Ice – The Ship Hull NemesisBy Steven Ferry
Part I: Shipping In Ice
For as long as men have traveled and traded by water-routes, ice has been a nemesis for ships and their hulls. And with good reason since, on average, sea ice covers about 25 million square kilometers (9,652,553 square miles) of the planet—amounting to about two-and-a-half times the area of Canada.
To wage ice battle, even in the earliest days of polar exploration, sailors used strengthened ships to ply icy waters. Naturally, these ships were originally wooden and based on existing designs but reinforced, particularly around the waterline, with double planking to the hull and strengthening cross members inside the ship. Often, bands of iron were wrapped around the waterline as well—forming what’s known, to this day, as the Ice Belt.
Exploring the Arctic
What would possibly lure explorers and traders into such unfriendly waters? Well, curiosity, for one, and the hope of charting new trade routes for another.
In fact, as early as 330 B.C., a curious Pytheas sailed north from Greece and, by all accounts, reached Iceland or Northern Norway.
A little later, in 890 C.E., a Norwegian Viking chieftain called Ottar travelled northeast to explore the extent of his country. It is known that he reached the White Sea in the southern inlet of the Barents Sea.
At the end of the 16th century, the British and Dutch started looking in earnest for a northern passage to the East. This time the driving motive was to outmaneuver the Spanish and the Portuguese who, by this time, controlled the sea traffic to the Far East.
Today, both the Northwestern Passage, hugging the northern Canadian coast, and the North Sea Route (also called the Northeastern Passage), hugging Russia’s northern coast, have been charted and sailed successfully.
Discovering the Antarctic
Antiquity pictured the Antarctic as the country where the antipodes lived—those who walk upside down—in a baking hot climate. By the end of the 1500s, however, seafarers began bringing back another, much colder version of this world. A world that was generally left alone until the beginning of the 20th century, when Norway, among others, began whaling these icy seas. At the height of this activity, Norway deployed 9 factory ships and over 100 whaling vessels.
Today, Antarctic whaling is illegal and the traffic volume is nowhere near that of other seas, with the main shipping activities in the Southern Oceans being fishing, research, and tourism.
The majority of the world’s ships do their best to avoid icy waters. Most succeed. There are, however, several regions where ice-going vessels are the norm, especially during the winter months.
While Norway’s Arctic shipping evolved gradually—mainly by expanding its fishing and hunting regions—recently, oil companies have begun setting their sights on exploration and recovery in the Arctic.As a major stakeholder, Norway is planning to deploy ice-class ships and cold-climate drilling rigs to meet this demand.
The country is also sailing Arctic ice-reinforced cruise vessels during the summer months, while deploying ice-going cargo vessels to transport coal from the Svea mines on Svalbard year-round.
Greenland has mirrored Norway’s cruise industry, and over the past few years has seen an annual growth in tourism of 30-40%.
Greenland also deploys several ice-reinforced cargo vessels to supply the many settlements along the coast.
Rising raw-material prices on the world market have also led to several new mining projects with shipping needs; possible oil and gas reserves in both East and West Greenland also may call for additional ice-going vessels.
At this time, Greenland has no specially built icebreaker, but new Coast Guard ships are ice-reinforced to tackle most normal ice conditions.
Sweden and Finland
Sweden and Finland—which between them surround the Baltic Sea, the Gulf of Finland, and the Gulf of Bothnia—have for a long time had to deploy ice-going vessels and icebreakers to sail these waters in the winter.
As a result, both countries have led in the development of ice-going ships and in establishing regulations to operate them safely.
During the winter months the deployment of icebreakers is coordinated between the two countries, while in the summer these vessels are used for expeditions to the Arctic/Antarctic, or rented out to the Navy or for offshore purposes.
As an example, Sweden’s largest icebreaker, the Oden, has played an important role in international expeditions both in the Arctic and Antarctic.
Over the last few decades, Finland especially has focused its efforts on technological ice-vessel improvements and through the Aker shipyards—which has its own ice laboratory and which has built a large part of the Russian ice-going fleet—Finland is possibly the largest supplier of high ice-class ships in the world.
