Advancements in Rail Infrastructure

Rail industry is on the verge of technology explosion with exciting new era of innovation based on Big Data, Machine Learning and Artificial Intelligence. The next generation automation with the weight of Big data, ML and AI with advanced algorithms and data analysis software will enable the industry to enhance safety, reliability and service to customers. While human interventions in the operations will be limited, the industry will poise towards greater value to customers.

The origin

Railway system in Great Britain is the oldest in the world where rail transport using steam locomotives commenced in 1825 on Stockton-Darlington public rail line. Since then, Railways have become the key component of industrial revolution across the world. Railways have reduced the cost and time of passenger travelling and goods shipping. In line with the continuing revival in the rail industry, diesel locomotives replaced the initially introduced steam locomotives and now diesel locomotives are being replaced by electric locomotives mainly due to environmental concerns and energy conservation. Many countries in the world have already processed it completely. In modern era, time is the crucial and precious factor of the economy and rapid transit has become the need of the century. Higher speed and shorter journey time have become the objectives of modern transport systems. Accordingly, countries across the world started implementing rapid public transportations by investing in electrical rail systems in view of road congestion and rising fuel demands as well as for reducing CO2emissions thereby global warming.

Some of the recent outcomes in rapid rail transportation systems are high speed / semi high-speed rail, maglev trains etc. and modern train sets like tilting trains. The introduction of many sophisticated systems has increased the operational safety of fast-moving trains.

High speed rail (HSR) system runs significantly faster than traditional trains using specialized rolling stock and dedicated tracks. World’s first high-speed rail system started its operation in Japan in 1964 and it got popularity as the bullet train and the train has attained maximum speed of 210 kmph in its journey. Now many countries have developed high speed rail infrastructure for faster mobility. Though there is no worldwide standard for defining high speed rail, now rail speed more than 250 kmph is considered as high-speed rail. High-speed trains are usually designed to be operated on standard gauge tracks having large turning radius. Rolling stocks will have state of the art design with high level of technology to attain basic characteristics like limited axle load, high traction power, optimized aerodynamic shape etc.

Semi high-speed rail (SHSR) is a variant of High-speed rail (HSR) system which will be designed to operate in the speed range of 180 – 250 kmph. Geometrical standards like turning radius can be optimized in SHSR and accordingly the corridor can be materialized with comparatively lower cost and socio- environmental impact. Subsequently train can be operated by charging comparatively lower fares which will support majority of the public to use the system. However, detailed cost-benefit analysis shall be conducted to select whether HSR or SHSR is to be adopted for implementation, based on the traffic demand and requirements forecasted in the selected corridor. If geometrical features in the existing track are suitable, semi high speed trains have the option of operating on the existing track.

Maglev (derived from magnetic levitation) is a system of train transportation which is different from conventional train transportation which drives forward by using friction between wheels and rail. Maglev trains replace wheels by two sets of magnets, one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction.Compared to conventional high-speed trains, Maglev trains can attain very high speed and Shanghai maglev train in China has recorded a maximum speed of 430 kmph. Track maintenance and rolling stock maintenance is found to be minimal for maglev trains. Due to the higher initial cost and risks in operation, Maglev trains are not broadly accepted and researches are going on to further improve this system. Currently Maglev trains are operational only in 3 countries viz. China, Japan and South Korea.

Technologies have been developed to increase the speed of the train on regular tracks. Tilting train set is one such technology. Tilting trains are designed to counteract the centrifugal force experienced when a train negotiates a curve. As an effect of the centrifugal force, both sitting and standing passengers will lose their balance. Centrifugal forces are counteracted by tilting the carriages towards the inner track curve. Tilting is caused by two ways; Passive tilt in which inertial forces cause the tilting and Active tilt which will be a computer-controlled power mechanism. Tilting trains are mainly used for high speed rail operations.

Aluminium coaches are used instead of steel coaches as a part of modernisation of rail coaches. The lighter weight carriages consume lesser energy compared to steel coaches and help to increase train speeds. Aluminium coaches have better resistance against corrosion and require comparatively less maintenance. Countries in Europe and Japan have been using aluminium coaches for at least 15 years.

The safety and efficiency of high-speed rail operations have improved through the implementation of new technologies and operational innovations. Some of the technologies and systems developed for improving the working condition of rolling stock wheels are (i) wayside detectors which identify defects on passing rail cars, (ii) wheel profile monitors to capture and analyse the working condition of wheels, (iii) wheel temperature detectors, (iv) trackside acoustic detector systems to evaluate the sound of internal wheel bearings etc. The new track and infrastructure technologies include (i) defect detector vehicles to detect internal flaws in rails, (ii) improved metallurgy and improved fastening systems to reduce track failure, (iii) ground penetrating radar and terrain conductivity sensors to identify underground problems like excessive water penetration and deteriorated ballast which hinder track stability.  Now non-destructive inspection techniques are being developed to identify defects in rail car casting and coupling systems. Remote control locomotive technology, in which rail personnel on the ground can operate and control locomotives in rail yards with a hand-held transmitter, is a new technology in the field. Computer modelling softwares are being used in the construction and operation of rail systems for better output. For enhancing the operational safety, Positive Train Controls (PTC) are designed to automatically stop or slow down a train before the occurring of accidents like train-to-train collisions, derailments caused by excessive speed, unauthorized incursions by trains onto sections of track where maintenance activities are underway etc.

Research and development for future high-speed systems (infrastructure, tracks, electric power supply, signalling, rolling stock, operation and control elements, safety and security devices, etc.) must take into account the requirements from customers, society, operators, etc. Researches must be done to achieve more speed, standardisation and modularity of rolling stock, optimization of operating costs etc.The future of rail transport depends on how the railway system and its energy needs will be projected aiming at least 30 years ahead.

Written by: Anil Kumar G, Joint General Manager, Kerala Rail Development Corporation Ltd

Midhun Joseph, Section Engineer, Kerala Rail Development Corporation Ltd

*The views expressed in the article are personal

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