As Marine Engineers’ Beneficial Association (MEBA District 1) members picketed its ships, Liberty Maritime Corporation of Lake Success, N.Y., today announced that it has entered into a new collective bargaining agreement with
Maersk Line, Limited and Rickmers-Linie (America), Inc. have announced a partnership to provide breakbulk and project cargo shipping using two newly-built multi-purpose ships to be operated under the U.S. flag. The partnership
Bahamian shipowner Campbell Shipping Ltd. has signed an order with Tsuji Heavy Industries (Jiangsu) Co., Ltd. located at Zhang Jia Gang, China for two 37,500 dwt double-hull log fitted bulk carriers, with
George Economou led DryShips Inc. (NASDAQ: DRYS) has entered into a definitive agreement to acquire the outstanding shares of OceanFreight Inc. (NASDAQ: OCNFD) for consideration per share of $19.85, consisting of $11.25
Rand Logistics, Inc. (Nasdaq:RLOG)) today announced that it has signed a binding asset purchase agreement, that will see its subsidiary, Lower Lakes Towing Ltd. acquire the Maritime Trader, a Canadian flagged dry
Cardiff, U.K., based Graig Ship Management Limited has taken delivery of the 79,600 dwt bulk-carrier King Peace. It is providing full technical management and crewing of the ship on behalf of Shanghai-based
Deltamarin has received the first order for its B.delta37 standard bulk carriers, which have gotten market interest of the market with their improved cubic capacity and low fuel consumption compared to other
Whatever may be happening on the Baltic Dry Index, shipowners are still ordering bulk carriers. Among shipyards getting bulker orders is China’s Yangzijiang Shipbuilding (Holdings) Ltd. It reports that it entered into
“Orders are drying up. We are faced with an unimaginable situation at which our dock may soon be empty,” wrote Choi Kil Seon, Chairman of the world’s largest shipbuilder, Hyundai Heavy Industries, in a letter to employees this past March. Complacency had set in during the boom years of the 2000’s, he said, despite strenuous efforts to compete with Chinese shipbuilders.
His stark warning has been echoed around shipbuilding halls across Asia. Chinese shipbuilding is undergoing massive retrenchment with the closure of many second-tier shipyards and massive state aid for those still in business. Meanwhile, Japanese shipyards fear a slump that could prove worse than the crash that followed the 2008 financial crisis. Shipyard executives fear the worst as current projects come to an end and have no pipeline of business to speak of.
About 5,000 miles away, workers in the high-tech Kleven Shipyard just outside Ulsteinvik on Norway’s west coast may or may not be aware that their counterparts in Asia are staring into the abyss. And they would certainly not recognize the term complacency in any aspect of shipyard operation.
A combination of effective marketing, chunky investment in automation and robotics, clever use of the country’s export credit arrangements, and close cooperation with Rolls-Royce ship designers who work just across the fjord, has enabled the family-owned shipyard to build up an order book now potentially worth more than $1.8 billion.
Early in July, the yard announced its latest contract for the construction of two—with an option for an additional two—ice-strengthened expedition ships designed by Rolls-Royce (rendering pictured at right) for Norway’s Hurdigruten. Hurdigruten operates a fleet of cargo and passenger vessels around the country’s 15,700-mile coast. The order, worth billions of Norwegian krone, is the largest in Hurdigruten’s history and is a major coup for the shipyard and Rolls-Royce which, in addition to vessel design, will supply about $15 million of equipment for each ship.
Together with the yard’s existing 16-ship order book, Kleven now has work for the rest of this decade. Ships under construction include six anchor handlers for Maersk Offshore, four high-tech stern trawlers of Rolls-Royce design for German, French and Spanish owners, the world’s most advanced cable layer with the highest DP3 position-keeping for ABB, two Rolls-Royce design live fish carriers, a deep-sea mining vessel for de Beers, and two luxury megayachts for a New Zealand entrepreneur. Talk about a diverse order book.
How has the yard been able to buck the global trend, particularly in one of the most expensive parts of the world? Certainly the Norwegian Export Credit Guarantee Agency has played an important role by making attractive financing terms available for foreign owners and vessels to be deployed overseas. But the yard’s management has spent almost $60 million on upgrading yard facilities over the past five years.
The robotic welding process, using lasers, continues to evolve, with a vision control system recently installed and developed by the University of Trondheim. The automated process allows welding rates of more than 300 feet per hour transforming manual rates of a typical eight feet per hour. “This is how we believe we can stay ahead of our competition and be competitive on price,” said a yard representative recently.
