3. Shiphandling Theory: Motion
• Various forces acting on the ship create
movement.
• Newton’s Laws of Motion
1. Unless acted upon by an outside force:
• An object in motion tends to stay in motion.
• An object at rest tends to stay at rest.
2. The resulting motion of an object is the
sum of all forces acting on it.
3. Every action has an equal and opposite
reaction.
6. Controllable Forces
Propellers
• Provides the most important source of
force on a ship.
• (Usually) makes ship go forward.
• Most ships have 2 propellers.
• Aircraft carriers / Patrol Craft have 4.
• Frigates have 1.
7. Controllable Forces
Propellers
• Forces resulting from the use of the
propellers:
• Forward (or reverse) thrust
• Side Force
8. Controllable Forces
Propeller Thrust
• A result of the propeller spinning on its
shaft.
• Caused by a pressure differential
between the opposite sides of the
propeller blade.
9. Controllable Forces
Propeller Thrust
Resulting Thrust
Low Pressure
Water Flow
Propeller
Blade
High Pressure
Rotation of
propeller blade
10. Controllable Forces
Controlling Propeller Thrust
• Depends on type of propellers
• Fixed Pitch Propellers
• Controllable Pitch Propellers
11. Controllable Forces
Controllable Pitch Propellers
• Found on all gas turbine ships and
some diesel amphibs
• 0 - 12 kts
• shaft rotates at 55 RPM
• thrust (speed) controlled by changing the
pitch of the propeller blade
12. Controllable Forces
Controllable Pitch Propellers
• >12 kts
• thrust controlled by changing the speed
(RPM) of the shaft.
• The shaft always spins in same
direction whether going forward or
backward.
13. Controllable Forces
Fixed Pitch Propellers
• Found on steam ships (carriers, subs,
amphibs)
• Cannot change pitch of propeller
• Thrust (speed) controlled by changing
speed of the shaft
• To go backwards, must stop shaft and
spin the shaft in the opposite direction.
14. Controllable Forces
Side Force
• Causes stern to move sideways in the
direction of propeller rotation.
Propeller
15. Controllable Forces
Side Force
Side Side
Force Force
Single Screw Astern Ahead
Going Ahead Twin Screw
Side
Force
Bottom
16. Controllable Forces
Screw Current
• Consists of two parts
• Suction Current - going into the propeller
• Discharge Current (Prop Wash)- comes out
of the propeller
Suction Current Discharge Current
Acts on Rudder
Propeller
17. Controllable Forces
Rudders
• Used to control ship’s heading by
moving the stern.
• To have an effect, must have a flow of
water across the rudder.
• Normally this flow of water is the
discharge current of the screw.
18. Controllable Forces
Rudder
Water
• Acts a wing Flow
High Pressure Area
Low High Pressure Area
Low
Rudder Rudder
Force Force
19. Controllable Forces
Propellers / Rudders
• Primary means of controlling the stern
Thrust
Side Force
Rudder Force
20. Controllable Forces
Pivot Point
• Imaginary point on the ship’s centerline
about which the ship pivots
Pivot Point
Thrust
Side Force
Rudder Force
22. Controllable Forces
Pivot Point
• Usually located 1/3 the length of the
ship from the bow. (Just behind the
bridge.)
• Pivot point is not fixed
23. Controllable Forces
Forces which affect
location of the Pivot Point
• Headway or Sternway
• Ship’s Speed
• Anchors
• Mooring Lines
• Tugs
24. Uncontrollable Forces
Wind
• Acts on the sail area of the ship
• Exposed superstructure
• Hull structure
• Ships tend to back into the wind
• 30kts of wind = 1kts of current
Current
• Acts on the underwater part of the ship.
• Creates set and drift.
25. Uncontrollable Forces
Depth of Water
• Squat - Occurs a high speeds
• bow of a ship rides up onto the bow wave
• stern of a ship tends to sink
• Shallow water effects.
