Feature 2 | ICE CLASS
“Although reduced ice cover might
superficially imply a reduced requirement for ice-breakers and tugs, if traffic volumes increase, then there may be an increased demand for ice-breakers on routes which were not previously commercially viable and also to cater for increases in traffic on routes where there is a desire to extend the seasonal availability of those routes.” As far as machinery issues were considered,
he highlighted at the recent Tripartite meeting, increased redundancy and or robustness of main and auxiliary machinery, increase in power demand for systems such as trace heating of external piping, provision of deck steam lines, heating of accommodation & work areas and a potential increased in power for ‘Polar Class’ notations. “Te need to guarantee performance in
low temperature may lead to changes in a wide range of equipment, not just for obvious considerations such as the need to avoid low temperature brittleness in steel structure and pipework, but also, for example, potential requirements relating to the viscosity and
effectiveness of lubrication and hydraulic fluids along with consideration of the need for equipment controls, valves and various mechanical devices to be operable by seafarers wearing heavy clothing. “Tere may be a consequent general impact
on new ships if increased availability of high latitude routes encourages owners to make some basic provision for potential use on Polar routes at some point during the commercial life of the ship.” Mr Tongue added that the treatment of
redundancy for machinery is still a matter of concern in relation to IMO discussions on the Energy Efficiency Design Index . “It is likely that if a vessel is designed with the intention of polar operation, then even with no formal ice-class solutions, such as twin shaſt / heavier shaſt / redundancy of prime mover could be reasonable considerations and would need careful assessment. Similarly systems which have no, or very little, power demand on ships intended for general service may need to draw power for effective operation in low temperatures”.
“More specific consideration of the bridge
and navigational equipment provided to ships may be necessary. For example, particular consideration could be necessary for the provision of suitable equipment to guarantee the availability of effective operational and emergency communications at high latitudes, Tongue says. “For ships regularly operating in
ice-covered waters consideration might be given to additional/ more powerful radar systems and/or consideration of the provision of SONAR, thereby leading to additional increases in the need for electrical power. In addition to more obvious considerations
such as the operability of equipment in low temperature environments, the effectiveness at low temperature of the various fire-fighting media may need to be assessed. Tere may be related issues such as for example the need to ensure that fire-fighting water can be either adequately cleared from open decks for example as it is deployed or that any resulting icing is manageable.” NA
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Shaft_ad_190x130_v3_QR.indd 1 The Naval Architect January 2012 9/26/11 11:31 AM
NEW!
Ice Impact feature in Torsional Vibration module
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