However, while the Kleven story may be exceptional—other yards in Norway’s usually bustling Sunmøre region are wrestling the challenge of an unprecedented offshore downturn—the design and shipbuilding innovation evident in northern Europe still facilitates construction of some of the world’s most sophisticated vessels.
In a radius of just a few miles from Kleven, there are several Vard yards, now owned by Fincantieri, the Havyard and across the fjord, next door to Rolls-Royce is Ulstein. Between them, these shipbuilders have completed some of the most sophisticated vessels ever built. They include the latest generation seismic survey ships, light well intervention vessels, offshore construction vessels and ultra-sophisticated cable layers.
Norway is not alone, however, in blazing a shipbuilding innovation trail. Finnish ship designers have unmatched expertise in ice-class design and construction, likely to be in heavy demand as warming seas enable navigation through the Northern Sea Route. Presumably with this in mind, Russia’s United Shipbuilding Corporation completed the acquisition of what is now called Arctech Helsinki Shipyards at the end of 2014.
Sited adjacent to the ice model test basin now known as Aker Arctic Technology Inc, the Helsinki shipyard has undergone various changes in ownership over the years, but has always focused primarily on ice-class design and construction. More than 500 ships have been built since it was established 151 years ago and more than 60% of the icebreakers now in operation around the world were built there.
The Helsinki yard has pioneered a range of ice-class innovations over the years, often with others. These include ‘double-acting’ vessels, which can break ice by bow or stern, azimuthing propulsion for ice operation, heeling and air-bubbling systems, shallow-draft icebreaker designs for inland waterways and coastal seas, and nuclear-powered icebreakers.
The shipyard continues to innovate. In 2014, the shipyard delivered the first “oblique icebreaker” to Russia’s Federal Agency of Sea and River Transport. The Baltika has an asymmetric hull and three azimuthing thrusters with a total installed power of 9 MW. She can break ice ahead, astern or sideways and can open up a 160-foot channel in two-foot thick ice.
The shipyard’s most recent delivery is the first dual-fuelled icebreaker to be powered by LNG and diesel. The Polaris, with a bollard pull of 200 tonnes, is powered by two 6.5 MW stern Azipods and one 6 MW unit, all supplied by power and automation company ABB. She is the Finnish Transportation Agency’s eighth icebreaker.
Polaris will be powered by Wärtsilä’s dual-fuel engines capable of operating on both liquefied natural gas (LNG) and low sulfur diesel fuel. Wärtsilä’s scope of supply consists of one 8-cylinder Wärtsilä 20DF, two 9-cylinder Wärtsilä 34DF, and two 12-cylinder Wärtsilä 34DF engine. Additionally, Wärtsilä secured a five years maintenance agreement for all engines and generators including spare parts, remote online support, CBM monitoring and training services.
The EURO 123 million ($136 million) vessel, classed by Lloyd’s Register, also has an emergency response and oil spill recovery capability and completed sea trials successfully in June. Her 800 m3 of LNG storage will provide an endurance of up to 30 days when operating in the Gulf of Bothnia.
Norway has led the way in the development of gas-powered ships and Rolls-Royce has been one of the pioneers. Designed by NSK Ship Design, the gas-powered cargo ship M/S Høydal features a Bergen gas engine, Promas combined rudder and propeller, and a hybrid shaft generator from Rolls-Royce. The ship was built at Tersan Shipyard in Turkey and delivered to NSK Shipping. The DNV GL class Høydal transport fish feed manufactured by BioMar to the numerous salmon and trout farms of northern Norway.
Boaty McBoatface lives on
Rolls-Royce engineers are also designing the 128m polar research vessel RRS Sir David Attenborough, which will be built at Cammell Laird’s site in Birkenhead on Merseyside, England. As you might recall, the project drew worldwide attention and almost blew up the internet when the public overwhelmingly chose the name “Boaty McBoatface” for the £200 million vessel during a “Name Our Ship” campaign held by Britain’s Natural Environmental Research Council. The council saved face—pun somewhat intended—by choosing the fourth most popular name submitted, “Sir David Attenborough,” after the famous British naturalist.
NERC says a remotely operated vehicle used by the Sir David Attenborough in its research will be named Boaty McBoatface instead.
