The Magazine for Underwater Professionals
Fugro, the Netherlands, has begun a site characterisation programme at the Hollandse Kust (noord) Wind Farm Zone. Carried out under a further contract for the Netherlands Enterprise Agency (RVO.nl, part of the Ministry of Economic Affairs and Climate Policy), the geotechnical workscope comprises seabed investigations and borehole drilling at two lots. Other deliverables include standard and advanced laboratory testing and an integrated geological/geotechnical soil model which will be used by future developers of the wind farm to prepare their bids.
The fieldwork is taking place from Fugro vessels including the state-of-the-art geotechnical drilling vessel Fugro Synergy. Deployment of two of Fugro’s most recent technical innovations will enhance safety and bring improved operational efficiency to the project, according to the company. The team of geophysical, geological and geotechnical experts will complement the company’s innovative technology to optimise an integrated deliverable, the firm said.
“Our geotechnical innovations will ensure that we deliver data of the highest quality to RVO.nl and obtain it in a safe manner,” said Sven Plasman, Fugro project director. “From Fugro Synergy we’ll operate the Fugro SEADEVIL, an offshore geotechnical tool that optimises vertical control during drilling and enables our team to acquire high quality samples. The seabed cone penetration testing will be carried out using our SEACALF MkIV system; its coiled rod requires no manual handling, ensuring safer operations, while the continuous drive system yields high quality data. Both of these innovative systems are fundamental to reducing operational costs and are integral elements of Fugro’s specialised support for the offshore wind industry.”
Frank van Erp, project manager at RVO.nl described how the Netherlands Enterprise Agency, executing the offshore wind energy permit tender, is expected to set a new benchmark in providing high quality site surveys and investigations. “Our aim is to use the latest techniques to ensure the package of site studies we deliver for developers preparing bids is the best it can be, so they can fully optimise wind farm designs. We are confident Fugro’s state-of-the-art techniques will play a key role in this,” he said.
With a total capacity of 700 megawatts, the Hollandse Kust (noord) Wind Farm Zone is located 10 miles (16 kilometres) off the west coast of the Netherlands. In 2017, an earlier contract with the Netherlands Enterprise Agency saw Fugro complete a geophysical survey of the area to map the position of existing cables and pipelines, as well as the possible presence of other obstacles.
UK-based Bibby HydroMap has begun site operations at the Borssele 1 & 2 offshore wind farm in the Dutch North Sea on behalf of Ørsted, Denmark.
The work involves the company’s dedicated survey vessel Bibby Tethra mobilised with a suite of high specification survey equipment.
The vessel will acquire multibeam bathymetry, sidescan sonar data, sub-bottom profiler data and UXO magnetometer data.
The 752-megawatt Borssele 1 & 2 wind farm is located at the southern edge of the Dutch border, less than one kilometre from the Belgium border, and located some 23 kilometres offshore. The wind farm will be built in water depths between 14 and 38 metres and will cover an area of 128 square kilometres.
Ørsted (formerly DONG Energy) secured the concession rights to build the Borssele 1 & 2 in July 2016.
The wind farm will feature 94 Siemens, Germany, Gamesa eight-megawatt turbines and has a grid connection agreement with TenneT, the Netherlands, in place.
The commissioning is scheduled for the end of 2020.
Van Oord, the Netherlands, has expanded its cable laying and burial capabilities with the deployment of its new trencher Dig-It, which has started its first job at the 450-megawatt Borkum Riffgrund 2 offshore wind farm in the German North Sea.
Dig-It is a tracked remote-controlled trench jetting and cutting system and has been mobilised on the offshore supply vessel Rem Saltire to support the cable-laying vessel Nexus at Riffgrund 2. The work should be completed this summer.
Van Oord said Dig-It is also known as the Q Trencher 1600 and has total installed power of 1200 kilowatts.
Once a cable has been laid on the seabed, the trencher can bury wires up to three metres deep depending on the configuration and soil characteristics.
A joint US and Australian expedition to survey Australia’s first submarine, HMAS AE1, has provided detailed new images of the 103-year old shipwreck, which lies on the seafloor off the Duke of York Islands in Papua New Guinea (PNG).
The Royal Australian Navy’s HMAS AE1 was lost at sea with all hands on 14 September 1914, and its fate had remained a mystery until its discovery in December 2017. It was the first loss for the RAN and the first Allied submarine loss in World War I but ultimately a tragedy felt by all Australians.
The recent survey was undertaken by Microsoft co-founder Paul Allen’s research vessel Petrel and coordinated by Find AE1 Ltd, Australia, in partnership with the Australian National Maritime Museum, the Royal Australian Navy, Curtin University, Australia, the Western Australian Museum and the Submarine Institute of Australia. Approval for the survey was granted by Papua New Guinea National Museum and Art Gallery. The ship’s ROV, fitted with HD video and stills cameras, undertook a comprehensive, non-invasive inspection of the submarine, revealing fascinating new information.
RV Petrel diverted to the Duke of York Islands following a series of successful expeditions that located the World War II shipwrecks of USS Lexington, USS Juneau and USS Helena.
“The AE1 has a special place in Australian maritime history and I’m proud of our partnership with the Australian National Maritime Museum and others that brought an end to the mystery of the AE1’s final resting place,” said Paul Allen. “For all of us associated with Petrel, we view this work as a means to honour the courage and sacrifice of crew of the AE1.”