28. Shiphandling: Terms
Turning Circle: The path described by a ship’s
pivot point as it executes a 360° turn.
Tactical Diameter (180°)
Final Diameter (360°)
30. Shiphandling: Terms
Advance and Transfer
• Advance
• Distance gained toward the direction of the
original course after the rudder is put over.
• Transfer
• Distance gained perpendicular to the
original course after the rudder is put over.
34. Shiphandling: Terms
• Headway
• moving forward thru the water
• Sternway
• moving backwards thru the water
• Bare Steerageway
• the minimum speed a ship can proceed
and still maintain course using the rudders
35. Shiphandling: Ground Tackle, Mooring Lines
Mooring Lines
6 5 4 3 2 1
After Quarter Forward Quarter After Bow Forward Bow
Spring Spring Spring Spring
Stern Spring Lines Bow
Line Line
36. Shiphandling: Ground Tackle, Mooring Lines
Mooring Lines
• Lines
• 1-6
• Lines 1 and 6 are thicker than others
• Mooring procedure
• fake out lines
• safety brief
• heaving lines
38. Shiphandling: Ground Tackle, Mooring Lines
Sequence:
• Stand by lines • Slack
• Take in the slack • Ease
• Take a strain • Take to the capstain
Commands:
• Heave around • Double up
• Avast heaving • Single up
• Hold • Take in
• Check
44. Shiphandling: Ground Tackle, Anchors
Anchors
• Most common anchor
• Standard Navy Stockless
• Most ships have two
• Deep water anchor - 14 shots of chain
• Normal anchor - 12 shots of chain
• Shot - 15 fathoms (90 feet)
47. Shiphandling: Ground Tackle, Anchoring
Anchoring
• Approach
• Standby
• Let Go the Anchor
• Reports
• P. 194 (Seamanship)
• Anchor watch
48. Shiphandling: Getting Underway, Mooring
• Concerns:
• Watch the stern/pier
• Watch for other
ships
• Winds / Currents
• Set on or set off pier?
• Using mooring lines
and tugs as
necessary to control
bow / stern
49. Shiphandling: Getting Underway, Mooring
The Ideal Approach
• Approach on a converging course 10 to
20 degrees from the heading of our
berth.
• When parallel, swing the rudder
opposite the pier, and stop the ship.
• Stop headway by backing outboard
engine.
• “Walk” the ship in by tensioning line 1;
“twist” the stern with the engines.
50. Shiphandling: Getting Underway, Mooring
Less than Ideal Conditions
• Being Set On:
• Stop parallel to the pier, with 1/2 a beam
width of open water between you and the
pier.
• Allow the current to push you onto the
pier.
• Being Set Off:
• Make your approach at a larger angle to
the pier at a considerable speed.
• Be careful not to part your bow line.
51. Shiphandling: Getting Underway, Mooring
• Easier than anchoring
• Buoy held securely by several anchors.
• Chance of dragging reduced.
• Two methods
Requires:
• Ordinary
MWB / RHIB with boat crew
• Trolley Your ship
A buoy
52. Shiphandling: Standard Commands
Conning Officer
• Drives the ship’s heading and speed
through standard commands (orders) to
the helm and leehelm
• Helm - controls the rudder
• Leehelm - controls the propellers
53. Shiphandling: Standard Commands
Basic Format
Conning Officer Helm / Leehelm
Command
Verbatim Repeat back
(Carries out command)
Report
Acknowledges Report
57. Shiphandling: Standard Commands
• Direction: Either left, right or “Rudder
amidships”
• Amount: Expressed as a number of
degrees of rudder (10, 15, etc.), or one
of the following: (nominal values given)
• Standard: 15°
• Full: 30°
• Hard: 35°(maximum rudder angle)
• Course: >10 degree change
58. Shiphandling: Standard Commands
COMMANDS TO THE HELM
Format Example
-Direction "Right. . ."
"Left. . ."
