Precautions polar water

In general, during ice ship navigation, an ice pilot and ice breakers are provided to help commercial vessel operations by safely leading the vessels through the ice but there are a few other measures to be followed by the vessel’s crew during ice ship navigation.

The ship should avoid any alternate available route at all costs

A very careful lookout for leads through ice is always needed

Engines should be kept running under manoeuvring conditions in in order to help the ahead and astern movements be carried out without time delay

Avoid navigating through ice at night (if possible)

Avoid anchoring in heavy concentrations of ice

In addition to these precautions, there are some actions to be taken while moving towards sub- zero temperature with ice covered waters, to ensure safe ship navigation, as follows:

  1. Inform the engine room of the proximity of ice
  2. Inform the crew of the proximity of ice
  3. Close all watertight doors
  4. Moderate speed as appropriate in the conditions
  5. Increase the frequency of sounding tanks and bilges
  6. Monitor ice advisory service broadcasts
  7. Transmit danger messages in accordance with SOLAS

Precautions while Entering and Navigating within Ice Limits

Precautions you will take while entering ice limit:

  1. The route recommended by the Ice Superintendent through the appropriate reporting system i.e., ECAREG or NORDREG, is based on the latest available information and Masters are advised to adjust their course accordingly.
  2. Do not enter ice if an alternative, although longer, open water route is available.
  3. Enter the ice at low & speed to receive the initial impact: once into the pack.
  4. Increase speed gradually to maintain headway and control of the ship, but do not let the speed increase beyond the point at which she might suffer ice damage.
  5. Be prepared to go Full Astern at any time.
  6. Navigation in pack ice after dark should not be attempted without high-power searchlights which can be controlled easily from the bridge.
  7. If poor visibility precludes progress, 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, blocks of ice will also be prevented from jamming between the blades and the hull.
  8. Propellers and rudders are the most vulnerable parts of the ship; ships should go astern in ice with extreme care, and always with the rudder amidships. If required to ram ice when brought to a halt, ships should not go astern into unbroken ice, but should move astern only in the channel previously cut by their own passage.
  9. All forms of glacial ice (icebergs, Bergy bits, growlers) in the pack should be given a wide berth, as they are current-driven whereas the pack is wind-driven. Large features of old ice may be moving in a direction upwind or across the wind according.to the direction of the current.
  10. Wherever possible, pressure ridges should be avoided and a passage through pack ice under pressure should not be attempted. The ship may have to be stopped in the ice until the pressure event is ended.

Precautions you will take while navigating within ice limit

  1. Obtain latest ice information by all available means.
  2. Mark ice limit on appropriate charts.
  3. Plot all floating-icebergs position and their direction of drifting and speed.
  4. Follow the route recommended by the Ice Superintendent via the Marine Communications and Traffic Services Centre (MCTS). This route is based on the latest available information and Masters are advised to adjust their course accordingly if changes are recommended during the passage.
  5. Extra lookouts must be posted and the bridge watch may be increased, depending on the visibility.
  6. Reduce speed to a minimum to receive the initial impact of the ice.
  7. The vessel should be at right angles to the edge of the pack ice at the entry to avoid glancing blows.
  8. The point of entering the ice must be chosen carefully, preferably in an area of lower ice concentration
  1. Correct Approach to Ice Field: Reduced Speed and Perpendicular to Edge.
  2. The engine room personnel should be briefed fully as to the situation and what may be required of them, as it may be necessary to go full astern at any time, and engine manoeuvres will be frequent as speed is constantly adjusted.
  3. The ship should be ballasted down to ice draft, if appropriate, or to such a draft that would offer protection to a bulbous bow, rudder, or propeller (as applicable).
  4. Once the ice is entered, the speed of the vessel should be increased slowly, according to the prevailing ice conditions and the vulnerability of the ship.
  5. If visibility decreases while the vessel is in the ice, speed should be reduced until the vessel can be stopped within the distance of visibility, if in doubt, the vessel must stop until the visibility improves.
  6. If the vessel is stopped, the propeller(s) should be kept turning at low revolutions to prevent ice from building up around the stem.
  7. Follow open water patches and lighter ice areas even if initially it involves large deviations of course.
  8. Do not allow the speed to increase to dangerous levels when in leads or open pools within an ice field, or when navigating open pack conditions.
  9. Changes in the course will be necessary when the vessel is in ice. If possible, course changes should be carried out in an area of open water or in relatively light ice, as turning in ice requires substantially more power than turning in water.
  1. Avoid turning in heavy ice – seek lighter ice or open water pools.
  2. If the vessel must make a sharp turn, the star manoeuvre will have to be performed
  3. 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 and in any case the ship should never ram astern.
  4. Avoid backing in ice whenever possible. If you must move astern, do so with extreme caution at dead slow.
  5. Any ship that is not strengthened for operating in ice should avoid floes that are rafted or ridged
  6. The easiest way to avoid being beset Is to avoid areas of Ice under pressure. The most common pressure situation occurs when open pack ice closes because of prevailing winds, but it may also occur when tides, currents, or on-shore breezes blow ice onto the shore, if proceeding along an open water lead between ice and shore, or ice in motion and fast ice, watch for a change in the wind direction or tide as the lead can close quickly.

Pressure in Ice Field Closes Track behind Vessel

  1. Abandoning ship in ice-covered waters is possible, if necessary, by landing lifeboats or life rafts on the ice, if the ice is thick enough to take their weight. Vessels fitted with quick-release drop-lifeboats without davits should never attempt to launch them into ice, but should lower them gently to the ice-surface by using the recovery equipment in reverse.
  2. Flushing out ice with wash while the bow is fixed with a spring line.
  1. 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.
  2. Keep the engine(s) on standby at river berths or strong tidal areas where ice is in motion.
  3. Mariners are advised not to rely solely on the radar for the detection of icebergs because they may not appear as clearly defined targets.
  4. The absence of sea clutter also may indicate that ice is present.
  5. 3-centimetre radars (x-band) provide better ice details while 10-centimetre radars (s-band) show the presence of ice and ridging at a greater distance
  6. Marine radar provides an important tool for the detection of sea ice and icebergs. However, do not rely solely on your radar in poor visibility 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.
  7. A very close pass from the iceberg should be avoided because the underwater portion of the iceberg can protrude some distance away from the visible edge of the iceberg at the sea surface.

Navigating Around an Iceberg and Bergy Bits

  1. Growlers are almost impossible to detect by radar. They pose an immense threat to ships. Constant visual and radar monitoring must be maintained in any area where growlers are expected.
  2. Do not try to force your way thru the ice.
  3. Change over to diesel oil prior entering the ice.
  4. Full rudder is used in emergency only. Violent rudder movement may swing the stem into ice and damage the propeller.
  5. On deck, all the pipelines are drained and isolated.
  6. Keep damage control gear ready – cement, collision mats, etc
  7. Check heating systems of machinery and accommodation regularly.
  8. Avoid anchoring in ice flow. If unavoidable, keep engine ready for immediate use.
  9. The ship stopped in ice inshore, must always point seaward.

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