7.1 Life-Saving Appliances: Lifejackets, Immersion Suits & Lifebuoys

7.1 Life-Saving Appliances: Lifejackets, Immersion Suits & Lifebuoys

Personal survival at sea depends fundamentally on the immediate availability, proper maintenance, and proficient donning of Life-Saving Appliances (LSA). Under the International Convention for the Safety of Life at Sea (SOLAS 1974, Chapter III) and the mandatory International Life-Saving Appliance (LSA) Code, every merchant vessel must be equipped with certified personal life-saving gear engineered to preserve human life during shipboard disasters. For General Purpose (GP) Ratings undergoing training under the Directorate General of Shipping (DG Shipping), Ministry of Ports, Shipping and Waterways, Government of India, mastering the technical specifications, stowage rules, testing schedules, and operational use of lifejackets, immersion suits, thermal protective aids, and lifebuoys is a vital statutory competency.

---

1. SOLAS Chapter III Regulatory Architecture

SOLAS Chapter III sets out international standards for life-saving appliances and arrangements. The technical details of each appliance are codified in the International Life-Saving Appliance (LSA) Code (IMO Resolution MSC.48(66)).

• Statutory Readiness: Under SOLAS Regulation III/20, all life-saving appliances must be in working order and ready for immediate use before the ship leaves port and at all times during the voyage.
• Approval Standards: All life-saving equipment installed aboard merchant ships must be approved by the vessel's maritime Administration (e.g., DG Shipping in India) or an authorized Recognized Organization (such as the Indian Register of Shipping, Lloyd's Register, or DNV) and stamped with statutory approval marks.
• Signage and Markings: All LSA stowage locations, escape paths, and emergency stations must be marked with standardized photoluminescent IMO safety symbols compliant with Resolution A.760(18).

---

2. Lifejackets: Types, Construction & Performance Requirements

Lifejackets provide positive buoyancy, keeping an exhausted or unconscious seafarer's airway clear of the water.

+-----------------------------------------------------------------------------------+
|                         SOLAS LIFEJACKET MANDATORY ATTACHMENTS                    |
+-----------------------------------------------------------------------------------+
|  [ Retro-Reflective Tape ]  --> Minimum 400 cm² distributed across upper surfaces  |
|  [ Marine Whistle ]         --> Firmly corded, plastic non-jamming ball type       |
|  [ Lifejacket Light ]       --> >= 0.75 candela in all directions, >= 8 hours      |
|  [ Lifting Strop / Loop ]   --> High-tensile webbing loop to haul wearer aboard    |
|  [ Buddy Line ]             --> Buoyant line with snap-hook to tether survivors     |
+-----------------------------------------------------------------------------------+

Types of Lifejackets

1. Inherently Buoyant Lifejackets:
   • Constructed with closed-cell flexible foam (such as polyethylene or polyvinyl chloride foam) enclosed inside a durable, weather-resistant, bright orange or high-visibility red nylon cover.
   • Highly durable, puncture-proof, and requires minimal mechanical maintenance.
   • Bulky to stow, but immediately buoyant upon water entry without needing inflation.
2. Inflatable Lifejackets:
   • Employed extensively on workboats and bridge watches due to their compact, non-restrictive design.
   • Features at least two independent inflatable buoyancy chambers.
   • Inflates automatically upon water immersion via a hydrostatic or water-soluble capsule triggering a high-pressure $CO_2$ gas cartridge, supplemented by a manual pull-cord lanyard and oral inflation tubes on each chamber.

SOLAS LSA Code Performance Criteria

To achieve statutory certification, an adult lifejacket must fulfill rigorous physical performance tests:

• Donning Time: Must be capable of being correctly donned within 1 minute without assistance, following a single demonstration.
• Water Impact Resistance: The wearer must be able to jump safely from a height of at least 4.5 meters into the water without injury and without dislodging or damaging the lifejacket.
• Righting Capability: Approval tests compare performance with a standard reference test device (RTD). For installations covered by the amendment from 1 January 2026, average turning time to a face-up position with nose and mouth clear must not exceed the RTD time plus 1 second.
• Freeboard and Stability: Average mouth clearance must be at least that of the adult RTD; average torso and face-plane angles must be no less than the corresponding RTD angles minus $5^\circ$.
• Swimming Capability: Allows the wearer to swim short distances and board a survival craft without impedance.

