Railway Technology: Kavach, Vande Bharat, High-Speed Rail
Complete notes on Indian railway technology: Kavach train protection, Vande Bharat train sets, high-speed rail, LHB coaches, freight corridors and record bridges.
By GK24 Editorial Team· Published · 4 min read

Indian Railways is one of the largest railway systems in the world under a single management, and over the past decade the questions asked about it in general awareness papers have shifted from route lengths and zone names to technology. Three items carry most of those questions: Kavach, the indigenous train protection system that returns to the news each time the Railways clears a newer version of it for wider installation; the Vande Bharat train set; and the high-speed corridor being built between Mumbai and Ahmedabad. This chapter sets out those three and the smaller items that go with them.
Kavach: the indigenous train protection system
Kavach is an Automatic Train Protection system, which means a system that acts on a train when the driver does not. It was developed by the Research Designs and Standards Organisation, the research wing of Indian Railways at Lucknow, together with Indian manufacturers, and it was first known as the Train Collision Avoidance System before being adopted as the national Automatic Train Protection standard. It is certified at Safety Integrity Level 4, the highest of the four levels used in railway signalling, which means the probability of a dangerous failure is designed to be extremely low.
The system has three parts that work together. Radio frequency identification tags are fixed to the track between the rails and at station points; equipment on the locomotive reads those tags to know exactly where the train is and how fast it is going; and station Kavach units linked by radio and by optical fibre pass information between locomotives and stations. On that basis Kavach applies the brakes automatically if the driver does not brake for a signal at danger, stops a train from passing a red signal, prevents two locomotives fitted with the system from colliding head on or from behind, repeats the line-side signal inside the driver's cab so that the driver can see the aspect in dense fog, and enforces speed limits over curves and turnouts. What it cannot do is prevent an accident caused by a broken rail, a landslide or a defective coach, because it works on train movement and not on the track structure, and that limitation is worth remembering because questions are set on it.
The Vande Bharat train set
Vande Bharat is India's indigenous semi-high-speed train set, designed and built at the Integral Coach Factory in Chennai and flagged off for the first time on 15 February 2019. Its central feature is distributed traction: instead of a locomotive pulling a rake of coaches, the propulsion equipment is slung under the coaches themselves, so the train is a self-propelled electric multiple unit. That design gives faster acceleration and braking, which matters more than top speed on a crowded network with frequent stops, and it removes the need to turn a locomotive at the end of a run. The train set is designed for 160 kilometres an hour and has been tested above that. Automatic plug doors, sealed gangways, regenerative braking that returns energy to the overhead line, bio-vacuum toilets, a passenger information system and rotating seats in the executive chair car are its other features, and the rakes are built to work with Kavach. A sleeper version and a shorter-distance intercity version of the same train set family have followed.
High-speed rail
| Item | Detail |
|---|---|
| Corridor | Mumbai to Ahmedabad, about 508 kilometres |
| Technology | Japanese Shinkansen, with a soft loan from Japan |
| Implementing agency | National High Speed Rail Corporation Limited |
| Design speed | 320 kilometres an hour |
| Notable structure | A 21 km tunnel including about 7 km under Thane creek, India's first undersea rail tunnel |
A bullet train differs from a semi-high-speed train not only in speed but in its track: it needs dedicated ballastless track, no level crossings, gentle curves and its own signalling, which is why a high-speed corridor is built afresh rather than laid over an existing line.
Other technologies worth knowing
LHB coaches, named after the German firm Linke Hofmann Busch whose design they follow and now built at Kapurthala, replaced the older ICF coaches; they are lighter, run more smoothly and have anti-climbing features that stop coaches from riding over one another in a collision. The two Dedicated Freight Corridors, the Eastern and the Western, carry goods traffic away from passenger lines and are managed by a separate corporation, and the Western corridor is built for double-stack container trains. Head-on generation draws power for coach lighting and air conditioning from the overhead line instead of a diesel generator van. The WAG-12B electric freight locomotive of 12,000 horsepower, assembled at Madhepura in Bihar, is the most powerful locomotive on the network. Gatimaan Express, introduced in 2016, was the first Indian train to run at 160 kilometres an hour. Among structures, the Chenab bridge on the Udhampur, Srinagar and Baramulla rail link is the highest railway arch bridge in the world, standing about 359 metres above the river bed, the new Pamban bridge is India's first vertical lift sea bridge, and the Bogibeel bridge over the Brahmaputra in Assam is the country's longest rail and road bridge.