-Amount ". . standard rudder. . ."
". . .ten degrees rudder. . ."
-Course ". . .steady course two zero zero."
". . .steady on course one one five."
59. Shiphandling: Standard Commands
COMMANDS TO THE HELM
• Exception: Course changes of 10° or
less:
• For small course changes, a specific rudder
angle is not given. This allows the Helm to
use up to 10° of rudder to make the course
change.
• The standard command is:
• Direction: “Come right/left”
• Course to steer: “Steer course ___”
60. Shiphandling: Standard Commands
OTHER HELM COMMANDS
• Desired action: Increase or decrease
rudder angle from a previously ordered
angle
• Command:
• “Increase your rudder to ________”
• “Ease your rudder to _______”
• Note: Anytime a new rudder angle is
ordered, a steering/steady course must
be repeated if it is desired.
61. Shiphandling: Standard Commands
OTHER HELM COMMANDS
• Desired action: Change rudder angle to
an equal amount of rudder in the
opposite direction
• Command: “Shift your rudder”
• Note: Again, if desired, course to steer
must be repeated.
62. Shiphandling: Standard Commands
OTHER HELM COMMANDS
• Desired action: Steady the ship on the
current heading
• Command: “Steady as she goes”
• When given, the Helm immediately
determines ship’s head at the instant of the
command, and steadies the ship on that
course.
• This should normally be given only with the
rudder at or near amidships.
63. Shiphandling: Standard Commands
OTHER HELM COMMANDS
• Desired action:
Determine current • Desired action:
ship’s heading Warn the Helm
• Command: “Mark to steer more
your head” exactly
• When given, the Helm • Command:
immediately “Mind your
determines ship’s
helm”
head at the instant of
the command,and
reports it to the Conn.
64. Shiphandling: Standard Commands
HELM REPLY
• Whenever an order to the Helm is
given, the Helm repeats the order back
to the Conn verbatim.
• This assures the conning officer that the
order was heard and understood
correctly.
65. Shiphandling: Standard Commands
HELM REPLY
• Examples:
• The Conn orders: “Right standard rudder,
steady course 260.”
• The Helm replies: “Right standard rudder,
steady course 260, aye.”
66. Shiphandling: Standard Commands
HELM REPLY
• Order: “Mark your head”
• Reply: “Mark my head, aye. 283.”
• Order: “Mind your helm”
• Reply: “Mind my helm, aye.”
67. Shiphandling: Standard Commands
HELM REPLY
• If the helm does not understand an
order from the Conn, the helm will
reply:
“Orders to the helm”
• The Conn should immediately check
his/her order and restate it clearly to
the Helm.
68. Shiphandling: Standard Commands
REPORT & ACKNOWLEDGEMENT
• Once a desired action is complete, the
Helm reports it to the Conn.
• The Conn acknowledges all reports with
“Very well’
• If the Conn does not acknowledge a
report, the Helm should repeat the
report until acknowledged.
69. Shiphandling: Standard Commands
EXAMPLES
Order: “Right standard rudder, steady
course 298.”
Reply: “Right standard rudder, steady
course 298, aye.”
Report: “Sir, my rudder is right standard,
coming to new course 298.”
Report: “Sir, steady on course 298,
checking 309.”
70. Shiphandling: Standard Commands
EXAMPLES
Order: “Come left, steer course 345.”
Reply: “Come left, steer course 345, aye.”
Report: “Sir, my rudder is left 5°, coming
to new course 345.”
Report: “Sir, steady on course 345,
checking 352.”
71. Shiphandling: Standard Commands
EXAMPLES
Order: “Right full rudder.”
Reply: “Right full rudder, aye.”
Report: “Sir, my rudder is right full, no
new course given.”
Report: “Passing 230 to the right.”
Order: “Belay your passing heads.”
Reply: “Belay my passing heads, aye.”
72. Shiphandling: Standard Commands
EXAMPLES
Order: “Ease your rudder to right 15°.”
