Skill or Will? (2)
A very popular saying in the English Language says: “when the going gets tough, the tough get going”. We think this saying perfectly matches ice navigation-related issues.
Although the concept of an “ice class ship” is not a new one, technology has developed in the years following. Even ice breaker ships evolved from being constructed of plain wood and being operated by steam engine, like the pictured City Ice Boat No. 1, to today’s full steel hulled ice ships, propelled through nuclear power.
The first ice ship that used nuclear power to break the ice in its route waters was the Soviet ship Lenin in the year 1959. But whilst icebreakers are special-purpose vessels designated for breaking ice floes, sheets, and piles in cold climates where the water is mainly icy, ice-class ships are usually general-purpose design ships with the additional level of strengthening and arrangements for navigation and sustenance in ice.
Construed and construction’s rules for ice navigating ships define what Ice Class the ship belongs to. These classifications reflect the ship’s ability to performs amid sea ice and, after the American Bureau of Shipping.
“Ice-classes” are set in a hierarchical order going from A5 through A0, followed by B0, C0 and D0 – from strongest to weakest – to indicate the degree to which the hull has been fortified. But back on the “must-have-skills-set” a commander of a vessel navigating in polar water needs, this comprehends 5 fundamental points to be kept on mind:…
1. Manoeuvring in Ice. Ice navigation should be made at right angles to the leeward edge where the ice is loose or broken. If a floe cannot be avoided then it should be hit squarely with the stem. A glancing blow may throw the vessel off course so, entry in ice, should always be done at low speeds. Once into the pack speed can be increased to maintain headway and control so as to avoid ice floes to hit hull, rudder or propeller. Avoid sharp alterations of course.
2. Lookouts. Keep looking for leads through the ice (navigable channel within an ice field). Add more lookouts at forward or at higher ends for safety concerns. Reckoning should be carried out from the ship’s bridge to get a better view of the ice accumulation.
3. Engine care. During ice navigation, engines should be kept running at all times and under manoeuvring conditions in such a way that the ahead and astern movements can be easily carried out without time delay. Also, when ice approaches the stern of the vessel while manoeuvring, bursts of the engines should be given accordingly to keep ice from accumulating.
4. Navigation at night. At night, it is preferred to “heave to” since the leads or lanes cannot be seen. Most ice navigators stop the vessel along the edge of the ice and leave the vessel drifting along with the pack. Also, seawater lubricated tail end shafts, are in the danger of getting frozen. To avoid freezing, vessels with single screws should have their aft peak tank filled with water and have it kept warm using steam hose injection, or other alternative means. The vessel should keep her engines running with the propeller on low RPM to avoid seizure by ice.
5. Anchoring. Anchoring in heavy concentrations of ice or when ice is moving may break the cable. Better looking for conditions like light brash ice, rotten ice or widely scattered floes with the main engine on immediate notice. The anchor should be brought in as soon as the wind threatens to move ice onto the vessel.
All Rosetti Superyachts’ vessels are also equipped with Dynamic Positioning (DP1 e DP2) an advanced technology borrowed by Rosetti Marino’s know-how able to automatically maintain the vessel‘s position and heading, by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompasses, provide information to the computer pertaining to the vessel’s position and the magnitude and direction of environmental forces affecting its position.
Inspired from one of the most intelligent sea mammals on Earth, the last born RSY 65m Explorer “ORCA” (Killer Whale) is engineered after the newest techniques and technologies for ice navigation and has it all: DP1&2, Remote Controlled Navigation System and certification Ice-Class D0, as if to say, she’s ready to roam the polar water in 36 months, after the order is placed.