The Offshore Industry is going through the doldrums at present, largely driven by a fall in oil prices after a period of considerable growth in that marine sector. Whilst large segments of company fleets are being laid up and some companies are ceasing their offshore work altogether, state of the art newbuilds continue to come on stream. One such new vessel was the 17.078gt Multipurpose Offshore Construction Vessel (OCV) Edda Freya. Østensjø Rederi ordered the 149.80m long ship from Kleven Werft A/S on 18th October 2013 for delivery in the spring of 2016.

Based in Haugesund, Norway, Østensjø Rederi has been providing maritime services worldwide since 1974 in the areas of Accommodation, Offshore and Towage. The company currently operates a fleet of 9 offshore ships, 1 accommodation ship and 19 tugs (which includes the Solent Towage fleet). Company owner, Johannes Østensjø established Østensjø Rederi and maintains a passion for innovation and vessel design, along with the dedication to progress. In 1973 the contract was signed for the first of four supply vessels with a ship yard in South Africa. In 1975 Østensjø Rederi was the first operator in the world to introduce high sides on platform supply vessels (PSV) to ensure deck workers’ safety. This is an industry standard today. The first major platform supply deal was signed in 1976 with British Petroleum (BP) at the Forties field near Dundee. In 1982 the Edda Fjord became the first PSV to use dynamic positioning (DP), another industry standard of today. In 1999 Østensjø Rederi and Solstad Offshore teamed up to create the subsea contractor DeepOcean. In 2007 the PSV Edda Fram was delivered as the first offshore vessel with Voith Schneider propulsion with the first ever Voith Schneider propelled subsea, and accommodation vessels following. This time was also a booming period for vessel commissioning, with 11 ships under construction, whilst in 2008 DeepOcean was sold. During 2011 the monohull accommodation vessel Edda Fides came into service, becoming the first vessel of her type in the world. In 2013 the PSV Edda Ferd was delivered, becoming one of the first Diesel Electric Hybrid vessels in the market and thus achieving both substantial fuel and emission reductions. Three years later the company became the first shipping operator in the world to get 9001:2015 accreditation from DNV. The advanced OSV Edda Freya is the latest milestone for Østensjø Rederi, being the largest investment in the history of the company. The keel of build No. 373 was laid at Kleven Verft A/S in Ulsteinvik, Norway, on 5th November 2014.

The Kleven Group has been a strong brand name within the shipping industry for many decades, both for newbuildings and for service. From August 2012 Kleven Maritime adopted Kleven as the name for the group with the shipyards continuing as Myklebust Verft and Kleven Verft. Kleven is a family-owned company with deep roots in the local communities in which it is based. The companies in the group have a history that dates back almost one hundred years and the foundations of the company of today were laid by Marius Kleven in 1944.

Multipurpose Hybrid

The newbuild was launched on 15th August 2015 prior to being fitted out at the shipyard and undergoing sea trials. The naming ceremony was held at the Kleven Verft A/S yard on 15th April 2016 with the ship being christened Edda Freya by godmother Kjersti Bårdsen. The vessel is 138.80m long between perpendiculars with a beam of 27.698m, a scantling draught of 8.325m and a hull depth of 12.00 metres. The OCV is powered by two MaK 8 M32 E (Caterpillar Marine) generator sets with a power output of 4,400kW each plus two MaK 6 M32 E units at 3,300 kW each and two MaK 6 M20 C at 1,140 kW each. The new M 32 E engine solutions boast an increased power rating of 550 kW per cylinder at 720 and 750rpm and with total output ranging from 3,300 kW for the six cylinder configuration to 4,950 kW for the nine cylinder configuration. The Caterpillar designed variable speed electric generator sets are integrated into a floating frequency electric drive system. A Cat C18 emergency generator with a capacity of 425 kW is also integrated into the vessel’s machinery. The Norwegian Cat dealer Pon Power AS spearheaded Caterpillar Marine’s efforts to win the contract.

