HELSINKI -- Aker Arctic recently launched the first of three new icebreaker tug vessels for operations in the Caspian Sea. All three are to come from the STX Braila shipyard in Romania.
The 50-metric ton (55-ton) bollard pull vessel has been named Mangystau-1, after the region in which it will be based. It has been bought by a group of Kazakhstan companies within Caspian Offshore Construction LLC, and is scheduled for delivery in August.
The ARC 104 concept, developed by Aker Arctic, complies with requirements set by AGIP KCO, operator of the Kashagan field in the Kazakh sector.
Aker Arctic has performed basic design for the construction yard, including class approvals for the Bureau Veritas ice class Ice Class IA Super, Special service - North Caspian Sea Icebreaker, which provides ice breaking capability up to 0.6 m (1.9 ft) level ice thickness.
According to Aker Arctic, the main challenge was the ultra-low operating draft of 2.5 m (8.2 ft), combined with the high icebreaking capacity. For this reason, the vessels will be equipped with three Schottel SPR 2020 1.6 MW azimuthing pulling thrusters, totalling 4.8 MW. The propellers are driven by four Caterpillar 3512 C type diesel engines, each rated at 1.79 MW and operating at 1,800 rpm.
The vessels are winterized to work in temperatures down to -35 oC (-31 oF), and they also feature an over-pressurized interior, designed to maintain safe operation in the event of an accidental H2S blow-out.
The superstructure can also accommodate 300 evacuees from the Kashagan production platforms.
Main data for the vessels include:
Length over all -- 66.0 m (216 ft)
Breadth -- 16.4 m (54 ft)
Depth -- 4.4 m (14.4 ft)
Design draft --3 m (9.8 ft)
Min.operating draft --2.5 m (8.2 ft).
STX completes first Kashagan icebreaker