Loose Water

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Lesson 4.3
Loose Water
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SAILORS CREED
I am a United States Sailor. I will support
and defend the Constitution of the United States
of America and I Will obey the orders of those
appointed over me. I represent the fighting
spirit of the Navy and those who have gone
before me to defend freedom and democracy around
the world. I proudly serve my countrys Navy
combat team with Honor, Courage, and
Commitment I am committed to excellence and fair
treatment of all.
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CREED OF THE UNITED STATES COAST GUARD
I am proud to be a Unites States Coast
Guardsman. I revere that long line of expert
seamen who by their devotion to duty and
sacrifice of self have made it possible for me to
be a member of a service honored and respected,
in peace and in war, throughout the world. I
never, by work or deed, will bring reproach upon
the fair name of my service, nor permit others to
do so unchallenged. I will cheerfully and
willingly obey all lawful orders. I will always
be on time to relieve, and shall endeavor to do
more, rather than less, than my share. I will
always be at my station, alert and attending to
my duties. I shall, so far as I am able, bring
to my seniors solutions, not problems. I shall
live joyously, but always with due regard for the
rights and privileges of others. I shall
endeavor to be a model citizen in the community
in which I live. I shall sell life dearly to an
enemy of my country, but give it freely to rescue
those in peril. With Gods help, I shall
endeavor to be one of His noblest Works
I am proud to be a Unites States Coast
Guardsman. I revere that long line of expert
seamen who by their devotion to duty and
sacrifice of self have made it possible for me to
be a member of a service honored and respected,
in peace and in war, throughout the world. I
never, by work or deed, will bring reproach upon
the fair name of my service, nor permit others to
do so unchallenged. I will cheerfully and
willingly obey all lawful orders. I will always
be on time to relieve, and shall endeavor to do
more, rather than less, than my share. I will
always be at my station, alert and attending to
my duties. I shall, so far as I am able, bring
to my seniors solutions, not problems. I shall
live joyously, but always with due regard for the
rights and privileges of others. I shall
endeavor to be a model citizen in the community
in which I live. I shall sell life dearly to an
enemy of my country, but give it freely to rescue
those in peril. With Gods help, I shall
endeavor to be one of His noblest Works A
UNITES STATES COAST GUARDSMAN.
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We must walk before we can run!

• Lets review HW problems 1, 2, 3 and Lesson 4.2

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References

• NSTM 079 Volume 1
• NTTP 3-20.31
• Damage Control Book, section II (a)

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ENABLING OBJECTIVES

• Explain why FSE impairs stability.
• Compute FSE.
• List methods to reduce FSE.
• Explain why FCE impairs stability.
• Compute FCE.
• Describe pocketing, surface permeability, size of
  hole, and venting on FSE and FCE.
• Correct stability curve for FSE and FCE.

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CLASS TOPICS
1. Free Surface Effect2. Example3. Free
Communication Effect4. Example
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FREE SURFACE EFFECT
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FREE SURFACE EFFECT
GZ2 GZ3
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(No Transcript)
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GG3
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FREE SURFACE EFFECT
B BREADTH OF COMPTL LENGTH OF COMPTWf
SHIP'S DISPLACEMENT
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POCKETING - SHALLOW
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POCKETING - ALMOST FULL
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POCKETING
(NO POCKETING EXISTS)
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SURFACE PERMEABILITY
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SLUICE VALVES - Closed
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(No Transcript)
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FREE SURFACE EFFECT

• Independent of the depth of the liquid
• Greater w/ increased length and width of the
  compartment
• Increases as draft decreases (de-ballasting)
• Can be reduced by pocketing

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CLASS TOPICS
1. Free Surface Effect2. Example3. Free
Communication4. Example
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Wo 3500 LT
FSE?
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FSE B3 x L
12 x 35 FT3/LT x WF
.45 FT
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CLASS TOPICS
1. Free Surface Effect2. Example3. Free
Communication4. Example
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FREE COMMUNICATION EFFECT
FREE COMMUNICATION EFFECT
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FREE COMMUNICATION EFFECT
FREE COMMUNICATION EFFECT
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FREE COMMUNICATION EFFECT
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(No Transcript)
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FREE COMMUNICATION EFFECT(All 3 must exist)

• COMPARTMENT OPEN TO THE SEA
• COMPARTMENT PARTIALLY FLOODED
• COMPARTMENT OFF-CENTERLINEOR UNEVEN ABOUT
  THECENTERLINE

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(No Transcript)
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• COMPARTMENT OPEN TO SEA
• COMPARTMENT PARTIALLY FLOODED

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Free Communication Effect

• Size of the hole will reduce FCE. (Formula
  assumes entire skin of ship is open to sea)
• Venting will reduce FCE. (More air transfer
  more water communicating into the compartment.)
• Increases as draft decreases (de-ballasting)
• Can be reduced by pocketing

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CLASS TOPICS
1. Free Surface Effect2. Example3. Free
Communication4. Example
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Wo 2880 LT L 28 FT Depth 4 ft B 29 FT
40 ft
20 ft
y
20 ft 14.5 ft
28 FT
y 5.5 ft
14.5 ft
29 FT
wFLOODING 28 FT 29 FT 4 FT
35 FT3/LT
wFLOODING 92.8 LT
WF W0 wFLOODING 2972.8 LT
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B x L x (y)2
35 FT3/LT x WF
FCE
.24 FT
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Quiz

• Why does FSE impair stability?
• ANS Horizontal weight shifts off centerline
  cause a virtual rise in G, reducing GM.
• Factors that reduce FSE?
• ANS Compartment size, pocketing, baffle plates,
  surface permeability, sluice valves, venting.
• Which variable is the determining factor in the
  FCE equation?
• ANS Y the distance from the ships centerline
  to the compartments center it is squared.

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Quiz

• What three factors must be present for FCE to
  exist?
• ANS 1) Off centerline or Uneven about
  centerline. 2) Open to the sea 3) Partially
  flooded.

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Instructor will now

• Assign Practice Problems for lesson 4.3
  (Stability Problems 4, 7. Try problems 8, 11)
• Read Student Guide!!
• Homework 2 Due end of class TODAY!