From the emergence of technology to now we have seen many faces of it. Once upon a time which were mannual now with the help of technology has become electronic. From small to big all have become electronic. Among them one of the most important one is the Railway Electronic Interlocking System.
Indian Railways is one of the Asia’s biggest railway system and the lifeline of the inter-state people. Today India’s railway system has surpassed all the difficulties and have built tracks at the very difficult places too. Today crores of people travel through rails for various reasons.
Though there were tracks built on difficult places, many train tragedies have taken place. Recently the Odhisha train tragedy that took many lives has made us question about the railway safety. To avoid such instances this electronic interlocking system was introduced.
Electronic interlocking is a crucial safety measure in the railway system. Its primary purpose is to prevent conflicting movements between trains by ensuring that signals are not changed in an improper sequence. This system aims to ensure that trains receive a signal to proceed only when the route is proven safe.
Railway interlocking is of British origin, where numerous patents were granted. In June 1856, John Saxby received the first patent for interlocking switches and signals. Interlockings using electric motors for moving switches and signals became viable in 1894, when Siemens in Austria installed the first such interlocking.
The interlocking system ensures that the movable sections of track, known as points, are appropriately aligned and securely locked in the correct position prior to permitting a train to pass over them.
The signalling appliances and tracks are sometimes collectively referred to as an interlocking plant. An interlocking is designed so that it is impossible to display a signal to proceed unless the route to be used is proven safe.
Interlocking is a safety measure designed to prevent signals and points/switches from being changed in an improper sequence. For example, interlocking would prevent a signal from being changed to indicate a diverging route, unless the corresponding points/switches had been changed first.
A minimal interlocking consists of signals, but usually includes additional appliances such as points and Facing Point locks and derails, and may include crossings at grade and movable bridges.
In electronic interlocking, the control and supervision of train movements is carried out through software and electronic components. It utilises computers, programmable logic controllers and communication networks to manage and coordinate signalling, points and track circuits. This system makes sure that signals are cleared to proceed only when the route ahead is safe and clear.
This system is the alternative to the conventional relay interlocking system.
Compared to electro-mechanical or conventional panel interlocking, the electronic interlocking system is more advantageous – it reduces space requirement, is safer and more reliable. This system is also used in countries such as Australia, Japan, USA, Germany and France.
In India, electronic interlocking has been adopted on a large scale, with 347 stations in the country being provided the system in 2022.
According to a railway report as of December 31, 2022, 45.5 per cent of India’s rail network is provided with electronic interlocking.
The electronic interlocking system can malfunction and when it does, it flashes a red signal, indicating a need to be checked. The interlocking system can malfunction under certain conditions, such as its sensors being damaged, human manipulations, and wrong rewiring during maintenance.
India has designed its own locking system called ‘Kavach’.