CLO value
A unit to express the relative thermal insulation value. One CLO = 0.1555 °C x m2 / W
Dry suit
A garment that stops the entry of significant quantities of water upon immersion, the insulation depends on the wearer staying dry.
Wet suit
A garment that allows the controlled entry and exit of water when the wearer is immersed. By keeping a stationary layer of water close to the body, this will work as an insulation layer.
Immersion suit
A suit intended to protect the wearer from the effects of immersion in cold water.
Constant wear suit
A floatation garment is a type of constant wear suit designed to keep the wearer warm and dry at work and protect against drowning in water with a degree of thermal protection against cold shock and hypothermia. These garments are also technically classified as PFDs or buoyancy aids, always offering a minimum of 50 Newtons buoyancy. By means of the inherent floatation buoyancy foam lining, this type of garment will keep wearers afloat indefinitely and allow them to swim without undue encumbrance. However they will not automatically self-right the wearer from a face-down position. For this the use of a compatible lifejacket is required , preferably of a 275N buoyancy level to ensure optimum self-righting performance is achieved.
Abandonment suit
An immersion suit, designed to permit rapid donning in the event of an imminent immersion.
Inherent buoyancy material
Buoyancy provided by a material which is less dense than water, e.g. a closed cell foam, and forming a permanent part of the garment.
Personal Flotation Device (PFD)
A safety device for persons engaged in activities, whether in relation to their work or their leisure, in or near water. PFDs, when correctly worn, should give a reasonable assurance of safety from drowning to a person who is immersed in water by providing a specific amount of extra buoyancy to increase the chances of survival...
PFDs can be divided into the following two main classes:
Within these main two classes there are a number of levels of support, types of buoyancy, activation methods.
Buoyancy aid
Garment or device which when correctly worn and used in water, will provide a specific amount of buoyancy to assist the wearer to float in a vertical or upward position with the airways clear of the water. This type of device will NOT self-right the wearer from a face-down position.
Floatation garment – constant wear suit
A floatation garment is a type of constant wear suit designed to keep the wearer warm and dry at work and protect against drowning in water with a degree of thermal protection against cold shock and hypothermia. These garments are also technically classified as PFDs or buoyancy aids, always offering a minimum of 50 Newtons buoyancy. By means of the inherent floatation buoyancy foam lining, this type of garment will keep wearers afloat indefinitely and allow them to swim without undue encumbrance. However they will not automatically self-right the wearer from a face-down position . For this the use of a compatible lifejacket is required , preferably of a 275N buoyancy level to ensure optimum selfrighting performance is achieved.
Inflatable life jacket
Personal flotation device from which the buoyancy is obtained by inflating it by mouth (orally inflated) or from a compressed CO2 gas cylinder; either manually by pulling a handle operated by the wearer, or automatically without the wearer carrying out any action, but as a result of immersion in water, either by a hydrostatic mechanism or a cellulose cartridge type of mechanism. Mullion 150N and 275N inflatable life jackets are made of a single-chamber bladder (EN / ISO standards) or double-chamber bladder (required for IMO/SOLAS regulations). A ‘stand alone’ automatic life jacket will self-right the wearer if correctly donned; it will turn over a person falling into the water face down, even if he/she is unconscious, it will NOT, however protect against cold shock or hypothermia. These are mainly worn on their own in warmer climates where there is less risk of cold water immersion and shock.
They can also be worn in conjunction with a constant wear suit, the latter being the ideal combination to give the wearer all round protection. Where the two are worn together, it is important to follow the donning instructions strictly and check and test their compatibility as one can counteract the other and have a negative effect on the self-righting properties. For example a 150 Newton life jacket worn with a constant wear floatation suit is not recommended for self-righting purposes; for this application we advise the use of a compatible 275 Newton lifejacket. If in doubt please contact Mullion for guidance.
Double-chamber buoyancy systems
Buoyancy provided by 2 separate inflatable compartments, such that if mechanical damage occurs to one, the other can still operate and provide sufficient buoyancy on its own (required for IMO / SOLAS application).
Hypothermia
A condition where the body core temperature is below 35°C, that is, 2°C lower than the ‘normal’ core body temperature (=37°C). The state of hypothermia is of a higher risk to a person immersed in cold water than in a cold air environment, due to the fact that water is a greater conductor of heat than air. Consequently the body cools much more rapidly in water than in still air of the same temperature (approximately 25 times faster).