Required Attachments and Markings

• Lifejacket Light: Powered by a lithium battery or water-activated seawater cell. Must emit a continuous or flashing (50–70 flashes per minute) white light with a luminous intensity of at least 0.75 candela in all directions of the upper hemisphere, maintaining this intensity for at least 8 hours.
• Signalling Whistle: A high-decibel, corrosion-proof plastic whistle securely corded to the jacket body.
• Retro-Reflective Material: Fitted with at least $400\text{ cm}^2$ of approved retro-reflective material, placed high and distributed for detection from air and surface craft.
• Lifting Strop and Buddy Line: Fitted with a dedicated high-strength lifting loop to hoist the survivor from the sea, and a buoyant lanyard (buddy line) with a snap-hook to link survivors together in the water.

Shipboard Carriage Scales

SOLAS Chapter III mandates complete lifejacket coverage for every person aboard, plus statutory reserves:

• Adult Lifejackets: One for every person on board the ship complement.
• Watchstanders & Remote Stations: Additional lifejackets must be stowed on the navigation bridge, engine control room (ECR), and any other remote watch station.
• Child Lifejackets: Provide child lifejackets for at least 10% of passengers or for every child aboard, whichever is greater.
• Infant Lifejackets: Sized for infants weighing under 15 kg.
• Oversized Lifejackets: A sufficient number of suitable lifejackets must be provided for persons with a chest girth up to $1,750\text{ mm}$ and a body weight up to $140\text{ kg}$.
• Stowage: Clearly marked, easily accessible lockers in crew cabins, public spaces, and near muster stations.

---

3. Immersion Suits & Thermal Protective Aids (TPA)

Cold-water immersion can cause an immediate gasp and uncontrolled breathing, followed by loss of useful muscle function. These effects can cause drowning before hypothermia develops. Longer immersion cools the body core; collapse can also occur around rescue. A correctly fitted lifejacket protects the airway, while suitable clothing and immersion protection reduce cooling.

                               IMMERSION SUIT ANATOMY

                  +----------------------------------------------+
                  |  Watertight Face Seal (Neoprene / Rubber)    |
                  |  Full-Length Waterproof Front Zipper (Waxed) |
                  |  Attached 3-Finger or 5-Finger Mitts/Gloves  |
                  |  High-Tensile Lifting Strop & D-Ring         |
                  |  Attached Seawater-Activated Light & Whistle |
                  |  Integrated Boots with Non-Slip Tread Soles  |
                  |  Exhalation Ankle Valves (Vents Trapped Air) |
                  +----------------------------------------------+

Immersion Suits (Survival Suits)

An immersion suit is a full-body protective garment designed to reduce thermal shock upon entering cold water and prevent hypothermia.

• Carriage Requirements: Under SOLAS III/32.3, cargo ships carry a suitable immersion suit for every person aboard. Provide additional suits at work/watch stations remote from normal suit stowage, for the people normally there. The Administration may waive suits for ships constantly in warm climates other than bulk carriers.
• Insulated vs. Uninsulated Suits:
  • Insulated Suits: Often made from closed-cell neoprene, typically 5 mm thick, providing insulation and buoyancy. Wear a lifejacket unless the suit is approved and marked for use without one; a buoyancy pillow alone does not establish that approval. Anti-exposure suits are a separate LSA category for rescue-boat crews and evacuation parties.
  • Uninsulated Suits: Made of waterproof fabric; must be worn with warm woolen clothing underneath and worn in conjunction with an approved lifejacket.
• Donning Standard: Must be capable of being unpacked and donned without assistance within 2 minutes, including any associated clothing and lifejacket.
• Impact and Mobility: The wearer must be able to climb up and down vertical ladders at least 5 meters in length, jump from a height of 4.5 meters into the water without damage or water leakage, and swim short distances to board a liferaft.
• Thermal Insulation Standard:

  Important

  Under the LSA Code, an insulated immersion suit must provide sufficient thermal insulation so that the wearer's core body temperature does not drop more than $2^\circ\text{C}$ after 6 hours of continuous immersion in calm, circulating water at temperatures between $0^\circ\text{C}$ and $2^\circ\text{C}$.