Exam Point of View
Papers ask what Kavach is, who developed it and what it can and cannot do, so keep the Research Designs and Standards Organisation, Safety Integrity Level 4 and the phrase Automatic Train Protection together, and remember that Kavach cannot stop an accident caused by a broken rail. On Vande Bharat the favourite questions are the factory, which is the Integral Coach Factory at Chennai, the first run on 15 February 2019, the design speed of 160 kilometres an hour, and the meaning of distributed traction. On high-speed rail examiners ask the country whose technology is used, which is Japan, and the implementing body, which is the National High Speed Rail Corporation Limited, and they offer France and Germany as distractors. Gatimaan Express as the first 160 kilometre an hour train and the Chenab bridge as the highest railway arch bridge are the two record facts most often set.
Important Facts
| Kavach, what it is | Indigenous Automatic Train Protection system of Indian Railways |
|---|---|
| Kavach, developed by | Research Designs and Standards Organisation, Lucknow, with Indian firms |
| Kavach, earlier name | Train Collision Avoidance System |
| Kavach, safety rating | Safety Integrity Level 4, the highest level |
| Kavach, key components | Trackside RFID tags, locomotive equipment, station units, radio and optical fibre links |
| Vande Bharat, built at | Integral Coach Factory, Chennai |
| Vande Bharat, first run | 15 February 2019 |
| Vande Bharat, design | Distributed traction, a self-propelled electric multiple unit, 160 km an hour |
| High-speed corridor | Mumbai to Ahmedabad, about 508 km, design speed 320 km an hour |
| High-speed technology and agency | Japanese Shinkansen; National High Speed Rail Corporation Limited |
| LHB coaches | German Linke Hofmann Busch design, anti-climbing, built at Kapurthala |
| Most powerful locomotive | WAG-12B of 12,000 horsepower, assembled at Madhepura, Bihar |
| First 160 km an hour train | Gatimaan Express, introduced in 2016 |
| Highest railway arch bridge | Chenab bridge, about 359 metres above the river bed |
| Other record bridges | New Pamban, India's first vertical lift sea bridge; Bogibeel, the longest rail and road bridge |
Practice MCQs on this topic
Kavach, developed by Indian Railways, is:
- A.An Automatic Train Protection system
- B.An online ticket booking platform
- C.A new railway track gauge
- D.A mobile application for tracking freight
Show answer
Correct answer: A. An Automatic Train Protection system
Explanation
The correct answer is A, an Automatic Train Protection system. Kavach is an electronic safety system that acts on a moving train when its driver does not: it applies the brakes if a signal at danger is being approached without braking, holds a train back from passing a red signal, and keeps two locomotives fitted with the system from closing on each other. Option B describes services run by the Indian Railway Catering and Tourism Corporation, which is a separate arm of the Railways altogether. Option C is wrong because a gauge is the distance between the rails, and Indian Railways uses broad gauge of 1,676 millimetres on its main network; Kavach is fitted on existing track and changes nothing about the gauge. Option D is wrong because freight tracking is done through the Freight Operations Information System, a data application, and not by a safety system fitted to locomotives and stations.
Which organisation of Indian Railways developed the Kavach system?
