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THE ART OF SHIPHANDLING

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    1. THE ART OF SHIPHANDLING

    2. Objectives: To Review... Controllable Forces Indirectly Controllable/Semi-Controllable Forces Uncontrollable Forces Shiphandling Evolutions (towing, small boats, tugs) Coaching

    3. SHIPHANDLING FORCES CONTROLLABLE PROPELLER RUDDER BOW THRUSTER ANCHORS LINES TUGS

    4. PROPELLER FORCES

    5. PROPELLER SIDE FORCES FOLLOWING WAKE EFFECT INCLINATION EFFECT SHALLOW WATER SUBMERGENCE EFFECT HELICAL DISCHARGE EFFECT

    6. FOLLOWING WAKE EFFECT Ships hull drags water with it Upper half of prop works through water with greater velocity than bottom half Net effect: Stern walks to port when going ahead

    7. INCLINATION EFFECT Hull shape causes water to rush in and up under stern Increases relative velocity of water in front of stern Right half works through water with greater velocity than left half Net effect: stern moves to starboard

    8. HELICAL DISCHARGE EFFECT Water discharged off the left side of prop moves up and to starboard is trapped against the rudder by the hull Water discharged off right side of prop moves down and to port Water flow creates increased relative pitch on the upper half of prop Net effect: stern moves to starboard

    9. SHALLOW WATER SUBMERGENCE EFFECT Top half of prop is closer to surface than lower half Water is less dense near surface (more air churned into it) Lower half of prop exerts more force as result of working thru more dense water Net effect: stern moves to starboard

    10. Side Forces on Stern (Going Ahead) Following Wake Inclination Shallow Water Sub Effect Helical Discharge Total

    11. Side Forces on Stern (Going Astern) Following Wake none Inclination Shallow Water Sub Effect Helical Discharge Total

    12. SINGLE PROPELLER VARIABLE PITCH

    13. Two Basic Types of Props CONVENTIONAL blades dont move pitch is fixed or variable shaft changes direction prop is solid chunk of metal fewer malfunctions CPP blades change pitch pitch creates thrust fore and aft shaft turns one direction more complex and more malfunctions

    14. TWIN PROPELLERS FIXED BLADE/VARIABLE PITCH (CONVENTIONAL)

    15. CONTROLLABLE PITCH PROPELLERS

    16. STERN ISSUES PROPELLER FORCES RUDDER PLACEMENT COORDINATING RUDDER & ENGINES IMPLICATIONS OF ALL STOP PUMP TO THE RUDDER (KICK AHEAD)

    17. PIVOT POINT

    18. BOW THRUSTERS / PROPS

    19. SHIPHANDLING FORCES SEMI-CONTROLLABLE PASSING SHIP EFFECTS OVERTAKING MEETING SHALLOW WATER EFFECTS SQUAT BANK SUCTION / CUSHION INCREASED TACTICAL DIAMETER MOMENTUM/INERTIA

    20. MEETING & OVERTAKING

    21. SHALLOW WATER EFFECTS SQUAT PROPORTIONAL TO: SPEED DISPLACEMENT DEPTH & BREADTH OF CHANNEL CAN CAUSE SHIP TO STRIKE BOTTOM CAUSES WET WELLS TO INCREASE DEPTH UNEXPECTEDLY AND OUT OF CONTROL REDUCED RUDDER EFFECTIVENESS INCREASE IN TORQUE / LESS SPEED SHIPS WAKE CAN BE AN INDICATOR

    22. SQUAT

    23. BANK SUCTION/CUSHION

    24. MOMENTUM & INERTIA MOMENTUM: Generally, we consider momentum as the motion of a ship at the time we no longer want it, especially when we have taken action to obtain the opposite effect. ... Momentum is the quality of motion measured by the product of mass & velocity. INERTIA: Inertia is the quality of motion that causes a ship to resist a change in motion. A force exerted on a ship will result in motion after inertia has been overcome. Hoover - Behavior and Handling of Ships