The data collected during this first ROV examination of AE1 will be used by the Australian National Maritime Museum to develop a shipwreck management plan in cooperation with the PNG government and the PNG National Museum and Art Gallery.
“We are very grateful to Paul Allen and the crew of RV Petrel for making this survey possible. These incredible images and the new information they provide will help the museum tell the story of AE1 and its brave crew, and ensure their service and sacrifice are remembered by future generations,” said Australian National Maritime Museum director Kevin Sumption.
The still images of the shipwreck site will also be developed into a detailed 3D digital model using techniques developed by Curtin University and the Western Australian Museum. This will allow the Find AE1 team and museum researchers to further examine AE1 and refine understanding of what happened to it 103 years ago.
Aberdeen, UK-based subsea services provider Bibby Offshore has become the first to deploy a pioneering diving safety system in the North Sea. The company provided its divers with the innovative Compact Bailout Rebreathing Apparatus (COBRA) during a recent contract with BP North Sea.
Working at depths of up to 110 metres, the Bibby divers used the COBRA system to deliver electrical umbilical installation, subsea control module change-out, and production and controls system integrity testing, deisolation and commissioning services.
COBRA, developed by JFD, UK, is a bailout system which offers divers up to 45 minutes of fully independent breathing gas in an emergency situation.
Bibby Offshore’s deployment of the system is a first for the North Sea since its introduction to market last year, with the company playing a key part in testing during 2017.
Howard Woodcock, chief executive at Bibby Offshore, said: “The safety of our personnel is paramount at all times. COBRA significantly enhances the time our saturation divers have to return to the diving bell in an emergency situation – a step-change in improving subsea safety and one we will adopt in the future across our fleet.
“As leaders in diving safety, it is imperative that our divers are equipped with the best equipment and leading technology. Having the full support of the client for the introduction of the COBRA rebreathers during operations on its offshore assets, clearly demonstrates the alignment between the client and Bibby Offshore in an ongoing commitment to advancements in industry safety.”
The autonomous underwater vehicle Autosub Long Range (ALR), known affectionately around the world as Boaty McBoatface, has been successfully recovered following its first under-ice mission beneath the Filchner Ice Shelf in West Antarctica. The success marks a significant milestone in proving the vehicle’s capability.
From January to February 2018, the AUV was deployed in the southern Weddell Sea during RV Polarstern cruise PS111 as part of the Filchner Ice Shelf System (FISS) Project – a collaboration involving leading UK research institutions including British Antarctic Survey (BAS), the National Oceanography Centre (NOC), the Met Office Hadley Centre, University College London, the University of Exeter and Oxford University, and international partners including Alfred Wegener Institute (AWI), Germany, and University of Bergen (UiB), Norway. The AUV plays a critical role in the project that aims to investigate and describe the current state of the complex atmosphere-ice-ocean system.
Boaty spent a total of 51 hours under the Antarctic ice, travelling 108 kilometres over the duration of the deployment. The vehicle reached water depths of 944 metres, and spent 20 hours exploring beneath a section of the ice shelf that was 550 metres thick.
Steve McPhail, head of AUV Development at the NOC, said: “I am delighted in the success of this mission. For the engineers involved, this was a very challenging deployment that was not without risk. We knew that the environment was harsh, with minus 20 degrees Celsius air temperatures and sea temperatures very close to the freezing point of seawater. Under the ice shelves there are significant tidal currents and the high southerly latitudes pose difficulties for the AUV’s underwater navigation. Once in the ice shelf cavity we had neither detailed information on the thickness of the ice, nor the depth of the water. We had no communication with the AUV for 90 per cent of its time in the water.
“Waiting for the AUV to return after a 48-hour mission into a largely unknown environment is – to say the least – exciting, and as a result I was very relieved each time the AUV turned up, on time, and in the right place, circling 900 metres below the ship. Even then our problems were not over. With the surface of the sea frozen, we needed RV Polarstern’s help to create an ice hole through which we carefully navigated the AUV.”
The AUV carried two sets of CTD sensors measuring the salinity and temperature of the water. It was also equipped with a micro-structure probe to measure ocean turbulence, a sensor to measure the amount of phytoplankton in the water (by measuring the fluorescence of their chlorophyll) and a sensor to detect the turbidity of the water. Acoustic instruments (ADCPs) also measured the water current up to 80 metres above and below the AUV’s position, and accurately measured the depth of the seabed, and the draft of the ice along the vehicle’s track.
The Filchner-Ronne Ice Shelf is the second largest of its kind in the world. Covering an area of around 450,000 square kilometres, it holds a greater volume of ice than any other floating glacier tongue. Climate researchers are particularly interested in whether more glacial ice is currently being transported into the ocean, since this process is related to rising sea levels. In addition, so-called ‘deep water’ forms near the ice shelf, which is a key driver of global ocean circulation and therefore impacts upon the climate system everywhere on the planet.
The PS111 research team involved many different disciplines including oceanography, meteorology, sea-ice physics, bathymetry, geology and marine biology. Each share an interest in obtaining data from a region that, due to its permanent ice cover, can only be accessed using icebreakers such as the RV Polarstern and AUVs capable of travelling under the ice.