The project is the biggest commercial shipbuilding contract in Britain and one of the biggest for more than a generation. When delivered in 2019, the Sir David Attenborough will carry out oceanographic and other scientific work in both the Antarctic and Arctic as well as transporting supplies to Antarctic research stations.
The research vessel will be Polar Code 4 ice class, with an endurance for voyages up to 19,000 nautical miles, space for a total of 90 people and a large cargo capacity. The vessel is also designed to generate very low levels of underwater radiated noise and minimize the risk of pollution. Onboard laboratories will allow the prompt analysis of samples.
As part of its £30 million contract, Rolls-Royce will supply the diesel electric propulsion system which will include new Bergen B33:45 engines, two nine-cylinder and two six-cylinder engines, and two 4.5m diameter Rolls-Royce Controllable Pitch Propellers (CPP). The powerful, efficient and compact engines and strong propellers will be able to push the vessel through approximately one meter thick level ice with extremely low underwater radiated noise, avoiding interference with survey equipment or disturbing marine mammals and fish shoals.
According to Jørn Heltne, Rolls-Royce, Senior Vice President for Sales in Ship Design & Systems, Rolls-Royce will also deliver automation and control systems, including its Dynamic Positioning system and Unified Bridge.
Also, Rolls-Royce deck handling systems will support a wide range of tasks, such as towing scientific equipment for subsea acoustic survey equipment using up to 12,000m of wire, or deploying equipment over the side or through a moonpool to collect seawater and seabed samples at depths of up to 9,000m.
OEMs capitalize on new era of ‘smart shipping’
Rapid advances in satcom technology is finally enabling shipping to go digital and make the most of ship-shore connections. While a handful of companies have wired up their ships over the last few years—notably the world’s largest container line, Maersk, high-throughput broadband now facilitates 24/7 connectivity and introduces a new era of remote monitoring, diagnostics, predictive maintenance and shore-side support.
Other transport modes have been using these technologies for some time, but satellite coverage across the world’s oceans has remained a challenge. Many thousands of unconnected ships still provide manually prepared noon reports for managers ashore, an asset monitoring procedure which some from outside shipping can scarcely believe.
Rolls-Royce, through its TotalCare service, has been monitoring the performance of thousands of jet engines for years. Instead of signing service agreements and charging customers for call-outs, spare parts and attendance at unexpected breakdowns, the company’s “power-by-the-hour” concept is aimed at keeping planes in the air and avoiding any downtime.
Earlier this year, London-listed Inmarsat launched Fleet Xpress, a high-throughput broadband service available through its Global Xpress network on its latest satellite constellation. As well as enabling a completely new range of ship-shore connections including internet, email, social media and video conferencing, third party app providers can procure bandwidth on Fleet Xpress to provide their own “smart” services (see accompanying feature, “Fleet Xpress brings ‘smart’ ship tipping point,” for more details).
Systems similar to the Rolls-Royce TotalCare service are now being introduced in shipping. Wärtsilä recently paid EURO 43 million ($47.5 million) for Finnish energy management and analytics firm Eniram which has sensor and analytics equipment installed on about 270 vessels and a turnover of EURO 10 million ($11 million) in 2015. The Helsinki-based firm has established a sound track record in raising vessel efficiency by optimizing trim, engine load and speed, thereby saving fuel and cutting emissions.
The acquisition will strengthen the company’s recently launched Wärtsilä Genius service in which key components are monitored in real time, exceptions noted, and maintenance procedures optimized. A virtual service engineer will also be available as part of the service and the company plans to make more details available at this year’s SMM in September.
Competitor ABB is preparing to open its fourth “Integrated Operations Center” in the United States later this year, probably in Houston. The company has already opened a facility for its offshore clients in Billingstad, Norway, and two similar centers for shipping customers in Helsinki and Singapore.
A fifth center is also likely to be set up in China. By mid-year, ABB had established real-time connections between the centers and clients’ ships, enabling ABB personnel to track performance and provide shore-side support if necessary. Meanwhile Rolls-Royce Marine is also in the process of setting up connections to monitor its equipment in operation at sea.
Following a successful remote monitoring pilot project, Radio Holland recently struck a deal with China Navigation Company for the maintenance of its navcom equipment onboard the owner’s newbuild, multipurpose vessels and bulk carriers.
