ENG Exam 6.7-6.14

Buoyancy

Upward force a floating/submerged object experiences, equal to the weight of water

Displacement

Weight of water displaced by the ship = actual weight of the ship (measured in tons).

Draft

Vertical distance from keel to waterline (how deep the ship sits in water).

• Mean Draft: Average of forward and aft draft

• Navigational Draft: Includes projections like sonar domes/screws

Trim

Permanent difference between forward and aft draft (bow deeper = trimmed by bow).

If the front (bow) or back (stern) is deeper in the water — that’s trim.

Roll

Temporary inclination port or starboard due to wind or waves

Pitch

Temporary moving of bow or stern up or down due to wave action

List

Permanent Inclination to port or starboard

side-lean (due to off-center weight distribution).

Heel

Temporary inclination port or starboard due to turning

Sagging

Middle of ship sinks lower than bow/stern (compression at deck, tension at keel).

Hogging

Middle of ship rises above bow/stern (compression at keel, tension at deck).

Define COB and how it moves

Fallows waterline

is the center of the underwater hull volume when viewed in transverse direction

It’s the point at which all buoyant forces can be considered to be acting in a vertical direction

Waterline moves up, so does the buoyancy moves up

When the ship rolls starboard, the center of buoyancy (B) moves starboard

Define COG and how it moves

Point where all ship's weight acts

Moves towards weight addition, and away from weight removed

If something heavy added to the top of the ship, gravity moves down (away from the weight added)

GM (Metacentric Height)

• Distance between Center of Gravity (G) and Metacenter (M)

• Indicates stability:

  • Large GM = quick (snappy) roll

  • Small GM = slow (sluggish) roll

Stability is reduced when: Fluid conditions

COG is high and off center

Free Surface

Free communication

Free Surface Effect

• Caused by sloshing in partially filled tanks/compartments

• Water moves with heel → COG shifts → reduced stability

• Controlled with baffles, swash plates, or pocketing

• Breadth (width), not depth, makes it worse

Free Communication Effect

Occurs when:

• Space is open to sea

• Space is partially flooded

• Space is off-centerline

→ Water freely enters/leaves → shifts COG → virtual rise of COG
→ Bad for stability

Compartmentalizing Benefits

Reduce Free surface Effect

Isolates Casualty

• Maintains watertight integrity

• Provides damage control zones

Material Conditions of Readiness (Fittings Classification)

• X-RAY: Least protection, used in safe port conditions

• YOKE: At sea/after hours

• ZEBRA: Full protection, set during battle stations/General Quarters

• MODIFIED ZEBRA/YOKE: Adjusted for balance of safety/habitability

• CIRCLE X/Y/Z: Can be opened without special permission (like for inspections or movement).

• DOG ZEBRA: Used for darken ship

• WILLIAM: Sea suctions/ventilation (normally open for ship operation)

• CIRCLE WILLIAM: Closed during CBR (chemical/biological/radiation) attacks to protect air quality

Who is responsible for CCOL(Compartment Check-Off List)

Divo

posted at the entrances

Temporary hull conditions/ Persistent hull conditions Chart

Forward/ Aft Temporary Permanent

……………..PITCH……..TRIM

Port/ Starboard

………………ROLL, HEEL ….LIST

Stability Reference Points

Mother Geese beats kids

Metacenter

Gravity

Buoyancy

Keel

Danger Angle

is the point where your ship is starting to lose stability — if it tilts (heels) past this angle, it becomes dangerous.

Compartment Numbers Label

1st number: Deck #

2nd number: Forward most aft

3rd number: Position relative to waterline

Last Letter: Compartment use

FR202: forward most frame

210: After most frame

S-5 S is division responsibility

5 is work center responsibility

3 Main Material Conditions of Readiness

X-RAY: in homeport

YOKE: import

ZEBRA: during battle, emergencies or General quarters

2 center gravity conditions

COG is high and off center

Installed CO2

Charlie fire

found in paint lockers, flammable liquid rooms, electrical/machinery spaces

Fills the room with CO2 which removes oxygen so fire goes out

Halon 1301

Bravo fire (flammable liquids)

Found in engine rooms, generator spaces, boiler room, flammable storage areas

Chemically interrupts the fire reaction

Ventilation shut off automatically

60 sec delay if manned

30 sec if unmanned

Must wear SCBA

produces toxic gas like Cyanide

HFP

Bravo fire

replaces Halon 1301 on newer ships

stored as liquid, becomes gas when sprayed

puts out fire physically by absorbing heat

Does not damage ozone layer like Halon

Electrically safe

AFFF

Bravo fire

Found in Machinery rooms, fuel storage, Bottom of engine spaces

foam and sea water mixed to smoothe the fire

May produce Hydrogen sulfide gas

Hearing protection is required

Water Mist System

Alpha Fire

A system that sprays a fine mist of freshwater to put out fires.

