® seamanship chapter 8 marlinespike. ® slide 2 of 35usps® seamanship learning objectives ...
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Seamanship
Chapter 8
Marlinespike
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Slide 2 of 35USPS® Seamanship
Learning Objectives
Marlinespike seamanship encompasses the art and science of working with rope and line.
With the completion of this material the recreational boater should understand knots, bends, hitches and splices. It also includes the selection and use of line and the proper care of line.
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Definitions
Marlinespike• A pointed tool used in
splicing to open the strands of rope or cable.
Marlinespike Seamanship• General knowledge of
knots, bends, hitches, splices, and care of rope.
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Definitions
Rope• Cordage made of natural or synthetic
fibers, also can be made of steel wire.
Line• Name given rope aboard a boat. Each
line is given a specific name, such as: anchor line, halyard, main sheet, spring line or dock line. A few are still called rope, as in bell rope.
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Definitions
Working Part• Section of line used in forming a
knot
Standing Part• The part of a line that is made fast• The portion of the line not used in
forming a knot• The part of the line around which
the knot may be tied• In use, normally under strain.
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Definitions
Bitter End• Inboard end of a line, chain or cable• The end made fast to the boat
Working End• Attached to an anchor or cleat, etc.
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Bight Standing part Free end Turn Round turn
BightRound Turn
Turn
Free End
Standing Part
DefinitionsDefinitions
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Braided• Diamond braid over a core• Easy on hands• High strength• Slippery
Common laid rope• 3 strands twisted• Tends to kink• Stretches more• Hard on hands• Inexpensive
Choosing A Line
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Rope Strengths
Safe load is 20% of breaking strength Dacron® is the trade name for
polyesterfiber
Breaking Strength of RopeDiameter Manila Nylon Polyesterfiber Polypropylene
Inches Pounds Pounds Pounds Pounds3/8 1350 4000 3800 21501/2 2650 7100 6500 39005/8 4400 11000 10400 60003/4 5400 15000 14400 80001 9000 27000 24000 14400
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Effect of Knots
Strength of Knots and SplicesPrecentage of Original Rope Strength
Figure Eight 45% Overhand Knot 60%Square Knot 45% Half Hitch 65%Sheet Bend 55% Anchor Bend 75%Bowline 60% Short Splice 85%Clove Hitch 60% Eye Splice 90%
Lines are weakened by:• Knots• Splices
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Nylon• Strongest and most elastic• Elasticity absorbs shock• Good for anchoring and
mooring Polyester (Dacron®)
• Minimum of stretch• Good for running rigging
aboard sailboats Polypropylene
• Not as strong as nylon or dacron
• Subject to abrasion, chafe & deterioration from sunlight
• Good point - it floats
Material
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Chafing Gear
Protects line from chafing on chocks and hawse Pipes
Commercially available
Home made using old Water hose
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Start by lacing line over your hand
Form generous loops until line is coiled
Make two turns around coil
Feed working end through coil
1 2 3 4
Coiling a Line
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Tosser• Splits line coil in
half• Tosses line
underhand to the receivers side
Receiver• Holds an arm out
as a target. • Lets line fall over
an out-stretched arm
Heaving a Line
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Basic Knots or Bends
A good knot is easy to tie and easy to untie
Knots or bends weaken line by as much as 50%
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Take a 3/4 turn under the horn away from the load
Lead the free end over and under the opposite horn
Lead the free end over and under the other horn
Tuck the free end under the last turn
Cleat Hitch
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Start by forming an underhand loop
Lead the free end under the standing part
Feed the free end through the loop formed by the underhand loop
Pull the knot tight
Figure Eight
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Good Uses• Furling sails
• Reefing sails
• Lashing small stuff
Should not be used for a varying load
Reef or Square Knot
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Use to join two lines of different diameter• Form a bight in one
line• Lead the free end of
the second line through the bight and around the Standing part of the first line
• Tuck the free end of the second line under the standing part of line two
• Snug up the bend
Sheet Bend
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Form an overhand loop
Feed the free end through the loop
Feed the free end around the standing part
Feed the free end into the loop
Bowline
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Form an underhand loop around the post Lead the free end above the turn Now form another underhand loop around the post Use a half hitch as a “locking knot” to keep the
clove hitch from slipping
Clove Hitch
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Make a round turn around the post or a ring
Lead the free end around the standing part forming an underhand loop
Repeat the last step
Round Turn & Two Half Hitches
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Take a round turn around the anchor ring or a post
Make a turn around the standing part
Feed the free end through the center of the round turn
Make a round turn around the standing part and snug up the bend
Anchor Bend
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Make a round turn around the standing part of a second line or post
Lead the line above the round turn Make a turn around the line
Rolling Hitch
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Whipping• Used to keep the
end of a line from unraveling
Methods• With ‘small stuff’ or
twine• Taping• Liquid whip• Melting nylon line
ends
Common Whipping
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Caring for Lines
Overloading Avoid kinks & sharp
bends Avoid chemicals Protect against chafing Regular cleaning
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Stow carefully Coiling Flemishing
Caring for Lines
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Winch
Start by wrapping the line clockwise Pile the wraps up from the bottom
to the top Make more turns for a heaver load
The correct way to wrap a line around a
winch.
This will not jam.
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Winch
This is the incorrect way to lead a line to a winch.
This will jam.
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Blocks and Tackle
Block• A nautical name for a pulley
Sheave• Roller in a block over which a line
passes as it goes through the block
Tackle• Arrangement of line and blocks used
to provide increased mechanical advantage
Winch• Geared drum turned by a handle and
used to pull lines such as sheets and halyards
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Blocks and Tackles
1:1 2:1 3:1 4:1 5:1
A B C D E
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Making an Eye Splice
Step 2
AB C
bc
a
Step 1
A B C
abc
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Step 4
AB
C
bca
Making an Eye Splice
AB C
bc
a
Step 3
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Step 5
Making an Eye Splice
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Chapter 8