Auto inflating life-jackets

[John Kennett]

Originally Posted by Louise

One type uses a salt tablet which triggers the jacket to inflate when it dissolves. This kind can occasionally go off when you don't want it to, e.g. if the lifejacket gets very wet. Just ask Mr Kennett...

The other 'hammar' type works by water pressure so is not likely to inflate 'accidentally'.

I have had passengers' lifejackets inflate twice. Each was caused by very substantial amounts of water cascading into the boat. Interestingly one was a conventional auto lifejacket, the other was a Hammar -- on neither occasion did my lifejacket inflate as I was hiding behind the console at the time!

I would have no hesitation in chosing the cheaper conventional type over the more expensive Hammar as I don't think that the advantages are particularly significant.

The cheaper type do fire occasionally if left soaking wet in the boot of a car for a week or so, but that's no way to treat essential safety gear anyway.

Crewsaver products tend to be made of heavier material and have a more robust feel. Definitely worth the extra money if you are going to be using them every day. For leisure use the cheaper ones are absolutely sufficient. I have six XM brand auto jackets that we have been using for years with no problems.

John

[chaskins]

Thanks again everyone for your thoughts and advice.

I have certainly learned great deal

Thanks

Chris

[Squirrel]

Originally Posted by Richard B

R U sure? I think that only the date label on the pressure device tells this. The coloured indicator only indicates whether the device has fired or not if I remember correctly.

Hmm, no I'm not now you come to mention it. I just remember reading in the instructions that there were three different indicators, green, red/green and red, but I guess if its been set off then it needs to be replaced, which is different to indicating when it needs to be replaced, if you get what I mean!!

[Simon Hawkins]

Originally Posted by Squirrel

Hmm, no I'm not now you come to mention it. I just remember reading in the instructions that there were three different indicators, green, red/green and red, but I guess if its been set off then it needs to be replaced, which is different to indicating when it needs to be replaced, if you get what I mean!!

Instead of relying on the indicators why not unscrew the gas canister and check that it has not been pierced by the fireing mechanism as it may of been used and then manually deflated and repacked.

[Richard B]

Simon, this isn't necessary. The indicator is part of the firing mechanism and so will definitely indicate red if it has fired.

I thought you would have know this from using the Crewsaver life jackets that the RNLI supply.

[Nickytynick]

Am I being stupid here or are there at least three types of auto jacket.
1)Hammar
2)Salt Crystal
3)'Blotting Paper type'

I have a Compass 275n Auto which has been set off a couple of times by mistake (long story). I had it recharged by someone else the first time but did it myself the second. The 'release' machanism consists of two plastic rings inside each other, one smaller than the other with what looks and feels like densly folded blotting paper holding the two together. When the paper gets soggy, it releases the inner ring releasing the spring loaded spike and firing it into the CO2 cylinder.

Or am I getting horribly confused?

Nick

[Simon Hawkins]

Originally Posted by Richard B

Simon, this isn't necessary. The indicator is part of the firing mechanism and so will definitely indicate red if it has fired.

I thought you would have know this from using the Crewsaver life jackets that the RNLI supply.

Richard

Of course I know that but surely isnt it best to check the cannister as if it has a whole in it then surely this is absolute proof that the jacket has been fired. Why take chances unneccesarily !!

[Richard B]

Originally Posted by Simon Hawkins

absolute proof that the jacket has been fired...

- is provided by the red/green indicator!

The firing mechanism covers the top of the CO2 cylinder. So as long as it's assembled reasonably carefully without debris, the only way that it can be pierced is by the firing mechanism actuating (manually or automatically). Because the red/green indicator is attached to the mechanism, you can see the status of this. The only problem that I can perceive is if someone reassembles the whole thing after firing, using a new firing mechanism and a used CO2 bottle. This might be a concern for shared use of a lifejacket, but not for my personal lifejacket.

[tim griffin]

I think Simon is making a very valid point , we should all check our lifejacket cannisters on a regular basis , in fact the RNLI will send you a leaflet on how to maintain your lifejacket free call 0800 328 0600 its very informative
all the best

[Simon Hawkins]

Originally Posted by Richard B

- is provided by the red/green indicator!

The firing mechanism covers the top of the CO2 cylinder. So as long as it's assembled reasonably carefully without debris, the only way that it can be pierced is by the firing mechanism actuating (manually or automatically). Because the red/green indicator is attached to the mechanism, you can see the status of this. The only problem that I can perceive is if someone reassembles the whole thing after firing, using a new firing mechanism and a used CO2 bottle. This might be a concern for shared use of a lifejacket, but not for my personal lifejacket.

