1. SHIPHANDLING – MANOEUVRING INFORMATION
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
1
• IMO REQUIRES SHIPS TO BE PROVIDED WITH A PILOT CARD, WHEELHOUSE POSTER AND MANOEUVRING BOOKLET.
• THE PILOT CARD CONTAINS DETAILS REGARDING THE CURRENT CONDITION OF THE VESSEL WITH REGARD TO THE
LOADING, PROPULSION AND MANOEUVRING EQUIPMENT AS WELL AS OTHER RELEVANT EQUIPMENT. NO SPECIAL
MANOEUVRING TRIALS ARE REQUIRED FOR PREPARATION OF THE PILOT CARD.
• THE WHEELHOUSE POSTER IS TO BE PERMANENTLY DISPLAYED ON THE BRIDGE. IT MUST CONTAIN GENERAL
PARTICULARS AND DETAILED INFORMATION DESCRIBING THE MANOEUVRING CHARACTERISTICS OF THE SHIP.
• TESTS ARE CARRIED OUT TO DEMONSTRATE COMPLIANCE WITH IMO MANOEUVRING PERFORMANCE
REQUIREMENT AND FOR PREPARING THE WHEELHOUSE POSTER. TESTS TO BE DONE IN CALM WEATHER.
• FOR TURNING CIRCLE :
• APPROACH SPEED NOT LESS THAN 90% OF 85% MCR. RUDDER HARD OVER BUT NOT REQUIRED TO BE
OVER 35 DEG.
• TURNS TO BOTH PORT AND STBD, IN SHALLOW [DEPTH/DRAFT RATIO 1.2] AND DEEP WATER [DEPTH/DRAFT
RATIO >4.0]. TURNS IN BOTH LOADED AND BALLAST CONDITION.
• IMO REQUIRES ADVANCE TO BE LESS THAN 4.5 SHIP LENGTHS AND TACTICAL DIAMETER LESS THAN 5 SHIP
LENGTHS.
• TESTS ARE ALSO CARRIED OUT FOR STOPPING DISTANCE, EMERGENCY MANOEUVRES, AND COURSE KEEPING ABILITY.
• THE MANOEUVRING BOOKLET MUST CONTAIN COMPREHENSIVE DETAIL OF THE SHIPS MANOEUVRING
CHARACTERISTICS AND INCLUDES ALL INFORMATION FROM THE WHEELHOUSE POSTER. MOST INFORMATION CAN
BE ESTIMATED BUT SOME REQUIRE TRIALS TO BE CONDUCTED. INFORMATION MAY BE SUPPLEMENTED IN THE
COURSE OF THE SHIPS LIFE.
2. SHIPHANDLING – THE PILOT CARD
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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3. SHIPHANDLING – CONTENTS OF THE PILOT CARD
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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THE PILOT CARD IS INTENDED AS A REFERENCE FOR THE PILOTS USE AND CONTAINS THE FOLLOWING INFORMATION.
• THE SHIPS GENERAL PARTICULARS:
o NAME, CALL SIGN, YEAR BUILT
o DRAFTS F/A/M, AIR DRAFT
o LENGTH, BREADTH, DEPTH
o DISPLACEMENT, DEADWEIGHT
o AN OUTLINE OF THE VESSEL WITH DIMENSIONS INCLUDING BULBOUS BOW
• PROPULSION AND MANOEUVRING EQUIPMENT:
o MAIN ENGINE PARTICULARS AND POWER, INCLUDING RPM/PITCH AND SPEEDS IN LOADED AND BALLAST
CONDITIONS AT FULL/HALF/SLOW/D.SLOW AHEAD AND ASTERN. ALSO NUMBER OF CONSECUTIVE STARTS,
ASTERN POWER, CRITICAL RPM ETC.
o THRUSTERS – BOW AND STERN – POWER AND MAX RUNNING TIME
o RUDDER/S – TYPE AND DEGREE OF ROTATION
o STEERING GEAR – NUMBER AND STATUS
• STATUS OF OTHER NAVIGATIONAL EQUIPMENT AND GEAR:
o ANCHORS, WHISTLES, SIGNAL LIGHT
o INDICATORS FOR RUDDER, RPM, ROT, TELEGRAPH ETC
o GYRO [INCL.ERROR], SPEED LOG
o RADAR/ARPA, AIS, ECDIS, ECHO SOUNDER, VDR AND COMMUNICATION EQUIPMENT LIKE VHF ETC.
