Technology Train Protection Systems
🔒 Train Protection Systems – Indian Railway GK for RRB Exams
Technology Category | Useful for: JE, NTPC, ALP, Group-D & all RRB Technical Cadres
1. What is a Train Protection System (TPS)?
A combination of on-board + track-side electronic safety gear that automatically applies brakes if the driver fails to observe a signal, exceeds speed limit, or is about to collide.
Golden Rule in RRB papers:
“Any system that prevents SPAD (Signal Passed At Danger) is a TPS.”
2. Evolution – Indian Railways Chronology
| Year | Milestone | Place/Train | Significance |
|---|---|---|---|
| 1956 | First AWS (Auxiliary Warning System) trial | EMU services, Mumbai | Imported UK technology |
| 1985 | RDSO formulates “ATP” specs | All-India | Indigenous development begins |
| 1997 | First TPWS trial | Central Railway | GEC-Alstom kit |
| 2002 | ACD (Anti-Collision Device) pilot | NF & SER | Konkan & SER routes |
| 2012 | TPWS made mandatory | 160 kmph + routes | Board order E(M&C)II/2012/CR/1 |
| 2016 | Kavach (original name “Train Collision Avoidance System – TCAS”) pilot | South Central Railway | Made-in-India SIL-4 certified |
| 2022 | Kavach commissioned on 1,465 Route km | SCR + WCR | Target 3,000 Rkm by 2024 |
3. Key Terminology (RRB Favourite)
| Abbreviation | Full Form | One-line for Exam |
|---|---|---|
| SPAD | Signal Passed At Danger | #1 cause of collisions; TPS avoids it |
| AWS | Auxiliary Warning System | Legacy electro-mechanical TPS |
| TPWS | Train Protection & Warning System | European (UK) technology adopted by IR |
| ETCS | European Train Control System | Umbrella; Levels 1-3 |
| KAVACH | Indigenous ATP | SIL-4, interoperable with existing signalling |
| ACD | Anti-Collision Device | GPS-based, but not a full TPS |
| SIL-4 | Safety Integrity Level-4 | Highest CENELEC safety standard |
4. Kavach – The Star of 2022-23 Papers
Developer:
Research Designs & Standards Organisation (RDSO) + 3 Indian vendors –
- HBL Power, 2. Medha Servo, 3. Kernex
Operating Principle:
“RFID + RFID readers on track + On-board computer + Auto-brake”
Salient Features
- Works in complete absence of GPS → hence reliable in ghats/tunnels
- 2 km ‘overlap’ protection envelope behind each train
- Maximum service braking distance: 1,400 m (for 160 kmph)
- Reaction time: ≤ 1 s
- Brake application gradation: 10 % → 100 % in 5 steps
- Frequency band: 27.095 MHz (ISM)
- Packet latency: < 500 ms
- Safety integrity: SIL-4 (10⁻⁹ dangerous failures/hr)
Deployment Status (Feb 2024) – RRB Data Capsule
| Parameter | Value |
|---|---|
| Total route commissioned | 1,465 Rkm |
| Stations equipped | 139 |
| Locos fitted | 2,200 (WAG-9, WAP-7, WDP-4D etc.) |
| Target 2024 | 3,000 Rkm (2,000 in SCR, 1,000 WCR) |
| Cost per Rkm | ≈ ₹ 1.0 crore (50 % cheaper than ETCS-L1) |
5. TPWS (European) vs Kavach – Table for Quick Revision
| Point | TPWS | Kavach |
|---|---|---|
| Origin | UK (Invensys / Siemens) | India (RDSO) |
| Technology | Magnetic ‘train stop’ + balise | RFID + radio modem |
| Max speed catered | 160 kmph | 160 kmph (ready for 200) |
| Interoperability | Only with dual-colour LED signals | Same, + future ETCS-L2 |
| Cost (per loco) | ₹ 70 lakh | ₹ 40 lakh |
| Maintenance | Foreign spares | Indigenous |
| Status on IR | 650 Rkm (WR & CR) | 1,465 Rkm (SCR, WCR) |
6. Important Statistics Asked in Previous Papers
- Maximum test speed of Kavach during certification: 160 kmph (RDSO trial – Oct 2021)
- Total collisions in 2021 (pre-Kavach): 15 → dropped to 2 in 2023 on Kavach routes
- Frequency of RFID tags: 27.095 MHz
- Safety integrity level: SIL-4 (probability of failure < 10⁻⁹ per hr)
- Brake initiation time: < 1 second
- Overlap distance behind train: 2 km
- Budget 2023-24 allocation for Kavach: ₹ 4,000 crore
- ‘Kavach’ was originally named: TCAS (Train Collision Avoidance System) in 2012 project document
7. Frequently Asked Theory Bits
Q. What is the primary aim of any TPS on Indian Railways?
Ans. To prevent SPAD (Signal Passed At Danger) and thereby avoid collisions.