“The maintenance agreement with Radio Holland has been designed to dovetail with the end of the warranty period for our newbuildings,” says Martin Cresswell, Fleet Director, China Navigation Co. Pte., “and is a continuation of the excellent cooperation that we have built over the last few years. The agreement incorporates remote monitoring, which we believe will significantly reduce out of service periods, increasing operational safety.”
MAN Diesel’s largest two-stroke engine yet
Just this past June, China State Shipbuilding Corporation (CSSC) acquired Wärtsilä’s 30% shareholding in Winterthur Gas & Diesel Ltd. (WinGD). WinGD, Winterthur, Switzerland, will continue as an independent, international company to develop and innovate its two-stroke low-speed marine engine portfolio serving all merchant markets and customers worldwide.
WinGD was one of the earliest exponents of diesel technology. It started the development of large internal combustion engines in 1898 under the “Sulzer” name.
“With the transfer of the shares in WinGD from Wärtsilä Cooperation to CSSC, we will be able to establish even closer cooperation with one of the leading global shipbuilding conglomerate CSSC enabling us to accelerate the development of reliable, efficient and innovative two-stroke low-speed engines meeting the market demands of merchant shipping of the future. WinGD will continue to work with the Wärtsilä Corporation Service Network to serve our customers for after-sales support,” says Martin Wernli, CEO of WinGD.
In other news in the two-stroke diesels, this past May, the 19,437-TEU MSC Jade was delivered by Korea’s Daewoo Shipbuilding & Marine Engineering (DSME) with what is the largest and most powerful engine yet from MAN Diesel & Turbo. Built by Doosan Engine in Korea under license from MAN Diesel & Turbo, the MAN B&W 11G95ME-C9.5 two-stroke engine is rated at an impressive 75,570 kW (103,000 hp).
The G95 is a popular choice in the large containerships (9,000 to 21,000 TEU), with 68 sold in the segment since August 2013.
“We attribute the G95’s popularity in this segment to its ability to provide sufficient power for such vessels to reliably achieve their desired operating speed,” says Ole Grøne, Senior Vice President Low-Speed Sales and Promotions, MAN Diesel & Turbo. “Here, the G95’s rpm ensures that a propeller of optimal size can be employed, in turn delivering a low fuel-oil consumption for an optimal fuel economy.
Japan’s Mitsui Engineering & Shipbuilding, another MAN Diesel licensee, completed the world’s first ME-GIE ethane-operated two-stroke diesel engine. The Mitsui-MAN B&W 7G50ME-C9.5-GIE will be installed in the first of three 36,000 m3 liquefied ethane gas carriers being built by Sinopacific Offshore Engineering in China.
MAN Diesel & Turbo reports that ethane was chosen as fuel over HFO because of its competitive pricing as well as the significantly shorter bunkering time it entails. As a fuel, its emissions profile is also better than HFO, as it contains a small amount of sulphur, 15-20 lower CO2 and emits signficantly fewer particles during combustion. The ME-GI engine can also easily be converted to run on methane, if the operator desires.
The use of ballast water is critical to the safe operation of ships, but also poses challenges due to the need to maintain the structural integrity of ballast water tanks (BWTs) despite highly corrosive conditions. Appropriate protective coatings act as barriers to corrosion and if applied carefully to properly prepared surfaces can significantly extend the life of BWTs. Two-coat epoxy systems are commonly used today, but rapid curing polyurethanes have performance properties that make them attractive as alternative coating solutions, including tunable properties that allow the formulation of flexible yet hard coatings that resist cracking, excellent adherence to steel, high resistance to corrosion, chemicals, and abrasion and fast return to service.
Ballast tanks located at the bottom, around cargo holds, and near the bow and stern of ships provide a mechanism for maintaining balance. Water is filled or released from the tanks to stabilize and trim ships during sailing and to keep them evenly afloat during the loading and unloading of cargo. Ballast water tanks (BWTs) are typically dedicated for this purpose. Ballast tanks are also used to adjust the buoyancy of submarines and stabilize offshore oil platforms and floating wind turbines.
In marine vessels (tankers, bulk carriers, etc.), ballast tanks typically comprise the largest surface area of steel. Corrosion of these tanks can therefore significantly reduce ship safety and operational life. In the past, ships suffering from severely corroded ballast tanks have experienced total failure of their hull shell plates. There is general agreement in the industry that prevention of corrosion in BWTs is the second most important factor after design integrity in determining the operating life of a ship.