Additionally, ever since Russia opened the oil terminal in Primorsk a few years ago, the Gulf of Finland has experienced considerable growth in tanker traffic, calling for icebreaker assistance. This need, while met, has been a great challenge since tankers as a rule are much wider than icebreakers.
The Busy Baltic
Not surprisingly, the Baltic during the winter months—when large parts of the waters are covered by ice—is one of the busiest areas in the world when it comes to icebreaker assistance and ice-going shipping. According to the Finish Maritime Administration, the total number of vessels needing icebreaker assistance in the Baltic during the winter of 2006-2007 was 4,327—hence a fleet of 20 icebreakers and a stable of ice-captains who rarely sleep.
Germany, Great Britain and Japan
The main efforts of these nations have been building icebreaking research ships to make their Arctic mark in a geopolitical context.
The United States and Canada
The U.S. and Canada, both with large oil and gas reserves in their northern territories, are planning to add to their ice-going fleets.
Canada also operates several ice-reinforced bulk ships for shipment of ore from the northern areas. As with Sweden and Finland, Canada is investing great resources in formulating efficient and secure rules for the operation of ships in its Arctic regions.
The U.S. also faces winter ice on the Great Lakes.
Russia, with its long northern shoreline, is more dependent on Arctic shipping than any other country in the world, and is without doubt the country that has focused and spent the most resources on research and ice-ship construction.
Also, over the last several years, Russia has developed her Northwestern oil and gas fields, as well as those at Sakhalin. These will eventually require additional ice-going ships to serve them.
Russia’s northern coastal area, which stretches over 165 degrees of longitude, was closed to all international traffic after the revolution in 1917, and was not opened again until 1987, when the then Soviet leader Mikhail Gorbachev announced the re-opening of The Northern Sea Route for western ships in his legendary Murmansk speech.
The near future will doubtless see increased activity in the oil and gas shipping sector, while the warming climate also spells increased transit traffic through the Northeastern Passage. How extensive the international traffic will be is uncertain, and will depend on how much Russia will charge for icebreaker support. In 2011, this was approximately $50,000 per day.
There are also indications that Russia will see a considerable growth in cruise traffic. Up until today, cruise traffic has largely been limited to expedition tourism with Russian ships, but gradually larger cruise ships will find their way into this area.
Several other countries face ice-shipping challenges, or are conducting research in the Polar Regions. In the northern hemisphere this includes, primarily Poland and the Baltic states.
Also, as a result of ice in both the northern Black Sea (the Azov Sea) and the Caspian Sea, the Ukraine and Kazakhstan do yearly battle with ice-covered harbors.
In the Southern hemisphere, ice-going activity will largely be connected to Antarctic research. Australia, South Africa, Chile and Argentina have all commissioned ships with a high ice class for this purpose, most of which are being built in Finland.
Here’s a brief summary of countries and regions that have ice cover at least some part of the year:
•Canada: Hudson Bay, Lake Winnipeg, Great Lakes
•Denmark/Greenland: Greenland Sea, Baffin Bay
•Finland: Baltic Sea, Gulf of Bothnia, Gulf of Finland
•Germany: Baltic Sea
•Norway: North Sea, Norwegian Sea, Barents Sea
•Russia: Baltic Sea, Kara Sea, Laptev Sea, East Siberian Sea, White Sea
•Sweden: Baltic Sea, Gulf of Bothnia
•United States: Alaska, Great Lakes
During the ice-season, these regions not only call for ice-class vessels (with ice-resistant hull coatings), but quite often also require icebreaker assistance.
Forecast: Arctic Shipping
Not only is the current ice water environment a busy place, growing busier by the year, but now a whole new area of icy waters is opening up commercially: the Arctic.
Today, the Arctic Ocean is still too icy and treacherous for open-water ships to traverse unaided by icebreakers, and the Northwest Passage is only navigable during the summer months once every seven years or so.
This, however, is changing and a predicted loss of sea ice will open up potentially lucrative new trade routes between the Atlantic and Pacific Oceans.
As this illustration shows, ships that currently have to navigate through the Suez or Panama canals can reach their destination a lot sooner via the top of the world (Santa’s Shortcut).
It is not surprising then, that a Financial Times article reports that as of July 2013, 204 ships had received permits to ply the Northern Sea Route, which connects East Asia to Europe via the waters off Russia’s northern coast. Last year, just 46 vessels made the trip. Two years ago, the number was four.
