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What is Saturation Diving?

Discussion in 'Commercial Divers' started by Akimbo, Oct 13, 2013.

  1. Akimbo

    Akimbo Lift to Freedom Volunteer Staff Member ScubaBoard Supporter

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    That was my thought, though I have not been aboard. She "looks" like she brings a higher day rate to the mix without a significant increase in sea-state bell ops. Do you have any idea how well she is competing with other North Sea DSVs?

    The sat system has a lot of wiz-bang automation, but it is hard to tell if there is much reduction operator head-count. System maintenance and troubleshooting looks like a nightmare.

    I was heavily involved with the Seaway Swan in the late 1970s. She had two bells and an 18-man sat system, but two-man lockouts were rare except on hyperbaric welding jobs.

    The Swan was an 8-leg semisubmersible with a 200 Ton crane and 100 Meter boom. She could operate in much higher sea states than mono-hulls because each bell had a moonpool/launch tube from above the main deck to the bottom of the port-side pontoon -- which was at 75'/23 Meters when ballasted-down for diving operations. The bells had a cursor system that went to the bottom of the pontoon. Bells could launch in Sea State 7, maybe even 8, in open water. My brother did some lockouts in Sea State 6 and could hardly notice the bell moving.

    Like the Uncle John, another semisubmersible DSV, she just proved to be too expensive. I understand she was converted to a drilling platform after she spent too much time tied up to the quay.

    Question: How did they get away with a 24-man system and only an 18-man hyperbaric lifeboat?
     
    EireDiver606 likes this.
  2. DCBC

    DCBC Banned

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    They have two independent 12 man systems; each serviced by an 18 man hyperbaric lifeboat. Although Technip is a co-owner, it has an 8 year exclusive operational contract. To my knowledge, she has only been operated in the North Sea.
     
    Akimbo likes this.
  3. Heliumthief

    Heliumthief Nassau Grouper

    # of Dives: I'm a Fish!
    Location: Scotland
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    The Arctic has two HLB's, each 18man. It's part of the Norwegian regulations. I'm guessing that the assumption is that one of the 6 man deco chambers (where the HLB's are accessed) will always be in deco, so the other 18 head to port, say, and the 6 deco head to stbd. The system is all one interconnected complex, the 4 inner '3' man chambers are the working teams, and the two outer 6 man chambers are out and in chambers. Of course, the system can be split into two depths easily due to the two TUP chambers and bells, and those could potentially be split into a different depth for every team, just by adjusting the wet pots and bells, but unlikely.
    the boat was built by DOF(the skandi prefix) and Technip for the Statoil contract in Norway, and Statoil had a lot of input into her design. She has also been over to Canada, and around the different N sea sectors but mainly Statoil in Norway. She hasn't, therefore, needed to 'compete' with any of the others, due to the firm contract, and being one of the few vessels allowed to work in the Norge sector. Big vessel, big Dayrate, 24 hour operation, 2 divers on the bottom all the time. The Techs on board were trained in the new systems, and can do their job well, and the automation in the system and dive control isn't intended to reduce numbers, it's designed to open a new chapter in system development. The original designs were even further out there!
    for my mind, though, the Seven Falcon is the most advanced DSV at the moment. 24 man, twin bell system, all automated like the Arctic and the Seven Atlantic, but the Bells can take 4 men, and there's a photo on the net somewhere taken by an ROV at the sea trials of both bells down, and 6 Divers in a human Pyramid! Hate to be the bellman...!
    most of the Newer DSV's in the North Sea can take sea states well over operationally acceptable limits. On my Vessel, we can be on the seabed in over 50 knots, and a few years ago, swells of 6 m were occasionally measured (down to 4 now) with the heave comp on the bells, but the ROV couldn't get in the water, the Crane was out of limits..and if the heave comp ****s itself, then the bell is a steel yoyo.
    the thing that killed the big Semi's like the Swan, Regalia, Semi 1/2 etc was after all the extra work putting in SSIV's after Piper Alpha, work generally turned to more hit and go jobs, inspection, etc, and they cost too much to mobilise, and were too slow to transit. When you could get a small single bell DSV right under the Platform and inspect everything for 50k a day, why pay 150k for a Semi to spend a week steaming to the same job?
     
    Akimbo likes this.
  4. Akimbo

    Akimbo Lift to Freedom Volunteer Staff Member ScubaBoard Supporter

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    I have heard and used the term "lockout" to describe a diver exiting the bottom hatch of a bell or habitat since the mid-1960s. It occurred to me that I never knew where the term came from and it really isn't very logical. Anyone know?

    The hatch is always open when the diver is out so there is never a pressure differential. Different compartments that can be independently pressurized in a chamber complex are sometimes called "locks" (double-lock chamber for example). Maybe it is from non-saturation divers exiting submarines or submarine escape training towers?
     
    Last edited: May 13, 2017
  5. descent

    descent Solo Diver

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    The escape trunk hatches on modern subs have an interlock that requires one to be dogged shut and secured before the other can be opened. The procedure for exiting the boat while it is still below the surface has been called locking out for as long as I can remember.

    A view upward into the aft escape trunk of the USS Virginia (SSN-774), staged with a couple of mannequins wearing sailor emergency escape suits.

    3069678888_41263f16be_b.jpg




    Egress. (safety boat and standby divers waiting above, at the end of the training ascent line)

    2147708833_0f29d33878.jpg




    Unloading special warfare goodies from storage in the sail after locking out. The trunks themselves are cramped. Larger equipment sometimes needs to be stored outside the pressure hull.