Corrosion prevention in BWTs is not a simple matter, however. The water in ballast tanks can have a high salt content, vary in the type and concentration of other ions and have a wide range for pH and may also contain corrosive chemicals. Empty ballast tanks, on the other hand, are exposed to corrosive atmospheres that cycle with the temperature of the tank. Tanks, when partially full, are also subject to continuous movement of the water.
In fact, different parts of ballast tanks corrode via different mechanisms and at different rates, and empty tanks behave differently than tanks that are often filled with water. For Example, some parts of tanks are exposed to cyclic heating and cooling and/or local heating from warm, adjacent cargo tanks and engine rooms. Additionally, the exterior of the BWT is exposed to the weather above the water line and the differing temperatures of the sea below the water line. Therefore the same tank can experience uneven thermal cycling due to the extreme differences in its exterior exposure. Because the upper portion of the tank is exposed to extreme thermal cycling and repetitive wet and dry service, anodic oxidation is the main source of corrosion in this part of the tank. On the other hand, the bottom area of a tank is constantly exposed to the sea and therefore is maintained at a lower temperature and is subject to cathodic blistering. Any microbes in sediment on the bottom can also cause microbial corrosion.
Many other factors such as bacterial biofilm, mechanical vibration and effectiveness of sacrificial or impressed current anodic protection play a moderate role in determining the rate of corrosion in ballast water tanks.
To prevent corrosion in BWTs, high-performance protective coatings are applied during construction of the ship. Typically two thin layers of a suitable coating with a total dry-film thickness of approximately 300-320 microns are sufficient to provide an effective barrier against corrosion. Such coatings must meet many regulatory requirements related to their environmental and performance characteristics.
Current Coating Technologies
Preferred coatings not only provide a long lifetime of protection (15 years or more is required by the International Maritime Organization (IMO) Performance Standard for Protective Coatings (PSPC)¾see below), they must be easy to apply under the varying conditions found at different shipyards around the world and easy to maintain. Coatings that provide greater coverage for less material usage and are more tolerant of poorer surfaces are also in demand. A low volatile organic compound (VOC) content (< 250 g/l) is also necessary.
The majority of BWT coatings applied today are epoxy-based systems. Most are solvent-based, high solids formulations, although some European shipbuilders use solvent-free coatings to meet the requirements of the EU Solvent Emissions Directive (SED). The latter 100% solids epoxy systems have good performance properties, but tend to suffer from poor wetting properties and slower curing rates at low temperatures. Good wettability is necessary to ensure that pitted areas are filled rather than bridged, and thus do not leave a void below the paint film that can act as a starting point for corrosion.
Rapid curing is a very desirable property for BWT coatings because it translates into shorter construction times for new builds and reduced time in dry-dock for recoating and repair. The US Navy has developed a series of 100% solids coatings based on amino polyols prepared from either alkanol amines and polyfunctional epoxy materials or polyamines and monofunctional epoxides that are applied using plural component equipment, which eliminates the poor flow concerns. They are referred to as “single-coat” systems because the necessary two coats can be applied in one day, rather than in two. The technology for a light-to-medium-duty coating based on a medium-viscosity resin has been licensed and is commercially available. In a study at a commercial shipyard in Asia, the rapid curing coating, which meets the IMO PSPC requirements, was shown to provide a nearly 40% increase in painting productivity and a 20% overall cost savings.
Advantages of Polyurethanes
Certain polyurethane (PU) coatings have also been shown to have significant potential as highly protective barrier coatings for ballast water tanks. Specifically, 100% solids rigid and structural polyurethane coatings are promising because they cure very rapidly, even at cold temperatures, and have superior resistance properties.
One of the major issues with epoxy coatings is their inability to build desired dry film thickness at sharp edges, corners, weld seams and other defect sites. Coating failures generally occur first in these areas, usually do to crack formation. Unfortunately, there are many of these sites present in BTWs. While the PSPC does require that sharp edges be addressed prior to coating, this problem remains a concern in the industry. Advances in epoxy coating technology have helped, but further improvements are still desired.
Polyurethanes have the key advantage of property tunability. Careful selection of the polyisocyanate and polyol segments can provide coatings with very specific properties. For ballast water tank applications, a hard coating is needed that retains some flexibility to allow for high film builds at edges, seams and defect sites. This unique mix of properties, which cannot be achieved with epoxy systems, is possible with polyurethane coatings. Careful preparation of the PU resin and development of the formulated PU coating can provide coatings with desirable edge retention properties.
