Survival in North Sea around 5 mins?

[PompeyPaul]

I was always led to believe a ditch into the north sea would be rapidly fatal. Was reading this article about a lady who fell off of a ferry and survived in the water, at night, for 30 mins.

BBC News - Ferry fall survivor Jeni Anderson reunited with crew (http://www.bbc.co.uk/news/uk-england-tyne-25445567)

[Genghis the Engineer]

In September.

G

[wiggy]

Wot Genghis said...

AFAIR it "we" (military Fast Jet) used to have to wear immersion suits once the sea temp was at or below 10 celsius...which from memory used to happen around September for the North Sea.

With the very important caveat that every case is different I'll offer you these tables:

Survival Time in Cold Water (http://www.engineeringtoolbox.com/survival-time-cold-water-d_1567.html)

[Genghis the Engineer]

Sea surface temperatures (http://www.bsh.de/en/Marine_data/Observations/Sea_surface_temperatures/SST_d.jsp#0)

Shows in September temperatures around 14 - 17 deg.C this last year. I'm not aware of anything that causes it to change much year on year.

http://www.bsh.de/aktdat/mk/nordsee/ns201337.gif

Relatively speaking, quite warm and comfortable. Wiggy's table would give you a couple of hours before exhaustion set in in a reasonably fit adult.

G

[englishal]

They always quote "worst case" times in survival time in cold water.

If you are a little bit tubby, fit, moving a lot, etc., then you will probably survive longer. Some people go swimming in the arctic and survive for seemingly amazing times, so it is possible.

[Genghis the Engineer]

True, also women generally can survive longer - thanks to the layer of insulating subcutaneous fat that under all other circumstances, they're likely to complain about.

I suspect that in most cases the real survival time is dictated by the ability to keep one's head above water - particularly given that few people are really that strong or well trained as swimmers.

G

[Maoraigh1]

If wearing a lifejacket, and woolen clothing under waterproofs, a layer of water will be trapped, and warm-up. Movement would lose that.
The water will not be at its coldest for a few months yet, if I recall the North Sea Pilot (Admiralty publication)
Survival time, clothed, varies greatly.
Thirty + years ago, after a trawler went down off Iceland in winter, the mate was the sole survivor . After hours in the water, he swam ashore, climbed a cliff, and managed to reach an inhabited house.

[piperboy84]

My dad is 80, up until 7 years ago the crazy old bastard used to drive down to the beach at Carnoustie and swim in the North Sea in all but the coldest of days. One day he ran into the water and the shock of the cold made him violently flinch which caused his falsers to be launched into the surf never to be seen again, he was not a happy camper.

[abgd]

My great uncle was involved in some trials where they tied a rope to him and threw him out of a lifeboat off the Edinburgh coast and timed how long it took before he went under. I'm not sure what time of year it was.

If people tried swimming, they tended to get cramps and sink pretty quickly. If they stayed still and conditions were calm then some of them did last much longer. I can't remember how long, but I think it was in the region of hours for some people. Genghis is right in that people sank before they became life-threateningly hypothermic.

Google scholar has lots of links to theoretical studies, and I imagine something similar must have been written up though I can't immediately find it. I suspect my uncle's experiment wouldn't make it past the ethics committees these days.

[Flyingmac]

For much of the year North Sea temperatures exceed those on land. Particularly in late Autumn- Winter.

The problem is that water will leech heat from the body around 20X faster than air will. Hence the advisability of a drysuit.

[cockney steve]

in some trials where they tied a rope to him and threw him out of a lifeboat

Typical tight-fisted Jocks....go shark-fishing and too tight to buy bait:}

[riverrock83]

When working for a large ferry company on the Irish sea, we were taught to remain still, tucked into as tight a ball as possible with knees as close to chest as life jacket would allow and to group together in concentric circles in the water, with the most vulnerable in the middle (I would have been responsible for potentially hundreds of passengers, although if groups were in the water it really would have been a bad day!).

I can't remember the figures quoted, but my memory was around 1 hour which could be extended to many hours if people grouped together (etc) and didn't panic.

No idea what these figures are based on, but they tally with what I was told:
Survival Time in Cold Water (http://www.engineeringtoolbox.com/survival-time-cold-water-d_1567.html)

[Heston]

The data for survival time in cold water is based on Nazi experiments on concentration camp inmates. Where else could such data come from?


Nazi human experimentation - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Nazi_human_experimentation#Freezing_experiments)

[Genghis the Engineer]

Nowadays we'd hopefully use computer modelling.

I have a copy of a British commando training manual from the start of WW2. There's a table there showing how long people will take to die from various types of attack. It isn't stated how that was worked out, but one suspects not entirely through anecdotal evidence either.

G

[hoodie]

The trouble with computer modelling, regardless of the field of study, is that the model requires validation with real world data. :(

[Sillert,V.I.]

