Chamber Procedures

Question 1

Requirements for BIBs during Saturation?

Answer 1

Immediately available
Suitable Stowage
Oxygen clean

Question 2

How often during saturation the status of external valves in chambers should be checked?

Answer 2

At the start of every shift in case maintenance has been carried out on the previous shift and the valves have not been reset.
Internal valves are designed as far as possible to be foolproof.

Question 3

Under normal condition what BiBs supply should be connected in to?

Answer 3

Bottom Mix

Note: A rich mix should only be connected for treatment purposes

Question 4

What are the size requirements for air chambers?

Answer 4

Main chamber should be large enough to allow two divers to lie down comfortably.
Minimum Internal diameter of 60 inches (1.5m).

Question 5

What are the size requirements for chambers surface supplied mixed gas diving?

Answer 5

if only one diver in the water and only one diver planned to be requiring decompression at any one time, the minimum diameter is 1.37 m (54”);

if more than one diver in the water and more than one diver planned to be requiring decompression at any one time, the minimum diameter is 1.50 m (60”);

in a 1.5m (or larger) diameter chamber there must be at least one fixed bunk, a minimum of 1.8 m long.

Question 6

What are the size requirements for saturation chambers?

Answer 6

large enough to stand up in and provide a healthy and safe environment for a lengthy occupation.

minimum internal diameter of 72 inches or 1800 mm.

DMAC 28 recommends a minimum diameter of 1.8m (72”) but preferably 2.15m (84”) for any saturation chamber within which medics may have to work.

Question 7

In a heliox environment what is the minimum oxygen percentage for combustion? At what point the risk of fire increase?

Answer 7

6%

Note: At initial compression and at the final stages of decommpression

Question 8

There are equalisation valves linking the main air chamber and the outer lock internally. The quarter turn valve in the main chamber (if fitted) is normally ……….. and the quarter turn valve in the outer lock is normally………. This allows equalisation from the outer lock if the divers in the main chamber are incapacitated.

Answer 8

Open

Closed

Question 9

The term “Two totally independent dedicated sources” means?

Answer 9

Could be two separate compressors, one of which is connected to the rig or vessel emergency electric power or separate power source (e.g. diesel) or one compressor plus compressed air storage containers.

Question 10

All Saturation Chamber hull penetrations must be provided with?

Answer 10

Valve on both sides to allow the valve to be closed off in an emergency or during maintenance.

Question 11

How often during saturation the status the external valves should be checked?

Answer 11

At the start of every shift in case maintenance has been carried out on the previous shift and the valves have not been reset. Internal valves are designed as far as possible to be foolproof.

Question 12

What bore pipe diameter should be pressurisation and exaust valves?

Answer 12

Large diameter.

Question 13

What is the difference between depth gauge connections and analysis connections?

Answer 13

Analysis can use crossover systems

Depth Gauge crossover systems are potentially very dangerous and must never be used.

Question 14

Saturation Chambers BIBs should be?

Answer 14

Suitable stowage
Immediate available
Oxygen clean

Question 15

Water supply in a chamber usually is pressurised containers with what percentage of gas?

Answer 15

2% or bottom mix.

Note: There must be a pressure relief valve on the container. There must be non-return valves on the mains water supply.

Question 16

What is important to know about toilet valves?

Answer 16

Must always be a gap between the toilet seat and the toilet bowl to prevent any potentially lethal suction accidents.

Question 17

Medical lock, when is not in use, should be always

Answer 17

Kept closed and dogged, remain at surface pressure with the outer door closed and clamped.

Question 18

Before operating the medical lock Chamber Control should always check with?

Answer 18

both surface and the divers

Question 19

The LST find a leak in the medical lock. Who he must contact immediately?

Answer 19

Must immediately inform the divers and the control room

Note: question on the final exame

Question 20

About view ports, what is important to know?