Offering both 720 and 750rpm the higher power output is ideal for diesel electric propulsion and auxiliary power applications complementing the multi-engine concepts which are typical for the offshore market. Compared to previous solutions the new design substantially reduces the carbon footprint of the generator set. Besides the higher engine power density, the length and weight of the package has been reduced by more than 15%, without compromising reliability, durability, vibrations and structural borne noise. A seamless integration of the control system into the vessel electronics is ensured by the new modular alarm and control system (MACS). With MACS, the M 32 E can also be perfectly integrated with the proven Cat high speed engines in mixed engine rooms by using common Cat Electronics components like the Cat ADEM™ A4 engine control module. In addition to having Heavy Fuel Oil (HFO) capability, the new M 32 E features the same reliability, maintenance intervals and lube oil consumption as the M 32 C product series. The M 32 E also provides the technical platform for the recently announced M 34 DF dual fuel engine and is EPA Tier 2 and IMO II compliant. The Edda Freya was delivered with a new diesel electric hybrid propulsion system, namely the Siemens BlueDrive+C developed by Siemens in co-operation with Østensjø Rederi. By using variable rotational speed with optimal operation of the diesel generator in combination with batteries, the system significantly reduces fuel consumption (15-20% per annum) and the emissions of nitrogen oxides (NOx) and greenhouse gasses (CO2/methane). The hybrid system is a 1050VDC, 546kWh Corvus ESS consisting of 84 Corvus Energy AT6500 advanced lithium polymer battery modules arranged into four 130kWh battery banks. This new system follows on from the Edda Ferd hybrid platform supply vessel (PSV) project completed by the same partners in 2014. The Corvus ESS (Energy Storage System) can also provide back-up power in the case of a blackout. The electrically driven propulsion units come in the form of two CP95/AG TS1000, 145rpm Scana Volda entities, each with a 4,300mm diameter and powered by four 2,100kW electric motors. The propulsion units are driven via two ACG TS 1000 Scana Volda reduction gearboxes of the twin input/single output type. The ship achieved 16 knots during trials. To reflect her offshore work the Edda Freya is equipped with five 2,050kW Brunnvoll Tunnel Thrusters (two in the bow and three in the stern) and two 1,500kW Brunnvoll Retractable Azimuth Thrusters. These are used in conjunction with the ship’s DP3 enabled Kongsberg Maritime Dynamic Positioning System (KPOS DP-21) with eight position reference systems. Automation for the thrusters and propulsion is provided by Kongsberg K-Chief 700 and Siemens RCS systems.

Deepsea Construction

The Edda Freya can house a maximum crew of 140 with accommodation located on the forward lower decks of the ship in 64 single cabins and 38 double cabins. The ship’s offices, mess room, services and utilities are also located forward. Atop the bow is a 26.10 metre diameter and 16 tonne capacity heli-deck. Located aft of the superstructure is the 2,300 cubic metre cargo and working deck.

