Efficient cable-laying ship has flexibility to support fibre-optic and subsea power cable work
With Japan making a big push to develop offshore wind, Japanese submarine cable installation company Kokusai Cable Ship Co (KCS) has invested US$53M in enhancing its fleet, with the addition of the 5,757-dwt KDDI Cable Infinity. The two other vessels in the KCS fleet are the 25-year-old cable-laying vessels, KDDI Ocean Link and KDDI Pacific Link, making KDDI Cable Infinity the first newbuild for the company in a generation.
The largest vessel ever built by Sri Lanka’s Colombo Dockyard, KDDI Cable Infinity is 111.3 m in length, 21.5 m in breadth, with 8.8 m depth, with maximum load-laying draught of 7.1 m. The cable layer has a speed of 14.5 knots with accommodation for 80.
Intended for subsea operation, cable installation and repair of both optical and power cables, KDDI Cable Infinity is fitted with a 2,000-tonne-capacity carousel system with a spooling arm installed on the main deck.
UK-based Maats Tech Limited completed final commissioning and documentation stages of the cable equipment supply to Colombo Dockyard. Maats Tech’s total work scope included the fibre/power cable carousel, a spooling arm to assist with carousel packing, and a stern lay wheel. KDDI Cable Infinity will primarily be used for fibre optic lay, but several innovative features allow the carousel to be used either as a fibre tank, or as a power cable carousel. Observed MAATS business director Gavin Rippe: “The equipment design allows the operator to execute its core business of offshore fibre optic installation, but also to easily convert to subsea power cable lay.”
Such capability will allow KDDI Cable Infinity to support the development of offshore wind projects in Japan. Having passed a bill to promote the use of territorial waters for offshore renewable energy development in March, the Japanese government in July identified 11 areas as potentially suited for offshore windfarm projects, located in 100 m of water or less, with the ability to cite wind turbines up to 315 m in height.
Fitted with passive roll reduction tanks to minimise ship motion, improve seakeeping and station keeping, KDDI Cable Infinity is well suited for operations offshore Japan. The vessel has low resistance hull lines to increase speed and improve fuel consumption.
Propulsion power for the diesel-electric vessel is supplied by four generator sets, developing 2,300 kW each. Three of the four generators are sufficient to cope with the highest propulsion power demands, ensuring high reliability. The vessel is also fitted with an exhaust gas scrubber and a selective catalytic converter (SCR) to comply with IMO 2020 0.50% sulphur cap regulations. Transit at economic speed with two engines efficiently running will optimise fuel consumption.
Built to ClassNK class, the vessel has a bollard pull of 80 tonnes, operational range of 18,520 km and dynamic positioning (DP) capability to class 2 for precision manoeuvring and station keeping. KDDI Cable Infinity has two azimuth thrusters, two tunnel thrusters and one retractable azimuth bow thruster.
Norway’s Vard Designs supplied the basic design and production drawings for constructing KDDI Cable Infinity, a Vard 9 01 design.
It’s unusual for such a complex vessel owned by a Japanese firm to be built outside of Japan. Colombo Dockyard PLC is a joint collaboration between Japanese shipbuilder Onomichi Dockyard Company Limited, which controls a 51% interest in the shipyard, and Sri Lankan government institutions that hold a 35% stake. The remaining interest is held by public entities. Colombo Dockyard, established in 1974, is a central part of the Sri Lankan government’s efforts to develop a local industrialised base and its national export strategy from the shipbuilding sector.