Umbilical severed at 80 meters in North Sea

[DCBC]

It doesn't. If the Hot Water umbilical is severed, you're screwed. At DCIEM we experimented with a closed-circuit hot water suit and a device that would circulate and heat water and deliver a limited amount to the core in an emergency, but it wasn't deemed successful. With the SLS even the mix is heated (to approx 70 degrees F) using the hot-water input.

If this Diver was following procedure, he should have attempted to go back to the Bell and not just wait. I realize that this isn't always possible, but that would be the first priority.

From the IMCA Supervisor's Manual:

42 Loss of Hot Water

42.1 If the hot water system fails the diver must start his return to the bell immediately. If he is breathing
heliox he will start to suffer from hypothermia in a matter of minutes.

42.2 While he is returning to the bell he should be adequately supplied by the head of water in the
umbilical and by water remaining in the boiler. This may need to be mixed with cold water manually to
supply water at the correct temperature. The surface crew should meanwhile be switching over to a
back-up heating system or back-up machine. Back-up heating may be provided by on-board steam.

43 Loss of Gas Supply – Diver

43.1 The diver will start to return to the bell immediately. Before turning on his bail-out he must check
that there is no risk of losing his gas through a free flow. The Diving Supervisor will be monitoring the
diver’s breathing and if he notices any significant changes he will alert the bellman.

43.2 If the problem has arisen in the diver’s gas supply to the bell, the bellman will be warned by the
changeover valve switching over to the on-board supply. He should notify the diver and Diving
Supervisor and the diver should return to the bell.

How does it deliver warm gas and hot water with a severed umbilical??? You get some exothermic heat from the absorbent but not much. Check my math but 2½ gallons/minute at 110° F (typical hot water suit requirement) is around 1,400 BTU/Minute starting with 45° water.

It will be interesting to learn what rig he was on and if any gas was left.

 

[Akimbo]

It doesn't. If the Hot Water umbilical is severed, you're screwed. At DCIEM we experimented with a closed-circuit hot water suit and a device that would circulate and heat water and deliver a limited amount to the core in an emergency, but it wasn't deemed successful. With the SLS even the mix is heated (to approx 70 degrees F) using the hot-water input...

I am surprised the gas heats to such a low temperature. The gas heaters used below 600' in the 1970s heated to 85°.

... If this Diver was following procedure, he should have attempted to go back to the Bell and not just wait. I realize that this isn't always possible, but that would be the first priority.

From the IMCA Supervisor's Manual:...

From what little I know, it makes sense that he didn't (or maybe couldn't). They knew where he was working on the structure when the umbilical was severed and he knew the there was no chance of finding the bell. I don't recall what time of day it was but I imagine not seeing lights on the bell is a good indicator to stay put.

 

[John C. Ratliff]

I am going to agree with Akimbo on this one; he had lost his umbilical lines, and was on his emergency gas. He knew where he was, and the tender inside the bell knew his last location. If he had swam out to try to find the bell, he could have become disoriented an lost. The bell, upon return, would not have found him, and he could not have found the bell on his own. His response was the only hope he had of being found, and only through teamwork and a bit of luck was he able to survive. Had he made any other decisions, he most probably would have been lost.

SeaRat

 

[Bombay High]

With a severed Umbilical, and the bell being pulled half a kilometre away, this was, I think, his only hope of being found - and the transponder helped

 

[DCBC]

I am surprised the gas heats to such a low temperature. The gas heaters used below 600' in the 1970s heated to 85°.

The thermal regenerator of the Divex SLS is situated beside the canister. It is a passive device which recovers heat from the exhaled gas passing to the counterlungs. It uses this heat to pre-heat the gas passing from the counterlungs back to the diver. Such a system certainly has its limitations (especially if the hot-water umbilical is severed), but any heat is better than nothing. Don't you think?

Diver’s respiratory heat loss increases with depth, as the density of the breathing gas increases. By IMCA policy, there must be gas heating for divers deeper than 150 msw (495 fsw). At 200 msw (660 fsw) the gas should be supplied at a temperature of about 75°F and at 300msw (984 fsw) 80°F.

From what little I know, it makes sense that he didn’t (or maybe couldn’t). They knew where he was working on the structure when the umbilical was severed and he knew the there was no chance of finding the bell. I don’t recall what time of day it was but I imagine not seeing lights on the bell is a good indicator to stay put.

Under the circumstances I agree. My point was that in the description he stated that he was "following safety procedures" and stayed where he was. In-fact his training told him to do the opposite i.e. get back to the bell and not stay where he was.

""The red light alarm was initiated; dive control was informed and both divers instructed to get back to the bell stage as soon as and as safely as possible." It would seem however that he had no choice. One lucky guy!

 

[Akimbo]

… I think, his only hope of being found - and the transponder helped

I would like to know more about the transponder if anyone runs across the info.

• Always on or manually turned on in an emergency?
• Does it have an operational use? Helping a ROV find the working diver maybe?
• Acoustic and/or strobe light?
• Umbilical powered with emergency battery or do they have to keep them charged?
• Is it stand-alone or built into the diver’s helmet mounted light or TV camera?

Man, this incident is fascinating and haunting at the same time.

 

[d_lafleur]

This has been a great read, for the Rec. Tec. and a fellow offshore worker point of view.

Cool heads survive.

Does anyone know if the DSP (Dive Support Vessel) was DP1 or DP2? We have both, with which the DP2 have two systems which allow the crew to select the "working one" in an incident.

 

[Akimbo]

Looks like DP II

http://www.bibbyoffshore.com/downloads/BIBBY_TOPAZ(1).pdf

 

[Bombay High]

I would like to know more about the transponder if anyone runs across the info.

• Always on or manually turned on in an emergency?
• Does it have an operational use? Helping a ROV find the working diver maybe?
• Acoustic and/or strobe light?
• Umbilical powered with emergency battery or do they have to keep them charged?
• Is it stand-alone or built into the diver’s helmet mounted light or TV camera?

Man, this incident is fascinating and haunting at the same time.

This is what they are using:

http://www.km.kongsberg.com/ks/web/nokbg0397.nsf/AllWeb/1B58E93D7B3A1061C1256C370047D8D7/$file/164508ad_HiPAP500_Brochure_lr.pdf?OpenElement​

http://www.km.kongsberg.com/ks/web/n...D?OpenDocument

 

[d_lafleur]

I am going to take a poll of our marine vessel people to find out how often we have had any type of DP I or II go "off site" and how far they had to go. I would assume, it doesnt happen often.