Answer 20

Complete renewal is necessary within 10 years of fabrication.
Mounted in the correct size of housing with the correct size of O-rings or other sealing gaskets.

Question 21

ECUs for saturation is important to maintain the atmosphere of

Answer 21

Oxygen
Carbon Dioxide
Humidity
Temperature

Question 22

CO2 and odours in the ECUs usually is removed by?

Answer 22

Soda Lime and Purafil or activated charcoal in the filter.

Question 23

Chamber Control Room should have voice communications with part of the vessel?

Answer 23

dive control
medical and equipment locks,
the gas storage hold,
bell trunking
diving superintendent.

Question 24

A non return valve must be fitted in saturation control panel ?

Answer 24

Yes, to prevent accidental leakage between mixes, in case of several mixes are connected to a common pressurisation-line.

Question 25

What is the minimum amount required of calibration and zero gas to be maintained during saturation? Soda Lime and purafil?

Answer 25

Cal gas - 3 weeks supply

Soda Lime and Purafil - about two weeks without further supplies being received.

Question 26

Higiene in a saturation chamber is important. State de general procedures that should be followed?

Answer 26

• rubbish must be passed out of the chamber every day
• even minor injuries must be treated immediately
• bedding usually every three days, but daily if there is infection
• chamber must be cleaned thoroughly on a daily basis
• chamber sumps must be kept dry

Question 27

Chambers may be swabbed to check for infection. What areas and items ?

Answer 27

toilet, sink, walls, sumps, shower heads, ECU drip tray, helmet liners, suits, bedding, headsets

Question 28

Sometimes, Swabs are taken from the divers 24 hours before pressurisation. At what moment the use of preventive ear drops should start in this case?

Answer 28

At this time.

Question 29

If a diver suffers an ear infection, but he has symptoms in only one ear. What is the procedure for treatment?

Answer 29

He should be given treatment for ear drops and, if necessary, a suitable painkiller. Preventative drops must be discontinued. He requires one labelled bottle of drops for each ear.
He should also take ear swabs to allow the infection to be identified.

PS: If two or more divers show symptoms, it may be advisable to carry out regular swabbing of all the divers’ ears.

Note: Question on the exam paper

Question 30

Is correct to say that Under normal conditions, regular ear swabbing in divers is advisable.

Answer 30

Regular swabbing is not advisable because it can cause damage to the ear canal and increase the risk of infection.

PS:
All use of ear drops, swabs and chamber cleaning should be checked and logged by the life support supervisor.

Note: Question on the exam paper

Question 31

When Gases must be analysed at the quad?

Answer 31

Before connection and at the control panel after connection.

Question 32

First few metres of pressurisation must be carried out using a breathable mix. If this is not the case and a breathable mix is not used, what precautions must be taken?

Answer 32

the divers must be on BIBS for at least the first 10 msw (33 fsw);
the pressurisation must be stopped at about 1-3 msw (3-10 fsw) to check for leaks.

Question 33

In a Daily Routine in Saturation the Environmental parameters are? how often should they be logged?

Answer 33

oxygen – about 400 mb (0.4 atm);
carbon dioxide – equal/less than 5 mb (0.005 atm);
nitrogen – less than 1000 mb (1 atm);
temperature – 25-33°C (77-92°F);
humidity – 50% to 70%;
depth – within 0.3 msw (1 fsw) of the specified depth.

Every Hour

Question 34

How often analysers should be calibrated in saturation control?

Answer 34

Analysers should be calibrated before every sat and every shift change thereafter or as indicated in company manuals.

Question 35

What are the safety considerations in a split saturation chamber system?

Answer 35

Unbreathable Atmosphere
Common lines
Leak through the door seals

Question 36

In case of evacuation is not possible and there is a fire in the chamber what action should be taken?

Answer 36

• All divers in the system should go onto the BIBS immediately and attempt to extinguish the fire or pass the burning material out through the medical lock.
• Electrical power to the chamber should be turned off and the chamber should be flushed.