While Arctic shipping lanes will not put the Suez and Panama canals out of business anytime soon, new UCLA research predicts that these frigid routes will become more accessible in the future.
“The development is both exciting from an economic development point of view and worrisome in terms of safety, both for the Arctic environment and for the ships themselves,” said lead researcher Laurence C. Smith, a professor of geography at UCLA.
The researchers predict that by mid-century even ordinary shipping vessels would be able to navigate previously inaccessible parts of the Arctic Ocean, and so would not need icebreakers to blaze their path as they do today.
“We're talking about a future in which open-water vessels will, at least during some years, be able to navigate unescorted through the Arctic, which at the moment is inconceivable,” said co-author Scott R. Stephenson, a Ph.D. candidate in the UCLA Department of Geography.
“Nobody's ever talked about shipping over the top of the North Pole,” Smith said. “This is an entirely unexpected possibility.”
The blue lines on picture 6 show the fastest routes available for common open-water ships during the summer, while the red lines show routes available for Polar Class 6 ships with moderate icebreaker capacity. By 2040-2059, as shown, there would be many more routes.
Even the fabled and notoriously treacherous Northwest Passage, which traces Canada's coastline and offers the most direct route from Asia to eastern Canada and the north-easternmost part of the U.S., is expected to become more viable for Polar Class 6 vessels and possibly even ships with unreinforced hulls, which make up the lion’s share of the world's commercial fleet.
While this prospect is attractive to business, the researchers stress that the lack of current regulations poses safety, environmental, and legal issues that have yet to be resolved. The prospect of open-water ships entering the Arctic Ocean in late summer heightens the urgency for comprehensive international regulations that provide adequate environmental protection, vessel safety standards, and search-and-rescue capability, they said.
The Polar Code
While different countries and jurisdictions have some rules and regulations in place pertaining to Arctic shipping, including rules to protect the polar environment, the International Maritime Organization (IMO) is still at work reconciling such rules into a Polar Code.
Many had hoped that this code would already have been in place, but as of this writing, it is still with a sub-committee considering various proposals from countries concerned.
The current estimate is that there will be an International Polar Code in place governing both safety and environmental Arctic shipping issues, but not until 2016.
The Fragile Polar Environments
As the UCLA and other reports point out, increased arctic shipping does pose a threat to the fragile and, as yet, pristine polar environment, where over centuries, polar biota have adapted to extreme conditions characterized by large variations in temperature and light, and the effects of snow and ice.
However, these adaptations have made some plants and animals more sensitive to human environmental impact.
Though it normally (and unfortunately) takes a back seat in these discussions, the projected increase in Arctic shipping could, if not managed responsibly, have a devastating effect on the polar environment.
These potential catastrophes come in these forms:
•First, and most dramatic, are accidental spills—either through collision or other mishaps—of oil and other toxic material;
•Second, the toxic substances used in conventional, and typically fragile, hull coatings are scraped off along with the paint when ships move through icy waters;
•Third, toxic antifouling systems in general use leach heavy metals and highly toxic biocides or emit other toxic substances into the water as a matter of course;
•Fourth, a grave environmental hazard to polar waters is posed by the translocation of invasive, non-indigenous aquatic species in the form of hull-borne fouling organisms;
•Fifth, biocidal antifouling coatings create a copper-tolerant or biocide-tolerant type of non-indigenous species which are particularly dominant and harmful to the environment they invade; and
•Finally, atmospheric emissions such as GHG and black carbon increase in direct relation to fuel consumption—a rough hull can increase the fuel cost, and with it harmful emissions, by as much as 40%.
The polar-zone ice creates a hazardous and harsh environment for ships that heightens the possibility of wrecks, spills and other forms of environmental damage.
Oil spills come in two varieties: a struck tanker can leak crude oil into the waters, as in the case of the Exxon Valdez; or a tanker or other ship can leak its own bunkers, consisting usually of heavy fuel oil (HFO), which is even more harmful to the environment than crude.
There are proposals on the table to ban the use of HFO for Arctic-going vessels, only permitting the use of distilled (and less hazardous) fuels.
Aconventionally hull-coated ship plying icy waters for a season reports back to drydock virtually coat-free—just metal.