It uses high-pressure pumps to turn water into tiny droplets (mist)

The mist flash cools the air and fire area

It reduces oxygen and cools the flames without soaking everything

safe for electronics

Battle Dress

• FRV Coveralls (flame-resistant)

• Pant cuffs tucked into boots or socks

• Life preserver worn or at station

• Flash hood and flash gloves (protect skin from burns)

• No metal, empty pockets

• Everything buttoned up

Firefighter’s Ensemble (FFE)

Helmet – protects head from heat and falling stuff

Outer suit – flame- and steam-resistant

Gloves and boots – for burns and sharp debris

Flash hood – covers neck and face (gold = firefighting)

Protects from heat, steam, sharp objects, and more while actively fighting a fire

SCBA

It lets you breathe clean air in toxic or smoke-filled spaces.

• Air tank (30 or 45 minutes of air)

• Face mask with voice amp

• Pressure regulator and harness

4500 PSI

EEBD

Your last-resort air supply for getting out of smoke or toxic areas — NOT for fighting fires.

10 minutes of air

Orange case, activates when you pull it out

Has mouthpiece and nose clip

Disposable – one-time use only

Two way to tell EEBD is ready for use

Gauge (green in color)

Orange

Not be expired

Anti Flash Gear

protects you from flash burns caused by sudden bursts of intense heat or flame, especially during fires or explosions on a ship.

-Flash Hood Kevlar blend

Flash Gloves 100% cotton

Electronic Box Fan

powered by electricity

Moves 3200 cubic feet of air /min

RAM 2000 Fan

powered by water

Moves 2000 cubic feet of air /min

Types of Ventilation

• General

• Supply

• Exhaust

• Natural
  

Collective Protection System (CPS) Levels

level 1: shelter envelope

level 2: min

level 3: max operational envelope

Active Desmoking

is the controlled removal of smoke and heat from spaces outside the fire compartment (but near it), to help fire teams see and breathe better.

based on the scene leader’s recommendation and RPL's approval.

Toxic

Atmosphere with harmful substances where exposure must stay below OSHA standards. Respirators required if above limits.

PEL (Permissible Exposure Limit):

Maximum amount of a substance personnel can be exposed to toxic gas without harm, set by OSHA.

LEL (Lower Explosive Limit)

Lowest concentration of a flammable gas that can ignite.

UEL( Upper Explosive Level)

Highest concentration of flammable gas that can ignite. Above this is too rich to burn.

IDLH (Immediately Dangerous to Life and Health): Any space where:

Flammable agents present above 10% of LEL

Oxygen greater then 22%

Oxygen less than 19.5%

Toxins high enough to prevent escape within 30 minutes without health effects

4 requirements of Fire Watch:

All sides of the hot work area must be watched

1. 30-40-50 Rule

   • Stay on watch 30 min after work or until cool to the touch.

   • No hot work within 40 feet of painting/chemical cleaning.

   • Move flammables 50 feet from the work site.

     Wear PPE (goggles, helmet, hearing protection, respirator if needed).

4 primary forms of radiation

Alpha

Beta

Gamma

neutron

Radiation Treatment

Time

Distance

Shielding

PPE

Gloves and Boot Covers

worn with JSLIST to protect hands and feel, used during MOPP 4 level

M50

Eye and respiratory protection against airborne contaminants

JSLIST

protective suit against CBRN threats (Chemical, Biological, Radiological, Nuclear).

MOPP Levels

0 Normal everyday operations

1 suspected CBR-N attack

2 possible CBR-N attack

3 probable CBR-N attack

4 imminent CBR-N attack

casualty Power Benefits

• Preservation of watertight integrity

• Simplicity of installation and operation

• Flexibility of application

• Interchangeability of parts and equipment

what are 4 loads you could power with casualty power

weapon system like CWIS

External Communications

DC Equipment

Lighting systems

Engineering Systems

Advantage of using bulkhead terminal and riser terminal

maintain watertight integrity of the ship

casualty power loads connect all horizontal cables _____ to _______

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