The Flotation Device Standards appear complicated but in reality they are fairly straight forward. They are linked to a level of Buoyancy declared in Newtons and the higher the level of Newtons Buoyancy, the greater the uplift that the device will give in the water.
You may see the standards declared as EN (European Norm) ISO (International Standards and some declared with the BS (British Standards) in a combination eg BS EN 396. For the purposes of this information I will refer to them as EN.
EN Standards quoted can be either the old 3 figure standard eg EN396 or the new standard EN12402-3. A device with the old standard EN396 would be quite acceptable. The differences between the old and new standard are relatively minor technical changes. Each level declares a buoyancy eg EN396 is 150N, but that may not be the actual buoyancy. A children’s EN396 device will almost certainly give less than 150N ACTUAL buoyancy and many adult ones may give more, but they meet the testing requirements of EN396 150N.
EN393 / EN12402-5 is the 50N standard and the devices are fixed buoyancy. These devices are for use mainly in sheltered waters, where help is close at hand and the wearer should be a competent swimmer. They may also be used when a more bulky or higher buoyancy device may actually create problems for the wearer or active water sports such as Jet Skiing. These might be used by an angler or canoeist.
EN395 / EN12402-4 is the 100N standard and the devices are fixed buoyancy. They are aimed at the same user as the EN393 but due to the extra fixed buoyancy they can be more bulky but offer a more substantial option for calm waters. They can be used by non-swimmers.
EN396 / EN12402-3 is the 150N standard. These are designed for both inshore and offshore in all but the most severe conditions. They are designed to self-right the wearer in the water. They can be made out of foam such as the emergency jackets seen on ferries, but are typically the inflatable jackets. They can be supplied with manual and automatic inflation options.
EN399 / EN12402-2 is the 275N standard. These are designed for offshore and severe conditions. They are designed to self-right the wearer in the water. They can be supplied with manual and automatic inflation. They are also more appropriate for users who may be carrying extra weight, such as a tool belt.
Both the EN396/12402-3 and EN399/12402-2 are designed to self-right the wearer in the water which can be particularly important if the wearer has lost consciousness or are unable to turn themselves for any reason. HOWEVER users have to understand that this self-righting is not guaranteed and often other factors may hamper the lifejackets efforts to turn the wearer in the water such as:
- Incorrectly secured lifejacket. Is it tight enough? Is the buckle securely fastened? Yes I have seen wearers who slip on their jacket and don’t fasten it. Lifejackets need to be fastened properly.
- Wearing an additional buoyancy device. I’ve seen many 150N or 275N lifejackets worn over EN 393 fixed buoyancy clothing, sometimes a jacket only, but also a flotation suit or 2 piece option. The problem with this is that the EN393 buoyancy acts first, as soon as the wearer hits the water and then the auto inflate lifejacket acts a few seconds later. By the time the lifejacket has inflated, the wearer may be flat on the surface like a piece of driftwood. The lifejacket relies on the feet and legs dropping in the water to aid the self-righting of the wearer so additional buoyancy, particularly below the waist may hamper the turning effect.
- Heavy waterproof clothing can affect the turning mechanism. It counteracts it in a way similar to the EN393 flotation clothing mentioned above. Waterproof clothing will create it’s own buoyancy when the wearer goes in the water. Air will be trapped and this trapped air may well have an affect on the self-righting of the wearer.
Whilst resistance to the turning mechanism is something to be aware of, it is still much better to wear a lifejacket. Assess your own circumstances and decide which level is best for you before you go on to select.
SOLAS is the International Convention for Safety of Life at Sea and is looked after by the IMO – International Maritime Organisation. SOLAS lifejackets have slightly different requirements to a EN lifejacket and are usually available as 275N options, although some 150N options are available.
The main difference is that a SOLAS device will have 2 chambers. So when you look at the bladder laid flat out it will have a front chamber and a back chamber. It will therefore have 2 inflators, one which is attached to the front and one to the back. So a SOLAS lifejacket is a heavier, bulkier lifejacket as it will have an inflator on both left and right hand side of the horseshoe jacket. It will also have the additional centre layer of material to separate the chambers. Both chambers would usually inflate together but that doesn’t mean 550+ N of buoyancy. Each chamber is fitted with an overpressure valve so excess CO2 escapes during inflation.
There are some other differences such as compulsory provision of a SOLAS light, a buddy line and more stringent requirements on the servicing.
The idea behind the twin chamber is that it one fails to inflate, there is a second chamber. There may also be a quicker inflation as a result of the 2nd inflator, as the water may reach that side first.
SOLAS lifejackets are mainly found in the commercial sector and with companies that are involved in International Shipping, Oil & Gas, Offshore Wind etc.