And what happened to the coat? It was scraped off by the ice and left to contaminate the polar waters. If this was a biocidal antifouling coating, tons of toxic heavy metals and biocides are left behind in the polar regions.
For as long as ships have been around, their owners have attempted, with varying degrees of success, to surface treat their underwater hulls with coatings to prevent the adhesion and growth of fouling organisms that, once settled in, cause severe drag, reducing vessel speed and maneuverability, and greatly increasing fuel consumption.
Today, two major approaches are used:
•Foul-release coatings, usually employing silicones or fluoro-polymers designed to prevent strong adhesion of foulants. These are paints that are very easily scraped off in icy waters.
•Biocidal antifouling coatings which typically contain heavy metals and other biocides which are toxic to foulants upon release, and which are slowly but continuously released from the coating during its ablative process.
Let’s note the derivation of “biocide” — bio, life; cide, kill. In other words, these antifouling systems work by releasing heavy metals and poisonous chemicals designed to kill marine life. Such coatings do not stop releasing the toxic substances in icy waters, and kill much more marine life than intended. They can also lead to the translocation of copper-tolerant or biocide-tolerant invasive species which are even more dominant in the invaded environment than usual.
Any owner of even a small boat may be surprised to find how quickly the below-waterline hull, while sitting in the water, is populated by marine life of various forms and sizes—this marine life, transported to a zone where it is not native, then classifies as non-indigenous species (NIS) some of which are a nuisance or worse in the new environment.
That problem, times, say a thousand, is what ship owners face on an ongoing basis while in port—especially warm-water ports.
If the ship in question is then heading for polar waters, it faces a dilemma: either use biocidal antifouling to keep the NIS population in check—to then release the biocides and the biocide-tolerant species into the polar ecosystem—or, since conventional hull coatings are very hard to under-water clean of such marine life, bring a hullfull of non-indigenous marine life into the Arctic where it soon will be scraped off by ice and so deposited into a pristine and vulnerable environment where it then proceeds to wreak havoc.
Is there a third option? Fortunately, as you will see in Part II, there is.
Part II: Ice-going ships, their hulls and protective coatings
If a ship with a fouled hull is heading for polar waters, it faces a dilemma: either use biocidal antifoulingto keep the NIS population in check—to then release the biocides and the biocide-tolerant species into the polar ecosystem—or, since conventional hull coatings are very hard to underwater clean of such marine life, bring a hull full of non-indigenous marine life into the Arctic where it soon will be scraped off by ice and so deposited into a pristine and vulnerable environment where it then proceeds to wreak havoc. Fortunately, as you will see in this part of the article, there is a third option.
Two types of vessels normally ply the icy waters: icebreakers, and ice-class ships.
An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters and, as the name suggests, break a passage through the ice. For a ship to be considered an icebreaker, it requires three traits most normal ships lack: a strengthened hull, an ice-clearing shape and the power to push through sea ice.
Icebreakers clear paths by pushing straight into ice pockets. The bending strength of sea ice is so low that the ice normally breaks without noticeable change in the vessel's trim. In cases of very thick ice, an icebreaker can drive its bow onto the ice, sometimes repeatedly, to break it under the weight of the ship.
The chart attached shows where the world’s 111 icebreakers are deployed, i.e. which countries own and operate them, sheds light on where icy waters are a front-burner problem.
As shown, Sweden, Denmark and Finland have 20 ice breakers between them, in order to cover a relatively small area of ocean: the Baltic Sea, the Gulf of Finland and the Gulf of Bothnia.
Then, again, Russia deploys 40 ice breakers, telling its own tale.
Canada, not surprisingly deploys six icebreakers, while the United States (covering both Alaska and the Great Lakes) deploys seven.
Ice Class ships
As far as coping with icy waters goes, the next rung down from the icebreaker is the ice class ship.
What Ice Class means
In short, a ship is considered ice class if it has a strengthened hull to enable it to navigate through ice. Additionally, an ice-class vessel requires structural reinforcements, particularly at the ice belt. Most of the stronger classes also require several forms of rudder and propeller protection.
The American Bureau of Shipping(ABS) has a system of ice classes which includes classes A5 through A0, B0, C0, and D0. The A5 class is the strongest built of the classes, with D0 being the weakest.
