Navy Diving Manual Rev 6 Chapter 8 Surface Supplied Air Diving Operations

Front 1

What is the maximum working depth for air diving operations using the MK 21 MOD 1 and KM-37 UBAs?

Back 1

190 fsw

Front 2

When is an EGS mandatory for MK 21 MOD 1 and KM-37 UBAs?

Back 2

1. Deeper than 60 fsw
2. When diving inside a wreck or enclosed space

Front 3

True or False. The Diving Supervisor may elect to use an EGS that can be man-carried or located outside the wreck or enclosed space and connected to the diver with a 50 to 150 foot whip.

Back 3

True

Front 4

Planned air dives below 190 fsw require whose approval?

Back 4

CNO

Front 5

What does the EGS system for MK 21 MOD 1 and KM-37 UBAs consists of?

Back 5

1. An adequately charged ANU approved SCUBA cylinder
2. Either a K- or J- valve (with reserve turned down)
3. First stage regulator set at manufacturer’s recommended pressure, but not lower than 135 psig.
4. Relief valve set at 180 ± 5 psig over bottom pressure
5. A submersible pressure gauge is also required on the first stage regulator

Front 6

What defines an adequately charged SCUBA cylinder with regards to EGS?

Back 6

Defined as the pressure that provides sufficient air to bring the diver to his first decompression stop or the surface for no-decompression dives. It is assumed that this will give topside personnel enough time to perform required emergency procedures to restore umbilical air to the diver.

Front 7

When the MK 21 MOD 1, KM-37 system is used, the air supply system must be able to provide an average sustained flow of ______ acfm to the diver.

Back 7

1.4 acfm

Front 8

When planning a dive, calculations are based on ______ acfm for descent and bottom phase and _______ acfm for ascent and decompression phase.

Back 8

1.4 acfm, 0.75 acfm

Front 9

What are the MK 21 MOD 1 and KM-37 minimum, desired, and maximum overbottom pressure requirements?

Back 9

0-60 fsw 90, 135, 165
61-130 fsw 135, 135, 165
131-190 fsw 165, 165, 165

Front 10

What is the minimum overbottom pressure when using a double exhaust kit installed on the MK 21 MOD 1 and KM-37 at a depth of 0-60 fsw?

Back 10

135 psig is the minimum instead of 90 psig

Front 11

What is the over-bottom pressure set at for the first stage regulator on the EGS for the MK 21 MOD 1 and KM-37?

Back 11

At manufacture’s recommended pressure, but not lower than 135 psig

Front 12

What is the relief valve set at on the first stage regulator on the EGS for MK 21 MOD 1 and KM-37?

Back 12

180 +/- 5 psig

Front 13

Why is there a relief valve installed on the first stage for the MK 21 MOD 1 and KM-37 EGS?

Back 13

To prevent rupture of the low pressure hose should the first stage regulator fail.

Front 14

If the EGS is located topside, what should the first stage regulator be adjusted to?

Back 14

150 psig

Front 15

What is the variation of air consumption of divers using MK 21 MOD 1 and KM-37?

Back 15

It varies between .75 and 1.5 acfm when used in demand mode

Front 16

When the MK 21 MOD 1 and KM-37 is used in the free flow mode, how many acfm are consumed?

Back 16

Greater than 8 acfm

Front 17

For diver life support systems not capable of sustaining 165 psig over bottom due to system design limitations, what psig is authorized?

Back 17

135 psig

Front 18

The MK 20 MOD 0 is authorized for use to a depth of _____ fsw with surface-supplied air.

Back 18

60 fsw

Front 19

What does the EGS assembly consists of for MK-20?

Back 19

1. An adequately charged ANU approved SCUBA cylinder with either a K- or J-valve.
2. An approved SCUBA regulator set at manufacturer’s recommended pressure, but not lower than 135 psi
3. An extended EGS whip 50 to 150 feet in length.
4. If the diving scenario dictates leaving the EGS topside, adjust the first stage regulator to 150 psig.
5. An approved submersible pressure gauge.

Front 20

What is the breathing gas flow requirements for the MK 20 MOD 0?

Back 20

1.4 acfm

Front 21

What is the minimum overbottom pressure for the MK 20 MOD 0?