You would be amazed how many lifejackets I have seen where the gas cylinder has been pierced, but the firing mechanism is still in tact. I personally know that my lifejackets have not been fired but if I was to use someone elses lifejacket then I would check the cannister. Their is no point checking it after you end up in the water and it not inflating the jacket. The point which I am trying to get across is that dont trust other peoples lifejackets without giving them a thorough checking over.

[Richard B]

Simon, whilst I agree with the principle of the point you're making, you've changed your argument!

You originally said:

Originally Posted by Simon Hawkins

...check that it has not been pierced by the fireing mechanism...

but now you say that:

Originally Posted by Simon Hawkins

...I have seen where the gas cylinder has been pierced, but the firing mechanism is still in tact

Have you investigated the reason for these "failures"?

Is it possible that:
a) The lifejacket has been actuated manually by the pull-cord? (on a salt-tablet jacket, the salt tablet would be visibly ok wouldn't it, although if I remember correctly some of their mechanisms have a red/green indicator which may be actuated by the manual pull. On a "Hammar" type jacket, the mechanism would indicate "fired")
b) A used CO2 canister has been mistakenly fitted?
c) Debris in the assembly has damaged the top of the cylinder?
d) Manufacturing defect in the firing mechanism?
e) Manufacturing defect in the cylinder?

Given that you've stated "pierced" rather than just a leak (which may be almost invisible?) then this would seem to rule out c and e.

Whilst an RNLI leaflet is useful I'm sure, Tim, I would rather fully understand the operation of my lifejacket and be able to evaluate the value of generic information which may or may not be applicable to the type I use.

[Pete7]

Originally Posted by Richard B

Whilst an RNLI leaflet is useful I'm sure, Tim, I would rather fully understand the operation of my lifejacket and be able to evaluate the value of generic information which may or may not be applicable to the type I use.

http://www.rib.net/forum/showthread.php?t=7229

[Cork Rib]

One very big problem with gas lifejackets is the cylinder working itself loose up the threads so that the firing pin is out of range when fired or that much of the gas escapes. On one occassion when doing sea safety checks, I came across three in a row, two loose and one with the cylinder completely detached !! All gas jacket cylinders need to be checked very regularly. It would be interesting if ribnet members checked their jackets and posted how many loose or detached cylinders were found.


Jon

[Richard B]

Nice one, Cork RIB... been itching to get out of my chair and do this all afternoon!

1. Crewsaver hammar auto, 4-years old, never checked before, about 1/32nd of a turn to tight.
2. Crewsaver freedom hammar 2-years old, 15months since cylinder and actuator replacement, fully tight.

[Searider]

Originally Posted by Cork Rib

One very big problem with gas lifejackets is the cylinder working itself loose up the threads so that the firing pin is out of range when fired or that much of the gas escapes. On one occassion when doing sea safety checks, I came across three in a row, two loose and one with the cylinder completely detached !! All gas jacket cylinders need to be checked very regularly. It would be interesting if ribnet members checked their jackets and posted how many loose or detached cylinders were found.


Jon

It would also be a good idea to orally inflate your jackets and see which ones hold air overnight.

Did this with my 5 this spring - 2 went down and so went to Crewsaver for a proper service and repair.

[Richard B]

Cheers, Duncan - you may just have saved my life!

[codprawn]

No doubt mentioned before but which is best to have - auto or manual? I would have thought auto cos if you get thrown overboard and knoecked out you will still float - others say that if the RIB capsises and you are stuck underneath the last thing you want is an inflated lifejacket - any comments please???

[John Kennett]

My choice is for automatic as I reckon that the chances of ending up under a capsized hull are much less than the chances of being dazed, disorientated and suffering from thermal shock to the degree that the toggle just doesn't get pulled.

It's only a lifejacket when it's inflated!

John

[codprawn]

That's what I thought - and far more likely to be thrown clear than stuck underneath - I suppose the faster you go the further you will be thrown clear!!!

[Jelly]

There was a case in the offshore siesmic industry a few years ago then auto life jakets cost the lives of two people when they got trapped inside a cabin on a work boat when it inverted. The crew on deck survied.

I use a manual for inshore or safety boat work and an auto for offshore trips.

I think the type Nick was refering too with the plastic color and blotting paper top and bottom is a salt tablet type, Secumar and I think the early crewsaver autos used different mechanisums but very similar tablets.
rgsd
James