About Fog Pass Devices
- It is a GPS based navigation device that helps the loco pilot to navigate during dense fog conditions.
- It provides on-board real-time information (Display as well as voice guidance) to Loco Pilots regarding location of fixed landmarks such as Signal, Level Crossing gate (Manned & Unmanned), Permanent Speed Restrictions, Neutral Sections etc.
- It displays approach indications of the next three approaching fixed landmarks in geographical order accompanied with a voice message approximately 500m on approach.
- General features of Fog Pass Device
- Suitable for all types of sections like single line, double line, electrified as well as non electrified sections.
- Suitable for all types of electric and diesel locomotives, EMUs/MEMUs/ DEMUs.
- Suitable for train speeds up to 160 KMPH.
- It has built-in rechargeable battery back-up for 18 hrs.
- It is portable, compact in size, light in weight (not more than 1.5 Kg including battery) and of robust design.
- Loco Pilot can carry the device easily with him to the locomotive on resuming his duty.
- It can be easily placed on the cab desk of a locomotive.
- It is a standalone system.
- It is unaffected by weather conditions like Fog, Rain or Sunshine.
Q1) What is the Global Positioning System (GPS)?
It is a U.S. government satellite-based navigation system that currently consists of at least 24 operational satellites. GPS works in any weather conditions, anywhere in the world, 24 hours a day, with no subscription fees or setup charges. The U.S. Department of Defense (USDOD) originally put the satellites into orbit for military use, but they were made available for civilian use in the 1980s.
Last updated on August, 2026
→ UPSC Mains 2026 will be conducted on 21st, 22nd, 23rd, 29th and 30th August 2026.
→ Check out the latest UPSC Syllabus 2026 here.
→ UPSC Mains Admit Card 2026 is expected to be released in early August at upsc.gov.in or upsconline.nic.in
→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2027 for structured answer writing practice, expert evaluation, and exam-oriented feedback.
→ Join Vajiram & Ravi’s UPSC Mentorship Program 2027 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.
→ Go through the UPSC Mains Previous Year Papers to enhance your preparation.
→ Download UPSC Mains Essay Paper 2025, UPSC Mains GS Paper-I 2025, UPSC Mains GS Paper-II 2025, UPSC Mains GS Paper-III 2025, UPSC Mains GS Paper-IV 2025, UPSC Mains English (Compulsory) Paper 2025, UPSC Mains Hindi (Qualifying) Paper 2025 here.
→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.
→ UPSC Calendar 2027 has been released.
→ Also check Best UPSC Coaching in India