Thermal Protective Aids (TPA)

• Construction: A bag or suit fabricated from waterproof aluminized polyethylene or polyester laminate with extremely low thermal conductivity.
• Function: Designed to reduce both convective and evaporative heat loss from an individual's body inside a survival craft. Covers the entire body of a person wearing a lifejacket, leaving only the face exposed.
• Deployment: Readily unpacked and donned within moments without assistance inside a survival craft or rescue boat. Does not provide inherent buoyancy and is not designed for swimming in open water.
• Carriage: Under the LSA Code, lifeboats and liferafts must carry at least 2 Thermal Protective Aids or a number equal to 10% of their licensed passenger capacity, whichever is greater.

---

4. Lifebuoys: Construction, Attachments & Distribution

Lifebuoys are personal rescue appliances deployed overboard to provide emergency buoyancy to a person who has fallen into the sea (Man Overboard / MOB).

                                SOLAS LIFEBUOY

                                  .---''''---.
                                /     Top      \
                               /   [RETRO TAPE] \
                              |  .------------.  |
                              | /              \ |
                  [GRAB LINE] ||                || [GRAB LINE]
                   (4 LOOPS)  ||  Inner Diam:   ||  (4 LOOPS)
                              | \   >= 400 mm  / |
                              |  '------------'  |
                               \   [RETRO TAPE] /
                                \    Bottom    /
                                  '---....---'
                               Outer Diam: <= 800 mm
                               Standard Mass: >= 2.5 kg
                               Bridge Wing MOB: >= 4.0 kg

LSA Code Construction Standards

• Dimensions: An outer diameter of not more than 800 mm and an inner diameter of not less than 400 mm.
• Material: Constructed of inherently buoyant material, such as solid closed-cell polyurethane foam encased in a tough, high-density polyethylene orange shell. Inflatable chambers, cork shavings, or kapok are strictly prohibited.
• Grab Lines: Fitted with a rot-proof buoyant grab line with a diameter not less than $9.5\text{ mm}$, securely attached at four equidistant points around the outer perimeter to form four equal loops.
• Retro-Reflective Tape: Fit approved retro-reflective material about 50 mm wide around, or on both sides of, the lifebuoy at four evenly spaced points.
• Ship Name Marking: Must be marked in block Roman capital letters with the vessel's name and port of registry.

Mass and Bridge Wing Quick-Release Units

• Standard Lifebuoy Mass: Must have a minimum mass of 2.5 kg to prevent it from being blown away by high winds when cast into the water.
• Bridge Wing Quick-Release Lifebuoy Mass: Lifebuoys installed on navigation bridge wing quick-release chutes must have a minimum mass of 4.0 kg (often weighted with internal lead ballast). This heavier mass is necessary to overcome mechanical friction, drop freely when released from the bridge, and pull the release pins of the attached self-activating smoke signal and self-igniting light.

Lifebuoy Accessories

1. Self-Igniting Light: Emits a continuous or flashing white light of at least 2 candela in all directions of the upper hemisphere for a minimum duration of 2 hours. Use an approved light appropriate to the vessel; SOLAS requires electric-battery-type lifebuoy lights on tankers.
2. Self-Activating Smoke Signal: Emits a dense cloud of highly visible orange smoke for a continuous duration of at least 15 minutes. Must float upright in water and operate without burning explosively or igniting surrounding fuel slicks.
3. Buoyant Lifeline: A non-kinking, buoyant synthetic rope with a diameter $\ge 8\text{ mm}$ and a length equal to at least double the height at which it is stowed above the waterline in the lightest seagoing condition, or 30 meters, whichever is greater.