All other major classification societies have a similar system of ice classes, and converting between ice classes is relatively easy. In most cases, only the names of the classes are changed while the specifics of the Arctic class remain similar or identical.
ABS Class A5 is the only Arctic Class that may act independently in extreme Arctic waters with no limitations. Other classes are subject to limitations on time of year, required escort (always with a vessel of higher ice class) and ice conditions.
Finnish-Swedish Ice Class
According to the regulations issued by the Swedish Maritime Administration and the Finnish Transport Safety Agency (TraFi), merchant ships operating in first-year ice—i.e. ice new for the season and not remains of last season’s ice—in the Baltic Sea are divided into six ice classes based on requirements for hull structural design, engine output and performance in ice. International classification societies have incorporated the Finnish-Swedish ice class rules into their own rulebooks and offer equivalent iceclass notations that are recognized by the Finnish and Swedish authorities.
Ships of the highest ice class, 1A Super, are designed to operate in difficult ice conditions mainly without icebreaker assistance while ships of lower ice classes 1A, 1B and 1C are assumed to rely on icebreaker assistance.
IACS Polar Classes
The International Association of Classification Societies(IACS) published a set of Unified Requirements for Polar Class Ships to complement the IMO Guidelines for Ships Operating in Arctic Ice Covered Waters. This will effectively unify the ice classes for all IACS member societies. Seven Polar Classes are proposed in the requirements, abbreviated as PC1 through PC7.
500 and counting
Today, there are about 500 ice-classed ships in the world, a number that is expected to grow significantly as the Arctic passages (the Northwestern Passage and the Arctic Sea/Northeastern Passage) open up for shipping.
As those who sail icy waters are well aware, ice damages hulls. How much or how little depends on skill, foresight, and—to a degree—luck.
This damage normally comes in two forms: structural damage to the hulls, and damage to the hull coatings.
Structural hull damage
Hull damage from icy waters includes:
•Dents on the plating, frames, stringers and web frames. As mentioned, these are often cumulative.
•Fractures: Cracks and ruptures occur most often on the plating. These can be found on ships that are in bad repair. The reason for ruptures is often that plating has worn out. Cracks are usually observed in a junction of plate and frame below water-line level.
•Wear in paint: Ice pieces wear a ship’s paint due to abrasion. This can be seen clearly at the water line level, but also in the bilge and the bottom areas.
•Bilge keel damage: Bilge keel dents, scrapes, and ruptures are often incurred by passenger vessels while maneuvering in harbor or in an ice channel.
In September 2013 the tanker Nordvik hit an ice floewhile on the Northern Sea Route and was holed and started taking in water. Ice damage can be sudden and serious or can simply wear the hull down over time, creating a growing hazard for the ship and the environment.
Events or situations that cause structural ice damage include:
•High speed in ice: This relates especially to ships of high propulsion power compared to their size.
•High speed in an ice channel may damage a ship’s side shell and plating above the water line on the bow area due to extended ice loading by the bow wave.
•Damage in an ice channel: Mid- and aft-ship hull areas may be in contact with the channel edges when the ship is turning.
•Compressive ice: The ice channel may close due to the moving ice field. In this situation, the ship becomes stuck in ice, and damage often occurs in the mid-ship area on the flat side region.
•Ice ridges: Ice ridges may extend 3 m above and 20 m below the water level.
•On ships in bad repair or with insufficient ice strengthening, ice damage to the hull is often cumulative, i.e. dents and scrapes incurred during successive winters.
•An often overlooked cause of structural hull damage is corrosion. When the protective paint coating is scraped off, the underlying steel is exposed to the highly corrosive seawater. In Antarctica the ice may also contain lava which adds to its corrosive effect on the steel. As a result, the now unprotected steel plates are worn away by the abrasion of the ice and the corrosive effects of seawater.
Hull coating damage
If ice contact—and we’re not talking ramming icebergs here—can do this much structural damage, it is no wonder that it can be murder on hull coatings.
Included with this press release are some photos of the hull of an icebreaker recently returned to drydock after Polar service, as well as some in which you can see the hull of an ice-going cargo ship after a year in ice with conventional hull paint.
