THE ART OF SHIPHANDLING: THE ART OF SHIPHANDLING


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


SHIPHANDLING FORCES CONTROLLABLE: SHIPHANDLING FORCES CONTROLLABLE PROPELLER RUDDER BOW THRUSTER ANCHORS LINES TUGS


PROPELLER FORCES : PROPELLER FORCES LONGITUDINAL THRUST TRANSVERSE THRUST (SIDE FORCE OR PADDLEWHEEL FORCE)


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


FOLLOWING WAKE EFFECT: FOLLOWING WAKE EFFECT Ship’s 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


INCLINATION EFFECT: 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


HELICAL DISCHARGE EFFECT: 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


SHALLOW WATER SUBMERGENCE EFFECT: 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


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


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


SINGLE PROPELLER VARIABLE PITCH: SINGLE PROPELLER VARIABLE PITCH TURNS CW AHEAD TURNS CCW ASTERN STERN WALKS SAME DIRECTION PROPELLER TURNS


Two Basic Types of Props: Two Basic Types of Props CONVENTIONAL blades don’t 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


TWIN PROPELLERS FIXED BLADE/VARIABLE PITCH (CONVENTIONAL): TWIN PROPELLERS FIXED BLADE/VARIABLE PITCH (CONVENTIONAL) SIDE FORCES CANCEL ENGINES OPPOSED ALL FORCES COMPLEMENT TO TWIST SHIP AHEAD ASTERN


CONTROLLABLE PITCH PROPELLERS: CONTROLLABLE PITCH PROPELLERS STERN WALKS TO STBD GOING ASTERN HARDER TO TWIST 225’ TURN INBOARD ALL THE TIME Single Screw CREEP


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


PIVOT POINT: PIVOT POINT HEAD WAY, STEADY COURSE & SPEED AHEAD BELL FROM DIW... LONG STEERING LEVER FROM PROPS/RUDDERS ASTERN BELL FROM DIW... NO EFFECTIVE STEERING LEVER UNTIL SOME STERN WAY


BOW THRUSTERS / PROPS: BOW THRUSTERS / PROPS 270 090 BOW THRUSTER 180’WLB/225’WLB BOW PROP 378’ WHEC


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


MEETING & OVERTAKING: MEETING & OVERTAKING


SHALLOW WATER EFFECTS SQUAT: 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 SHIP’S WAKE CAN BE AN INDICATOR


SQUAT: SQUAT 2.5 X DRAFT SLOW DOWN TO REDUCE EFFECTS


BANK SUCTION/CUSHION: BANK SUCTION/CUSHION


MOMENTUM & INERTIA: 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


MOMENTUM: 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


SHIPHANDLING FORCES UNCONTROLLABLE: SHIPHANDLING FORCES UNCONTROLLABLE WIND CURRENT SEAS


SEAMANSHIP EVOLUTIONS: SEAMANSHIP EVOLUTIONS ANCHORING LINES AND LINE HANDLING TOWING


ANCHORING: ANCHORING


ANCHORING SYSTEM SERVES AS:: ANCHORING SYSTEM SERVES AS: PORTABLE MOORING SYSTEM EMERGENCY BRAKE ADDITIONAL CONTROLLABLE FORCE (POOR MAN’S TUG)


GROUND TACKLE: GROUND TACKLE ANCHOR SHACKLES CHAIN/LINE WILDCAT/WINDLASS STOPPER


Slide31: ANCHOR CHAIN MARKINGS FIRST SHOT 1 SHOT = 15 FATHOMS = 90 FEET 2ND 3RD 4TH 15 FATHOMS 30 FATHOMS WIRE WRAPS WIRE WRAPS LAST SHOT RED - NEXT TO LAST SHOT YELLOW


RELATIVE HOLDING FACTORS: 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)


SCOPE OF CHAIN: 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


Slide34: WIND AND CURRENT BOW FOLLOWS FIGURE EIGHT PATTERN - -HORSING - - HEAVY WEATHER


Slide35: HAMMERLOCK MOOR OR WIND SHIFT WIND SHIFT ANCHOR AT SHORT SCOPE DRAGS AND ACTS AS A SNUBBER


PRECISION ANCHORING: PRECISION ANCHORING . WIND DROP BEARING 190T HEAD BEARING 284T SHIP’S HEADING 290T


PRECISION ANCHORAGE: 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


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


POOR MAN’S TUG: POOR MAN’S TUG PIVOT POINT SHORT OR LONG SCOPE OF CHAIN MAY BE USED


LINES AND LINE HANDLING: LINES AND LINE HANDLING


MOORING LINES: MOORING LINES 1 2 3 4 5 6 BOW LINE FWD BOW SPRING AFTER BOW SPRING FWD QTR SPRING AFT QTR SPRING STERN LINE DOCKING PILOTS MAY NOT USE LINE NUMBERS


MOORING LINES: MOORING LINES 1 2 3 4 BOW LINE BOW SPRING QTR SPRING STERN LINE Is Springing on Line 3 an option?


LINES: 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


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


DOUBLING LINES FOR HEAVY WEATHER: DOUBLING LINES FOR HEAVY WEATHER USE AN EYE AND A BIGHT ALL THREE PARTS MUST TAKE EQUAL STRAIN PIER BOLLARD TAKE A SINGLE ROUND TURN BEFORE PASSING BIGHT FAIRLEAD TO 2ND BIT & FIGURE 8


ORGANIZING FOR SUCCESS: 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


TOWINGA Command Perspective: 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


TOWINGTHE COMMAND PERSPECTIVE: TOWING THE COMMAND PERSPECTIVE SELECTING THE APPROACH ABORTING AN APPROACH SHIPHANDLING CONSIDERATIONS WEATHER SAFETY


PROVIDE A CATENARYFOR SAFETY'S SAKE: PROVIDE A CATENARY FOR SAFETY'S SAKE CATENARY IS A FUNCTION OF  SCOPE  SPEED  DIRECTION NORMALLY 2 TO 3 SHOTS OF CHAIN IS ADEQUATE