    2156901509_86e5039335.jpg
     
  6. Akimbo

    Akimbo Lift to Freedom Volunteer Staff Member ScubaBoard Supporter

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    Submarines have had escape trunks since the 1930s when Charles "Swede" Momsen developed the McCann Rescue Chamber and Momsen lung, which is about the same time that submarine escape training towers were built. "Lockout" could be a carry-over from this since Captain Bond and several of the early Sealab divers had submarine backgrounds.

    It is interesting that the term has taken hold in the international commercial diving industry where a small percentage of divers came from the military. It is especially curious because the closest analogy would be disconnecting the bell from the transfer trunk rather than a diver the exiting bottom hatch.
     
    Last edited: Sep 21, 2014
  7. Papyone

    Papyone Angel Fish

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    Hello to all,
    I put my first message here to give a few more information concerning saturation diving.
    Saturation diving is a well-established practice used by a lot of diving companies, but did you know that the very first saturation dive made underwater was made in France in September 1962.
    This first saturation dive was made by the Belgian Robert Stenuit who stayed 24 hours at 200 feet (62 m).
    Later in 1964 The US NAVY conducted a saturation dive program under the name of SEA LAB.
    After that, the first commercial Saturation job was conducted in 1965 by Marine Contractors Inc., of Southport, Connecticut.This diving operation consisted to replace faulty trash racks at the Smith Mountain Dam in Virginia.Therefore, during a period of 4 months, divers were kept under pressure for periods of about 5 days in a saturation diving system designed by Westinghouse Electric Corporation.To accomplish the work, 2 divers at the time were send on the bottom and spend hours at a depth comprised between 159 and 240 feet (47 - 72 m).
    One year later, the same saturation system was used by that company to do the first sea commercial saturation in the Gulf of Mexico.
    From then on, several diving companies started also to use this diving technique.

    But in fact, we men are not the first to have worked in saturation.

    Around 1937, donkeys and mules were used for hauling material during the construction of the Milwaukee tunnel.

    To do the work, the animals were kept under pressure for weeks or even months, but unfortunately they systematically died during decompression.

    In 1938, a certain Dr Edgar End, concerned by this problem established a dive decompression profile to demonstrate that the animals (and humans) could be decompressed safely after a long period of time under pressure and to prove his theory, on the 19 December 1938 he put a volunteer diver named Max Nolh under pressure in a recompression chamber.

    The diver stayed at a depth of 100 feet (30 m) for a period of 27 hours and was then decompressed within 5 hours.
    Reaching the surface, Nolh suffered from decompression sickness, but he recovered well after the recompression treatment.
    Although this dive was not yet called a saturation dive, we can say that our brave ancestor Max Nolh was the first sat diver of the world.
     
    Akimbo likes this.
  8. Akimbo

    Akimbo Lift to Freedom Volunteer Staff Member ScubaBoard Supporter

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    Thanks Papyone, nice summary. Here are some references for those interested in more saturation diving history.

    Papa Topside: The Sealab Chronicles of Capt. George F. Bond, USN is probably the best overall history. It talks about all of the early saturation experiments from Captain Bond's perspective.

    Cousteau's first air saturation experiment, Conshelf I in 1962 at 33'. See Chapter 18
    The Living Sea by Jacques Yves Cousteau with James Dugan

    Cousteau's Conshelf 2 experiment, which was documented in a book and 1964 Academy Award winning movie, World Without Sun

    Cousteau's Conshelf 3 1965 experiment in 336' published in Volume 129, #4 of the National Geographic, April 1966

    Ed Link's experiments in saturation diving starting with an 8 hour dive to 60' in 1962 (not truly a saturation dive but near enough) followed about a month later with Robert Sténuit's 24+ hour dive to 200' in a one-man bell. Sténuit and Jon Lindberg (son of Charles Lindbergh) made a 49 hour dive to 432' in an inflatable habitat called SPID in 1964.
    The Deepest Days by Robert Sténuit

    Excellent history of the US Navy's Sealab 1-3 experiments
    Sealab: America's Forgotten Quest to Live and Work on the Ocean Floor by Ben Hellwarth. BTW, Ben is a Scubaboard member.

    This book explains a lot about why the US Navy suddenly became so interested in saturation diving.
    Blind Man's Bluff: The Untold Story of American Submarine Espionage: Sherry Sontag, Christopher Drew

    Some saturation history, mostly cold-war stuff, but really interesting.
    The Silent War: The Cold War Battle Beneath the Sea by John Pina Craven

    This is an offshore oilfield diving perspective, a bit US-centric but very good:
    The History of Oilfield Diving by Christopher Swann

    Detailed account of a North Sea saturation diving accident on a DSV.
    Into the Lion's Mouth, The Story of the Wildrake Diving Accident by Michael Smart

    Salvage and deep water treasure hunt:
    Goldfinder: The True Story of $100 Million In Lost Russian Gold -- and One Man's Lifelong Quest to Recover It by Keith Jessop
     
    Last edited: Dec 20, 2014
    Schwob likes this.
  9. Heliumthief

    Heliumthief Nassau Grouper

    # of Dives: I'm a Fish!
    Location: Scotland
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    Can't reccomend the last three books high enough...
     
  10. emoreira

    emoreira Dive Resort

    # of Dives: 200 - 499
    Location: ARGENTINA
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    Thanks Akimbo for this nice list !
    I have already read two of the list :
    - Sealab
    - Into the Lion's Mouth

    This gives me home work. I have now a lot to read !
     

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