Had to do some maintenance in my swimming pool recently; the water temp is about 7C and I simply couldn't believe how quickly my body went numb on entering the water.

Did it in the end by standing in a hot shower wearing a tracksuit, putting lightweight waterproofs on over that & then getting in the pool.

I can easily believe you wouldn't be able to function in any meaningful way once immersed in the North Sea.

I always carry a liferaft when crossing the channel in a single but tbh I'm not optimistic about my chances of successful deployment and entry should the worst happen.

[riverrock83]

There are a number of courses run throughout the country on deployment and entering life rafts (and righting them if they turn over!).
I completed a course before working for a shipping company, but the practicalities are the same.
The rafts we were using were larger (10 person AFAI remember) and we all managed to get in, although it was a real struggle for some people.

Training was in a swimming pool but final scenario was in darkness with wave machine, flashing "lightning" and noise of thunder which really concentrated the mind!

[dubbleyew eight]

I go swimming in the ocean here in perth wearing togs and a tee shirt.
it has truly amazed me just how warm the tee shirt keeps me in the water.

[Sillert,V.I.]

Training was in a swimming pool

The difference between a swimming pool at normal swimming pool temperatures and one at 7C has to be experienced to be believed.

It took me by surprise.

[NorthernChappie]

My dad is 80, up until 7 years ago the crazy old bastard used to drive down to the beach at Carnoustie and swim in the North Sea in all but the coldest of days. One day he ran into the water and the shock of the cold made him violently flinch which caused his falsers to be launched into the surf never to be seen again, he was not a happy camper.

Its a Carnoustie thing. My version of yours took up cycling after he was officially classed as blind. Gave it up after a crash and hospital stay. Remaining mother is now doing it by driving - dementia, dicky hip, walking stick et al.

Anyway on topic, only way I get in the North Sea is dry suit diving gear.

[Genghis the Engineer]

There are a number of courses run throughout the country on deployment and entering life rafts (and righting them if they turn over!).
I completed a course before working for a shipping company, but the practicalities are the same.
The rafts we were using were larger (10 person AFAI remember) and we all managed to get in, although it was a real struggle for some people.

Training was in a swimming pool but final scenario was in darkness with wave machine, flashing "lightning" and noise of thunder which really concentrated the mind!

Sounds like Fleetwood? Not to everybody's taste, but I really enjoy my 3-yearly trip up there.

G

[mad_jock]

You can do the course in Aberdeen bay as well.

The difference between a swimming pool at normal swimming pool temperatures and one at 7C has to be experienced to be believed.


the old RIGIT offshore survival centre had a north sea simulator. I only had to do it once before they closed it.

It was more like a near death experience. water temp was 5 degs, they had a wave machine, fans to give wind then you got turned upside down in the dunker and had to get into a raft. Without any doubt good training but they were finding people were leaving the industry rather than doing it again.

Having had a dry suit become a wet suit with a zip failure its a bit of shock to the system. Personally I always went for the neoprene dive suits because you at least got some sort of thermal protection if it flooded. I did meet a guy who was on a mixed gas dive to 95 meters who's membrane flooded with 140mins of deco still to do. He got to the surface semi conscious and was flown to the hyperbaric centre. By rights he should have been dead but he is still walking around and clam diving. They recon the cold shut everything down and stopped the bubbles getting to important bits.

[Pace]

NC

In my 20s I did a lot of diving ( still dive now but warm water only ; ) I can remember in one of the big freezes walking over a flooded Quarry with thick ice.
We cut a round hole and with wet suits dived under the ice.
The water was clear and it was amazing to watch streams of bubbles pooling under the ice roof above'!
I had a full wet suit with neoprene undergarments not a dry suit and then the suit tore under the armpit.
It was horrendous and I beat a hasty retreat back to the hole and out of the water!
How long would you last in ordinary clothes in water like that ? My guess 15 to 30 minutes if you had not succumbed to a cardiac arrest with the shock

Pace

[wiggy]

Like many on Pprune I've been thrown into the North Sea on a few occasions and done the odd survival drill in an outside pool in winter (UK), both with and without an immersion (dry) suit :mad:

I can easily believe you wouldn't be able to function in any meaningful way once immersed in the North Sea.

I wouldn't be that pessimistic, even at 7 celsius, but you do lose the use of your hands very quickly, so getting survival kit and hopefully location aids deployed ASAP is paramount.

[mad_jock]

Coldest I dived in was 4 degs on the west coast of Ireland.

I think I only ever did 2 wet suit dives in Scotland. Then the student loan came through and a drysuit was purchased.

BTW to those that haven't used one, drysuit sort of imply that you don't get wet. This isn't completely true for a lot of users. When (note not if) you get a leak with the boys its tracks straight towards your gonads I am informed by the girls it goes straight for their breasts.