With the appropriate choice of starting materials, it is also possible to formulate polyurethane systems with curing times that allow for the application of perfectly smooth, high-build coatings. These barrier coatings are applied with no defects in one continuous application and serve as abrasion- and impact-resistant protective barriers to corrosion. Furthermore, because they contain no solvent, 100% solids polyurethane coatings are “green” coatings that meet stringent environmental regulations, and most are odor-free, providing a better shipyard application environment than high-solids epoxies.
Surface adhesion, as for all coating applications, is crucial for BWT coatings and has a significant impact on coating performance. More forgiving coatings that have strong adhesion to the different types of steel used in shipbuilding and the different types of surface conditions that can be present are therefore highly desired for the protection of ballast water tanks. Polyurethanes meet this requirement and generally surpass the adhesion properties of many epoxy systems.
The inherent barrier properties of polyurethane coatings are also excellent. PUs show high resistance to corrosion and chemicals. In addition, they provide superior abrasion and impact resistance, which is not true for epoxies systems. Finally, the very rapid curing of polyurethanes over a wide temperature range makes them suitable for application to water ballast tanks regardless of where they are built or dry-docked and ensures reduced coating times during newbuilding and fast return to service for repair/maintenance operations.
Performance Requirements: PSPC and Invasive Species Control
The IMO PSPC became effective in 2008 and provides specific requirements for the types of corrosion control coatings that can be used on ballast water tanks, as well as appropriate application, inspection and maintenance procedures. Extensive documentation is also specified in the standard. The intent is to have all BWTs coated with systems that will provide a 215-year service life.
Coating systems must be pre-qualified/certified prior to use in ballast water tanks. Certification can be obtained from an approved, independent testing laboratory, through demonstrated performance in the field for a minimum of five years, or by presenting results from previous, relevant tests. Coating application during the newbuilding process must be extensively monitored, and inspections performed at numerous phases. For example, testing of the surface profile and water-soluble salt content are required before application of the first coat, and a thorough inspection of the first coat is necessary before the second coat can be applied. These requirements can slow down the coating process and increase the cost. Consequently, rapid-cure coatings that allow the application of two coatings in a single day are attracting significant attention.
Recent regulations attempting to prevent the spread of invasive species through ballast water must also be considered when installing BWT coatings. There have been several cases of the transport of invasive species around the world, some of which have had severe ecological and/or economic impacts. However, many of the current chemical technologies available for destroying harmful marine organisms in ballast water are based on oxidizing agents (e.g., chlorine dioxide, ozone) that are damaging to the coatings and can lead to corrosion problems. Mechanical systems based on filtration/separation and those that use ultraviolet radiation tend to be less problematic. Therefore, it is crucial that testing of corrosion control coatings for ballast water tanks be performed under maximum treatment conditions for a given application.
A Word about Surface Preparation, Quality Assurance and Maintenance
As with all coatings, surface preparation is critical to the performance of BWT coatings. In fact, lack of proper surface preparation is one of the main causes for coating failures in ballast water tanks. It is imperative that appropriate surface preparation standards (SSPC/NACE/ASTM) be met. Attention should be paid to both surface profile and soluble salt content.
Application conditions must also be considered, as temperature and relative humidity during application can affect the ultimate performance of many coating systems, particularly epoxies. While most large, modern shipyards have enclosed areas for conducting abrasive sand blasting and painting (with temperature and humidity control), some smaller facilities do not. Work is therefore performed under ambient conditions using power tools, which can result in poor surfaces for coating. Polyurethanes offer advantages in these situations, as they have superior adhesion to poor surfaces and temperature and humidity do not impact their curing or ultimate performance properties.
PUs are Good for Potable Water Tanks
The properties of polyurethanes that make them ideal as corrosion protection coatings for ballast water tanks also make them well-suited for use as protective systems for marine potable water tanks. Many polyurethanes meet the requirements of the ANSI (American National Standards Institute)/NSF (National Sanitation Foundation) Standard 61 – Drinking Water System Components, which establishes stringent requirements for the control of leachables and extractables from materials that come in contact with either potable water or products that support the production of potable water.
Conclusion
Preventing corrosion in ballast water tanks is crucial for ensuring the safety and longevity of on marine vessels. While epoxy systems are currently the most common coatings used in this application today, properly formulated, fast-curing polyurethanes are attractive alternatives with significant potential to reduce lengthy coating processes, increase shipyard productivity and thus reduce costs.
