Mangystau-1 was built for the account of Kazakhstan-based Caspian Offshore Construction, the operating company for a group of firms in that country that placed the contract for the design of the new class. The vessel’s name derives from the Kazakh region that will be her base. The 50 tonne bollard pull icebreaking tug supply vessel was handed over in August.
Aker Arctic’s ARC 104 concept forms the basis of the new design and successfully fulfils all of the highly demanding requirements established by AGIP KCO, the operator of the huge Kashagan offshore oil field, including the high local content required by Caspian Offshore Construction.
The contract for the construction was signed in spring 2009 and all of the first three vessels are due to be delivered by the summer of 2011. Aker Arctic’s design was classed by Bureau Veritas and bears the class notation Ice Class IA Super, Special service – North Caspian Sea Icebreaker. It is capable of breaking 0.6m level ice.
Aker Arctic’s CEO and president Mikko Niini told OSJ that the great challenge in developing the design of the icebreaking tugs was their operating draught – which at 2.5m is shallower than any previous vessels of this type – and their need for high icebreaking capability. He noted that in some places the water in the northern Caspian is only 3m deep.
“The harsh ice conditions together with shallow water posed a huge technical challenge, but one that we have managed to solve by using features from our earlier icebreaking supply vessels and Russian river icebreakers,” Mika Hovilainen, chief designer for the ARC 104 project, explained.
The new vessels will each have three Schottel type SPR 2020 1,600kW azimuthing pulling thrusters to provide 4.8MW, all driven by a quartet of Caterpillar 3512C diesel engines of 1,790kW each at 1,800 rpm.
The icebreaking vessels are also winterised to work in temperatures down to -35°C and have an overpressurised interior to safeguard the crew and allow them to continue safe operation should an ‘H2S blow-out’ occur. The light oil of the Kashagan field has a high hydrogen sulphide (H2S) content.
The design of the superstructure of the new vessels allows the accommodation of 300 evacuees from oil production platforms in the field.
Mr Hovilainen said that the ARC 104 had to have more power and even less draught than any vessels that have been designed before. This is because the icebreaking tug was intended for use in very shallow waters, where it will push and tow barges and be responsible for ice management.
Mr Hovilainen also noted that the ice strengthening of the hull was also a special development by Aker Arctic’s Arctic research centre. He said the other key challenge that Aker Arctic faced when designing the ARC 104 was AGIP KCO’s ‘zero tolerance’ policy concerning the vessel’s environmental performance. The vessels have to operate without producing pollution that could damage the fragile ecosystem in the area.
“Technically the project has been extremely successful so far,” said Mr Hovilainen. “All of the testing has gone well and according to schedule, although the final verification of the design will not take place until the winter of 2010/2011 in the Caspian, when the conditions are at their worst, although I am confident that this vessel will be a success.” OSJ
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