Transcript CHAPTER 8 MAN OVERBOARD

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.
Recovery should not exceed
6 to 8 minutes
MAN OVERBOARD
Several recovery
techniques are
demonstrated along with
vessel approach
techniques such as the
Williamson method.
Procedures for marking the
location of personnel in
the water with a flare or lifering 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.
MAN OVERBOARD / GPS MOB
MOB / DIFFERENT SITUATIONS
« Immediate action » situation
Casualty is noticed on the bridge and action is
initiated immediately
"Delayed action" situation
Casualty is reported to the bridge by an eye witness
and action is initiated with some delay
"Person missing" situation
Person 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
BOUTAKOV (WILLIAMSON) MANOEUVRE
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
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
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
IAMSAR RESCUE MANOEUVRES
SECTOR SEARCH
SECTOR SEARCH
One single ship rescue
Operation
Recommanded for MOB
manoeuvre
Advantage
Ship comes back very
fast to initial starting
position
EXPANDING SQUARE SEARCH
EXPANDING SQUARE SEARCH
Preferred to « Sector
Search » when dubious
initial position
PARALLEL TRACK PATTERN / NO CURRENT
Doubtful position
PARALLEL TRACK PATTERN / WITH CURRENT