A Bundle of Advanced Technology

Wednesday, February 13, 2002
The close cooperation of the Finnish Maritime industry is evidenced in the highly capable icebreaking ships that it produces. Icebreakers are essential to Finland’s existence, as the specialized ships enable the country to keep its shipping lanes operational during the harshest winter months. However, traditional icebreaker design made for poor navigating vessels in open water, and thus were rendered useful during only the winter months. This was acceptable, but very expensive, as icebreakers by nature represent a significant maintenance challenge and cost. The solution: creating a new design icebreaker that could be used, profitably, year-round. This was don by the Finnish board of Navigation, which has built at Finnyards and operated a trio of vessels that break ice in the winter, and work as supply ships in te North Sea oilfields during the summer. Bringing these two combinations of capabilities in a single vessel means advnanced hull design. To be able to carry more load, the hull had to be constructed using 500 Mpa yield strength TMCP steel with excellent impact strength properties, supplied by Rautaruukki. The hull plating of icebreakers and other ice-going vessels is subjected to ice erosion that can remove protective paint coatings and leave the hull exposed to seawater. Under such extreme circumstances, preferential corrosion can develop in the vicinity of welded joints, e.g. the weld metal, the heat affected zone (HAZ) or fusion line (FL). The location and extent of preferential corrosion depends on the compositions of the weld metal and base plate and the heat input used in welding.

Accelerated weld metal corrosion can be prevented using a sufficient filler metal. HAZ and FL corrosion can be a problem when high strength shipbuilding steels are used, especially for low heat input welds. Rautaruukki Steels of Finland, in cooperation with shipyards, has developed a range of RAEX POLAR steels for structures having stringent requirements on the seawater corrosion resistance of welded joints. The Finnish marine cluster is particularly renowned worldwide for its advanced products and systems born of necessity to keep its vital shipping lanes open during the harshest winter conditions. Moreover, the country’s industry traditionally works in tandem to co-develop and bring to fruition the systems, a technique that ensures that the solutions are the culmination of real working conditions. The RAEX POLAR series of steels have been specifically developed to avoid HAZ and FL corrosion problems. The chemical composition of the steels is balanced to provide an optimum combination of corrosion resistance, strength, toughness and weldability. The corrosion resistance of all of the RAEX POLAR line is verified in specially designed corrosion tests, which lasted six months, under the auspices of the classification societies.

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter July 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

Insights: Kunkel Weighs in on Propulsion Technology

LNG? Methanol as fuel? Hybrid systems? Tier 4? Reducing noise? Cutting emissions without crushing fuel economy? Marine News readers have questions and Bob Kunkel has answers.

A Sea Change in Waterjet Technology

Longtime waterjet propulsion equipment provider NAMJet introduces key advancements for the workboat sector. Back in 2011, when boat builder Birdon went looking

ATB Design Comes of Age

The emerging trend of marrying the design of an articulated tug and barge (ATB) to a particular propulsion system to maximize efficiencies of that system has, of late,

Finance

U.S. Awards $61.8 Mln for Port Projects

U.S. Transportation Secretary Anthony Fox today announced 40 awards totaling nearly $500 million in funding for the  FY 2016 Transportation Investment Generating Economic Recovery (TIGER) grants.

Moody's: Challenges Ahead for Asian Port Operators

Moody's Investors Service says lackluster global growth, weak commodity prices, high capital expenditure commitments and a liner industry struggling with overcapacity

Swiber Applies for Judicial Management Instead of Liquidation

Singapore oilfield services company Swiber Holdings Ltd said on Friday it has applied to place itself under judicial management instead of liquidation.   Swiber

 
 
Maritime Contracts Maritime Security Maritime Standards Navigation Offshore Oil Pipelines Port Authority Ship Electronics Shipbuilding / Vessel Construction Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0789 sec (13 req/sec)