- A.Research Designs and Standards Organisation
- B.Centre for Railway Information Systems
- C.Indian Railway Catering and Tourism Corporation
- D.Dedicated Freight Corridor Corporation of India
Show answer
Correct answer: A. Research Designs and Standards Organisation
Explanation
The correct answer is A, the Research Designs and Standards Organisation, usually written as RDSO. It is the research, design and standards wing of Indian Railways, has its headquarters at Lucknow, and developed Kavach in partnership with Indian manufacturers, first under the name Train Collision Avoidance System. Option B, the Centre for Railway Information Systems, builds and runs the computer systems of the Railways, such as passenger reservation and freight information, and does not design signalling hardware. Option C, the Indian Railway Catering and Tourism Corporation, handles catering, online ticketing and tourist trains. Option D, the Dedicated Freight Corridor Corporation of India, was set up to build and manage the Eastern and Western freight corridors. All four are genuine railway bodies, which is why the question is a test of what each one actually does.
Kavach has been certified at which Safety Integrity Level?
- A.SIL-1
- B.SIL-2
- C.SIL-3
- D.SIL-4
Show answer
Correct answer: D. SIL-4
Explanation
The correct answer is D, SIL-4. Safety Integrity Level is a scale of four grades used for safety related electronic systems, and level four is the most demanding, meaning the probability of a dangerous undetected failure is designed to be the lowest of all. Signalling and train protection systems on main line railways are built to this level because a single failure can cost many lives, and Kavach was certified accordingly before being adopted as the national Automatic Train Protection standard. Options A, B and C, the lower levels, are used for systems whose failure carries a smaller consequence, such as some industrial process controls and auxiliary equipment; accepting a lower level for train protection would defeat its purpose. A candidate who remembers only the phrase highest level will still get this question right, because SIL-4 is the highest of the four.
Which of the following accidents can Kavach NOT prevent?
- A.A train passing a signal at danger
- B.A head-on collision between two locomotives fitted with the system
- C.A derailment caused by a fractured rail
- D.Overspeeding on a curve with a speed restriction
Show answer
Correct answer: C. A derailment caused by a fractured rail
Explanation
The correct answer is C, a derailment caused by a fractured rail. Kavach works on the movement of trains: it reads the position and speed of a locomotive from trackside tags, compares that with the signal and the permitted speed, and brakes the train when the driver does not. It therefore covers options A, B and D, which are all failures of driving or of spacing between trains. It has no way of knowing that a rail has cracked, that a landslide has covered the track or that a coach axle is defective, because it does not inspect the track structure or the rolling stock. Those hazards are addressed by separate measures such as ultrasonic flaw detection of rails, track recording cars and coach maintenance schedules. Examiners set this distinction precisely because Kavach is often described loosely as an anti-accident system.
Vande Bharat Express train sets are designed and manufactured at:
- A.Rail Coach Factory, Kapurthala
- B.Integral Coach Factory, Chennai
- C.Chittaranjan Locomotive Works
- D.Modern Coach Factory, Raebareli
Show answer
Correct answer: B. Integral Coach Factory, Chennai
Explanation
The correct answer is B, the Integral Coach Factory at Chennai, which designed the train set under the project name Train 18 and rolled out the first rake. Option A, the Rail Coach Factory at Kapurthala in Punjab, builds LHB coaches and other passenger stock but did not design this train set. Option C, Chittaranjan Locomotive Works in West Bengal, builds electric locomotives, and a Vande Bharat rake does not use a locomotive at all, since its propulsion equipment is distributed under the coaches. Option D, the Modern Coach Factory at Raebareli in Uttar Pradesh, is the newest of the coach factories and also builds LHB stock. All four are production units of Indian Railways, so the question is really asking which unit does which job, and coach design of this kind belongs to Chennai.
The first Vande Bharat Express was flagged off in which year?
- A.2016
- B.2019
- C.2021
- D.2023
Show answer
Correct answer: B. 2019
Explanation
The correct answer is B, 2019. The first Vande Bharat Express was flagged off on 15 February 2019, after the train set had been built at the Integral Coach Factory under the name Train 18 and tested on Indian track. Option A, 2016, is the year in which Gatimaan Express began running at 160 kilometres an hour and became India's first semi-high-speed train, and a candidate who mixes the two milestones will pick it. Option C, 2021, saw further trials and orders but no first service. Option D, 2023, is the year in which the number of Vande Bharat services grew quickly across the country, which is why many candidates associate the train with that year; the expansion, however, came four years after the first run. Pairing 2016 with Gatimaan and 2019 with Vande Bharat keeps the two apart.
