Speed Restrictions
Speed Restrictions – Railway GK Capsule
1. What is a “Speed Restriction”?
A speed restriction is any mandatory reduction below the sanctioned sectional speed, ordered through a “Speed Certificate” or “Special Instruction”. It may be temporary (TSR – Temporary Speed Restriction) or permanent (PSR – Permanent Speed Restriction).
2. Technical Definitions & Key Terms
| Term | Definition | Reference |
|---|---|---|
| Sanctioned Speed | Maximum speed approved by CRS for a section. | Indian Railway Way-Works Manual 2021 |
| Booked Speed | Speed at which a train is timetabled; ≤ sanctioned speed. | IRCA Conference Rules |
| Permanent Speed Restriction (PSR) | Notified in Working Time-Table (WTT) & Permanent Way diagrams. | SOD (Schedule of Dimensions) |
| Temporary Speed Restriction (TSR) | Imposed through caution orders, valid ≤ 6 months unless extended. | SOD 4.04, 4.05 |
| Warning / Caution Order (CO) | Written advice to Loco Pilot; issued by Section Controller. | G&SR 9.13 |
| Speed Certificate | Issued by PWI & approved by DEN; countersigned by Sr. DOM. | Way-Works Manual 7.3 |
| Traction-wise restriction | Different limits for Electric & Diesel stock on same track. | RDSO circular EW-02-2019 |
3. Speed Restriction – Categories & Values
A. Geometry-based PSRs (typical)
| Curve Radius (m) | Grad. ≤ 1 in 100 | Grad. 1 in 50–100 | Grad. ≥ 1 in 50 |
|---|---|---|---|
| ≤ 400 | 50 km/h | 45 km/h | 40 km/h |
| 400–875 | 75 km/h | 70 km/h | 65 km/h |
| ≥ 875 | 100 km/h | 95 km/h | 90 km/h |
B. Points & Crossings
- Ordinary switch (1 in 12): 15 km/h on facing & 30 km/h on trailing.
- CMS (Cast Manganese Steel) 1 in 16/20 with thick-web tongue rail: 50 km/h (facing) & 75 km/h (trailing) after 2018 retrofit.
C. Bridges
- Ghat section arch bridges (span < 30 m): 75 km/h (BG), 50 km/h (MG heritage).
- RC / PSC girder with longitudinal articulation: 110 km/h (BG) subject to oscillation test ≤ 0.15 g vertical acceleration.
D. Track Quality Index (TQI) based TSR
Introduced 2022: if TQI > 65 (1.5 m chord versine > 12 mm) → 20 km/h reduction till resurfacing.
4. Historical Timeline
- 1854: First speed “limit” – 30 mph (≈48 km/h) for “express” on GIPR.
- 1926: “Speed Certificate” system formalised after derailment of Howrah–Bombay Mail at Agra.
- 1957: Maximum for steam hauled passenger fixed at 90 km/h; freight 65 km/h.
- 1969: Rajdhani introduced with 120 km/h; first 1 in 20 switches allowed 60 km/h.
- 1988: CRS authorised 130 km/h on Delhi–Agra section (first < 160 km/h).
- 2014: Mission Raftaar – aim to raise sectional speed to 160 km/h on Golden Quadrilateral.
- 2018: Automatic ‘Signalling based Speed Restriction’ (SBSS) rolled out on Ghaziabad–Aligarh.
- 2020: First 160 km/h Goods train (Roll-on Roll-off) run on New Delhi–Mumbai WR route under T-14 policy.
- 2023-24: Kavach (ETCS-L1) mandatory for > 130 km/h; restriction removed when train under ATP supervision.
5. Current Status & Recent Updates (2023-24)
- Mission 160: 8,000 km identified; PSR removed/relaxed on 1,400 km after infrastructure up-gradation.
- Vande Bharat (VB): Operates at 130 km/h on existing track; no additional PSR if track category ≥ “Good-very good” (TGI 41-50).
- KAVACH corridor: Wherever KAVACH commissioned, TSR of 10 km/h imposed during commissioning phase; lifted after 30 days of stable operation.