Hull coating damage—effects
Apart from the most obvious impact—losing major areas of hull coating that leaves the hull exposed and unprotected, thereby shortening the hull life—the other major impact is significant loss of fuel efficiency.
A rough and fouled hull can invoke a fuel penalty of 40% or more. Even a fairly smooth hull with a heavy slime layer can carry a 20% fuel penalty. Extra fuel burned to propel the ship means extra, unnecessary atmospheric emissions including Nitrogen Oxides (NOx), Sulfur Oxides (SOx), CO2, and black carbon. These emissions have been shown to be more harmful in polar regions than in other waters.
The fuel penalty is also economic: fuel is not cheap. In fact, adding 25-40% to the fuel bill can make the difference between profit and loss.
These factors apply to any vessel sailing in any conditions, but the polar regions are particularly sensitive to harmful air emissions and it is therefore even more important to do anything possible to reduce such emissions from ships operating in these zones.
A smooth hull that is not subject to coating degradation but remains smooth for the life of the ship—or even becomes smoother with regular cleaning—greatly helps reduce this fuel penalty.
Also, a hull coating that permits regular and easy in-water removal of fouling, including slime, is the other part of the equation. The fuel penalty can be kept as low as the few percent that would result from the slime layer that accumulates in between cleanings.
The costs of trading in icy waters
Conventional hull coatings, as shown earlier, are mostly, if not all gone after even one season in the ice, calling for a drydock visit to have the coating reapplied.
This has been a very familiar story to Wim van Eck, partner in W&R Shipping, who has spent most of his seafaring career as a captain, trading mainly in the North of Europe and the Baltic Sea: “Of course, we always were confronted with the fact that in the winter time when you were sailing through the ice, your paint would disappear and so you had to drydock in order to repaint during the summer time.”
Is there a way around this annual repainting in drydock?
Conventional Ice-grade coatings
One solution is to apply a more durable, ice-grade coating.
However, even though there are several ice-grade coatings available, by one manufacturer’s own admission, many of these require extensive care in application:
“It is fair to acknowledge that some shipyards have expressed reluctance when asked to apply [our product]. And, since proper application is critical with any hull coating, their concerns must be addressed.
“Because [our product] has a very low solvent content, it cures rapidly, ‘going off’ within minutes. It is so viscous that it must be heated for spraying and must be applied to steel with a relatively deep 75-micron blast profile in one coat, 500 microns thick.
“Here, the solution is application by way of a hot twin-feed spray machine, where the curing agent and the base are heated and mixed at the point of application immediately before spraying. In short, the ratios of the curing agent and the base are preset, and delivered automatically.
“Some shipyards more accustomed to single pump coatings delivery have expressed concern over the perceived complexity of this method.”
Okay, this is one solution, but is there a way around its complexity? Yes, there is.
Stephen Lee, former Senior Marine Engineer for British Antarctic Survey—the BAS’s equivalent of a Technical Superintendent—was instrumental in the initial research which led to replacing the Antarctic-going research and supply vessel RRS Ernest Shackleton’s underwater hull coating in 2009.
He recalls: “We looked at all the alternatives, including a product called Ecospeed, making many comparisons between all of the products available.
“For instance, because of the nature of our business and where we operate, we also required a paint system that would have significant environmental benefits as well as conforming to the polar code and latest classification societies regulations. We required a paint system that was cost effective in purchase, application, and maintenance.
“We wanted a simplified paint system that no matter where you went in the world, a paint contractor would be able to apply it without having to rent expensive equipment or shielding to ensure application could continue.
“We also wanted to be able to conduct minor repairs either by the yard paint contractor or our own crews. Ecospeed gave us this capability.
“Application of some of the more traditional icebreaker paint requires twin feed paint system which requires a great deal more care during the application process, as well as ensuring all the environmentals are correct, which can include tenting up space heaters around the area that is to be painted.
“The other paint options were very comparable with Ecospeed in terms of purchase price and performance in the broadest of terms, but the main, huge difference was the actual cost and complexity of application of the paint.
