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CHAPTER 8 MAN OVERBOARD. MAN OVERBOARD. A major concern of maritime operations is recovering personnel who have fallen overboard and safely transferring them from the water to the deck of a boat or hatch of a lifeboat. Several recovery systems are demonstrated.
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MAN OVERBOARD A major concern of maritime operations is recovering personnel who have fallen overboard and safely transferring them from the water to the deck of a boat or hatch of a lifeboat. Several recovery systems are demonstrated. Recovery should not exceed 6 to 8 minutes
MAN OVERBOARD Several recovery techniques are demonstrated along with vessel approach techniquessuch as the Williamson method. Procedures for marking the location of personnel in the water with a flare or life-ring are discussed along with alternative rescue methods.
MAN OVERBOARD / GPS MOB • The Man Over Board (MOB) function is a common feature for marine GPS units. • If a person falls overboard, the skipper uses this function to immediately mark the current location. • The GPS goes into a "Goto" mode and directs the skipper back to the point where the button was pressed.
MOB / DIFFERENT SITUATIONS « Immediate action » situationCasualty is noticed on the bridge and action is initiated immediately "Delayed action" situationCasualty is reported to the bridge by an eye witness and action is initiated with some delay "Person missing" situationPerson is reported to the bridge as "missing"
IMMEDIATE ACTION • First reaction: throw a lifebuoy with light in the direction of the person overboard / call the bridge / • Shout: « man overboard »
BOUTAKOV (WILLIAMSON) MANOEUVRE Rudder hard over (in an "immediate action" situation, only to the side of the casualty) After deviation from the original course by 60º, rudder hard over to the opposite side. When heading 20º short of opposite course, rudder to midship position and ship to be turned to opposite course
SINGLE TURN Rudder hard over (in an "immediate action" situation, only to the side of the casualty) . After deviation from the original course by 250º, rudder to midship position and stopping manoeuvre to be initiated.
SCHARNOW TURN Rudder hard over After deviation from the original course by 240º, rudder hard over to the opposite side. When heading 20º short of opposite course, rudder to midship position so that ship will turn to opposite course.
IMMEDIATE ACTION SITUATION SINGLE TURN will take the ship back to the scene of the casualty most quickly. WILLIAMSON TURN requires more time and will temporarily take the ship farther away from the scene of the casualty. SCHARNOW TURN is not appropriate.
DELAYED ACTION SITUATION WILLIAMSON TURN will take the ship to the scene of the casualty most surely (When the ship has reached the manoeuvre commencement point, search speed must be reduced so as to enable fast stopping)SCHARNOW TURN cannot be carried out effectively unless the time elapsed between the occurrence of the casualty and the commencement of the manoeuvre is known.
MISSING PERSON SITUATION • Both WILLIAMSON TURN and SCHARNOW TURN take ship back into her wake. Less distance is covered, and thus time is saved, with SCHARNOW TURN.When ship on opposite course after carrying out SCHARNOW TURN, the manoeuvre commencement point will be some ship's lengths behind her stern. Between one and two nautical miles may be saved. Standard man-overboard manoeuvres are not guaranteed to return a ship into its wake: should be regularly practiced to account for the particular ship characteristics and the effects of environmental conditions on the ship and the person in the water.
MISSING PERSON SITUATION Comparison between Williamson and Scharnow For Scharnow: time between casualty and start of manœuvre must be known
BOUTAKOV (WILLIAMSON) MANOEUVRE Remarks • First heading change: between 40° and 70° - depending on the ship’s manoeuvring characteristics (for VLCC: 40°) • Second heading change: 180° + value of first heading change • Engine revs to be mofified after 2nd heading change • Anticipate with counter-rudder due to momentum of the ship • Effects of wind and current will alter the curve • Stop the vessel ot windward of the victim
BOUTAKOV (WILLIAMSON) MANOEUVRE Advantage • Auto-recovery • Ideal with reduced visibility Disadvantages • Great distance between victim and ship during the turn • Victim pass behind the stern from Ps (Sb) to other side: lost from view • The slowest MOB manœuvre: between 6 and 12 minutes: victim remain 15 minutes in the water
SINGLE TURN Remarks • « Immediate action » manœuvre • Change of heading: between 250° and 300° due to the momentum of the ship • Duration: between 4 and 7 minutes • Revs to be modified at the end of the turn • Trials recommanded • Stop the vessel to windward of the victim
Williamson turn versus Single turn Under favourable dailight conditions A simple round turn is the best way To get back to a man overboard in a Hurry.
SCHARNOW TURN Advantages • Auto-recovery: ship is brought back on opposite course • Victim always in view of rescue team on the bridge • Time needed is shorter than Boutakov Disadvantage • Not an « immediate action » manoeuvre
ADDITIONAL MANOEUVRES • Stop the vessel and full astern • Double Turn • Single Delayed Turn
STOP THE VESSEL AND FULL ASTERN Advantages • « immediate action » manoeuvre • Recommanded whith limited initial speed • Brings the ship faster on the scene Disadvantages • With single screw ships: transverse thrust will turn the ship • Wind effects will alter the manœuvre • Only with motor ships / turbine ships are too slow to reverse • Momentum of big ships
DOUBLE TURN « immediate action » manœuvre • English variant: • First 180° change of heading • Ship back on opposite course • Start 2nd heading change when victim on three point athwartships • Reduce revs and approach at windward • Dutch variant: • Start 2nd heading change when actual speed = initial speed Some sources recommand this manœuvre with beam winds ↔ Boutakov with stern winds
SINGLE DELAYED TURN This is an « immediate action » manoeuvre Procedure • Ship keeps her initial heading for one mile • Start of turning circle • Stabilize vessel when new heading = initial heading + 180° + tangent of tactical diameter in miles Example: for a tactical diameter of 0,364 → 200° change of heading
MAN OVERBOARD Remarks • always stops vessel at windward: stopped vessel drifts faster than man in water • A man losses consciousness after 15 minutes in water at 5° • 1st approach must always succeed
AUDIBLE SIGNAL WITH SIREN OSCAR _ _ _ Will enhance moral of the victim
SECTOR SEARCH One single ship rescue Operation Recommanded for MOB manoeuvre Advantage Ship comes back very fast to initial starting position
EXPANDING SQUARE SEARCH Preferred to « Sector Search » when dubious initial position
PARALLEL TRACK PATTERN / NO CURRENT Doubtful position