Back 21

90 psig

Front 22

True or False. Flow and pressure requirement calculations for the MK-20 Mod 0 are identical to those for the MK 21 MOD 1, KM-37

Back 22

True

Front 23

The EXO BR MS is authorized for use to ______ fsw on air.

Back 23

190 fsw

Front 24

When is an Emergency Gas Supply (EGS) mandatory for the EXO BR MS?

Back 24

Deeper than 60 fsw and when diving inside an enclosed space

Front 25

What does the Emergency Gas Supply (EGS) consists of for the EXO BR MS?

Back 25

1. An adequately charged ANU approved SCUBA cylinder
2. Either a K- or J- valve (with reserve turned down)
3. First stage regulator set at manufacturer’s recommended pressure, but not lower than 135 psig.
4. Relief valve set at 180 ± 5 psig over bottom pressure
5. A submersible pressure gauge is also required on the first stage regulator

Which is the same as the requirements for MK 21 MOD 1 and KM-37 UBAs

Front 26

True or False. When diving enclosed spaces during ship husbandry operations using the EXO BR MS, the use of an approved second stage regulator with extended EGS whip 50 to 150 feet in length is permissible.

Back 26

True

Front 27

What is the breathing gas flow requirements for the EXO BR MS?

Back 27

1.4 acfm

Front 28

What is the overbottom pressure for dives shallower than 130 fsw using the EXO BR MS?

Back 28

135-165 psi

Front 29

For those systems which cannot maintain 135 psi overbottom pressure when diving shallower than 60 fsw using the EXO BR MS, ______ psi is permissible.

Back 29

90 psi

Front 30

What is the overbottom pressure for dives shallower than 130-190 fsw using the EXO BR MS?

Back 30

165-225 psi

Front 31

True or False. Flow and pressure calculations for the EXO BR MS are identical to those for the MK21 MOD 1, KM-37?

Back 31

True

Front 32

What are the basic components of the MK 3 MOD 0 LWDS?

Back 32

1. Control console assembly
2. Volume tank assembly
3. Medium-pressure air compressor (optional)
4. Stackable compressed-air rack assemblies

Front 33

The stackable compressed-air rack assemblies of the MK 3 MOD 0 LWDS consists of _______ high-pressure composite flasks (_______ cu ft floodable volume each). Each flask holds _______ scf of compressed air at _______ psi.

Back 33

Three, 0.935 cu ft, 191 scf, 3,000 psi

Front 34

What are the three configurations of the MK 3 MOD 0 LWDS?

Back 34

Configuration 1. Air is supplied by a medium-pressure diesel driven compressor unit supplying primary air to the divers at 18 standard cubic feet per minute (scfm) with secondary air being supplied by one air-rack assembly. Total available secondary air is 594 scf.

Configuration 2. Primary air is supplied to the divers using three flask rack assemblies. Secondary air is supplied by one flask rack assembly. Total available primary air is 1,782 scf at 3,000 psi. Total available secondary air is 594 scf.

MK 3 MOD 0 Configuration 3. Primary air is supplied to the divers using three flask rack assemblies. Secondary air is supplied by two flask rack assemblies. Total available primary air is 1,782 scf. Total available secondary air is 1,188 scf.

Front 35

What is the difference between the MK 3 MOD 0 and the MK 3 MOD 1?

Back 35

The MOD 1 is identical to the MK 3 MOD 0 LWDS except that the control console and volume tank have been modified to support 5,000 psi operations for use with the Air Supply Rack Assembly (ASRA). With appropriate adapters the system can still be used to support normal LWDS operations.

Front 36

What is the maximum depth for the ROPER diving cart?

Back 36

60 fsw

Front 37

Describe the Flyaway Dive System (FADS) III/

Back 37

The FADS III is a portable, self-contained, surface-supplied diver life-support system designed to support dive missions to 190 fsw (Figure 8 6). Compressed air at 5,000 psi is contained in nine 3.15 cu ft floodable volume composite flasks vertically mounted in an Air Supply Rack Assembly (ASRA). The ASRA will hold 9600 scf of compressed air at 5,000 psi. Compressed air is provided by a 5,000 psi air compressor assembly which includes an air purification system. The FADS III also includes a control console assembly and a volume tank assembly. Three banks of two, three, and four flasks allow the ASRA to provide primary and secondary air to the divers as well as air to support chamber operations.

