Life Jacket What is a life jacket?
If the wearer, of a life jacket, falls into the water in an unconscious or semi conscious state the life jacket will inflate keeping them afloat and turn them into a position whereby their mouth is clear of the water.
The above statement is important and it should not be confused with buoyancy aids which are designed to keep you afloat but not necessarily with your mouth clear of the water.
How do we know which is which? Life jackets and buoyancy aids are labelled with a buoyancy level number, Newton, which is a unit of buoyancy. There are 4 numbers which we need to be aware 50, 100, 150 and 275.
50 Newton is regarded as a buoyancy aid for use by competent swimmers close to shore or were help is close to hand. They do not have sufficient buoyancy to assist an unconscious casualty in staying afloat.
100 Newton is also a buoyancy aid but will keep you afloat in sheltered waters whilst waiting rescue.
150 Newton is a general offshore and rough weather life jacket. It will keep afloat an unconscious casualty and turn them into a safe position.
275 Newton is a offshore life jacket for rough weather and were the wearer may be wearing heavier clothing thus requiring more buoyancy. It will keep afloat an unconscious casualty and turn them into a safe position.
Operating mechanisms Broadly the operation of a life jacket falls into the following categories,
Manual inflate, usually via oral mouth piece. The user needs to be conscious and able to inflate life jacket which will take about 7 good breaths to fully inflate
Manual / Auto, has a pull cord which explodes a CO2 canister, thereby inflating the life jacket. Auto element is the rush of water into the firing mechanism dissolving the soluble pill thereby releasing the firing pin.
Manual / Auto, has a pull cord which explodes a CO2 canister, thereby inflating the life jacket. Auto element is the pressure change between the deck and the first few inches of water, this is a hydrostatic release.
Essential additions, not always fitted to life jackets are,
Crotch strap, prevents the life jacket from riding up over the casualties head
Light, that is activated by the water or when the life jacket is deployed
Retro reflective tape, reflects back to the rescuer when a light is shone in the direction of the casualty.
D ring for attachment of safety line, prevent you from going overboard in the first instance, if attached.
Spray hood to stop waves and spray entering the mouth
Whistle to attract attention
Optional extras Dye marker, highlighting your position in the water
Personal locator beacon, to aid search and rescue
Mini flares, red for night, smoke for day
Life jackets should be inspected regularly for the following,
Visual condition check of life jacket lung and straps
Manually inflate, should stay up for at least 24 hours any thing less then suspect a leak
Check CO2 cylinder by removing from holder and checking that it is still intact, no hole in the base. Finding a hole would suggest the life jacket has been inflated and repacked without changing the CO2 cylinder.
Check condition of CO2 cylinder, a large percentage of corrosion may suggest insufficient gas to inflate the life jacket to its maximum.
Check that it is the appropriate size CO2 cylinder for the life jacket
Replace the auto pill annually, these can become stale and take longer to dissolve thereby taking longer to inflate.
If life jacket has condition tags, check that all are displaying green any red then change components.
Alternatively check the instruction leaflet with the life jacket for recommended service intervals.
GT Yachting October 2012 |
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