Question 37

In event of a rapid pressure loss in a living chamber a series of events the divers will be liable to suffer, such as?

Answer 37

• decompression illness,
• barotrauma
• hypoxia as the ppO2 drops
• considerable noise affecting communication
• Misting will occur as the temperature drops
• Doors between chambers may seal.

Question 38

A saturation system should carry a variety of chemical sampling tubes, types of sampling tubes carried will depend on the type of diving operation. These sampling tubes are able to read what type of gas?

Answer 38

carbon dioxide,
carbon monoxide,
hydrogen sulphide,
benzene and
hydrocarbons

Question 39

Hyperbaric Evacuation of Saturation Divers should be an action of last resort, is considered when?

Answer 39

Only when the diving supervisor is certain that the divers under pressure will come to more harm if they remain in the diving system.

Question 40

The equipment that supports the hyperbaric evacuation arrangements includes…

Answer 40

hyperbaric rescue unit (HRU) – this can be a self-propelled hyperbaric lifeboat (SPHL) or hyperbaric rescue chamber (HRC);
life support package (LSP);
hyperbaric reception facility (HRF),

Question 41

It is acceptable to plan from the outset of a project to use a diving bell as a hyperbaric rescue unit.

True or False

Answer 41

FALSE

Question 42

There are four distinct phases from the decision to launch the HRU until safe decompression of the divers, what are they?

Answer 42

Phase A – transfer of the divers into the HRU and make it ready for launch (with a maximum time to undertake this – 15 minutes);

Phase B – the launch of the HRU and for it to be 100 m clear of the vessel/installation being evacuated (with a maximum time to undertake this – 30 minutes – the time starting when the instruction to launch the HRU is given);

Phase C – the transit of the HRU to the reception site The time taken to get the HRU to a safe haven should be as soon as possible and planning should be based on arrival at the safe haven within 75% of the HRU designed endurance The safe haven is where the HRU arrives on completion of transit. This can be the reception site, or the point at which the HRU is loaded onto transport and taken to the reception site;

Phase D – safe decompression of the divers The reception site is where the HRU will be taken for the safe decompression of the divers to be completed. The site can be the location for the LSP where the decompression can be carried out (or completed) in the HRC or SPHL using the LSP, or transfer into a portable HRF (which system is in place will have been agreed by the client), or a permanent HRF.

Question 43

Who’s decision is to decompress the divers in the HRU using an LSP or a HRF?

Answer 43

Decisions into which the divers can be transferred, decompressed and receive medical treatment should be based on a risk assessment directly involving the client.

Question 44

The International Maritime Organisation (IMO) has agreed on a standard set of warning instructions and other markings to be permanently displayed on every HRU. The warning instructions must be shown in how many locations?

Answer 44

2 separate locations.

Must be clearly visible when the HRU is floating.

Question 45

Bell diver rescue drills should be done how often?

Answer 45

Early in the sat period (first two to three bell runs) and every 14 days thereafter.

It is recommended that such drills should practice the recovery of a completely incapacitated saturation diver to the interior of the bell and that the drill should only end when the door inside the bell has been successfully closed.

Question 46

What is the minimum size requirements for HES?

Answer 46

Any chamber used for hyperbaric evacuation and manufactured after 1 January 2015 should have a minimum internal diameter of 69 inches or 1750 mm.

Question 47

How many scrubbers should be available on HRF/HRU?

Answer 47

2 scrubbers

Question 48

Hyperbaric rescue drills should be included in the regular on-board fire and boat drills, after agreement with…..

a. The ship’s captain or OIM.
b. Diving Supervisor
c. Client
d. Diving Contractor

Answer 48

a. The ship’s captain or OIM.

Question 49

In a wet bell operation, there must be sufficient quantities of therapeutic gas mixtures on board, in addition to the minimum quantities of medical oxygen, to carry out how many treatments?

Answer 49

Two full treatments.