I did once have two rechargeable battery's in my trackie bottoms pockets which started short circuiting against each other producing a blister on my thigh in the three seconds it took me to decide to pull my neck seal to flood my suit on purpose.

[riverrock83]

Sounds like Fleetwood? Not to everybody's taste, but I really enjoy my 3-yearly trip up there.

G

Yes. Also fire fighter training there... great fun!
Mind you - in our group we had one lady who had a panic attack in the water and someone else who tripped and broke something during the fire fighter training. For someone still in secondary school (as I was at the time) it all felt like a bit of an adventure :cool:

[Pace]

I think I only ever did 2 wet suit dives in Scotland. Then the student loan came through and a drysuit was purchased.

MJ

i never ever dived a dry suit only wet suits of varying degrees and we used to go into any patch of water whether lakes rivers quarries or the sea and at any time of year!

Nowadays I only dive warm clear seas in hot climates :ok:

pace

[mad_jock]

It was ok while you were in. It was the boat transits on the ribs and doing multiple dives it made a difference.

Also moving the air about made it very easy to sit in unusual attitudes if required. We also used to do surveys and stuff like that.

[englishal]

I did my first survival course at the RGIT in Aberdeen back in 91. In those days they made you find you way around a burning building without BA set on - people were coming out of the building puking - they called it Smoke Appreciation....and you certainly did appreciate what it was going to be like in a burning building. They also made you "abandon" a rig by jumping 4.5m into the freezing pool that Jock was on about, in the dark, with the waves etc....

Nowadays the Elf 'n' safety brigade have become involved. Real smoke has been replaced by a smoke machine (without BA set) and the maximum you can jump into the pool is 1.2m.....

I always carry a liferaft when crossing the channel in a single but tbh I'm not optimistic about my chances of successful deployment and entry should the worst happen.

You'd be better off with a survival suit and EPIRB I reckon....Getting into a life raft can be damn near impossible.

[mad_jock]

I seem to remember it was a bale of straw with some diesel chucked on it and then set alight gave the smoke.

[abgd]

Nowadays we'd hopefully use computer modelling.

I would simply disbelieve any figures based purely on computer models on principle. Biological systems are far more complex than mechanical systems and their fundamentals are much less well understood. Inter-individual variation, both physiologically and psychologically, is huge.

Different ethnic groups also differ e.g. in factors such as ability to reduce the blood supply to their skin which reduces the rate of heat loss. I don't know that it's clear whether this is nature or nurture. There is a marked effect of training on our ability to survive cold-water immersion.

[Pezzar]

I used to dive Stoney Cove in Leicester, there'd be snow on the ground but we still used to don our dry suits and go for it. Upon entering the water i can only remember the sheer pain and numbness on the head region, mainly around the frontal lobe area

[mad_jock]

they are still to my knowledge using humans to test these things.

Army and navy divers always seem to get the brunt of this tests.

You should have seen how the developed the decompression tables.

Load of goats first, then humans.

The have gone the computer models with gas half lives for various tissue types but when they test the models out its still a human that they test it on.

[Pace]

Amazing how many pilots are into Scuba diving! In clear water especially very clear water it's the closest thing to flying as you glide along shear drop offs! It can also be quite technical if you move into technical diving using tri mix or rebreathers!
Rebreathers interest me as they become more sophisticated as they are silent excellent if your into photography and do not want to scare off your subjects!
When I go for my recurrent in Florida I usually jump a hopper to one of the Caribbean Islands for a few days diving!
Try a shark feed in the Bahamas if you fancy mixing it with around 50 sharks all going crazy :E wouldn't do it again as felt it was a very artificial setup but worth the experience ;)

Pace

[mad_jock]

there is a thing called brown fat which your body can develop if continually cold. This fat generates heat. I never wore gloves while diving in Scotland and my hands never got cold in fact some of the girls used to warm there gloved hands up under water with them. And the fisherwomen who gut fish in sea water all day have loads of it and warm hands as well apparently.

There is also another thing which diving does to you after a while. We all have a reflex which shuts the windpipe when we get water spray in our mouths. Divers loose this.

Our bodies do funny things as well when holding our breaths. The extremity's shut down much quicker than normal.

the reason why I found this out was I was in for an op with a GA and while the gas pusher was prepping me he stuck an O2 sensor on my toe and ear. I was bored so decided to hold my breath. Within seconds the alarms started going off. The gas pusher looked round saw me bright eyed and gave the machine a boot. I then started breathing again and the alarms stopped. He turned round preparing the horse syringe of white milky stuff so I did it again. And again in seconds the alarms went off. He turned round and asked are you holding your breath. Which I then breathed again and laughed.

Interesting he said as he fired in the drugs.

He appeared the next day and got me to come in for some tests after I was recovered. I think he went on to do a study on divers about there reaction to oxygen starvation.