In compliance with SOLAS Chapter III (Regulation 20.8) and IMO Resolution A.761(18) (Recommendations on Conditions for the Approval of Servicing Stations for Inflatable Liferafts), marine liferafts must undergo mandatory annual inspection and periodic pressure testing at class-approved servicing stations. Proper inflation dynamics, chamber integrity, emergency pack replenishment, and Hydrostatic Release Unit (HRU) renewal are non-negotiable life-safety requirements.
Engineering Overview & Table of Contents
- 1. Statutory Standards: IMO Resolution A.761(18) Framework
- 2. Mandatory Pressure Tests: Working Pressure (WP) & NAP Testing
- 3. Gas Inflation Cylinders, Operating Heads & Relief Valves
- 4. Emergency Pack Replenishment (SOLAS A & B Packs)
- 5. Hydrostatic Release Units (HRU) & Painter Line Lashing
- 6. Dockside Exchange, Supply & Fast Turnaround Across Indian Ports
1. Statutory Standards: IMO Resolution A.761(18) Framework
Seanav operates fully certified marine liferaft service stations approved by major IACS classification societies and Directorate General of Shipping (DGS). Our stations maintain climate-controlled testing bays (temperature & humidity monitored) with calibrated barometers and digital manometers.
Our operational scope covers Liferaft Supply, Liferaft Annual Servicing, Liferaft Periodical Servicing, Liferaft Maintenance, and Liferaft Repacking across throw-overboard, davit-launched, and self-righting liferafts (6 to 50-person capacity) manufactured by Viking, Survitec (Zodiac / DBC / RFD), Lalizas, Fujikura, and Shanghai Youlong.
2. Mandatory Pressure Tests: Working Pressure (WP) & NAP Testing
Over operational service at sea, fabric rubberization can experience seam delamination or micro-porosity. IMO Resolution A.761(18) prescribes strict testing intervals:
Prescribed Liferaft Pressure Test Protocols:
- Working Pressure (WP) Test: Inflating both upper and lower buoyancy chambers to operational working pressure (approx. 100–120 mmHg / 13.3 kPa) using dry compressed air. Chambers must hold pressure for 1 hour; temperature-compensated pressure drop must not exceed 5%.
- Necessary Additional Pressure (NAP) Test: Required at the 10th year of service and annually thereafter. Buoyancy chambers are pressurized to 2 × working pressure (or manufacturer-specified test pressure) for 5 minutes with pressure relief valves gagged, ensuring seam shear strength and vulcanized joint cohesion.
- Floor Seam Integrity Test: Pressurizing bottom floor chambers to verify water ballast bag attachment strength, boarding ramp buoyancy, and thermal floor insulation integrity.
3. Gas Inflation Cylinders, Operating Heads & Relief Valves
The rapid automated inflation of a liferaft depends on high-pressure CO2/N2 gas cylinders discharging through operating heads into internal buoyancy chambers within 20–30 seconds:
- Liferaft CO2 Cylinder Refilling & Weighing: Precision tare-weight weighing to verify liquid CO2 charge (tolerance within ±5%). Cylinders exceeding 5-year intervals undergo statutory hydrostatic pressure testing at 250 bar.
- Cylinder Operating Head Overhaul: Dismantling piercing cutter assemblies, replacing rupture discs, inspecting pull-cable linkages, and testing firing pins.
- Pressure Relief Valves (PRV): Disassembling overpressure exhaust valves, testing opening/closing seat pressures, and replacing internal neoprene rubber sealing discs.
4. Emergency Pack Replenishment (SOLAS A & B Packs)
During the annual repacking procedure, expired safety rations and medical supplies must be systematically purged and replaced with newly manufactured, DGS/MED-certified items:
| Component Category | SOLAS Requirements | Seanav Servicing Scope |
|---|---|---|
| Pyrotechnics | 4 Rocket Parachute Flares, 6 Hand Flares, 2 Buoyant Smoke Signals | Expiry date audit; replacing dated units with fresh 3-year SOLAS/MED approved pyrotechnics. |
| Water and Rations | 1.5 L drinking water per person; 10,000 kJ food ration per person | Hermetic vacuum seal integrity check; replacing batch-dated rations. |
| First Aid Kit & Hardware | MED-approved survival kit, thermal protective aids (TPAs), radar reflector | Replacing medicines, sea anchor drogue lines, repair clamps, bellows, and spare sea-marker lights. |
5. Hydrostatic Release Units (HRU) & Painter Line Lashing
The Hydrostatic Release Unit ensures that if a vessel sinks before manual launching, the liferaft automatically releases at a water depth of 1.5 to 4.0 meters, reaches the surface, and inflates via the weak link. Seanav supplies and installs certified Hammar H20 and Thanner HRUs, ensuring precise painter line connection, weak-link shackle rigging, and physical expiry marking.
6. Dockside Exchange, Supply & Fast Turnaround Across Indian Ports
To prevent vessel delays during tight port calls, Seanav maintains an extensive pool of pre-inspected, class-certified replacement liferafts available on an immediate exchange basis. Our shore logistics teams collect landed liferafts, install exchange units at the ship’s cradle, and deliver newly serviced liferafts complete with original Class and Servicing Station Certificates across Kandla, Mundra, Mumbai, JNPT, Mangalore, Cochin, Chennai, and Visakhapatnam.
Book Liferaft Annual Servicing or Immediate Dockside Exchange
Explore our class-approved liferaft capabilities on our Inflatable Liferaft Servicing Landing Page or coordinate pickup at any Indian Port.