2. Saturation Diving
Saturation Diving is a safe and
economical way to use divers to
carry out tasks subsea.
Saturation Divers live in chambers
for up to 28 days, that are
pressurized to the same working
depth.
3. Sat System
The living chambers are on the
surface usually on the deck of a ship
or barge.
The normal min chamber
configuration is three living
chambers, two wet pots (entry
locks), diving bell and lifeboat.
4. Food Supplies
Diver’s receive their meals via
Medical Lock - is a two way pressure
vessel that is built into side of chamber
that can be vented to surface by Life
SupportTechnicians so LST’s can put
meals into divers. This is done by closing
door on inside of chamber then
informing LST.
LST then vents medical lock to surface
opens outer door. LST places meals into
medical lock closes outer door, pressurize
lock when medical lock is at same
pressure as divers in living chamber,
diver’s then open inner door of medical
lock and removed their meal. This
process happens whenever food or
equipment is need by diver’s.
5. Shower AndToilet
Wet Pots (entry locks) is joined to
living chambers and is separated by
two sealing doors this is where
divers have a toilet and shower and
is normally where the diving bell
locks onto the diving system
(chamber).
Trunk – Is a very short man-way that
connects to entry locks (wet pots) to
diving bell and is used when entering
or leaving diving bell, theTrunk can
be sealed at both ends when bell is
connected to diving system. Trunk is
vented to surface when bell is
locking off, this enables bell to safely
detach from diving system.
6. The Bell
Diving Bell – locks onto trunk and
the entry lock so Divers are able to
enter bell and transit to subsea work
site. Inside diving bell are 2 divers
helmets connected to separate
umbilical's
7. Blow Down
The Sat commences with a Blow
Down. Divers enter living chambers
when chamber is on the surface
normally at the start of a diving
contract. Diver’s enter chamber via
open chamber door they take mostly
personal belongings like anyone takes
when going on a long trip. Once all
divers have entered chamber the
chamber doors are closed and secured
by LST. The chamber is pressurized
with mixed gas (helium + oxygen).
This is done slowly so temperature in
chamber will not become too high also
mixed gas circulates and mixes evenly
with air already in chambers.
When Diver’s have been pressurized to
working depth that is the end of blow
down.
8. Diver’s
Bellman – Is a Diver in control of bell
and is responsible for safely connecting
Diver’s helmet and equipment to the
other two Diver’s that will leave the
bell. Bellman also feeds out umbilical
to Diver as Diver goes to job.
Diver 1 – Is the first diver to leave bell
and is in control of the dive and directs
all subsea work via Dive Supervisor’s
instructions
Diver 2 – Is next to leave bell and works
with Diver one.
Each dive, Diver’s change positions so
the next dive Dive 1 – changes to
Bellman. Diver 2 changes to Diver 1
and so on.
9. 1 hour Notice to Dive
One Hours Notice – Is when
LST has been informed by
Diving Supervisor to tell Divers
that they are required to be
ready to enter diving bell to
transit to do sub sea task.
Within that hour Divers
normally wake from rest, LST
locks in meal (breakfast),
Diving Supervisor briefs Divers
on task and Divers don their
diving suits.And Bellman go’s
into bell for bell checks
10. Bell Locking Off
Lock Off - Is when Diver’s 1 hour’s
notice has ended and Diver’s have
entered the bell via the entry lock
(Wet Pot) and trunk have closed bell
internal door and has asked the
Diving Supervisor to pressurize the
bell or vent trunk so bell can lock off
diving system.
11. Left Surface
After bell has locked off from trunk
bell is moved (trollied) to moon pool
or outboard of ship and lowered into
water and then down to working
depth.
12. OnThe Bottom
Got the door - Is when bell has been
stopped at working depth and
bottom door of bell has equalized
with that depth and diver 3 (bellman)
is able to open bottom door so
Diver’s can leave bell to do tasks.
13. Diver’s Lockout
Lock0ut – Is when Diver 1 leaves the
bell and swims to worksite. Diver 2
locks out 10-15 mins later. After Diver
1 is settled on job and has pulled
through his umbillical.
Divers are locked out for 6 hours to do
their subsea tasks. 10-15mins before
6hrs has lapsed Dive Supervisor
request Diver 1 back to the bell. The
Bellman then pulls up Diver 1’s
umbilical into bell until Diver is in bell.
While Diver 1 is returning to bell Diver
2 tidies up work site ready for next
dive team to continue the task. Diver
2 then returns to bell.
14. Back InThe Bell
Got a Seal – Once both divers are in
bell the Bellman will close bottom
door and pressurize the bell about
1m deeper than diving bell depth,
this he will check with internal depth
gauge and equalization valve.
When Bellman has confirmed he has
a seal on the bottom door he will
inform Diving Supervisor that he has
got a seal.
Left Bottom – After supervisor has
confirmed seal on bell, diving bell
will leave bottom. Bell will be
stopped after 5m of travel and
Bellman and Dive Supervisor will
check that bell bottom door is still
sealed. If seal is confirmed bell
continues upward travel.
15. On Surface
Bell Locked On –When bell has
returned to surface and trollied to
mate with diving system a hydraulic
clamp closes and locks the bell onto
trunk.
TUP – (Transfer Under Pressure) –
When Dive Supervisor pressurizes
trunk to the same pressure as diving
bell and wet pot so that Diver’s can
open bell door and move from bell to
wet pot (transfer under pressure)
once all three divers have moved
from bell to wet pot, a Bellman from
next team of Divers that is waiting in
wet pot will transfer into bell to start
diving bell checks (similar to what
pilots do before a flight) bell + trunk
doors will be closed returning Divers
remove wet suits and return to their
living chamber.
16. Decompressing
DECO – After 28 days or sooner
when subsea job is complete Diver’s
start decompressing (return to
surface) decompression time
depends on depth and company
diving tables.
When decompressing Diver’s
normally read books, watch movies
and eat a lot. Decompression can
take up to 10 days
