White paper 14_Opmaak 1 3/10/14 15:07 Pagina 1 WHITE PAPER Hull Protection for Ice-going Vessels N°14 PAPER WHITE HYDREX Tackling the special coating requirements of the hulls and running gear of ice-going ships and icebreakers The Hydrex Group www.hydrex.be White paper 14_Opmaak 1 3/10/14 15:07 Pagina 2 Copyright 2014 by Hydrex, nv. All rights reserved. White paper 14_Opmaak 1 3/10/14 15:07 Pagina 1 Hull Protection for Ice-going Vessels Part I: Introduction Part I. Introduction ce represents a severe hazard to ships. reduction in the ship’s scantlings of up to IIcy waters, icebergs, packed ice, old 1 mm in thickness of steel plate. This can add ice, first year ice, lava- or gravel-laden up to a significant reduction of steel or other ice or any other form of ice are all substrate and in the overall weight of the significantly more challenging to a ship vessel. than water. More than in any other marine The fuel efficiency of the hull coating is application, choices regarding ships that also very important, especially when one will sail in ice can be a matter of life or considers current fuel prices. A hull coating A hull coating that death. that reduces friction and remains smooth reduces friction over the ship’s life cycle will result in and remains There are many ice-specific class regulations tremendous fuel savings for the operator. smooth over the ship’s life cycle intended to reduce the risk of that hazard and But this is not just a point of economy. will result in promote safety for ships sailing in such Reduced fuel consumption means fewer tremendous fuel conditions. noxious, harmful atmospheric emissions savings for the When it comes to choosing a hull coating such as CO2, NOx, SOx and Particulate operator. for icebreakers and ships that sail or trade in Matter including black carbon. Hull fuel icy waters and their rudders and running gear, efficiency comes down to two main factors: certain key factors must be looked for. 1) long-term hydrodynamic smoothness and The first and most important is protection. low friction of the hull; 2) freedom from The steel or other material from which the biofouling, either by repelling it or by hull is made must be protected from this removing it before it accumulates to any harshest of harsh environments. This means large degree. While not nearly as significant a really tough coating which is resistant to a factor in icy waters as in temperate or the abrasion of the ice, which will adhere tropical climes, the control of fouling must under the constant pounding and scraping still be taken into account when choosing the that accompany sea voyages through ice. It best hull coating for trading or sailing in ice. also means a coating that is not brittle or Low friction is a key property of a hull inflexible and therefore subject to cracking or coating for an ice-going vessel or icebreaker. disbonding when the panels that make up This permits the vessel to move through the hull flex and bend, even permanently ice more rapidly, or at least less slowly, denting, under the impact the ship receives especially when the ice friction is increased from the ice. As soon as the hull coating is by a covering of snow. It also makes it easier damaged, corrosion of the underlying hull for an icebreaker to ram onto and reverse off can set in and spread. There is an economic the ice during icebreaking operations. This factor here too. Certain ice abrasion resistant is an economic factor but also a safety hull coatings are certified as such by the factor. Less fuel will be consumed by a classification societies. This certification ship operating in ice which has a low friction includes the provision that the coating, if coating on its hull. The danger of running correctly applied to the ice belt, will permit a out of fuel or having to curtail a voyage is - 1 - White paper 14_Opmaak 1 3/10/14 15:07 Pagina 2 Hull Protection for Ice-going Vessels Part I: Introduction reduced. application? How long will it last? Does it Environmental considerations are very need frequent and expensive repair or important. The Arctic, the Baltic, the Great replacement in dry-dock? If so, how difficult Lakes, the Antarctic, southern South America and/or expensive is it to repair/replace? Can and many other environments where ships it be safely cleaned in the water without operate in icy conditions tend to be relatively damage to the coating or harm to the marine pristine when compared to the much more environment? traveled sea routes and other waterways. These then are the main points which can Certain pollutants such as black carbon are be greatly influenced, for better or for worse, much more harmful in the same volume in by the choice of coating used on the hulls of polar waters than in tropical or temperate ice-going vessels and icebreakers: zones. These areas are particularly sensitive 1. Protection and safety. to the invasions of alien species and to the 2. Economy of operation and reduction of effects of heavy metals and other toxic total ownership costs. substances such as those leached by biocidal 3. Environmental sustainability. antifouling coatings and many foul-release 4. Ease of application. coatings. A further aspect which must be This White Paper examines the subject, considered when choosing a coating for the the types of coating available and the best hull of ice-going ships is the ease of applica- approach to choosing the right coating for the tion and maintenance of the coating. Does it hull and running gear of ice-going ships. require special conditions and equipment for - 2 - White paper 14_Opmaak 1 3/10/14 15:07 Pagina 3 Hull Protection for Ice-going Vessels Part II: Climate of change Part II. Climate of change or icy waters, particularly the Arctic precautions specifically for vessels operating FOcean, shipping traffic is in a major in polar regions. A number of suggestions state of flux. This has been big news, were put forward, and preliminary work was attributed to climate change and receding done, concentrating more on the safety aspects summer ice, opening heretofore impass- than the environmental ones. These suggested able ship routes and making Arctic travel or desired requirements included the use of ice possible or easier. Reports are somewhat abrasion resistant, non-toxic hull coatings, and conflicting on the subject but in general measures for preventing hull-borne invasions the forecasts are for increased or greatly of non-indigenous species in the form of increased shipping in icy waters. biofouling, which would mean ships sailing into Polar regions having a macrofouling-free Offshore oil and gas exploration and produc- hull. While work on the Polar Code had not tion activities in Polar regions, particularly been completed at time of original publication the Arctic, are increasing. The reserves of oil of this White Paper, shipowners and operators and gas in Arctic regions are estimated to be planning to sail in these waters need to take about one quarter of the world’s proven the possibilities into consideration as they sources.1 The countries that border the Arctic build new vessels or replace the hull coating Ocean are all increasing or planning to on ships in service. increase their shipping activities in the icy If delays on developing an acceptable waters of the Arctic region. Remote offshore Polar Code continue, it is quite likely that vessels are expected to stay on station for individual ports and States affected will long periods of time without going to dry- develop and impose their own requirements. dock. This poses a challenge to hull coatings This is far from optimum since the various in that they need to protect the vessel from nations and authorities involved are unlikely corrosion and be cleanable for underwater to come up with the same set of regulations, inspections in lieu of dry-docking (UWILD) and ships traveling between and among the by classification societies. Toxic antifouling various ports and States will need to keep coatings and other soft coatings are not track of and follow different sets of rules. Far appropriate for ice-going vessels since they simpler would be a rapidly completed, IMO- are easily damaged or scraped off by contact led Polar Code which can be agreed on by all with the ice. The additional factor of not affected States. going to dry-dock as in the case of off-shore These various factors are all coming exploration, production and storage vessels together to pressure shipbuilders, shipyards, The question is, how does one imposes severe requirements for toughness shipowners and ship operators to make the choose the best and durability on the coating used to protect correct decisions concerning the application hull coating the hulls of such vessels. and repair of hull coatings on ice-going vessels. system for this Work was started by the IMO in 2009 on a The question is, how does one choose the harsh and Polar Code supposed to recommend or dictate best hull coating system for this harsh and unforgiving safety and environment-related conditions and unforgiving environment? environment? 1Cambos, Philippe, et. al. “Technical Challenges Associated with Arctic LNG Developments: A Class Society Approach,” Bureau Veritas, Paris, (2013). - 3 - White paper 14_Opmaak 1 3/10/14 15:07 Pagina 4 Hull Protection for Ice-going Vessels Part III: Issues with Hull Coatings for Ice-going Ships Part III. Issues with Hull Coatings for Ice-going Ships hat are the special requirements eats away at the hull which then becomes Wfor hull coatings on ice-going thinner and less able to withstand the forces ships? of sea and ice.