ICE
SOURCES OF INFORMATION
• Mariner’s Handbook
• Ocean Passages for the World
• ALRS
• Sailing Directions
• Ice charts
• Routing Charts
• Weather facsimile charts
• Ocean routeing services
• Weather and Ice reports
SOURCES OF INFORMATION
• NAVTEX and SafetyNET ice reports
• International Ice Patrol
• US Coastguard, US Navy Ocean
Office, Canadian Ice Reconnaissance
Aircraft Facsimile Service, Baltic Ice
Service
• Port Authorities, Pilots and Pilotage
Authorities
SOURCES OF INFORMATION
• Ocean weather ships
• Ships departing from the Area
• Previous experience and knowledge of
individuals on board
• Previous records on board if vessel
had been to the area before
READINESS OF VESSEL
• Appropriate ice classification and notation
• Main engine and steering gear should be
reliable and well maintained
• Operational navigation and communication
equipment
• Operational radars capable of peak
performance
READINESS OF VESSEL
• Vessel to be adequately ballasted and
trimmed to have propeller fully immersed
in water. Trim should not be excessive.
• Ballast and fresh water tanks should not
be more than 90% full
• Good search lights
READINESS OF VESSEL
• International Code of Signals and
communication procedures
• Fenders
• Towlines
• Defrosters on bridge windows
READINESS OF VESSEL
• Accommodation heating
• Anti skid salt/grit
• Personnel protective and cold weather
gear
• Navigational publications for ice regions
and latest reports
• Adequate reserves of stores and bunkers
MASTER’S DUTIES and
Reports
• SOLAS , requires the master of every ship,
when ice is reported on or near the track, to
proceed at a moderate speed at night or to alter
course to pass well clear of the danger area. On
meeting dangerous ice, master is obliged under
SOLAS to send a report to ships in the vicinity
and to the nearest coast station.
CONTENTS OF OBLIGATORY REPORT
• Type of ice
• Position of the ice
• UTC and date of observation
Conditions for Freezing
Source Air Temperature
– Sea spray -2°C;
– Rain/drizzle 0°C;
– Fog/black ice 0°C;
Conditions
• In order for ice accretion to occur:
– the ship’s structure must be at the same
temperature as the air;
– the water must be cooled to its freezing point
through conduction with the ship’s structure;
– the latent heat released through freezing to be
dispersed through the ships structure;
– once ice has formed on the surface then the
latent heat is dispersed by the air.
Amount of Accretion
The lower the air temperature the greater the
accretion:
– Due to the ability of the structure disperse energy.
The lower the sea temperature the greater the
accretion:
– Due to the spray requiring less cooling to reach
freezing point.
The higher the wind speed the greater the
accretion:
– Due to the greater amount of spray and the wind chill
factor.
SIGNS OF DRIFT ICE
Visual detection can occur provided that visibility is good
and there is ample light.
Radar detection also has limitations.
• Ice blink appears as glare well before sighting ice. It
appears as:
• whitish or yellowish haze during clear daylight;
• whitish glare during day with overcast sky or low clouds;
• white patches in fog.
• Gradual lessening of ordinary swell or abrupt smoothing
of sea indicates that ice is to windward.
• Presence of marine life is another indicator of ice in the
vicinity.
An Iceberg is a massive piece of ice of greatly
varying shape, protruding 5m or more above
sea-level, which has broken away from a
glacier and which may be afloat or aground.
The leading edge of a glacier
A glacier flows down a valley
International Ice Patrol (IIP)
MISSION STATEMENT
The International Ice Patrol will monitor iceberg danger near
the Grand Banks of Newfoundland and provide the limits of all
known ice to the maritime community.
• To issue charts and • Data broadcast from
bulletins USA, details in ALRS
– Twice a day • Sources of information
– Fax once/day – Aircraft (IIP)
– When bergs south of – Ships (IIP & SOLAS)
48 N – Satellite
www.uscg.mil/lantarea/iip/home.html
ACTIONS TO ENSURE SAFETY
• Steer towards warmer conditions, or seek
shelter
• Head into wind at minimum speed to reduce
spray
• If weather does not allow to head into wind, run
before the wind at minimum speed to maintain
steerage
• If all fails and ice is building up on the vessel’s
structure, the last resort is to physically remove
it otherwise the adverse effects on stability due
to mass of ice at high levels on vessel may be
enough capsize the vessel.
OBLIGATORY REPORT
• On encountering air temperatures below
freezing associated with gale force winds
causing severe ice accumulation on ships,
master is obliged under SOLAS to send a report
to ships in the vicinity and to the nearest coast
station:
• Air and sea temperatures
• Force and direction of wind
• Position of the ship
• UTC and date of observation
NAVIGATION IN HIGH LATITUDES
• CONCEPT OF TIME
• As time zones meet on the poles, local time has
little significance. The normal phenomenon of
day and night are not noticed as there may be
very long days, nights and periods of twilight.
• CHARTS AND BEARINGS
• Charts are based largely on aerial photography.
Soundings, topography and navigational
information are sparse in most polar-regions.
The geographical positions of features may be
unreliable and errors in their positions will
become considerable as the distances increase.
• MERIDIANS AND PARALLELS
• Meridians converge at the poles and perimeter
of parallels reduces considerably Excessive
longitudinal curvature renders meridians and
parallels impracticable for use as navigational
references. The only significance is for plotting
positions derived from electronic systems like
GPS.
• DEAD RECKONING
• Every opportunity to fix ship’s position should be
availed. Systems like GPS, etc., have much
reduced the need for DR, but it should still be
maintained, as continued signals from GPS
satellites may not be guaranteed.
• USE OF COMPASSES
• At or near (85) the geographical poles, gyrocompass
becomes useless as it loses all its directive force. Gyro is
generally reliable up to latitude of about 70. At the
magnetic poles, magnetic compass becomes useless as
it looses all its directive force. Impact with ice and
frequent changes of course and speed introduce errors
that are slow to settle. Frequent comparisons of gyro and
magnetic compass should be made and logged and
azimuths taken regularly.
• ELECTRONIC AND RADIO AIDS
• GPS provides global coverage. Other position fixing
systems can be relied upon where available, after
making allowance for errors. Radar set up properly at
peak performance can be very useful for detection
purposes.
• CELESTIAL NAVIGATION
• Accurate celestial observations cannot be relied
upon due to long days and nights, as well as
extensive periods of cloud cover.
• Sun rises once in 6 months at pole
• Sun sets once in 6 months at pole
• Sun’s maximum altitude will be 23 27’ at pole
• Moon rises once a month at pole
• Stars with declination of more than 23 27’ in the
opposite hemisphere will never rise at pole
Movie Time….!!
• Titanic
• Breaking of Titanic
• Ice Navigation