• ANY DEFICIENCIES OR MANOEUVRING/BERTHING PECULIARITIES OR SPECIAL REQUIREMENT FOR BERTHING SUCH AS
STERN-TO OR STARBOARD SIDE ONLY, BOW-TO ETC.
4. SHIPHANDLING – THE WHEELHOUSE POSTER – part 1
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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5. SHIPHANDLING – THE WHEELHOUSE POSTER – part 2
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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6. SHIPHANDLING – CONTENTS OF THE WHEELHOUSE POSTER
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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THE WHEELHOUSE POSTER IS INTENDED TO PROVIDE MANOEUVRING INFORMATION FOR THE MASTERS’ AND PILOTS’
USE AND CONTAINS THE FOLLOWING INFORMATION.
• THE SHIPS GENERAL PARTICULARS:
o NAME, CALL SIGN, YEAR BUILT
o DRAFTS AT WHICH THE TRIALS WERE CONDUCTED
o PRINCIPAL DIMENSIONS - LENGTH, BREADTH, DEPTH, HEIGHT
o TONNAGES, DISPLACEMENT, DEADWEIGHT
o BOW AND STERN PROFILES, LENGTH OF PARALLEL MID BODY FOR BERTHING
• PROPULSION AND MANOEUVRING EQUIPMENT:
o MAIN ENGINE PARTICULARS AND POWER, INCLUDING RPM/PITCH AND SPEEDS IN LOADED AND BALLAST
CONDITIONS AT FULL/HALF/SLOW/D.SLOW AHEAD AND ASTERN. ALSO NUMBER OF CONSECUTIVE STARTS,
ASTERN POWER, CRITICAL RPM, CRASH ASTERN ETC.
o THRUSTERS – BOW AND STERN – AND THE EFFECT OF THRUSTER AT DIFFERENT SPEEDS
o RUDDER/S – TYPE AND DEGREE OF ROTATION, TIME FOR HARD OVER-HARD OVER
o PROPELLER/S – TYPE AND NUMBER, RIGHT HANDED OR LEFT HANDED OR CPP, IMMERSION
• IT ALSO INDICATES THE RESULTS OF:
o TURNING CIRCLE TEST IN SHALLOW/DEEP WATER IN LOADED/BALLAST CONDITIONS
o EMERGENCY STOPPING MANOEUVRES FROM FULL SEA SPEED-FULL ASTERN AND AT OTHER SPEEDS
o ESTIMATED SQUAT IN SHALLOW/DEEP WATER, CONFINED AND UNRESTRICTED WATER
o EMERGENCY MANOEUVRES FOR MOB
o PROVIDES FORE/AFT BLIND ZONES AT BALLAST/FULL LOAD
7. SHIPHANDLING – TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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• ADVANCE : PERPENDICULAR DISTANCE TRAVELLED
FROM START [EXECUTE] POSITION TO THE POINT WHEN
THE VESSEL’S HEAD IS AT 90 DEG TO ORIGINAL
HEADING.
• TRANSFER : PERPENDICULAR DISTANCE FROM
APPROACH COURSE TO THE POINT WHEN THE VESSEL’S
HEAD IS AT 90 DEG TO ORIGINAL HEADING.
• TACTICAL DIAMETER : PERPENDICULAR DISTANCE FROM
APPROACH COURSE TO THE POINT WHEN THE VESSEL’S
HEAD IS AT 180 DEG TO ORIGINAL HEADING.
