Offshore lifting

Low oil prices and reluctance from customers to invest in projects hasn’t stopped the offshore industry in developing new lifting products and finding new markets. Katherine Weir reports...

The slump in oil prices prompted many offshore equipment manufacturers to change their game plan in terms of equipment and viable markets. Even in this tough climate, however, there are still new products on the horizon and many impressive offshore projects ongoing or near completion.

Netherlands-based manufacturer Huisman said it has placed strategic focus on the offshore wind turbine installation industry. Timon Ligterink, sales and concepts engineer for cranes at Huisman, says, “The offshore wind turbine industry is relatively independent in relation to the oil and gas industry, but is similar in learning curve and technology that is applied in installing wind turbines offshore.

“Lately, the focus has been on developing equipment for installing 1,500 tonne monopiles and 10 megawatt wind turbines.”

Huisman’s most recent delivery is a 1,540 tonne leg encircling crane for the Seajacks Scylla, built to install the world’s next generation offshore wind turbines. In addition to the crane for the Seajacks Scylla, Huisman will also supply a new 1,600 tonne crane for Van Oord’s Aeolus, and a 3,000 tonne mast crane for Boskalis.

The latter crane is part of modifications to one of Boskalis’ F-class heavy transport ships to become a crane vessel for the offshore wind sector - a reaction to the downturn in the gas and oil sector. The vessel will have dynamic positioning and increased accommodation and is expected to be deployed by the end of 2017.

Palfinger Marine, the maritime manufacturing arm of Palfinger, says that the downturn seen over the last couple of years has not affected the drive to develop new deck equipment and handling solutions.

Jan Silgjerd, business manager at Palfinger Marine, says, “The focus is somewhat even stronger to come up with more cost effective and environmentally friendly solutions, to strengthen our competitiveness and win the projects that are actually materialised. The tough market also increases the drive to lowering costs in the long term for the customer. Cost saving programs and the willingness to do things in new ways opens up for new technology to conquer.”

The latest development from Palfinger Marine is a new crane design developed with oil and gas company Statoil in Norway for the Johan Sverdrup oil field. The company was awarded the contract for delivery of seven large offshore cranes with a total order value of approximately NOK 285 million (around US $35 million). The assembly of the first cranes is now well underway, Palfinger Marine says, and the testing phase of the fully assembled cranes will start soon. The first delivery will be made to Statoil in the first half of this year.

Silgjerd adds, “The wire luffing lattice boom cranes are fully electric driven and designed according to EN 13852-1 and NORSOK R002. The design is the first of its kind using standard AC electrical motors instead of expensive custom made motors with long lead time. This results in less expensive, and more available, spare parts as well as a less complex system design.

“The cranes have a lifting capacity of 60 tonnes and an outreach of 57 metres and are safe to use in significant wave height up to 6 m. We have put a lot of effort into optimising the load charts of the cranes. This has proven very successful and will be a huge advantage for the crane operator in heavy weather conditions.”

The design of the new crane came from Palfinger Marine’s experienced engineers in Bergen in close co-operation with a team of crane experts and crane operators from Statoil. The advantages with the new design are less vibration, lower levels of noise and (due to the advanced control system) smooth and predictable operations, the company said.

The cranes also have remote access, which ensures quick support and fault detection. The power consumption is lower compared to the performance, giving energy efficiency, and there is no risk for oil spill to the surroundings. The lifecycle cost for the cranes is reduced compared to conventional electro-hydraulic cranes, as electrical driven cranes have fewer components subject to wear and tear.

As well as the specialist cranes being built by Huisman for the wind turbine installation industry, the company is also focusing on lifting appliances for decommissioning of offshore oil and gas platforms in the North Sea. Huisman has the world’s largest offshore crane under construction for Heerema (2 x 10,000 tonne cranes for the Sleipnir), and has more recently contracted cranes for OOS (4 x 2,200 tonne) and Allseas, with a 5,000 tonne crane for the Pioneering Spirit.

Earlier this year, the Liebherr offshore crane division installed an offshore crane, type BOS 35000, on the heavy lift barge Giant 7. The entire project was conducted in the company’s production site in Rostock, northern Germany.

Gordon Clark, Liebherr sales director for offshore cranes, says, “The biggest challenge when assembling heavy lift giants like the BOS 35000 is the handling of oversized parts. The lattice boom is 78 m long. Its weight is more than 250 tonnes. With 390 tonnes, the machinery house is even heavier. These dimensions mean that two Liebherr type LHM 600 mobile harbour cranes were necessary to assemble the components.”

Offshore projects

Netherlands-based contractor Van Oord - along with Siemens - has completed the Gemini Offshore Wind Park in the Dutch part of the North Sea. Using the Aeolus offshore installation vessel, Van Oord has installed 150 wind turbines, bringing the supply of sustainable energy to the 1.5 million people in the Netherlands one step closer, the company said.

Van Oord and Siemens were responsible for the installation of the wind turbines. Matthias Haag, CEO at Gemini, says, “The installation of the 150th and last turbine in the wind park is a magnificent achievement. After the successful installation of the foundations, the offshore high voltage stations and 210 kilometres of export cables by Van Oord, the turbine installation also went according to plan. We are proud of everyone that contributed to the safe construction of Gemini.”

With a total capacity of 600 megawatts (MW), the Gemini Offshore Wind Park is one of the largest wind farms in the world, both in terms of size and production capacity.

Hornsea Project One, due to be located 120 kilometres off the Yorkshire coast of the UK, will have up to 240 wind turbines (each between 5 and 8 MW) covering approximately 407 square kilometres. Onshore construction of the project started in early 2016 with offshore construction due to begin in 2018.

Dong Energy took over full ownership of the project in February 2015 following years of development alongside SMart Wind. The company confirmed that Saipem will transport and install all four offshore platforms, Fred Olsen Wind Carrier and A2Sea are both chartered to supply wind turbine installation vessels and the export cable will be transported and installed by Tideway.

Project One has a potential total capacity of up to 1.2 gigawatts (GW). Once completed, the project will become the world's first gigawatt scale wind farm, far from shore.

In August 2016, the UK Secretary of State for Energy granted consent for the Hornsea Project Two offshore wind farm. Once completed this project will have up to 300 turbines and capacity of up to 1.8 GW. Project Two will be 89 km off the Yorkshire coast and would become the world’s biggest offshore wind farm.

With several projects well underway and others in the planning stages, it appears that the offshore lifting industry is still going strong. As well as carrying on with its busy crane order list, the company will also be developing and testing several fibre rope applications for deep subsea handling.

Timon Ligterink at Huisman concludes, “In the long run, Huisman will focus on reducing the cost of retrieving oil by building more efficient and slender crane designs. Especially for deep subsea as there is a lot to gain in this area.”