Nexans hopes to facilitate a transition towards clean-energy and develop transnational energy networks with its new cable layer
There is a growing demand for vessels capable of subsea high-voltage (HV) cable installation and French cabling and connectivity specialist Nexans is targeting this with its new cable-lay vessel Nexans Aurora.
Designed by Ålesund, Norway-based Skipstenisk, a designer with a focus on offshore, research and fisheries craft, the vessel is an ST-297 cable-lay vessel (CLV). It is designed to handle both deep-sea and near-shore cable-laying operations in severe weather conditions and will have a high degree of manoeuvrability and good station-keeping capabilities. It will undertake tasks including power cable laying, which includes bundle laying, cable jointing and repair and cable-system protection and trenching.
The vessel will have an overall length of 149.9 m, a beam of 31 m and a dwt of 17,000. It will have accommodation capacity for 90 people, high levels of redundancy and a dynamic positioning (DP) class of DP3.
“The construction of this new cable-laying vessel is a fundamental milestone in our commitment to cleaner energy,” said Nexans chief executive officer Arnaud Poupart-Lafarge, when plans for the vessel were first announced in July 2017.
“For many decades, Nexans has been acting for energy transition and sustainable development,” he added. “In this next exciting chapter of our capacity to meet customer expectations, the cutting-edge technology of the new ship will enable Nexans to support countries in their development of renewable power generation.”
Nexans decided to commission the cable layer as part of its mission to facilitate a transition towards clean energy and to develop transnational energy networks. It is designed to reduce the environmental impact, in line with Nexans’ corporate social responsibility policy and its commitment to sustainable development. Nexans Aurora will be compliant with the latest crew and vessel security requirements and will also comply with international safety standards.
"The 10,000-tonne cable carousel will be the world’s biggest, comprising a concentric ‘carousel-in-carousel’ design allowing it to process two cables simultaneously, or store a single length of cable weighing 10,000 tonnes"
Nexans Aurora will join Nexans Skagerrak, the first purpose-built ship for the transport and installation of submarine HV and power cables and umbilicals. Originally laid down in 1976, Nexans was a long-term charterer of Nexans Skagerrak for many years before acquiring the vessel in 2006. In 2010, it underwent a major conversion and upgrade project to boost its capabilities. In its 2017 full-year results, the company disclosed a need to acquire a second cable-lay vessel, created by historic highs in installation activity that year (nearly double the 2016 level, with plants operating at full capacity). Nexans Aurora is significantly larger than the 99.75 m long, 7,150 dwt Nexans Skagerrak, and its carousel capacity will also improve on that of its sister vessel, which is 7,000 tonnes. The 2017 results report also noted that the Nexans Aurora project will be “instrumental” to ensuring the company fulfils its 2021-2022 objectives.
Ulstein Verft, based in Ulsteinvik, Norway, has been contracted to construct the vessel and prepare topside equipment. Ulstein Group chief executive Gunvor Ulstein said: “We are very pleased that Nexans, a solid and important player, chooses Ulstein to construct their new flagship. We have a strong organisation with long experience in delivering advanced vessels.
“The contract was won in a tough, international competition. We look forward to a constructive and fruitful cooperation with Nexans in the years to come.”
Ulstein Verft managing director Kristian Sætre said: “We are experienced in constructing large and complex vessels and we look forward to commencing the work on the cable-laying vessel for Nexans.”
The vessel’s construction contract was originally awarded to Croatian-based shipyard Uljanik group, but was re-awarded to Ulstein in July this year.
Hampshire, UK-based turnkey carousel system specialist MAATS Tech has been awarded the contract to supply the vessel’s deck spread. The main item in this order is a 10,000-tonne cable carousel, which will be the world’s biggest, comprising a concentric ‘carousel-in-carousel’ design allowing it to either process two cables simultaneously, or store a single length of cable weighing 10,000 tonnes. Other aspects of the spread include a capstan hold back, two deck tensioners, lay wheels and an integrated control system.
MAATS Tech is supplying the vessel's deck spread, which will include the world's largest cable-lay carousel
The vessel will also have a 450-tonne capacity fibre-optic basket. The company has form in the provision of carousels for CLVs and pipelayers and has previously provided a 6,000-tonne deck carousel and 3,000 tonne below-deck carousel, along with loading and guiding systems for Lewek Connector, as well as a 2,000-tonne underdeck carousel and 750-tonne deck carousel for Skandi Vitoria.
Palfinger Marine was selected to provide a major deck equipment package comprising abandon and recovery winches, an A-frame, knuckle-boom cranes and overhead travelling gantry cranes. The full scope comprised one 150-tonne A-frame, two active heave-compensated abandon and recovery winches, two auxiliary abandon and recovery winches, two overhead travelling gantry cranes, two offshore knuckle-boom cranes and one offshore telescopic boom crane.
Palfinger Marine’s sales director for winches and handling equipment Sverre Mowinckel-Nilsen said: “We have been working on this project for almost two years and most of the equipment has been tailor designed to fit the vessel design. Being awarded with this order confirms our good reputation in the high-end vessel market. We are very proud for being chosen once again by Ulstein Verft for delivering our high-quality equipment and we are looking forward to working closely with the yard and owner on this project.”
Molde, Norway-based Brunvoll is providing the vessel’s propulsion and thruster package. This will consist of three 3,200 kW propeller-in-nozzle azimuth propulsion units with a propeller diameter of 2.9 m, alongside three bow-mounted thrusters: two 3,000 kW tunnel thrusters with a diameter of 3 m and a 3,000 kW retractable azimuth thruster with a diameter of 2.9 m.
All the units are controllable-pitch propeller systems and can run at variable rpm. Combining these two features, known as ‘combinator control’, brings several benefits, such as improved manoeuvrability and a reduction in noise and vibration levels aboard the vessel, less noise transmitted into the sea and lower energy consumption. The retractable azimuth thruster is Brunvoll’s AR115 model, the largest in the company’s portfolio, while the tunnel thrusters are of the FU115 type, often used on larger vessels in the oil and gas and cruise sectors. Brunvoll will also provide control, alarm and monitoring systems for all thrusters, as well as the BruCon-4 dual-redundant integrated bridge control system. The joystick-based system incorporates a touch screen, a customisable user interface and an integrated condition-monitoring system and is type-approved by DNV GL.
Nexans Aurora is targeted to be delivered and ready to commence operations by the third quarter of 2020.