Umbilical severed at 80 meters in North Sea

[DandyDon]

I seem to remember an old movie where a man and woman were trapped and she would intentionally drown as the hero swam her back to another habitat. She hypothesized that the cold would allow her to recover… this event is fantastic but a lot more believable than that movie.

The Abyss (1989) - IMDb

You got that right! "Suspended animation" is science fiction.

I don't remember the medical term for prolonged survival chances when drowning in cold water either. It was a catchy term for this discussion. One phrase I do recall is "They're not dead until warm and dead."

 

[EastEndDiver]

Don is that what you are reffering to?


The Mammalian Diving Reflex

Mammalian Diving Reflex: A Cool Artifact of Human Evolution | Evolvify

 

[DandyDon]

Don is that what you are reffering to?


The Mammalian Diving Reflex

Mammalian Diving Reflex: A Cool Artifact of Human Evolution | Evolvify

Yep, looks like it - thanks. I like the reference to hibernation and that it includes a note about children surviving better.

 

[Bombay High]

This has come from a Diver who was in Saturation along with the Diver whose umbilical was severed :

"Quick update for you all, Flakey was almost right but a few facts need clarifying:-
Both divers were outside the structure, looks like diver 1's umbilical got a turn around a external transponder bucket on side of structure when run off occurred. Vessel ran off 180 mts and did indeed part his umbilical. It took 26 mins to get the vessel back to over the structure, although the ROV had located him well before that, Chris the diver in question said he knew to try and conserve his gas even though he was freezing to death. He doesn't remember slipping into unconsciousness it just happened. It has been worked out that in total it took 46 mins to get him back in the bell, after 2 breaths by the bellman he started breathing on his own, he even stood up and out the way on his own steam to help in getting the bottom door down, once his breathing was restored he recovered quite quickly so they proceeded to start and warm him once the door was down and the bell was on its way up. (he was blue when they removed his hat). Diver 2 and the bellman were very professional in all of this as was the dive supervisor Craig Frederick, the lads themselves said Graig kept them focused and preempted everything.
Chris the diver climbed out of the bell and into the TL on his own steam and was warmed up further in the TL using the shower and wrapping him in towels, once stabilised he was transferred to the chamber. He appears to of made a full recovery and we have all been taking the piss at the lengths some people will go to for a short bellrun. ( obviously to try and lighten what was a very somber mood ) Chris has been very very very lucky. It brings it home just how quickly things can go pear shaped. The DP system is the prime suspect as the bridge said they had no control during the whole run off, that is being investigated with a fine toothcombe and we are all being decompressed as the investigation will be thorough and exhaustive time and getting back to work are not ab issue... I'll try and let you all know any outcomes when and if we find out !! "

In other news:

"I expect the HSE OSD will slap a "Prohibition Notice" on the vessel for this near fatality, so they wont be going anywhere just now. As far as I recall, a "Prohibition Notice" can only be lifted by the Ptocurator Fiscal in Scotland. We shall sea."

And further whispers in Scotland - Divers pressurise HSE to force the development of a new rebreather system as bailout. Bet the Oil companies say they dont have the funds for R&D

 

[Akimbo]

... And further whispers in Scotland - Divers pressurise HSE to force the development of a new rebreather system as bailout. Bet the Oil companies say they dont have the funds for R&D ...

I can't imagine a rebreather that can be reliable as a bailout system in such a harsh and demanding environment -- though it would be great for tech divers. Besides, unlimited bailout gas does not solve the far bigger problem of hyporthermia. It sounds like this diver may have passed out before breathing down his limited bailout gas anyway... granted he was pretty shallow. On the other hand think how fast he would chill on a 1% deep mix.

Translation of Bombay High's post for non-commercial divers reading this:

TL: Transfer Lock. The deck chamber that the bell mates/clamps to which is permanently connected to one or more living chambers. The "mating" process runs like this: The deck chamber complex and bell is pressurized on the shallow end (or above) of the working depth range. There is an internal pressure-seating hatch in both plus a trunk/skirt with a flange for big rapid acting clamps. Some bells have a second hatch on the side for mating, some "top mate" to the TL. The bell and TL trunks are clamped together and the O-ring sealed space between (about 24" in diameter) is pressurized/equalized making the bell, truck, and TL equal. At that point the hatches can open (Note: The pressure at 1 FSW on that hatch would be over 200 Lbs of force holding it shut). Hatches open, crews change, and the process is reversed and repeated 24/7.