What distinguishes a Vande Bharat train set from a conventional passenger train?
- A.It is hauled by a diesel locomotive
- B.It uses distributed traction and has no separate locomotive
- C.It runs on metre gauge track
- D.It is hauled by two locomotives, one at each end
Show answer
Correct answer: B. It uses distributed traction and has no separate locomotive
Explanation
The correct answer is B. A Vande Bharat rake is a self-propelled electric multiple unit: the traction motors and control equipment are slung under the coaches themselves, so power is spread along the length of the train instead of being concentrated in one vehicle. The result is quicker acceleration and braking, which saves more time on a network with frequent stops than a higher top speed would, and there is no locomotive to detach and turn at the end of a run. Option A is wrong because the train draws power from the overhead line and carries no diesel engine. Option C is wrong because it runs on broad gauge like the rest of the main network. Option D describes push and pull working, in which two locomotives are used at the ends of an ordinary rake, a different arrangement that is also in use on Indian Railways but is not what makes a train set.
The Mumbai to Ahmedabad High Speed Rail corridor is being built with technology from which country?
- A.France
- B.Germany
- C.Japan
- D.South Korea
Show answer
Correct answer: C. Japan
Explanation
The correct answer is C, Japan. The corridor uses the Shinkansen system, the high-speed technology Japan has run since 1964, and the project is financed largely by a soft loan from Japan carrying a long repayment period and a low rate of interest. Option A, France, operates the TGV and is a genuine high-speed exporter, which is why it appears as a distractor. Option B, Germany, runs the InterCity Express, and German technology is present on Indian Railways in another form, the LHB coach design, which is a further reason the option looks plausible. Option D, South Korea, runs the KTX network, itself derived from French technology. The corridor runs about 508 kilometres, has a design speed of 320 kilometres an hour and includes a tunnel of about 21 kilometres of which roughly 7 kilometres pass under Thane creek.
Which organisation is executing the Mumbai to Ahmedabad High Speed Rail project?
- A.Dedicated Freight Corridor Corporation of India
- B.National High Speed Rail Corporation Limited
- C.Rail Vikas Nigam Limited
- D.Indian Railway Construction International Limited
Show answer
Correct answer: B. National High Speed Rail Corporation Limited
Explanation
The correct answer is B, the National High Speed Rail Corporation Limited, a company set up specifically to build and later operate high-speed rail in India, with the Union Government and the Governments of Gujarat and Maharashtra as shareholders. Option A, the Dedicated Freight Corridor Corporation of India, was created for a different purpose, namely the Eastern and Western freight corridors that take goods traffic off passenger routes. Option C, Rail Vikas Nigam Limited, executes conventional railway projects such as doubling, electrification and new lines. Option D, formerly known as IRCON International, is a construction company of the Railways that builds projects in India and abroad and has worked on difficult Himalayan alignments. All four belong to the railway family, and the question tests which of them owns the bullet train project.
Which was the first Indian train to run at a speed of 160 kilometres an hour, introduced in 2016?
- A.Gatimaan Express
- B.Shatabdi Express
- C.Tejas Express
- D.Rajdhani Express
Show answer
Correct answer: A. Gatimaan Express
Explanation
The correct answer is A, Gatimaan Express, which began running in 2016 between Delhi and Agra and became India's first semi-high-speed train at 160 kilometres an hour, a speed the Agra route could take because of its straight alignment and fenced sections. Option B, the Shatabdi Express, was introduced in 1988 as a fast day train and normally runs up to 130 kilometres an hour, so it is fast but not semi-high-speed by this definition. Option C, Tejas Express, is remembered for a different first, being the train type handed over to the Indian Railway Catering and Tourism Corporation to operate, and for modern on-board features. Option D, the Rajdhani Express, was introduced in 1969 as the premier overnight train linking Delhi with State capitals, again at conventional speed. Vande Bharat later made 160 kilometres an hour the normal design speed.