Q. Which is the first rail section on which Kavach was commissioned?
Ans. Manikpur–Jhansi (393 Rkm) of South Central Railway.
Q. Kavach operates on which frequency band?
Ans. 27.095 MHz (ISM band).
Q. What is the highest safety integrity level achieved by Kavach?
Ans. SIL-4 as per CENELEC EN 50126/8/9.
Q. Name the three indigenous manufacturers of Kavach.
Ans. HBL Power Systems, Medha Servo Drives, Kernex Microsystems.
8. 15 MCQs – Train Protection Systems (RRB Pattern)
Instructions:
Choose the most appropriate answer. Each carries 1 mark, no negative (as per latest pattern).
-
The primary objective of a Train Protection System is to
A) Increase train speed
B) Reduce energy consumption
C) Prevent SPAD and control overspeed
D) Replace guard
Ans: C -
Indian Railways’ indigenous TPS is named
A) Raksha
B) Kavach
C) Suraksha
D) Rakshak
Ans: B -
Kavach has been certified to which Safety Integrity Level?
A) SIL-2
B) SIL-3
C) SIL-4
D) SIL-1
Ans: C -
The RFID frequency used by Kavach is
A) 13.56 MHz
B) 27.095 MHz
C) 900 MHz
D) 2.4 GHz
Ans: B -
Which of the following is NOT a feature of Kavach?
A) Automatic braking
B) Station-to-station voice communication
C) Collision avoidance
D) Speed enforcement
Ans: B -
The maximum overlap protection distance provided behind a Kavach-fitted train is
A) 1 km
B) 1.5 km
C) 2 km
D) 2.5 km
Ans: C -
Which organisation developed Kavach?
A) IRCTC
B) RDSO
C) CORE
D) CLW
Ans: B -
As per IR policy, TPS is mandatory on routes having operational speed of
A) ≥ 110 kmph
B) ≥ 130 kmph
C) ≥ 160 kmph
D) ≥ 100 kmph
Ans: C -
First section where TPWS (European) was commissioned in India is
A) Howrah–Bardhamam
B) Mumbai–Pune
C) Chennai–Gummidipundi
D) Delhi–Palwal
Ans: C -
The probability target for SIL-4 is
A) < 10⁻⁷/hr
B) < 10⁻⁸/hr
C) < 10⁻⁹/hr
D) < 10⁻⁶/hr
Ans: C -
Automatic brake application time of Kavach is
A) 2 s
B) 1.5 s
C) ≤ 1 s
D) 0.5 s
Ans: C -
Which rolling stock is presently factory-fitted with Kavach equipment?
A) WAG-12
B) WAP-5
C) WAP-7 & WAG-9
D) WDM-3A
Ans: C -
Cost per route km to deploy Kavach is approximately
A) ₹ 50 lakh
B) ₹ 1 crore
C) ₹ 2 crore
D) ₹ 1.5 crore
Ans: B -
‘Kavach’ was originally project-named
A) ASLV
B) TCAS
C) ATP-IR
D) RPS
Ans: B -
Which of the following technologies is GPS-independent?
A) ACD
B) ETCS-L3
C) Kavach
D) ERTMS-Radio
Ans: C
9. One-Minute Revision Card (Keep in wallet)
- TPS → Prevents SPAD + overspeed
- KAVACH → Indigenous, SIL-4, 27.095 MHz, ≤ 1 s brake
- Overlap → 2 km
- Routes done → 1,465 Rkm (Target 3,000 Rkm by 2024)
- Vendors → HBL, Medha, Kernex
- Speed cap → 160 kmph (ready for 200)
- Cost → ₹ 1 cr/Rkm (50 % cheaper than imported TPWS)
Pro-tip for Exam:
If option contains Kavach + SIL-4 + 27.095 MHz → tick confidently, 90 % chance it’s correct.
BETA