DP: Dynamic Positioning. A computer automatically drives the ship's main propellers and side-thrusters to maintain position within a few feet over the bottom... no anchors are used. It is safe for divers because the bell is lowered through a "moonpool" amidships (most stable point) so divers cannot contact rotating propellers. There is also a manual joy stick normally used for docking and minor maneuvering. Baring an operational requirement to maintain heading, the computer can rotate the ship around the moonpool heading into the seas/weather.

ROV: Remotely Operated Vehicle. Basically a highly maneuverable cable-powered swimming TV camera(s) driven by operators on the surface. All have lights and some navigation, some have manipulator$.

HSE: Health and Safety Executive. A British government agency tasked with diver (among others) safety... Sort of like OSHA in the US.

Bellman: Probably obvious, the bell operator and tender. Also a diver on alternate bell runs.

Diver's Umbilical: A collection of hoses and cables from inside the bell to the diver. The individual components are taped or seized together every 12-24" or can be ordered twisted together (candy-cane style).

They contain:

• Voice communications cable
• Breathing gas (from the surface backed up by emergency banks on the bell)
• Hot Water: ~2½ gallons/minute at 110° F at the suit/diver. The same hot water heats the bell through a heat exchanger
• Pneumofathomer Hose: A small hose (~¼" in diameter) connected to a precision pressure gauge (analog and/or digital) calibrated in feet and/or Meters of Sea Water on the surface to accurately monitor the diver's depth. Air or breathing gas is used to manually blow all the water out of the open-end hose by the console operator or dive supervisor creating a column of air. Some operations may replace this with an electronic transducer but the pneumo is still popular because it can be an emergency breathing gas source by shoving the hose in your hat... to say nothing of simple, rugged, and reliable.
• Hat-mounted Video and/or Lighting: Pretty standard these days but not universal. It can be separate or integrated with the communications cable
• Exhaust Hose (sat systems only): Returns breathing gas to the surface via a hat-mounted demand exhaust regulator and a negative-biased back pressure regulator usually at the bell. Filters on the surface removes CO2, moisture, and biological outgassing. Oxygen is automatically added and it is compressed at least several hundred PSI above working depth, if not into HP storage. Basically it is a powered rebreather with technicians on the surface augmenting automated monitoring… oh and essentially unlimited electrical power and gas storage.
• Strength Member: Some umbilicals include a rope, even though most of the individual components have a tensile strength high enough to tear a human body in half.

Did I miss anything? Sorry for the US/Imperial-centric units.

Maybe some of you with more recent experience can answer this: I don't know what kind of transponders are used. Are they mandated in the British and/or Norwegian Sectors? Are they acoustic pingers, strobes, or some other "homing" technology? Is there an operational use or just emergency?

 

[Bombay High]

Akimbo,
I have mixed feelings about the rebreather bailout. We all know how bailout rigs are treated topside. Rebreathers obviously will have to be treated differently.
Mark Longstreath has very cryptically hinted that there is a very rugged rebreather that is being built solely as bailout for very deep commercial divers. I will try to find out more, but it is apparently in development already. On a 300 plus metre lockout, I knew that my 7 litre twins were going to give me very little time to do any kind of problem solving for that kind of situation, a rebreather that can take the environment, depth and handling that comes with our work would be welcome .. even if you are frozen before your gas runs out

Pingers are commonly used now. I dont think they were mandated ... but now they will be.

---------- Post Merged at 12:14 AM ---------- Previous Post was at 12:11 AM ----------

BTW - they will at some point release the video footage from the ROV that located Chris unconscious on the North Sea floor ...

 

[CaveMD]

I think you guys may mean hypothermia rather than hyper.

Sent from my HTC PH39100 using Tapatalk 2

 

[Akimbo]

I think you guys may mean hypothermia rather than hyper…

You're right, typo on my part. Correction made

On a related note, some divers were killed in the mid-70s from hyperthermia. We all know about "heat of compression" from filling Scuba tanks. The same happens in chambers. Many sat complexes allow cross-connecting gauges in order to check them for accuracy and as backup in case of failure. Somebody had opened the cross-connect and the word didn't get back to the console operator (human factors sort of sucked).

The chamber that the gauge was actually connected to was unmanned and was about to be "surfaced" (pressure bled off) in order for crews to clean and repair. Bottom line, the operator heard gas blowing off, the pressure drooped on the gauge he thought was to the manned chamber, and started adding Helium as fast as possible in an attempt to overcome the "leak" (standard procedure). Lots of noise, yelling topside and over the unscrambler, and not much time passed.