• DRIFT ANGLE : ANGLE BETWEEN THE VESSELS HEAD
AND THE DIRECTION OF TRAVEL OF HER COG [TANGENT
TO THE PATH].
• TURNING RADIUS : STEADY RADIUS OF TURN AFTER THE
VESSEL HAS SWUNG THROUGH 180 DEGREES.
• FINAL DIAMETER : DIAMETER OF THE CIRCLE DESCRIBED
AFTER THE VESSEL SETTLES TO A STEADY TURN RATE.
8. SHIPHANDLING – THE PIVOT POINT
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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THE PIVOT POINT : THIS IS THE POINT ABOUT WHICH A VESSEL IS
ASSUMED TO SWING WHILE TAKING A TURN.
• IT IS NOT STATIC BUT MOVES ABOUT DEPENDING ON WHETHER :
o THE VESSEL IS STOPPED OR AT ANCHOR
o IS MAKING HEADWAY OR STERNWAY
o IS ACCELERATING OR AT STEADY SPEED
o THE VESSEL IS TRIMMED BY BOW OR STERN
• WITH THE SHIP STOPPED, THE PIVOT POINT LIES AT IT’S COG.
• AT ANCHOR, IT LIES AT OUTER EDGE OF THE HAWSE PIPE.
• WHEN MAKING HEADWAY AT STEADY SPEED, IT LIES ABOUT 1/4
LENGTH FROM THE BOW [LONG TURNING LEVER].
• WHEN MAKING HEADWAY AND ACCELERATING, IT LIES ABOUT 1/8
LENGTH FROM THE BOW [LONGEST TURNING LEVER].
• WHEN GOING ASTERN AT STEADY SPEED, IT LIES ABOUT 1/4 LENGTH
FROM AFT [SHORT TURNING LEVER].
• WHEN GOING ASTERN AND ACCELERATING, IT LIES ABOUT 1/8
LENGTH FROM AFT [SHORTEST TURNING LEVER].
• IT MOVES FURTHER FORWARD TOWARD THE GREATER IMMERSED
VOLUME WHEN TRIMMED BY HEAD.
• IT MOVES FURTHER AFT TOWARD THE GREATER IMMERSED VOLUME
WHEN TRIMMED BY STERN.
CG
SHIP STOPPED – EVEN KEEL
PIVOT POINT IS AT THE CG
PP
CG
MAKING HEADWAY – STEADY SPEED
PIVOT POINT IS 1/4L FROM THE BOW
PP
CG
MAKING HEADWAY – ACCELERATING
PIVOT POINT IS 1/8L FROM THE BOW
PP
CG
GOING ASTERN – STEADY SPEED
PIVOT POINT IS 1/4L FROM AFT
PP
CG
GOING ASTERN – ACCELERATING
PIVOT POINT IS 1/8L FROM AFT
PP
CG
AT ANCHOR - PIVOT POINT
IS AT THE HAWSE PIPE
PP
PP
9. SHIPHANDLING – HOW LATERAL RESISTANCE AFFECTS TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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• WHEN TURNING, A SHIPS TENDS TO ANGLE SIDEWAYS. WITH THE PIVOT POINT LYING TOWARD THE FORWARD PART
OF THE VESSEL, THE GREATER EFFECT OF LATERAL RESISTANCE LIES AFT OF THE PIVOT POINT AND TENDS TO LIMIT
THE SWING OF THE STERN. THIS RESULTS IN A SMALLER DRIFT ANGLE AND A GREATER TURNING CIRCLE.
• LESSER LATERAL RESISTANCE WILL ALLOW THE STERN TO SWING OUT MORE, RESULTING IN A LARGER DRIFT ANGLE
AND A SMALLER TURNING CIRCLE.
10. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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• STRUCTURAL DESIGN AND LENGTH OF THE VESSEL :
• LONG VESSEL – GREATER LATERAL RESISTANCE, LESSER DRIFT ANGLE – LARGER TURNING CIRCLE.
• FINE LINED VESSELS – TURN WITH MORE SPEED BUT SUFFERS INCREASED LATERAL RESISTANCE – HAS LESSER
BOW RESISTANCE SO PIVOT POINT NOT AS FAR FORWARD AS USUAL – HENCE HAS A LARGER TURNING CIRCLE.
• BOXY VESSELS - EXPERIENCE GREATER BOW RESISTANCE - PIVOT POINT MOVES FURTHER FORWARD – SPEED
REDUCES AND THERE IS LESSER LATERAL RESISTANCE – IT TAKES LONGER TO START TURNING BUT FINISHES
WITH A SMALLER TURNING CIRCLE.
CG
PP
CG
PP
12. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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• DRAUGHT OF THE VESSEL : GREATER DRAFT, MORE IN-WATER
RESISTANCE – LESSER DRIFT ANGLE - LARGER TURNING CIRCLE AND
VICE VERSA.
• TRIM BY STERN : PIVOT POINT SHIFTS A LITTLE AFT OF THE USUAL,
MOVING TOWARD THE GREATER IMMERSED AREA – HENCE THERE
IS A SMALLER TURNING LEVER AND CONSEQUENTLY A LARGER
TURNING CIRCLE. ALSO, THERE IS LARGER LATERAL RESISTANCE AFT
OF PIVOT POINT DUE TO GREATER IMMERSION AFT - HENCE
REDUCED DRIFT ANGLE – THEREFORE IT HAS A LARGER TURNING
CIRCLE BUT BETTER MANOEUVRABILITY.
• TRIM BY HEAD : OPPOSITE REACTION PROVIDED PROPELLER
IMMERSION IS NOT COMPROMISED. THE LESSER LATERAL
RESISTANCE AFT OF THE PIVOT POINT DUE TO LESSER IMMERSION
AFT INCREASES THE DRIFT ANGLE – THEREFORE IT HAS A SMALLER
TURNING CIRCLE BUT POORER MANOEUVRABILITY.
LR
LR
13. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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ENGINE POWER :
• GREATER SPEED AND FASTER WATER FLOW PAST
RUDDER – THEREFORE BETTER RUDDER RESPONSE
AND EXPECTED SMALLER TURNING CIRCLE.
HOWEVER, INCREASED LATERAL RESISTANCE RESULTS
IN A SMALLER DRIFT ANGLE AND INCREASES THE
TURNING CIRCLE.
• LOWER SPEED MEANS POORER RUDDER RESPONSE
AND EXPECTED LARGER TURNING CIRCLE, BUT LESS
LATERAL RESISTANCE AND LARGER DRIFT ANGLE
DECREASES TURNING CIRCLE.
• THEREFORE THERE IS OVERALL NEGLIGIBLE CHANGE
IN TURNING CIRCLE DUE TO CHANGE IN SPEED.
• TYPE OF RUDDER AFFECTS TURNING CIRCLE – HIGH
EFFICIENCY RUDDERS – SMALLER TURNING CIRCLE.
SMALLER CLEARANCE BETWEEN RUDDER AND HULL –
TIGHTER TURNING CIRCLE.
14. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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LIST :
• A VESSEL HAVING A LIST TENDS TO MAKE A LARGER TURNING CIRCLE
WHEN TURNING TOWARD THE LISTED SIDE AND WILL MAKE A TIGHTER
TURN WHEN SWINGING AWAY FROM THE LISTED SIDE.
SEE FIG.1 – STATIC HEEL 2.5DEG [S] – BLUE CIRCLE
STATIC HEEL -2.5DEG [P] – RED CIRCLE
STATIC HEEL 0DEG [UPRIGHT] – GREEN CIRCLE
• INCREASED LIST INCREASES THIS EFFECT.
