Automatic Work Life Jackets
Whether you need an automatic life jacket with 150 N or 275 N buoyancy depends on the medium, the equipment you are carrying, and your body weight. We can also supply life jackets that are sweat-resistant or heat-resistant.
A life jacket is a garment that automatically turns a person onto their back in the water and keeps their head above water to maintain a clear airway.
This function also applies if the person is unconscious, which is why such jackets are also called unconscious-proof. In contrast, a buoyancy aid only helps reduce the effort required for swimming, provided the person is conscious.
The outdated term “life vest” has been replaced by the term “life jacket” in the SOLAS Convention. Colloquially, the outdated term is still sometimes used for jackets that do not keep an unconscious person afloat but contain buoyancy elements in the back area.
On all ships and passenger aircraft, it is mandatory to carry sufficient life jackets for all passengers and crew members. At sea, good seamanship dictates wearing a life jacket in bad weather, darkness, or while on watch at the helm or at anchor.
However, a life jacket does not prevent a fall overboard (unlike a harness, also called a lifebelt), nor does it guarantee that a person who has gone overboard can be quickly located and recovered.
A buoyancy aid or life jacket helps reduce the necessary swimming movements and heat loss and can keep unconscious or weakened individuals afloat. This delays exhaustion and hypothermia, increasing the available time for rescue.
Preventive Life Jackets
For life jackets designed for preventive (and therefore continuous) wear, comfort is just as important as functionality. During manufacturing, maximum freedom of movement is a priority. Furthermore, since these jackets are often worn at work, they must withstand mechanical stress. Life jackets of this type are used in recreational and commercial shipping and are frequently combined with a lifebelt.
Intense Life Jackets
Life jackets not designed for continuous wear are typically carried as passenger life jackets on airplanes or ships. Since passengers on a passenger ship do not wear life jackets continuously, these life jackets are designed to be put on as quickly and easily as possible (even by laypersons). Comfort is not a primary focus with these solid-foam life jackets. They are less expensive, resistant to moisture, and require minimal maintenance. The increased space requirement is acceptable on most ships.
Due to limited storage space, inflatable life jackets are used on airplanes. These have the advantage of being activated or inflated only after leaving the aircraft, so they do not hinder evacuation.
The SOLAS Convention (Chapter III, Regulation 32) and the corresponding European and German standards define the following categories of buoyancy aids and life jackets:
- Buoyancy aids Type 50 Newton – DIN EN ISO 12402-5 (formerly DIN EN 393):
Minimum buoyancy of 50 Newtons; not designed to keep an unconscious person afloat; not suitable for children under 30 kg. Intended use: dinghy sailing, where a life jacket would be too bulky, or whitewater paddling. - Life jackets Type 100 Newton – DIN EN ISO 12402-4 (formerly DIN EN 395):
Minimum buoyancy of 100 Newtons; limited ability to keep an unconscious person afloat depending on clothing. Intended use: sheltered waters and inland waterways. - 150 Newton life jackets – DIN EN ISO 12402-3 (formerly DIN EN 396):
Minimum buoyancy of 150 Newtons; designed to keep an unconscious person afloat. Mostly fully automatic models (for recreational boating). Solid-foam models are still used commercially. Intended use: offshore with weatherproof foul-weather gear. - 275 Newton life jackets – DIN EN ISO 12402-2 (formerly DIN EN 399):
Minimum buoyancy of 275 Newtons; designed to keep an unconscious person afloat even when wearing heavy protective clothing. Intended use: offshore and extreme conditions.
For each category, it is essential to consider the maximum permissible body weight of the wearer. If this weight is exceeded, even certified life jackets cannot guarantee proper flotation. The applicable weight rating is typically printed directly on the buoyancy chamber.
Life jackets must also be designed so that their buoyancy elements turn an unconscious person onto their back to keep the airway clear. For a clothed adult, the buoyancy aids must provide a minimum of 230 N of buoyancy.
Solid Foam Life Jackets
Survival aids and simple life jackets with a minimum buoyancy of up to 100 Newtons are almost always solid-foam life jackets filled with a rigid, buoyant, and non-absorbent material such as polystyrene or, in older models, cork. They have the advantage of being inexpensive and virtually maintenance-free; however, they are comparatively bulky, restrict freedom of movement, and are not – or only partially – effective at keeping an unconscious person afloat.
Inflatable Life Jackets
Life jackets with a minimum buoyancy of 150 Newtons or more are typically equipped with inflatable buoyancy chambers and are referred to as automatic or inflatable life jackets.
Inflatable life jackets are equipped with a gas pressure cartridge that, in an emergency, can be triggered either automatically by contact of a compressed cellulose tablet with water or manually, inflating the life jacket within a very short time (a maximum of five seconds). In case the trigger mechanism fails, a mouthpiece is attached to the buoyancy chamber, allowing the user to inflate the life jacket by mouth.
The advantage of inflatable life jackets is that they are smaller when deflated and restrict freedom of movement significantly less than solid-foam life jackets, which is why they are more likely to be worn. However, disadvantages of automatic life jackets compared to solid-foam life jackets include the increased maintenance required due to the trigger mechanism and the associated maintenance costs, as well as the higher purchase price.
The lifespan of inflatable life jackets is limited to approximately 10–15 years, and they should also be serviced at least every two years (according to manufacturer recommendations). Salty, humid environments, dirt, and direct sunlight accelerate the aging of the material and the inflation mechanism. Certain areas of operation (e.g., construction, fire departments, etc.) can shorten the lifespan and necessitate more frequent maintenance. Some life jackets are available with special protective covers for specific applications, such as welding or firefighting.
Life jackets in the 150N class are only conditionally effective at keeping an unconscious person afloat; that is, they only reliably turn the wearer from a prone to a supine position when worn with light clothing. These life jackets fail when worn over multiple layers of clothing, including foul-weather gear. However, most 275N class life jackets allow for sufficiently rapid turning even with heavy clothing.
Additional Features
The buoyancy chambers of life jackets are generally brightly colored to improve visibility. Good life jackets are equipped with a whistle, a rescue loop, and reflective strips on the buoyancy chamber. Life jackets can be fitted with a flashing, blinking, or continuous light that marks the wearer’s position, thus simplifying or even making rescue possible. Some modern life jackets automatically transmit a GPS position signal.
A crotch strap ensures that a solid-foam life jacket doesn’t slip after a jump into the water, or that an inflatable life jacket fits correctly after inflation. A protective hood, which is pulled over the head and the entire vest when inflated, is also useful to reduce the risk of drowning due to heavy rain or breaking waves.
Inflatable life jackets usually have an integrated safety belt in the form of a chest strap. However, this chest strap with a D-ring only provides protection against falls from the deck and is not comparable to fall arrest systems used, for example, in commercial settings or climbing. The safety belt is also not intended for rescue operations, for example by helicopters that carry their own recovery equipment. (Wikipedia)