Front 38

What is the purpose of the Oxygen Regulator Console Assembly (ORCA)?

Back 38

To provide 100% oxygen to the diver’s umbilical’s for use during in-water oxygen decompression. It is designed to be used with any currently certified Divers Life Support System (DLSS).

Front 39

What is a lead line?

Back 39

The lead line is used to measure depth

Front 40

What is the recommended line used for a descent line?

Back 40

3-inch double-braid line is recommended, to prevent twisting and to facilitate easy identification by the diver on the bottom

Front 41

True or False. In use, the end of the descent line may be fastened to a fixed underwater object, or it may be anchored with a weight heavy enough to withstand the current.

Back 41

True

Front 42

What is a circling line?

Back 42

The circling line is attached to the bottom end of the descent line. It is used by the diver as a guide in searching and for relocating the descent line.

Front 43

What is the minimum stage line requirements?

Back 43

3-inch double braid, or 3/8-inch wire rope minimum

Front 44

How do you figure Minimum Manifold Pressure (MMP) for MK 21 MOD 1, KM-37, and EXO BR MS?

Back 44

(Depth in fsw × 0.445) + 90 to 165 psi, depending on the depth of the dive

The manifold supply pressure requirement is 90 psig over-bottom pressure for depths to 60 fsw, and 135 psig over-bottom pressure for depths from 61-130 fsw. For dives from 131-190 fsw, 165 psig over-bottom pressure shall be used.

Front 45

How do you figure Minimum Manifold Pressure (MMP) for MK 20 MOD 0?

Back 45

(Depth in fsw × 0.445) + 90 psi

Front 46

What are the requirements for primary air supply for surface supplied diving?

Back 46

It must be able to support the air flow and pressure requirements for the diving equipment designated. The capacity of the primary supply must meet the consumption rate of the designated number of divers for the full duration of the dive (bottom time plus decompression time). The maximum depth of the dive, the number of divers, and the equipment to be used must be taken into account when sizing the supply.

Front 47

What are the requirements for secondary supply for surface supplied diving?

Back 47

It must be sized to be able to support recovery of all divers using the equipment and dive profile of the primary supply if the primary supply sustains a casualty at the worst-case time (for example, immediately prior to completion of planned bottom time of maximum dive depth, when decompression obligation is greatest).

Front 48

All valves and electrical switches that directly influence the air supply shall be labeled how?

Back 48

“DIVER’S AIR SUPPLY- DO NOT TOUCH”

Front 49

What type compressors are the only ones authorized for use in Navy air diving operations?

Back 49

Reciprocating air compressors

Front 50

Lubricants used in air diving compressors for normal operations must conform to what military specifications?

Back 50

MIL-PRF-17331 (2190 TEP)

Front 51

Lubricants used in air diving compressors for cold weather operations must conform to what military specifications?

Back 51

MIL-PRF-17672 (2135 TH)

Front 52

True or False. Where the compressor manufacturer specifically recommends using a synthetic base oil, the recommended oil may be used in lieu of MIL-PRF-17331 or MIL-PRF-17672 oil.

Back 52

True

Front 53

If a line pull signal is not properly returned by the diver, the surface signal is sent again. A continued absence of confirmation is assumed to mean one of three things. Name them.

Back 53

1. The line has become fouled
2. There is too much slack in the line
3. The diver is in trouble

Front 54

There are three line-pull signals that are not answered immediately. Explain them.

Back 54

1. From diver to tender - 4 pulls “Haul me up” Acknowledgment consists of initiation of the action.
2. From diver to tender - 4-4-4 pulls “Haul me up immediately” Acknowledgment consists of initiation of the action.
3. From the tender to diver - 4 pulls “Come up” This signal is not acknowledged until the diver is ready to leave the bottom. If for some reason the diver cannot respond to the order, the diver must communicate the reason via the voice intercom system or through the line-pull signal meaning “I understand,” followed (if necessary) by an appropriate emergency signal.

Front 55

What are the following line pull signals from tender to diver?

1 Pull -
2 Pulls -
3 Pulls -
4 Pulls -
2-1 Pulls -
3-2 Pulls -
4-3 Pulls -

Back 55

1 Pull - “Are you all right?” When diver is descending, one pull means “Stop”
2 Pulls - “Going Down” During ascent, two pulls mean “You have come up too far; go back down until we stop you”
3 Pulls - “Stand by to come up”
4 Pulls - “Come up”
2-1 Pulls - “I understand” or “Talk to me”
3-2 Pulls - “Ventilate.”
4-3 Pulls - “Circulate”

Front 56

What are the following line pull signals from diver to tender?

