Lifebuoys, lights, smoke signals and lifelines
1The lesson in plain words
A lifebuoy is the first thing thrown to a person overboard. Some carry a light and smoke to mark the spot; others a floating line to pull them in.
What a lifebuoy is
A SOLAS lifebuoy is a ring of solid buoyant material, never inflatable, with an outer diameter of not more than 800 mm and an inner diameter of at least 400 mm. It weighs at least 2.5 kg and supports at least 14.5 kg of iron in fresh water for 24 hours. A grabline, a rope, forms four loops. It must survive a drop into the water from its stowage height or 30 m, whichever is greater. A quick-release buoy must be heavy enough to operate its mechanism.
Lights and smoke
At least half the lifebuoys carry a self-igniting light, a white light that switches on automatically when deployed. It provides at least 2 candela (cd), steady or flashing 50–70 times a minute, for at least 2 hours. The intensity requirement applies to both modes, using effective intensity for flashes. At least two also carry a self-activating smoke signal, giving highly visible smoke for at least 15 minutes. Two light-and-smoke buoys have bridge quick release. Bridge-release buoys must weigh at least 4 kg.
Buoyant lifeline
At least one lifebuoy on each side has a buoyant lifeline, a floating rope at least 8 mm thick with a breaking strength of at least 5 kN. It is at least twice as long as the height of its stowage above the waterline in the lightest seagoing condition, or 30 m, whichever is greater. The lifebuoys with lifelines are not the ones that carry lights or smoke signals.
How many and where
A cargo ship carries at least 8 lifebuoys if under 100 m long, 10 from 100 m, 12 from 150 m and 14 from 200 m. They are spread on both sides and on all open decks to the stern, ready to throw in seconds and never permanently secured. Each is marked in capital letters with the ship's name and port of registry, and carries retro-reflective tape.
2Key data
- Size and mass
- Outer ≤800 mm; inner ≥400 mm; ≥2.5 kg; bridge release ≥4 kg
- Buoyancy
- Supports 14.5 kg of iron for 24 h in fresh water
- Self-igniting light
- White; ≥2 cd steady or effective flashing; ≥2 h; 50–70 flashes/min
- Smoke signal
- At least 15 min of highly visible smoke
- Buoyant lifeline
- 8 mm, 5 kN; twice stowage height or 30 m, whichever greater
- Cargo ship numbers
- Under 100 m: 8; 100 m: 10; 150 m: 12; 200 m and over: 14
3Key points
- 1
Lifebuoy: solid buoyant ring, at least 2.5 kg, marked with the ship's name and port.
- 2
At least half carry self-igniting lights; two of these also carry smoke signals.
- 3
The light-and-smoke pair is released quickly from the bridge.
- 4
Lifeline buoys: line twice the stowage height or 30 m, whichever is greater.
- 5
Ready to throw, never permanently secured.
4Frequent mistakes
Wrong: Lash lifebuoys tightly to the rail so they are not lost in heavy weather.
Right: Lifebuoys must never be permanently secured. Seconds count in a man-overboard.
Wrong: Throw the lifebuoy straight at the person in the water.
Right: Throw it just beyond or beside them, so it does not hit them, and let wind or the line bring it within reach.
5Practice case & exam keys
Your 180 m cargo ship has 12 lifebuoys, six lights and two bridge-release light-and-smoke buoys. A separate lifeline buoy, stowed 22 m above the lightest-seagoing waterline, has a 30 m line. Is this acceptable?
Show the answer
The counts comply: 12 buoys, at least six lights and two bridge-release light-and-smoke buoys. The line does not comply. Its minimum length is twice the stowage height or 30 m, whichever is greater: 2 × 22 m = 44 m. Reject and report the short line so it can be replaced.
Exam keys
- Lifebuoy: outer ≤ 800 mm, inner ≥ 400 mm, mass ≥ 2.5 kg, 14.5 kg of iron for 24 h.
- Self-igniting light ≥ 2 h; smoke signal ≥ 15 min; two with both, quick release from the bridge.
- Lifeline: ≥ 8 mm, ≥ 5 kN, twice stowage height or 30 m, whichever is greater.
- Cargo ships: 8 / 10 / 12 / 14 lifebuoys by length band.
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