FIG.2 SHOWS THE VARIATION IN TURN CIRCLE FOR 5DEG LIST.
• TURNS TO PORT ARE SIMILAR TO THE STARBOARD TURNS.
Fig.1
Fig.2
15. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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DEPTH OF WATER :
• SHALLOW WATER - GREATER LATERAL RESISTANCE – LESSER
DRIFT ANGLE – ALSO INTERACTION EFFECT CAUSES LARGER
LIST IN SHALLOW WATER – RESULT IS A MUCH LARGER
TURNING CIRCLE. VESSEL WILL COMPLETE HER TURN
COMING FROM WELL AFT OF THE LINE WHERE SHE STARTED
THE TURN FROM.
LR
• DEEP WATER – LESS LATERAL RESISTANCE, LESS LIST WHILE TURNING, LARGER DRIFT ANGLE – SMALLER TURNING
CIRCLE.
16. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
16
• AMOUNT OF RUDDER APPLIED : GREATER RUDDER ANGLE
– TIGHTER TURNING CIRCLE BUT GREATER LOSS OF SPEED.
LESSER RUDDER – LARGER TURNING CIRCLE.
• DISPLACEMENT : LARGER DISPLACEMENT, DEEPER DRAFT,
MORE LATERAL RESISTANCE, LESS DRIFT ANGLE – LARGER
TURNING CIRCLE.
• PROPELLER ACTION : WITH A RIGHT HANDED PROPELLER,
TRANSVERSE THRUST TO STARBOARD WILL AID TURNING
TOWARD PORT – TIGHTER TURNING CIRCLE TO PORT. THE
REVERSE APPLIES WITH A LEFT HANDED PROPELLER.
• EXTERNAL FORCES : WIND, CURRENT AND SEA STATE WILL
AFFECT THE TURNING CIRCLE DEPENDING ON THE
DIRECTION IN WHICH THEY ARE ACTING.
• DISTRIBUTION AND STOWAGE OF CARGO : CARGO STOWED
AT FORE AND AFT PARTS OF THE VESSEL WILL MAKE IT
SLUGGISH AND SLOW TO RESPOND – HENCE LARGER
TURNING CIRCLE.
17. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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STANDING TURN :
• WHEN COMMENCING A TURN FROM STOPPED, SINCE THE
VESSEL IS CONTINUOUSLY ACCELERATING, THE PIVOT POINT
IS FURTHEST FORWARD [1/8L FROM THE BOW]. THE
TURNING LEVER IS GREATEST AT THIS TIME AND THE
TURNING CIRCLE WILL THUS BE SMALLER THAN WHEN
COMMENCING THE TURN WITH SPEED.
• THE VESSEL WILL COMPLETE THE TURN COMING IN FROM
AFT OF THE LINE FROM WHERE SHE COMMENCED THE
TURN.
18. SHIPHANDLING – FACTORS AFFECTING TURNING CIRCLE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
18
DRIFT ANGLE :
• A LARGE DRIFT ANGLE MEANS THE
VESSEL HAS TURNED THROUGH A LARGER
ANGLE AND WILL THEREFORE DESCRIBE A
SMALLER TURNING CIRCLE.
• A SMALL DRIFT ANGLE MEANS THAT
SOME RESISTANCE IS PREVENTING THE
VESSEL FROM TURNING FULLY AND SHE
WILL THUS DESCRIBE A LARGER TURNING
CIRCLE.
DRIFT ANGLE
TANGENTS TO
THE CIRCLES
CG
19. SHIPHANDLING – STOPPING DISTANCE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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• IMO REQUIRES THAT STOPPING ABILITY OF THE VESSEL BE
TESTED GOING FULL ASTERN FROM FULL SEA SPEED AND FULL
ASTERN FROM FULL AHEAD. RECORD OF THE SHIPS TRACK,
RPM, SPEED, TRACK REACH, HEAD REACH AND SIDE REACH
MUST BE PROVIDED. STOPPING DISTANCE MUST BE WITHIN 15
SHIP LENGTHS BUT WHERE SHIPS OF LARGE DISPLACEMENT
MAKE THIS IMPRACTICABLE ADMINISTRATIONS MAY PERMIT
UPTO 20 SHIP LENGTHS.
