⚓ What Is a Second-Generation EPIRB?
Complete Guide for Seafarers (Tron 60AIS Example)
🎬 Watch Onboard Test Video Below 👇
🆘 What Is an EPIRB?
The Second Generation EPIRB Tron 60AIS represents the latest advancement in maritime distress alerting technology. This beacon transmits emergency signals via satellite and AIS, ensuring faster response and improved safety at sea.
An EPIRB (Emergency Position Indicating Radio Beacon) is a vital GMDSS device used to transmit a distress signal when a vessel faces a life-threatening emergency such as sinking, collision, or fire.
Once activated—either manually or automatically—it sends a digital alert via COSPAS-SARSAT satellites to shore-based Rescue Coordination Centres (RCCs), enabling quick response and saving lives at sea.
⚙️ Working Principle of an EPIRB 🛰️
An Emergency Position-Indicating Radio Beacon (EPIRB) is designed to alert search and rescue (SAR) authorities to a vessel in distress anywhere in the world.
It operates through the COSPAS-SARSAT satellite system, using precise digital signals that include the vessel’s unique identity and GPS position.
🔹 Step-by-Step Working Process
- Activation
- Manual: The crew pulls the safety pin and slides the switch to “ON.”
- Automatic: The Hydrostatic Release Unit (HRU) triggers the beacon when submerged about 4 m underwater.
- Signal Transmission (406 MHz)
- The EPIRB transmits a 406 MHz digital distress signal containing:
- Unique beacon ID (linked to vessel MMSI)
- GPS coordinates (if GNSS-equipped)
- Time and status data
- The EPIRB transmits a 406 MHz digital distress signal containing:
- Satellite Detection (COSPAS-SARSAT System)
- MEOSAR, GEOSAR, and LEOSAR satellites detect the signal.
- MEOSAR ensures global coverage and fast location (<10 minutes).
- Data Relay to Ground Stations
- Satellites forward the signal to Local User Terminals (LUT) and Mission Control Centres (MCC).
- These calculate the position and forward it to Rescue Coordination Centres (RCC).
- Rescue & Homing Phase
- RCCs launch SAR units (aircraft/ships).
- Homing signals (121.5 MHz or AIS) help rescuers pinpoint the exact spot.
📘 Modern EPIRBs like the Tron 60AIS use both satellite and AIS communication for faster rescue responses.
🌊 Importance of EPIRB in Maritime Safety
EPIRB is one of the most vital components of the GMDSS (Global Maritime Distress and Safety System).
It ensures that even if the ship sinks or loses power, a distress message is still transmitted.
Thousands of lives have been saved thanks to timely alerts sent via EPIRBs.
⚓ How the Hydrostatic Release Unit (HRU) Works
The HRU automatically releases the EPIRB when the vessel sinks.
- At about 4 m depth, water pressure activates the HRU’s blade, cutting the securing strap.
- The EPIRB then floats free and activates automatically.
- HRUs must be replaced every 2 years or as per manufacturer’s expiry.
📜 IMO Regulations and Minimum Requirements
As per SOLAS Chapter IV Reg. 7.1.6 and IMO Resolution MSC.471(101):
- Every SOLAS vessel must carry one float-free 406 MHz EPIRB.
- The beacon must operate via the COSPAS-SARSAT system.
- New installations after 1 July 2022 must comply with Second-Generation EPIRB (SGB) standards, including:
- AIS transmitter
- GNSS receiver (GPS / GLONASS / Galileo)
- Return Link Service (RLS) capability
🛰️ Reference: IMO MSC 101/24 Annex 24 & MSC.471(101)
⏱️ Minimum Operating Hours
EPIRBs must transmit continuously for at least 48 hours once activated and operate between –20 °C to +55 °C, withstanding storage from –30 °C to +70 °C.
🚀 What Is a Second-Generation EPIRB (SGB)?
The Second-Generation EPIRB (SGB) represents a new standard of maritime distress signaling using the MEOSAR satellite system for faster, more accurate global coverage.
🔹 Key Features
✅ Multi-GNSS positioning (GPS, GLONASS, Galileo)
✅ AIS transmission for local vessel tracking
✅ Return Link Service (RLS) – blue light confirmation when RCC receives distress
✅ Accuracy ≤100 m
✅ Detection <10 minutes
✅ Improved battery life and diagnostics
⚙️ Technical Specifications (General SGB EPIRB)
| Parameter | Specification |
|---|---|
| Frequencies | 406 MHz (COSPAS-SARSAT), 121.5 MHz (Homing), AIS 161.975 / 162.025 MHz |
| Output Power | 5 W (406 MHz), 100 mW (121.5 MHz), 1 W (AIS) |
| Battery Life | ≥48 h continuous operation, 11 years standby |
| Standard | COSPAS-SARSAT T.001 / T.007, IMO MSC.471(101), IEC 61097-2 Ed.4 |
| Operating Temp | –20 °C to +55 °C |
| Deployment | Manual or automatic via float-free HRU |
⚓ Difference Between Old and New EPIRB
| Feature | First Generation EPIRB | Second Generation EPIRB |
|---|---|---|
| Satellite System | LEOSAR/GEOSAR | MEOSAR |
| Accuracy | ~5 km | ≤100 m |
| Detection Time | 30–45 min | <10 min |
| Return Link Service | ❌ No | ✅ Yes |
| AIS Signal | ❌ No | ✅ Yes |
| Battery Life | ~5 years | 5–11 years |
| Regulation | MSC.120(74) | MSC.471(101) |
⚙️ Tron 60AIS EPIRB – Example of Second Generation Beacon
🔹 Features
- 406 MHz + 121.5 MHz + AIS distress channels
- Multi-GNSS receiver (GPS, Galileo, GLONASS)
- RLS-ready via Galileo
- IR + regular LEDs for night SAR
- Battery life: 11 years 3 months
- Float-Free (FB-60) or Manual (MB-60) brackets
- Power output: 5 W (406 MHz), 1 W (AIS)
- Certified by IMO, FCC, MER(UK), ANATEL, IC, MLIT
🧪 Testing Procedure (Onboard)
🎬 Watch the Tron 60AIS Testing Video Below 👇
Steps:
- Check HRU and battery expiry.
- Verify mounting is clear and antenna undamaged.
- Activate TEST mode (not ON).
- Observe LED: green = pass / red = fault.
- Confirm AIS signal on ECDIS or AIS receiver.
- Record in GMDSS logbook with date & signature.
🧰 Testing should be done monthly and logged as per company SMS.
🛟 Maintenance & Inspection Tips
✅ Replace HRU every 2 years or before expiry.
✅ Conduct monthly self-tests and annual shore service.
✅ Ensure EPIRB registration with flag administration.
✅ Keep mounting area clear of obstructions.
✅ Verify float-free bracket is operational.
🧭 Final Remarks
The Second-Generation EPIRB, such as the Jotron Tron 60AIS, is a game-changer in maritime distress signaling — combining satellite alerting, local AIS visibility, and return acknowledgment for maximum safety.
Understanding its operation, testing, and regulatory requirements is essential for every seafarer.
⚠️ Educational Notice
This article and video are for educational and training purposes only.
Always follow your Company SMS, Manufacturer’s Manual, and Flag State Instructions.
Merchant Navy Life assumes no liability for operational use.
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