“The preparation is the same, 2.5 SA (near-white blast cleaning) over the hull, but the actual application, not having to get the environmentals right, not having to tent up the area, if it’s slightly cool not requiring space heaters, if the area is gingered slightly which may or may not require a sweep blast before you can put the primer on—there’s a huge amount of preparation and logistics that have to go into getting the initial coat of traditional ice-going paint onto the hull, whereas with Ecospeed it’s minimal as long as you have a good paint inspector, and only minimum environmentals are needed.”
Surface Treated Composite (STC)
Ecospeed, to understand its advantage, is a special glassflake reinforced Surface Treated Composite (STC)—a type of hull coating which not only offers hull protection performance that surpasses any conventional ice-grade coating, but which also accomplishes this feat through a simple, single-pump coating, welcomed by all shipyards.
The STC solution
No one is disputing that Arctic shipping will continue to increase. At the same time, shipping in and around the Baltic, Greenland, Alaska, the Great Lakes, and the Russian ice bound lakes will, if not increase, continue unabated as well.
This calls for a hull-coating solution that will solve the major problems facing ships sailing icy waters, as discussed above – a hull coating that:
•adheres to the hull even under the most adverse and icy conditions, and so continues to protect the hull;
•is entirely nontoxic and so does not release biocidal antifoulants into the environment or leave toxic debris scraped off on the ice;
•provides a smooth, strong,low friction coat which can be in-water cleaned easily of all biofouling prior to leaving warm-water ports to both increase fuel efficiency and to prevent translocation of NIS into icy latitude waters;
•does not require elaborate temperature and other arrangements or advanced shipyard technologies to apply
•is very durable and long-lasting, which is particularly important to offshore oil and gas exploration and production vessels which do not drydock very often – the coating should last 25 years or more; and
•is flexible so that it continues to adhere to the steel plates of the ship even when they are flexed and distorted by impact with the ice.
This hull coating exists. It is a glass-flake reinforced Surface Treated Composite (STC).
A coating that:
•provides long-lasting, smooth, low friction protection of the hull even in extremely harsh environments;
•is nontoxic, nonpolluting, noncontaminating;
•provides the best answer to preventing the spread of hull-borne NIS;
•is very fuel efficient and so provides significant reduction in fuel costs, GHG, black carbon;
•is easy to apply; and
•can be cleaned underwater as often as needed, improving its surface texture over time, without damage to the coating or harm to the environment.
When it comes to protecting the hulls of ice-going vessels, the nontoxic glassflake reinforced STC Ecospeed has proven to be remarkably durable, typically outperforming other specialized ice class paints.
It has demonstrated excellent attachment to the hull, low friction properties, and successful resistance to extremely icy conditions, withstanding the harshest winter seas and ice on numerous occasions.
Over the last ten years, about 30 Ecospeed-coated vessels have sailed the northern Baltic Sea, Canada and the polar regions during winter, some even as far as the North and South Poles. These vessels, frequently enduring the impact of large pieces of floating dry ice, or the pummeling of the ice which is part of the icebreaker’s stock-in-trade, have shown no ice damage, and very little coating deterioration; and none of these vessels required more than just a few touch-ups during their drydock visits.
Certified abrasive resistant coating
Consequently, Ecospeed has received the Lloyd’s Register certificate that recognizes the coating as an abrasion resistant ice coating. This allows owners of vessels intending to navigate in ice conditions to reduce the thickness of the plating of the ice belt—the area on the bow just above the waterline that is most prone to mechanical damage from sailing through ice—if this area is coated with Ecospeed.
Interscan Schiffahrt controls a fleet of 23 container and multipurpose cargo ships ranging in size from 1,723 to 11,800 dwt. Many of these vessels trade in northern Europe, mainly in the Baltic.
Until 2005, all those ships trading in ice in the Baltic region went through a cycle of having all their bottom paint scraped off by the ice each winter and having to drydock and repaint every spring. The paint used was a standard epoxy coating.
In 2005, the superintendent engineer came across Ecospeed and decided to test the environmental and fuel saving benefits of this product on MV Patriot, an 82.3-meter ice class E2/Finnish 1B general cargo vessel.
Seven years later, Michael Tensing of Interscan says, “She was here recently and the paint still looks good. That’s the best advertisement you can have. You don’t have to do much to the paint. It’s only a can of paint for touch-ups, just cosmetics at the anchor pocket or if you have mechanical damage or something. The rest to my mind is really very good.”