• ADDITIONALLY ESTIMATED STOPPING ABILITY, WITH DETAILS OF
TRACK REACH, HEAD REACH, SIDE REACH, TIME AND TRACK
REACH DECELERATION [DISTANCE/ONE KNOT REDUCTION] IN
BOTH FULL LOAD AND BALLAST CONDITIONS MUST BE
PROVIDED FOR THE FOLLOWING CONDITIONS :
• FULL ASTERN FROM FULL SEA SPEED
• FULL ASTEN FROM FULL AHEAD
• FULL ASTERN FROM HALF AHEAD
• FULL ASTERN FROM SLOW AHEAD
• STOP ENGINE FROM FULL SEA SPEED
• STOP ENGINE FROM FULL AHEAD
• STOP ENGINE FROM HALF AHEAD
• STOP ENGINE FROM SLOW AHEAD
20. SHIPHANDLING – STOPPING DISTANCE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
20
TRACK REACH : ACTUAL DISTANCE TRAVELLED, ALONG THE
VESSELS TRACK, FROM THE TIME THE ASTERN ORDER IS
GIVEN TO WHEN THE VESSEL STOPS “DEAD IN THE WATER”.
HEAD REACH : PERPENDICULAR DISTANCE TRAVELLED
BETWEEN PARALLEL LINES 90 DEG TO THE INITIAL HEADING,
DRAWN FROM THE POINT WHEN THE ASTERN ORDER IS
GIVEN AND FROM THE POINT WHEN THE VESSEL STOPS
“DEAD IN THE WATER”.
SIDE REACH OR TRANSFER : PERPENDICULAR DISTANCE
BETWEEN THE INITIAL HEADING AND THE POINT WHEN THE
VESSEL STOPS “DEAD IN THE WATER”.
NOTE : THERE WILL BE A DELAY BETWEEN THE POINT
WHERE THE ASTERN ORDER IS GIVEN AND THE POINT
WHERE IT IS ACTUALLY EXECUTED AS THE PROPELLER MUST
STOP TURNING BEFORE IT’S DIRECTION IS REVERSED.
21. SHIPHANDLING – VARIOUS TYPES OF STOPS
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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STOP AND CONTINUE DRIFTING TILL “DEAD IN THE
WATER”. GREATEST TRACK AND HEAD REACH. LEAST SIDE
REACH OR TRANSFER.
FULL ASTERN TILL “DEAD IN THE WATER”. LESS TRACK AND
HEAD REACH. GREATER SIDE REACH OR TRANSFER.
HARD STARBOARD FULL TURN. SMALLEST HEAD REACH.
LARGE TRACK REACH AND SIDE REACH OR TRANSFER.
RUDDER CYCLING TILL “DEAD IN THE WATER”. LARGE
TRACK REACH. 2ND LEAST HEAD REACH AND SIDE REACH OR
TRANSFER.
FULL ASTERN
STOP HARD STBD
HARD STBD
H.AHD
HARD PORT
S.AHD
HARD STBD
STOP
MIDSHIP
F.AST
22. SHIPHANDLING – APPROX. STOPPING DISTANCE
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
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RELATIONSHIP BETWEEN THE LENGTH OF A SHIP AND THE SHORTEST STOPPING DISTANCE FOR A FULLY LOADED VLCC
STEAMING AT 12 KNOTS [SIMULATED].
SHIP LENGTH (M) SHORTEST STOPPING DISTANCE OF SHIP
210 10 TIMES THE LENGTH
250 13 TIMES THE LENGTH
300 15 TIMES THE LENGTH
WHEN SPEED IS BELOW 2.5KTS, THE STOPPING DISTANCE BECOMES QUITE SMALL COMPARED TO THE SHIPS LENGTH.