By the time they figured it out the manned chamber was at or below the rated working pressure (not sure if relief valves popped), at least two guys were dead (don't recall exactly). As I understood it, they didn't know how hot it actually got. A byproduct of living in Helium's high thermal conductivity is shirt sleeve comfortable at say 600' is about 90° F... +/- about 1°. 93° is far more sweltering than the hottest day in Houston and teeth chatter at 88°.

I had dinner with some of the diver's onboard about a month later. Pretty sad.

---------- Post Merged at 01:51 PM ---------- Previous Post was at 01:07 PM ----------

...I have mixed feelings about the rebreather bailout. We all know how bailout rigs are treated topside. Rebreathers obviously will have to be treated differently.
Mark Longstreath has very cryptically hinted that there is a very rugged rebreather that is being built solely as bailout for very deep commercial divers....

Saturation divers are more than technically competent enough to learn to maintain and dive rebreathers. But I ask anyone to imagine making a rebreather that is absolutely reliable when not used beyond pre-dive checks, on the back of a working diver that must squeeze through a small hatch, could wear holes in his hot water suit in one dive (without coveralls), uses a hat instead of a mouthpiece, and has about as much as he can monitor now.

Now picture two of these rigs inside a 6' diameter sphere with two divers, bellman, hats, umbilicals, and all the rest of the systems that goes in a bell... unless you leave them outside and put them on after the hatch is open on the bottom. Slipping on an open-circuit bailout hung outside with one small LP hose to the hat with a QD (Quick Disconnect like a BC but larger) is one thing, but hooking up and keeping water out of two big flex hoses and breathing bags, plus connecting the readout display??? Sounds awfully ambitious.

I can see keeping the CO2 canister and electronics over-pressured off the umbilical to keep them dry when not in use, but what about the flex hoses and breathing bags? The US Navy put breathing bags on the back in a cowling like the GE Mark 10 rebreather, but the "work of respiration" is bad enough at 1000' using a modern open circuit or reclaim hat. I am all for an improved and ruggedized rebreather, but sat divers will be the last to use them, not the first.

Oh, and then there is the issue of the efficiency of the CO2 absorbent at 36° F, unless we heat it with hot water too. Even all this would be OK if we could keep the diver from passing out from hypothermia within a few minutes. The phrase "diminishing returns" comes to mind.

Now, after sharing some of the technical obstacles with others, I sure hope it works because I would love a rebreather that reliable! No bubbles and constant PPO2 is as good as it gets, especially if reliability is so good that backup open circuit bottles are redundant.

 

[John C. Ratliff]

Akimbo,

The terms you are looking for are immersion hypothermia and cold water near-drowning.

Hypothermia and Near Drowning

In cold water near-drowning one complication is water in the lungs. If that water is sea water, then it stays in the lungs and can cause pneumonia later. It can also interfere with resuscitation efforts. If the water is fresh water, then it goes into the blood stream, and can cause further systemic complications; in the extreme, it can dilute the blood, cause the red blood cells to swell and ultimately burst due to the osmotic gradient change.

In this case, the helmet undoubtedly helped by keeping water from being breathed. This would have really complicated the recovery if he had breathed water.

SeaRat

 

[Akimbo]

…The terms you are looking for are immersion hypothermia and cold water near-drowning.

Hypothermia and Near Drowning...

I have heard of children that fell through ice recovering after 45 minutes, though they probably also had some water in their lungs. I don't recall any adults going this long in water that was probably closer to the mid 40° F mark than freezing. Do you have any info to the contrary?

... This has come from a Diver who was in Saturation along with the Diver whose umbilical was severed ...

... It took 26 mins to get the vessel back to over the structure, although the ROV had located him well before that, Chris the diver in question said he knew to try and conserve his gas even though he was freezing to death. He doesn't remember slipping into unconsciousness it just happened. It has been worked out that in total it took 46 mins to get him back in the bell, after 2 breaths by the bellman he started breathing on his own, ...

(bold red emphasis is mine) I wonder if anyone checked how much gas was left in his bailout? Until you experience it, it is hard to imagine the cooling impact of breathing HeO2 (not Trimix) with oxygen under 10%. Divers have lost hot water many times but were working hard (along with the bellman) to get back to the bell rather than trying to conserve bailout gas.

I have never heard of a diver blacking-out from hyporthermia, though drowning may have been "assumed" when bottles were found empty (which can easily happen after loss of consciousness, dropping the mouthpiece, and freeflowing). Do any of you Ice divers know of any?