1 Pull -
2 Pulls -
3 Pulls -
4 Pulls -
2-1 Pulls -
3-2 Pulls -
4-3 Pulls -

Back 56

1 Pull - “I am all right” When descending, one pull means “Stop” or “I am on the bottom”
2 Pulls - “Lower” or “Give me slack”
3 Pulls - “Take up my slack”
4 Pulls - “Haul me up”
2-1 Pulls - “I understand” or “Talk to me”
3-2 Pulls - “More air”
4-3 Pulls - “Less air”

Front 57

What are the following special line pull signals from diver to tender?

1-2-3 Pulls -
5 Pulls -
2-1-2 Pulls -

Back 57

1-2-3 Pulls - “Send me a square mark”
5 Pulls - “Send me a line”
2-1-2 Pulls - “Send me a slate”

Front 58

What are the following emergency line pull signals from diver to tender?

2-2-2 Pulls -
3-3-3 Pulls -
4-4-4 Pulls -

Back 58

2-2-2 Pulls - “I am fouled and need the assistance of another diver”
3-3-3 Pulls - “I am fouled but can clear myself”
4-4-4 Pulls - “Haul me up immediately”

Front 59

What are the following Searching Signals (With Circling Line) line pull signals from diver to tender?

7 Pulls -
1 Pull -
2 Pulls -
3 Pulls -
4 Pulls -

Back 59

7 Pulls - “Go on (or off) searching signals”
1 Pull - “Stop and search where you are”
2 Pulls - “Move away from the weight”
3 Pulls - “Face the weight and go right”
4 Pulls - “Face the weight and go left”

Front 60

What are the following Searching Signals (Without Circling Line) line pull signals from diver to tender?

7 Pulls -
1 Pull -
2 Pulls -
3 Pulls -
4 Pulls -

Back 60

7 Pulls - “Go on (or off) searching signals”
1 Pull - “Stop and search where you are”
2 Pulls - “Move directly away from the tender if given slack; move toward the tender if strain is taken on the life line”
3 Pulls - “Face your umbilical, take a strain, and move right”
4 Pulls - “Face your umbilical, take a strain, and move left”

Front 61

If you receive a line pull signal initiated by the diver who is on searching signals, what is it considered?

Back 61

A standard line pull signal

Front 62

If obstructions are encountered by divers on the bottom, how should they get passed them?

Back 62

Pass over the obstruction, not under or around. If you pass around an obstruction, you must return by the same side to avoid fouling lines.

Front 63

If it is anticipated that the diver may become covered by mud, as in a jetting or tunneling operations, what should the diver do?

Back 63

Keep the helmet steady-flow valve slightly open.

Front 64

What is the primary hazard with mud bottoms?

Back 64

The concealment of obstacles and dangerous debris

Front 65

When can divers working in submarine ballast tanks remove their diving equipment?

Back 65

When the atmosphere has been flushed twice with air from a compressed air source meeting the requirements of Chapter 4, or the submarine L.P. blower, and tests confirm that the atmosphere is safe for breathing.

Front 66

How often shall the air in a submarine ballast tank be tested?

Back 66

Hourly

Testing shall be done in accordance with NSTM 074, Volume 3, Gas Free Engineering (S9086-CH-STM-030/CH-074) for forces afloat, and NAVSEA S-6470-AA-SAF-010 for shore-based facilities.

Front 67

A diver should not descend on a line that cannot be cut. If job conditions call for using a steel cable or a chain as a descent line, whose approval is necessary?

Back 67

The Diving Officer

Front 68

What are the disadvantages of In-Water Decompression?

Back 68

Decompression in the water column is time consuming, uncomfortable, and inhibits the ability of the support vessel to get underway. Delay could also present other problems for the support vessel: weather, threatened enemy action, or operating schedule constraints. In-water decompression delays medical treatment, when needed, and increases the possibility of severe chilling and accident.

Front 69

The diver must remain within _____ minutes’ travel time of the diving unit for at least ___________ after surfacing from a surface decompression dive.

Back 69

30 minutes, 2 hours