- Digital Speed Restriction Module (DSRM): Pilot on Central Railway (2023); TSR now fed directly into Crew Lobby & Loco SI units.
- Penalty: Non-compliance of PSR/TSR – SPAD (Signal Passed At Danger) category “A” – suspension of LP/ALP for 7 days minimum.
- Environment-based: Pollution-control TSR of 80 km/h imposed in Delhi-NCR during GRAP-IV (Nov. 2023).
6. Procedure for Imposing / Withdrawing a TSR
- Detection – PWI / AEN during patrolling or USFD testing.
- Speed Certificate – filled in triplicate (white, pink, green).
- Approval – DEN within 24 h; countersignature Sr. DOM.
- Issue CO – Section Controller; copy to Crew Lobby, Station Manager, TPC.
- Posting – One notice at each station & in Guard’s journal.
- Review – every 30 days; extension beyond 6 months needs PHOD & CE concurrence.
7. Record Keeping
- SR Register – at every station; page numbered & audited quarterly.
- CO file – retained for 1 year.
- Speed Certificate file – retained for 3 years or permanent if converted to PSR.
8. Do’s & Don’ts for Candidates
✔ Do remember: “ sanctioned ≥ booked ≥ actual ”
✔ Do quote exact km/h from SOD when asked about curves, points.
✘ Don’t confuse “permanent” with “temporary” – PSR printed in WTT; TSR in CO.
✘ Don’t mix bridge restriction (generally 75-110 km/h) with turnout restriction (15-50 km/h).
9. Quick-Fire Facts
- Highest PSR in India: 160 km/h on Tughlakabad–Agra (WR) – 199 km.
- Longest continuous TSR: 30 km between Karjat–Lonavala ( ghat, wet-weather 55 km/h ).
- Only section with 200 km/h trial: Mumbai–Ahmedabad (but under NR; not yet operational).
- Minimum radius for 160 km/h: 1,750 m (transition length 120 m).
- Maximum cant deficiency allowed for BG: 100 mm (125 mm with CMS crossing & 160 km/h).
10. Practice MCQs
Q1. The maximum validity of a Temporary Speed Restriction without extension is
Ans. 6 months (SOD 4.05)Q2. Who is the competent authority to countersign a Speed Certificate?
Ans. Senior Divisional Operations Manager (Sr. DOM)Q3. A 1-in-12 ordinary turnout on BG has a Permanent Speed Restriction of
Ans. 15 km/h on facing directionQ4. The minimum radius for running trains at 160 km/h on BG is
Ans. 1,750 mQ5. Which of the following is NOT found in the Working Time Table?
Ans. Temporary Speed Restriction (TSR)Q6. The first section in Indian Railways to be sanctioned for 130 km/h was
Ans. Delhi–Agra (1988)Q7. For pollution control under GRAP-IV, a TSR of ___ km/h is imposed in Delhi-NCR.
Ans. 80 km/hQ8. The colour of the “pink” copy of Speed Certificate is retained by
Ans. Engineering departmentQ9. Maximum cant deficiency permitted for 160 km/h on BG is
Ans. 125 mm (with CMS crossing)Q10. If TQI value exceeds 65, the imposed speed restriction is
Ans. 20 km/h below sanctioned speedQ11. Which train was introduced in 1969 with 120 km/h booking speed?
Ans. Rajdhani ExpressQ12. The record keeping period for a Speed Certificate that has been converted to PSR is
Ans. PermanentQ13. Speed restriction imposed during KAVACH commissioning phase is
Ans. 10 km/h for 30 daysQ14. The highest operational PSR on Indian Railways at present is
Ans. 160 km/h (Tughlakabad–Agra)Q15. Non-compliance of a notified speed restriction is treated as which category of SPAD?
Ans. Category “A”Q16. The pilot digital module for online TSR feeding is called
Ans. DSRM (Digital Speed Restriction Module)End of Capsule – “Speed Restrictions”
Revise the figures daily; 2-3 questions are guaranteed from this topic in every Railway GK section.
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