The Chenab bridge, the highest railway arch bridge in the world, lies on which rail link?
- A.Udhampur, Srinagar and Baramulla rail link
- B.Konkan Railway
- C.Eastern Dedicated Freight Corridor
- D.Rishikesh to Karnaprayag line
Show answer
Correct answer: A. Udhampur, Srinagar and Baramulla rail link
Explanation
The correct answer is A, the Udhampur, Srinagar and Baramulla rail link, the line built to connect the Kashmir valley to the rest of the Indian network. The Chenab bridge on that link stands about 359 metres above the bed of the river, higher than the Eiffel Tower, and is built as a steel arch to span the deep gorge in an earthquake prone and wind swept setting. Option B, the Konkan Railway, along the west coast is famous for its own engineering, with long tunnels and tall viaducts and the anti-collision device developed there, but not for this bridge. Option C, the Eastern Dedicated Freight Corridor, runs across the plains of northern India where no such gorge exists. Option D, the Rishikesh to Karnaprayag line in Uttarakhand, is another Himalayan project with heavy tunnelling, and it is offered here precisely because it sounds equally mountainous.
The LHB coaches used by Indian Railways are based on a design from which country?
- A.Japan
- B.Germany
- C.South Korea
- D.Russia
Show answer
Correct answer: B. Germany
Explanation
The correct answer is B, Germany. LHB stands for Linke Hofmann Busch, the German firm whose design Indian Railways adopted at the end of the 1990s and now builds at Kapurthala and other coach factories. These coaches are made largely of stainless steel, are lighter than the older ICF coaches, ride more smoothly at high speed, and carry anti-climbing features and a centre buffer coupler so that in a collision the coaches do not ride over one another, which is the reason they are considered safer. Option A, Japan, supplies the Shinkansen technology for the high-speed corridor, not the coach design. Option C, South Korea, and option D, Russia, have supplied equipment to India in other sectors but not this coach design. Note the pattern examiners like: German coaches, Japanese bullet train and Indian train sets from Chennai.
Frequently Asked Questions
What is Kavach and who developed it?
Kavach is India's indigenous Automatic Train Protection system, developed by the Research Designs and Standards Organisation, the research wing of Indian Railways at Lucknow, along with Indian manufacturers. It was first known as the Train Collision Avoidance System.
How does Kavach prevent a collision?
Radio frequency identification tags on the track tell the locomotive equipment exactly where the train is and how fast it is going, and station units exchange that information by radio. If the driver does not brake for a signal at danger or for a speed restriction, the system applies the brakes itself, and two locomotives fitted with the system will not be allowed to close on each other.
What accidents can Kavach not prevent?
Kavach works on train movement, so it cannot prevent an accident caused by a broken rail, a landslide, sabotage of the track or a defect in a coach. It addresses collisions and signal overshooting, not the condition of the track or rolling stock.
What makes the Vande Bharat train set different from an ordinary train?
It uses distributed traction. The propulsion equipment is slung under the coaches instead of being housed in a separate locomotive, so the train is a self-propelled electric multiple unit that accelerates and brakes faster and needs no locomotive to be turned at the end of a run.
Whose technology is being used for India's first bullet train?
Japanese Shinkansen technology, with financing largely through a soft loan from Japan. The corridor runs about 508 kilometres between Mumbai and Ahmedabad and is being executed by the National High Speed Rail Corporation Limited at a design speed of 320 kilometres an hour.
Why are LHB coaches considered safer than the older coaches?
They follow a German Linke Hofmann Busch design, are made of stainless steel and are lighter, and they carry anti-climbing features and a centre buffer coupler that keep coaches from riding over one another in a collision, besides riding more smoothly at high speed.
Sources
- Kavach: the indigenous Automatic Train Protection system — Research Designs and Standards Organisation, Ministry of Railways
- Vande Bharat train sets — Integral Coach Factory, Ministry of Railways
- Mumbai-Ahmedabad High Speed Rail project — National High Speed Rail Corporation Limited