Reply: “Ease my rudder to right 15°,
aye.”
Report: “Ma’am, my rudder is right 15°,
no new course given.”
Order: “Steady course 143.”
Reply: “Steady course 143, aye.”
Report: “Ma’am, my rudder is right 15°,
coming to new course 143.”
73. Shiphandling: Standard Commands
EXAMPLES
Order: “Hard left rudder.”
Reply: “Hard left rudder, aye.”
Report: “Sir, my rudder is left 35°, no
new course given.”
Order: “Shift your rudder.”
Reply: “Shift my rudder, aye.”
Report: “Sir, my rudder is right 35°, no
new course given.”
74. Shiphandling: Standard Commands
EXAMPLES
Order: “Right full rudder.”
Reply: “Right full rudder, aye.”
Report: “Sir, my rudder is right 30°, no new course
given.”
Order: “Rudder amidships”
Reply: “Rudder amidships, aye.”
Report: “Sir, my rudder is amidships, no new
course given.”
Order: “Steady as you go.”
Reply: “Steady as you go, aye. Course 098.”
Report: “Steady on course 098, checking 107.”
75. Shiphandling: Standard Commands
ENGINE ORDERS
• For fixed pitch propellers, ship speed is
dependent on shaft rpm only.
• For controllable pitch propellers, ship
speed is dependent on shaft rpm and,
below about 12 knots, propeller blade
pitch.
• For gas turbines, the shaft is always
spinning when the engine is on line. “All
engines stop” is achieved by a blade pitch
of 0°.
76. Shiphandling: Standard Commands
ENGINE ORDERS
• Prescribed standard speeds are
predetermined ship’s speeds:
• “Standard speed” - normally 15 knots
• “1/3” - one third of standard speed
• “2/3” - two thirds of standard speed
• “Full” - speed higher than standard speed
• “Flank” - maximum speed
77. Shiphandling: Standard Commands
ENGINE ORDERS
Typical Prescribed
Standard Speeds
• Ahead
Bell Speed • Astern
1/3 5 Bell Speed
2/3 10 1/3 5
Std 15 2/3 10
Full 20 Full Max
Flank Max speed
speed
78. Shiphandling: Standard Commands
ENGINE ORDERS
Format Example
-Engines ”All engines. . ."
-Direction ". . ahead full. . ."
". . .back 2/3. . ."
-Speed ". . indicate 108 revolutions for 15
knots."
". . .indicate 072 revolutions and
20% pitch for 3 knots."
79. Shiphandling: Standard Commands
ENGINE ORDERS
• Engines: Port, starboard, or all engines.
Unnecessary for single screw ships.
• Direction: Ahead, back or stop, and
nearest standard speed (except for
stop)
80. Shiphandling: Standard Commands
ENGINE ORDERS
• Speed:
“..indicate ____ turns for __ knots.”, OR
“..indicate turns for __ knots.”
• For controllable pitch propellers below 12
knots:
“..indicate ___ turns and __% pitch for __
knots.”
OR, “..indicate pitch and turns for __ knots.”
-Note: If proceeding at a prescribed standard
speed, none of this is required.
81. Shiphandling: Standard Commands
MANEUVERING COMBINATIONS
• In maneuvering situations, where
frequent engine changes are expected,
the Conning Officer may set
“maneuvering combinations”.
• When set, the Lee Helm answers all
bells at the prescribed standard speed
increment.
• On ships with an EOT, this is indicated
by an RPM setting of “999”.
82. Shiphandling: Standard Commands
REPLIES AND REPORTS
• Reply: Verbatim repeatback is required.
• Reports: Lee Helm reports when action
is completed.
• Note: Every report must include the
complete status of all engines, even if only
one was changed.
• Acknowledgement: Conn will
acknowledge all reports with “Very well”
83. Shiphandling: Standard Commands
EXAMPLES
Order: “All engines ahead standard,
indicate 115 revolutions for 16 knots.”
