circle’s recently launched updated version report on, ‘Global Aluminium Industry: Key Trends to 2030.’ The report provides an extensive analysis of key trends anticipated throughout the aluminium value chain, spanning from bauxite extraction to various applications and considerations for sustainability. 

Aluminium shows immense potential in revolutionising railway construction, embracing not just coaches and waggons but also diverse signalling systems and station decor. Its intrinsic corrosion resistance may greatly lengthen the duration of railway coaches, stretching their operating lives to over 40 years while needing decreased maintenance. Considering that the average age of a train now in operation on the Indian Railways is 35 years, the use of aluminium may extend its useful life by another five years. The ability to successfully recycle aluminium at the end of its helpful life gives coaches and waggons a more excellent salvage value.