Sybarite
Well-Known Member
Would it be possible for a life-jacket to contain a self-inflating helium foil balloon with foil streamers to facilitate locating somebody in the water?
Life-jacket possibility?
- Thread starter Sybarite
- Start date
dt4134
Well-Known Member
Why stop at that? With enough He they could float several feet above the surface of the water awaiting rescue.
Sybarite
Well-Known Member
Any serious responses?
dt4134
Well-Known Member
Whaddyamean? My counter suggestion is at least as serious as your original proposal, with the added advantage that it would cut back the risk of hypothermia.
Think I might just go out and patent it.
lustyd
Well-Known Member
The only downsides I can think of are that you increase weight and bulk in the jacket and that helium is relatively expensive so refills would be costly. If they can justify £10 for a CO2 refill which is standard and used in many industries just think how much a helium one would be in a chandlery when there are no other uses for a small cylinder of it.
Great idea though, a small light could probably go up with it to aid spotting (like the one in Batman)
mjcoon
Well-Known Member
lustyd
Well-Known Member
There's no requirement for the gas to be a liquid. I don't think the CO2 even is a liquid in those cannisters, certainly it isn't in dive cylinders, and neither is the oxygen or nitrogen. Helium is often compressed in cylinders for Diving as well as for the fun balloon industry and as far as I'm aware it's not liquid in either scenario.
Sybarite
Well-Known Member
Rigger Mortice
N/A
mjcoon
Well-Known Member
No, it's not a requirement, just that gases are much more compact if liquified. I didn't know that CO2 was used for diving; what on earth for? Agreed O2 or N2 (again, is N2 used separately for diving? I know pure O2 is problematic) cannot be liquid in unrefrigerated tanks either. It's all a matter of quantities...
I think that a kite is a much better idea, but am unsure if automatic deployment could be achieved.
Mike.
Mistroma
Well-Known Member
You need to cool Helium a lot before you can persuade it to become a liquid. A few degrees above absolute zero will do it at moderate pressure. Don't even think about trying to keep it liquid at ambient temperature (unless you have a neutron star handy, kidding).
On the other hand, you can keep CO2 as a liquid even at 30C with only moderate pressure.
So the Helium would need to be held under pressure. Fairly easy to work out how much you'd need to lift a baloon & light and then you can work out the pressure needed to hold it in a cylinder (similar in size to ones used in lifejackets). They would be very heavy vs. CO2 cylinder.
I also suspect that as mentioned above, a tethered baloon would just blow along the surface with any wind. Small ones won't lift much and bigger ones have more windage.
I'm guessing that it isn't very practical and that's why they aren't sold.
On the other hand, you can keep CO2 as a liquid even at 30C with only moderate pressure.
So the Helium would need to be held under pressure. Fairly easy to work out how much you'd need to lift a baloon & light and then you can work out the pressure needed to hold it in a cylinder (similar in size to ones used in lifejackets). They would be very heavy vs. CO2 cylinder.
I also suspect that as mentioned above, a tethered baloon would just blow along the surface with any wind. Small ones won't lift much and bigger ones have more windage.
I'm guessing that it isn't very practical and that's why they aren't sold.
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LadyInBed
Well-Known Member
Make the LJ big enough and you can put what you like in it!
Marakei
Well-Known Member
ROFL!
DownWest
Well-Known Member
Probably the available electronic location systems make more sense. It is extremely difficult to see any small object at sea, even less if it is a little baloon near the water.
Didn't they try similar stuff in WW11?
DW
To add: lets talk cost. Most peeps buy a decent LJ at fairly low cost. The addition of such a kit would increase the bulk and cost of an LJ that you might need to wear everyday. People who really worry about the risks of being left in the water for some time would probably pay for a PLB. Not a lot.
Those that worry a lot more use short tethers.
Didn't they try similar stuff in WW11?
DW
To add: lets talk cost. Most peeps buy a decent LJ at fairly low cost. The addition of such a kit would increase the bulk and cost of an LJ that you might need to wear everyday. People who really worry about the risks of being left in the water for some time would probably pay for a PLB. Not a lot.
Those that worry a lot more use short tethers.
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Sybarite
Well-Known Member
The idea of the foil was to make it at least visible to radar.
DownWest
Well-Known Member
I got that, but if blown low on the water, it would be lost in the interference with the waves. Plus..people need to know you are about. The average watch officer on a ship is unlikely to see you, unless there is an alert. PLB?
As you know, we in France are required to carry all sorts of kit. Probably the mirror is a better chance of being spotted. (Not that you carry it on your LJ)
lustyd
Well-Known Member
CO2 isn't used for diving, it's a component of air, as is nitrogen. Divers (normal ones) use air in their cylinders. Advanced divers (or nutters, depending on your viewpoint) use oxygen and Helium to go deeper without the narcosis effects of nitrogen. They also reduce the oxygen content to reduce partial pressure and therefore the risk of oxygen poinsoning (yes, that's a real thing!) so often have almost pure helium in the cylinder - still a gas though, even compressed. They also use Argon in their suits to stay warm - useless for breathing though
bbg
Well-Known Member
I think there are some life jackets now with a small danbuoy-type protrusion from the shoulder. Gives a bit of visibility and uses the existing CO2 cylinder. The pressure keeps it pointing up.
Mistroma
Well-Known Member
Very true, and at some point you can call it a liferaft. ;^))
Mistroma
Well-Known Member
CO2 isn't used for diving, it's a component of air, as is nitrogen. Divers (normal ones) use air in their cylinders. Advanced divers (or nutters, depending on your viewpoint) use oxygen and Helium to go deeper without the narcosis effects of nitrogen. They also reduce the oxygen content to reduce partial pressure and therefore the risk of oxygen poinsoning (yes, that's a real thing!) so often have almost pure helium in the cylinder - still a gas though, even compressed. They also use Argon in their suits to stay warm - useless for breathing though
I'm pretty certain that CO2 is only present in air in a few hundred parts per million so a bit unfair to compare it with the main component Nitrogen. O2 poisoning must be pretty well known. I remember that from my diving days but must admit it's so long ago that I've forgotten the relevant partial pressure.