THE STOPPING DISTANCE OF A SHIP DEPENDS ON SPEED, DISPLACEMENT, HULL SHAPE, ENGINE POWER ETC.
A ROUGH GUIDELINE FOR BRINGING A SHIP TO A COMPLETE HALT FROM MANOEUVRING FULL AHEAD :
IN BALLAST : 3-5 TIMES THE SHIPS LENGTH
WHEN LOADED : 7-8 TIMES THE SHIPS LENGTH
VESSELS WITH LARGE FREEBOARD SUCH AS CONTAINER, RO-RO AND CAR CARRIERS AS WELL AS PASSENGER SHIPS ARE
EASILY AFFECTED BY WIND AND DEPENDING ON THE DIRECTION OF WIND MAY COME TO A STOP VERY QUICKLY OR MAY
CONTINUE DRIFTING OWING TO THE WIND AND BE IMPOSSIBLE TO STOP AT ALL.
23. SHIPHANDLING – CRASH ASTERN
2M/BR. EQP/TURN CIRCLE+STOPPING DIST - Capt. S.F. Gomez
23
• WHEN THERE IS AN EMERGENCY SUCH AS COLLISION, GROUNDING ETC. THE CONTROLS ARE TRANSFERRED
IMMEDIATELY TO THE ENGINE ROOM.
• THE BRIDGE WILL GIVE AN ASTERN ORDER BY TELEGRAPH, E/R WILL ACKNOWLEDGE THE SAME.
• WHEN THE TELEGRAPH IS ACKNOWLEDGED ONLY THE STARTING AIR CAM WILL REVERSE ITS DIRECTION BUT THE
FUEL CAM WILL REMAIN IN ITS RUNNING POSITION DUE TO RUNNING DIRECTION INTERLOCK, SINCE ENGINE IS STILL
RUNNING IN THE AHEAD DIRECTION.
• THE FUEL LEVER IN THE ENGINE CONTROL ROOM IS THEN BROUGHT TO ‘0’.
• AS SOON AS THE RPM OF THE ENGINE DROPS BELOW 40 % OF THE MAXIMUM CONTINUOUS RATING OR MCR
RPM OF THE ENGINE, APPLY BRAKING AIR A FEW TIMES WITHIN A SHORT TIME FRAME.
• THE BRAKING AIR WHEN SUDDENLY INJECTED INSIDE THE ENGINE CYLINDER, WILL OPPOSE THE MOTION OF THE
PISTON AND THE ROTATION OF THE CRANKSHAFT AND PROPELLER. THIS HELPS SLOW DOWN THE RPM.
• FUEL WILL NOT INJECT UNTIL RUNNING DIRECTION INTERLOCK OPENS, SO AS SOON AS THE RPM DROPS NEAR TO
ZERO, GIVE A FUEL AND AIR KICK BY BRINGING FUEL LEVER TO MINIMUM START SETTING.
• ONCE THE ENGINE IS RUNNING IN THE ASTERN DIRECTION INCREASE RPM TO FULL ASTERN.
• WHEN CARRYING OUT CRASH MANOEUVRING, SOME SAFETIES NEED TO BE BYPASSED TO AVOID TRIPPING OF
ENGINE IN THE MIDST OF THE EMERGENCY.
• WHEN THE SHIP STOPS AND SITUATION IS UNDER CONTROL, A DETAILED MAIN ENGINE INSPECTION IS TO BE
CARRIED OUT AS SOON AS THERE IS A CHANCE. THIS IS BECAUSE THE SUDDEN QUICK SLOWING DOWN AND
REVERSAL OF THE ENGINE MAY LEAD TO THERMAL SHOCK AS WELL AS FRACTURE/DEFORMATION OF ENGINE
COMPONENTS.