As he points out, there really is no other coating that could stand up to seven years of trading in ice and still remain intact and not in any need of repainting or anything beyond very minor touch-ups.
W&R Shipping experience
W&R Shipping has converted its existing fleet to Ecospeed and specified Ecospeed as the coating for any newbuilds ordered.
In 2007, cofounder Captain Wim van Ecke read about Interscan’s success with Ecospeed on vessels that, like his, were also trading in Baltic and Northern European ice every winter, and he decided to try Ecospeed on the W&R ships.
As a result, W&R has now standardized on Ecospeed, and for good reason. As Capt. Van Ecke points out, “Having Ecospeed on the hull can save us some days in drydock which would be needed to repaint if we were using a less durable coating.”
RRS Ernest Shackleton
When British Antarctic Survey’s RRS (Royal Research Ship) Ernest Shackleton left drydock in 2009, the hull was newly coated with Ecospeed.
After two seasons in the ice with Ecospeed the vessel neededno repair or recoating. Note that the section of hull above the waterline had not been coated with Ecospeed originally and this omission was subsequently corrected when the level of protection afforded by Ecospeed was clear to see.
When she returned to drydock after two seasons of battering her way through ice up to 2.5 meters thick with a high content of gravel and volcanic lava adding to its abrasiveness, the hull coating was virtually intact and undamaged, bar a very few nicks and scratches.
A very surprised Stephen Lee, then Senior Marine Engineer for British Antarctic Survey jokingly asked, “Are you sure you’ve taken this ship to the ice?”
According to Lee, the crew of the Shackleton reported that they had been pushing into 2-2.5 meter thick ice, “. . . and it’s just not touched it—just not touched it at all.”
Lee continued, “The biggest thing was the surprise at seeing the areas where you’d expect it to have sustained a lot of damage . . . when she first came out of the water and onto the blocks it was a complete shock to all those present. All of us there commented on the condition of the hull and in particular that there was negligible damage at the bows, merely some scratch marks. None of us there would have predicted this.”
A paint inspector’s surprise
Howard Jess was the paint inspector for the initial Ecospeed application to the Ernest Shackleton in 2009, and he viewed the hull again after two years in the ice.
“I was very impressed with the condition of the coating on the Shackleton after two seasons in the ice,”says Howard.“Apparently she had been trapped in the ice on several occasions and the procedure is to reverse and then crash forward at full speed. Yet the coating remained intact – pretty impressive.”
As this article was written, the Shackletondrydocked again, after four seasons in the ice, and the coating was found to be in incredibly good shape, as reported by the paint inspector Howard Jess.
While there are manufacturers of ice-specific hull coatings, and while there is no disputing the relative efficacy of such products, we have chosen to spotlight Ecospeed as the ice coating of choice because it comes with an unheard-of 10-year guarantee and because it is so easy to apply when compared to the complexity and temperature sensitivity required for applying the other ice coatings.
As admitted above by one of these manufacturers, many shipyards are in fact hesitant to work with these products since they can too easily spoil during application, and require meticulous preparation as well as expensive equipment and laborious environmental set-ups (such as dual nozzle sprayers, tenting and heating).
In contrast, Ecospeed is applied like any conventional, temperature-tolerant coating in two simple coats, each of 500µm with a three-hour minimum, no maximum overcoat time, to a total of 1,000µm dry film thickness (DFT).
Over the next several decades, ice-going traffic will continue to increase and along with that so will the potential damage not only to hulls and their coatings, but also to the pristine ecological environments seeing this traffic.
Therefore, choosing the best hull protection is no longer just an economical issue, but also an ethical one.
Another factor in choosing a protective hull coating is that the cost of an effective coating lies not only in the paint itself, but also in its ease or complexity of application, in its longevity, and in the fuel savings it makes possible. The difference between painting the hull every year and not having to do so for 25 years is considerable.
The right coating, then, requires careful consideration and a weighing of all relevant factors including total ownership cost.
As discussed above, the jury has returned with a verdict: The best choice—the one that meets both economic and environmental requirements—is a glassflake reinforced Surface Treated Composite (STC) coating.
Ecospeed has shown itself to be the toughest and most durable STC and the only one that comes with a 10-year guarantee.