Polar Code Part#2/5 - Ice Navigation and Sign of Ice
The main principle of Ice-Navigation is – “Freedom of
Movement of vessel”
- Master and Bridge Team to be well versed with the POLAR Code and ship specific Polar Water Operational Manual.
- Follow the route recommended by the Ice Superintendent via the Marine Communications and Traffic Services Centre (MCTS), through the appropriate reporting system i.e. ECAREG (Eastern Canada Vessel Traffic Services Zone Regulations) or NORDREG (Northern Canada Vessel Traffic Services). This route is based on the latest available information, Masters are encouraged to adjust their courses accordingly.
- Mark Ice limits on appropriate charts.
- Plot all floating icebergs position and their direction of drifting and speed.
- Extra look outs must be posted and the bridge watch may be increased, depending upon the visibility.
- Do not enter Ice if an alternative, although longer, open water route is available.
- Enter the ice at low speed to receive the initial impact, once into the pack, increase speed gradually to maintain headway and control of the ship.
- The vessel should be at right angles to the edge of the pack ice at entry to avoid glancing blows.
- Be prepared to go “Full Astern” at any time.
- The point of entering the ice must be chosen carefully, preferably in an area of lower ice
concentration.
- Navigation in pack ice after dark should not be attempted without high-power searchlights which can be controlled easily from the bridge, If poor visibility encounters, heave to in the ice and keep the propeller turning slowly as it is less susceptible to ice damage than if it were completely stopped.
- Follow open water patches and lighter ice areas even if initially it involves large deviation of course.
- Avoid turning in heavy ice, seek lighter ice or open water pools.
- Backing in ice is a dangerous manoeuvre as it exposes the most vulnerable parts of the ship, the rudder and propeller, to the ice. It should only be attempted when absolutely necessary.
- At the time of Berthing in Icy area: Flushing out ice with wash while bow is fixed with a spring line.
- Once the ship is secured, all efforts must be made to keep the ship alongside and not to allow ice to force its way between the ship and the dock.
- Keep the engines on standby at river berths or strong tidal areas where ice is in motion.
- Mariners are advised not to rely solely on Radar for the detection of icebergs, as it is not certain that Radar will detect all types and sizes of ice and it will not differentiate old ice from first year ice.
- Full rudder is used in emergency only. Violent rudder movement may swing the stern into ice and damage the propeller.
- On deck, all the pipelines are drained and isolated.
- Keep the damage control gear ready – cement, collision mats etc.
- Check heating systems of machinery and accommodation regularly.
- Ship stopped in ice inshore, must always point seaward.
- Ship should monitor the updated routing instructions from the Canadian Coast Guard Ice Operations Centers.
SIGN OF ICE IN THE VICINITY
When steaming through open water, it may be possible to detect the approach of ice by the
following signs:
1. Ice blink: this is a fairly reliable sign and may be the first indication that an ice field is in the vicinity. It can usually be seen for some time before the ice itself is visible and appears as a luminous reflection on the underside of the clouds above the ice. Its clarity is increased after a fresh snowfall. On clear days, ice blink is less apparent but may appear as a light or yellowish haze which would indicate the presence of ice. Ice blink can sometimes be detected at night, either from the reflection of moonlight, or from the ambient starlight in clear weather.
2. The sighting of small fragments of ice often indicates that larger quantities are not far away.
3. Abrupt moderation of the sea and swell occur when approaching an ice field from leeward.
4. In northern areas, and in Labrador and Newfoundland, the onset of fog often indicates the presence of ice in the vicinity
SUMMARY
The first principle of successful ice navigation is to maintain freedom of manoeuvre.
Experience has proven that in ice of higher concentrations, four basic ship handling rules apply:
keep moving - even very slowly, but try to keep moving;
try to work with the ice movement and weaknesses but not against them;
excessive speed almost always results in ice damage; and
know your ship's manoeuvring characteristics.