Situated amidships is a 150 tonne dual tensioner vertical pipe lay system (VLS) manufactured by Huisman of The Netherlands. Huisman has designed and delivered a large number of Flex-lay systems which combine capabilities for the installation of flexible pipelines, risers and in-line structures. The most notable features of a Flex-lay system are its vertical ramp, equipped with one or more tensioners, and a chute or wheel aligner on top. These systems also offer an efficient pipelay method with a specific advantage: the installed pipelines are less sensitive to fatigue and therefore require less complex installation and abandonment & recovery procedures. The VLS equipment includes two 75t 4-track tensioners, electrically driven retractable tensioners, a 185t below deck A&R winch, a service crane (18t capacity at an 8m outreach), two 10t hoisting beams, two 5t Moonpool tugger winches and two 2t product handling winches. A 3,000 tonne IMEC carousel for carrying the pipe is located below deck. The carousel has a diameter of 24.30m, a core diameter of 6 metres and an 8t safe working load spooling arm. On the port side of the Huisman VLS is the main 600 tonne maximum working load NOV Knuckle Boom Crane. In single fall/lift mode the crane can handle 400t at an outreach of 20m or 150t at an outreach of 40m. In double fall/lift mode the crane can handle 600t at an outreach of 14m or 400t at an outreach of 18m in special lift mode. This crane can operate to a depth of 3,000m. The auxiliary hook facility on this electro-hydraulic crane has a 25t capacity at 43 metres. Adjacent to this equipment, on the starboard side, is the NOV auxiliary Knuckle Boom Crane. In single fall/lift mode the crane can handle 70t at an outreach of 21m or 14t at an outreach of 45m. This crane can operate to a depth of 2,000m and the auxiliary hook facility on this electro-hydraulic hoist has a 10t capacity at 50 metres. Both are active heave compensation enabled so that vessel motion at sea is dampened whilst the cranes are in use. To assist the subsea work the Edda Freya also has two ROV moonpools with a net opening of 6.3m x 4.2m plus a work moonpool with a 7.2m x 7.2m net opening. The Remotely Operated Vehicle (ROV) system consists of two 220Hp Kystdesign Constructor WROVs capable of working to a submerged depth of 3,000m. The active heave compensated launching & recovery equipment and two ROV handling cranes are supplied by Macgregor. General deck equipment includes four 10t CT tugger winches plus an NOV knuckle jib crane (10t capacity at 15m outreach/5t capacity at 20m outreach). The working deck is prepared for a Reel Drive System with a six 400t reel capacity and offers a Deck Skid System for the movement of cargo and modules. The cargo deck can handle loads of 15t per square metre aft of the main crane and 10t per square metre forward of the main crane.

Offshore Debut

On 25th May the Edda Freya was formally delivered to Østensjø Rederi from the Kleven Shipyard. Designed by Salt Ship Design in close co-operation with DeepOcean, the vessel was then prepared for her first charter, a Statoil SURF installation contract with DeepOcean. The ship’s focus is on subsea cable laying operations, offshore construction and IMR operations and her maiden mission is performing installation work for Statoil on the Maria development in the Norwegian Sea and specifically, the modification of the Statoil platforms Kristin and Heidrun. The modification of these platforms is required in preparation of a possible tie-back from the near-by Mariadevelopment in the Norwegian Sea that is operated by Wintershall. Further work for the ship will include IMR2 (inspection, maintenance and repair), power cables, umbilicals, flexibles and manfolds and decommissioning projects. DeepOcean offers five main service streams including Survey and Seabed-mapping, Subsea Installation, Seabed Intervention, Inspection, Maintenance and Repair (IMR), and Decommissioning. CTC Marine Projects was established in 1993 as a private limited company in the North East of England, UK. CTC’s initial core business was the provision of fibre optic cable lay and seabed intervention solutions for the global telecommunication market. The company later diversified and added trenching services for the oil and gas industry and offshore renewables. As mentioned earlier, DeepOcean was established in 1999 by Østensjø Rederi and Solstad Offshore and then sold to CTC Marine in 2008. In 2013 it acquired a 50% interest in ADUS to form ADUS DeepOcean Ltd. ADUS DeepOcean’s stunning subsea 3D visualisations can be used to provide high quality 3D images of subsea structures such as offshore facilities, wind turbine foundations and seabed architecture.

After delivery to DeepOcean an enthusiastic project and offshore crew settled in on board the state-of-the art vessel. Rigorous tests were embarked upon including the first test runs with flexible product of the 150t Vertical Lay System west of Utsira, Norway. Future work for the Edda Freya includes a contract from Repsol Norge A/S to provide engineering, procurement, removal, and disposal of the Varg field subsea facilities in the Norwegian North Sea. The scope of work covers subsea pre-decommissioning surveys, recovery of FPSO mooring lines, anchor piles, risers, midwater-arch buoy and subsea structures, and onshore disposal and recycling of the recovered items.

Special thanks must go to Solveig Røkenes, Communication and Competency Supervisorat Ostensjo Rederi AS for their invaluable assistance with information and images. Some precise details of the ship’s layout were not available due to a GA Diagram not being supplied for reference or publication purposes.

TECHNICAL SPECIFICATIONS