Reply: “All engines ahead standard,
indicate 115 revolutions for 16 knots,
aye.”
Report: “Ma’am, engine room answers all
engines ahead standard, indicating 115
revolutions for 16 knots.”
84. Shiphandling: Standard Commands
EXAMPLES
(Continued from previous slide)
Order: “Indicate 122 revolutions for 17
knots.”
Reply: “Indicate 122 revolutions for 17
knots, aye.”
Report: “Ma’am, engine room answers all
engines ahead standard, indicating 122
revolutions for 17 knots.”
85. Shiphandling: Standard Commands
EXAMPLES
Order: “Port engine ahead 1/3, starboard
engine back 2/3.”
Reply: “Port engine ahead 1/3, starboard
engine back 2/3, aye.”
Report: “Ma’am, engine room answers
port engine ahead 1/3, starboard
engine back 2/3.”
86. Shiphandling: Standard Commands
EXAMPLES
(Continued from previous slide)
Order: “Starboard engine stop.”
Reply: “Starboard engine stop, aye.”
Report: “Ma’am, engine room answers
starboard engine stop, port engine
ahead 1/3.”
87. Shiphandling: Standard Commands
EXAMPLES
Order: “All engines ahead 1/3, indicate
pitch and turns for 5 knots.”
Reply: “All engines ahead 1/3, indicate
pitch and turns for 5 knots, aye.”
Report: “Sir, engine room answers all
engines ahead 1/3, indicating 075 turns
and 34% pitch for 5 knots.”
89. Shiphandling: Single Screw Ships
Ship Astern
Propeller Astern
Rudder Amidships
Ship follows the rudder:
Ship will tend into the wind:
Ship will tend to port very easily
Ship does not tend to starboard easily
96. Shiphandling: Tug Tie-Ups
Single Headline
• Simplest Tie-up
• Best to allow tug to
push or pull only
• Not good if complex
tug maneuvers
required.
97. Shiphandling: Tug Tie-Ups
Double Headline
• Not as simple
• Allows tug to push
or pull and complex
tug maneuvers
98. Shiphandling: Tug Tie-Ups
Power
• Most versatile tie-up
• Good for general
purpose use
• Holds tug securely
to ship.
99. Shiphandling: Man Overboard Recovery
Recovery Maneuvers
• Williamson Turn
• Anderson Turn
• Race Track
• Y-Turn
100. Shiphandling: Man Overboard Recovery
Easiest Method?
• Daylight: Anderson
• Night: Williamson
• Subs: Y backing
• Carriers: Racetrack
• Boat / Helo?
101. Shiphandling: Man Overboard Recovery
Recovery considerations
• Helicopter
• average time to ready for takeoff is 10-12
mins
• Small boat
• average time to launch 6-8 mins
• Ship
• fastest method
102. Shiphandling: Man Overboard Recovery
Small Boat Considerations
• PPE for boat crews
• manning
• coxswain
• bow hook
• corpsman
• boat officer
• signalman
• SAR swimmer
• 3-5 knots; no sternway
103. Shiphandling: Man Overboard Recovery
Initial Actions
• Applicable for all recoveries:
• Full rudder to side of ship where person fell
overboard.
• Full speed.
• Throw smoke float, life ring
• Keep in sight
• Pass the word
• 6 short blasts
• Mark on chart
• Man Boat Deck
• Notify other ships, Helos
• Receive muster report
104. Shiphandling: Man Overboard Recovery
Follow-on actions
• Notify Captain, TAO and Flag
• Hoist Oscar flag (day); turn on red-
over-red pulsating (night)
• Notify other ships in company
• Gather Vitals from CIC
• Time in water
• Water temp and stay time
• Bearing and range to man
105. Shiphandling: Man Overboard Recovery
Man Overboard
Kicks Stern Away Starboard Side
Right Full Rudder
All Engines Ahead Full