    25. MOMENTUM MASS X VELOCITY 82 WPB 76 TONS X 5 KTS = 5 TON MAC TRUCK TRAVELING 76 MPH 378 WHEC 3100 TONS X 1 KT = 5 TON MAC TRUCK TRAVELING 620 MPH

    26. SHIPHANDLING FORCES UNCONTROLLABLE WIND CURRENT SEAS

    27. SEAMANSHIP EVOLUTIONS

    28. ANCHORING

    29. ANCHORING SYSTEM SERVES AS: PORTABLE MOORING SYSTEM EMERGENCY BRAKE ADDITIONAL CONTROLLABLE FORCE (POOR MANS TUG)

    30. GROUND TACKLE ANCHOR SHACKLES CHAIN/LINE WILDCAT/WINDLASS STOPPER

    32. RELATIVE HOLDING FACTORS FIRM SAND 1.00 STIFF-DENSE CLAY 1.50 (PLASTIC) STICKY CLAY 0.66 (MEDIUM DENSITY) SOFT MUD 0.33 LOOSE COARSE SAND 0.33 GRAVEL 0.33 HARD BOTTOM 0.00 (ROCK, SHALE, BOULDERS)

    33. SCOPE OF CHAIN FIVE TO SEVEN TIMES DEPTH OF WATER IS A GOOD RULE OF THUMB IN HEAVY WEATHER, MORE CHAIN MAY NOT BE THE ANSWER ALTERNATIVES STEAMING TO THE ANCHOR HAMMERLOCK GET UNDERWAY

    36. PRECISION ANCHORING

    37. PRECISION ANCHORAGE FINAL APPROACH MANY TYPES ADJUST FOR SET AND DRIFT LET GO WHILE BACKING DOWN CORPORATE MEMORY WILL PRODUCE THE BEST APPROACH NAV FIX AS SOON AS ANCHOR IS LET GO ALWAYS HAVE AN ALTERNATE PLAN CHECK ANCHORAGE AREA FOR NAV HAZARDS AND OTHER SHIPPING

    38. EMERGENCY BRAKE KNOW WHERE YOUR STDBY ANCHORAGES ARE DURING TRANSIT IN RESTRICTED WATERS IF YOU HAVE TWO ANCHORS MAKE BOTH READY FOR LETTING GO

    39. POOR MANS TUG

    40. LINES AND LINE HANDLING

    41. MOORING LINES

    42. MOORING LINES

    43. LINES WHO GIVES ORDERS TO LINE HANDLERS? CO XO OOD CONNING OFFICER REFERENCE - NSTM CH 582 MOORING SYSTEM DESIGNED FOR 50 KNOT BEAM WINDS & 3 KNOT CURRENT

    44. STANDARD COMMANDS SLACK EASE TAKE TO POWER / CAPSTAN HEAVE AROUND SURGE CHECK HOLD - WHO GIVES THIS ORDER?

    45. DOUBLING LINES FOR HEAVY WEATHER

    46. ORGANIZING FOR SUCCESS WHY LINES PART WET NYLON LOSES 15% STRENGTH LACK OF CHAFFING GEAR LINES STORED WET ON REELS EXCEEDING WORKING LOAD OF LINE PERSONNEL INJURY SNAP BACK UNCONTROLLED SURGE IMPROPER HANDLING

    47. TOWING A Command Perspective TOWING "...Towing another vessel at sea is a maneuver that has been made difficult by too much planning and discussion..." CRENSHAW

    48. TOWING THE COMMAND PERSPECTIVE SELECTING THE APPROACH ABORTING AN APPROACH SHIPHANDLING CONSIDERATIONS WEATHER SAFETY

    49. PROVIDE A CATENARY FOR SAFETY'S SAKE CATENARY IS A FUNCTION OF ? SCOPE ? SPEED ? DIRECTION NORMALLY 2 TO 3 SHOTS OF CHAIN IS ADEQUATE