saturation divers

[salavaria]

I'm trying to find out more about the incredible job these people do. I have a number of questions regarding saturation diving, specifically in the North Sea. I'll start the ball rolling with this one. Hope someone out there can enlighten me.

I might be way off the mark here, and please put me right if that's the case, but I understand that divers might work on the sea bed and then 'live' in a pressurised facility for up to two weeks. Would this chamber also be on the sea bed? Or, in the case of divers working on oil rigs, would it be attached to the rig? How is this accessed? Do they walk to it, or use some kind of diving bell? How many people would occupy it during a shift?

Many thanks.

[fppf]

Sat Rats stay in a habitat that is on the surface vessel. They commute to work by a diving bell. The bell is locked to the habitat then the divers climb in. Then the bell is sealed and unlocked from the habitat and lowered to the working depth of the divers. Then they open the door and start diving operations. At the end of there shift the process is reversed.

[salavaria]

Many thanks for that. A few more questions, if you don't mind? What might be a typical routine job for 'sat rats' on an oil rig? How many divers would be involved in a shift? How long do shifts last? Would there be a leader? How many diving hours would an experienced saturation diver have under his belt? Any help much appreciated.

[fppf]

I'm not a commercial diver, just well rounded. I can answer some of those, but I would call a commercial diving school, I'm sure they would take the time to talk to you.

Commercial divers do any number of jobs, pipe setting and repairing, rig maintance, recovery, exct. I think they typicaly do one long dive per shift that can last up to 10-12 hours I heard, but not sure on that one. There is a whole team of people that sat rats trust there life with. There is one main dive operations manager that oversees everything. I have no clue how long it takes to be sat rat. The commercial diving industry is very structured, you first start out as poop boy and work your way up from there, tender for lines, then a diver, then deep diver, then sat rat for say. But I'm not sure of the whole order and steps it takes.

There are a few commercial divers here that may chime in for you.

[salavaria]

thanks fppf - you're a top man.

[fppf]

Actually I kind of like being at the bottom, on some wreck somewhere.

[Gene_Hobbs]

This was a nice review of commercial/ scientific techniques:
Beyerstein G. Commercial Diving: Surface-Mixed Gas, Sur-D-O2, Bell Bounce, Saturation. In: Lang, MA and Smith, NE (eds.). Proceedings of Advanced Scientific Diving Workshop: February 23-24, 2006, Smithsonian Institution, Washington, DC. Rubicon Research Repository: Item 123456789/4661

The wikipedia article is not bad... Saturation diving - Wikipedia, the free encyclopedia

It is also worth reading the US Navy Diving Manual for more specific information on equipment and techniques. We have more technical information in the RRR that can be found by searching for "saturation".

[muddiver]

Ok, probably old news now, but...

Saturation diving can take a week or months depending on the job. Typically the sat system is on either a barge or a ship so it can be moved around. They are not usually setup on an oil rig. There isn't enought room, and the dive company will want to move it as soon as the work is done.

Shifts are for eight hours locked out on the bottom for the diver and the bell tender. A sat team will work 24 hours a day, so there are a minimum of six divers in sat at any time. One of the divers is a medic so there is someone to take care of everyone else.

I don't know much about the North Sea, but you can visit The Commercial Diving Directory and someone there can fill you in.