SOLAS Minimum Lifebuoy Distribution for Cargo Ships

---

5. Shipboard Emergency Alarms, Muster List & Abandon Ship Protocol

During a shipboard crisis, discipline and swift muster save lives. Every seafarer must instantly recognize auditory emergency signals and react methodically.

Emergency Alarm Signals

• General Emergency Alarm (GEA): Signaled by seven or more short blasts followed by one prolonged blast ($-------$ ——) on the ship's whistle or siren, sounded simultaneously on the vessel's internal electric alarm bells and klaxons throughout accommodation and engine spaces.
• Fire Alarm: A continuous ringing of the ship's electric fire alarm bell, supplemented by public address (PA) announcements detailing the location and nature of the fire.
• Man Overboard (MOB) Alarm: Three prolonged blasts (—— —— ——, Morse code letter Oscar [O]) on the ship's whistle, repeated over the PA system.

The Muster List (Station Bill)

Under SOLAS Regulation III/37, every merchant vessel must establish and maintain an up-to-date Muster List (historically called the Station Bill). The Muster List must be conspicuously posted in multiple prominent locations before the vessel puts to sea, including the navigation bridge, engine control room (ECR), crew mess rooms, ship's office, and main accommodation alleyways.

• Information Displayed on the Muster List:
  • The precise audible emergency alarm signals for General Emergency, Fire, and Man Overboard.
  • The specific emergency muster station to which each crew member must report.
  • The assigned survival craft (Port or Starboard lifeboat, or designated liferaft) for every seafarer.
  • The designated officer in command of each muster station and survival craft, along with a nominated second-in-command substitute to ensure continuous leadership if the primary leader is incapacitated.
  • Specific, individual emergency duties assigned to each rating and officer.

Immediate Actions of a Trainee GP Rating upon Hearing the General Emergency Alarm

When the General Emergency Alarm sounds (7 or more short blasts followed by 1 prolonged blast), every trainee rating must execute a disciplined, rapid response sequence:

1. Stop Work and Make Safe: Immediately cease whatever work is underway. Shut down running power tools, isolate welding equipment or pneumatic lines, close open valves, and ensure the work site is left in a safe, non-hazardous condition.
2. Dress in Warm, Protective Clothing: Protect against heat loss, spray and wind exposure during abandonment and survival, including on warm-weather voyages. Put on the protective clothing specified in the emergency instructions:
   • 100% cotton long-sleeved boiler suit.
   • Warm thermal undergarments or a thick woolen sweater.
   • Heavy woolen or thermal socks and sturdy, lace-up safety footwear (never go to muster in sandals, slippers, or bare feet).
   • Woolen watch cap or beanie to minimize cranial heat radiation loss.
3. Don Certified Personal Life-Saving Appliances: Retrieve your assigned adult lifejacket. Don it carefully, fastening all chest buckles, waist belts, and crotch straps snugly to ensure it does not ride up over the head when jumping into the water. Carry your assigned insulated immersion suit in its protective carry bag, along with a warm wool blanket if mandated by the Muster List.
4. Proceed Promptly to Assigned Muster Station: Move briskly without running, shoving, or panicking. Follow marked photoluminescent escape route arrows along alleyways and stair towers. Never use accommodation elevators or cargo lifts during an emergency, as electrical power failure can trap occupants inside shafts.
5. Report to Muster Station Leader: Upon arrival at your assigned muster station, report immediately to the Muster Station Leader (such as the Chief Officer or Bosun). Answer clearly when your name is called during the muster roll call so that 100% crew accountability can be reported to the Master on the navigation bridge.
6. Carry Out Assigned Emergency Tasks: Execute your designated Muster List tasks without hesitation (e.g., fetching the EPIRB or SART from the bridge bracket, rigging the liferaft embarkation ladder, or connecting the lifeboat painter). Listen for commands and await the Master’s abandon-ship order by the method specified in the muster list.