Wind power is becoming increasingly important worldwide as countries try to reduce their reliance on fossil fuels. China is the world leader in wind power generation and is looking to boost its offshore capacity to 50 gigawatts by the end of 2029. This
is driving demand for specialised windfarm construction vessels from shipowners such as China Yantai Salvage, whose new heavy-lifting jack-up vessel, the De Jian, uses Wärtsilä transverse thrusters to ensure excellent station keeping and
Yantai Salvage Bureau
China Yantai Salvage is one of the largest marine salvage and offshore engineering contractors in Asia. When the company was looking to add a new heavy-lifting vessel to their fleet that could be used for both salvage projects and offshore engineering works, they turned to long-term partner Yantai CIMC Raffles shipyard, specifying Wärtsilä transverse thrusters in their design brief.
China Yantai Salvage’s new 132-metre jack-up and salvage vessel, the De Jian, will be used for rapid emergency salvage, heavy lifting and wind power installation in the seas around northern China. With a maximum operating depth of 50 metres and a variable load of 5,000 tons, the vessel is equipped with four 90-metre-long cylindrical legs and a hydraulic bolt-type lifting system to ensure it stays safely in place when work is being carried out. The vessel is self-lifting and self-propelling, and there is space onboard for 220 personnel. The De Jian was delivered on 15 April 2021 and by 9 May had already completed its first wind power installation.
Vessels for offshore engineering applications such as windfarm construction need excellent dynamic positioning (DP) capabilities and powerful thrusters to ensure superior station keeping, often in rough seas. De Jian has DP-2 dynamic positioning capability, supported by three Wärtsilä WTT-28FPD transverse thrusters installed at the bow of the vessel that extend the DP capability and help the De Jian to transit to and from its working locations.
“Wärtsilä transverse thrusters are designed to be highly efficient and environmentally friendly, working silently and with low vibration. With our skill and experience in computational fluid dynamics (CFD), we optimised the interface of our thrusters with the hull to minimise thrust loss and ensure that there is sufficient thrust capacity for the vessel’s dynamic positioning system,” explains Xiao Yun Chu, Project Manager at Wärtsilä.
“Wärtsilä thrusters save weight and space without compromising on hydrodynamic performance. The design has fewer components and the hydraulics are integrated, simplifying installation and reducing the need for maintenance.
The compact and lightweight thruster design was also a key deciding factor for China Yantai Salvage as the weight of equipment is always critical for jack-up vessels. “Wärtsilä thrusters save weight and space without compromising on hydrodynamic
performance,” shares Chu. “The design has fewer components and the hydraulics are integrated, simplifying installation and reducing the need for maintenance. Because Wärtsilä thrusters ensure optimal efficiency they reduce fuel
consumption, emissions and wear, cutting maintenance requirements further and giving vessels a high level of uptime, as well as helping to reduce operational expenses.”
As well as reducing emissions, all Wärtsilä thrusters are available with environmentally acceptable lubricants (EALs) and are fully compliant with all relevant environmental regulations worldwide.
“Jack-up vessels have strict requirements for equipment reliability, especially for thrusters,” points out Chu. “With over 50 years’ experience of thruster design and over 3,200 transverse thrusters delivered globally, Wärtsilä thrusters offer proven reliability in tough offshore applications. We are very proud that Wärtsilä has once again been selected to provide key equipment for jack-up vessels in the Chinese market.”
“Wärtsilä provide high-quality, high-performance equipment at a very reasonable price point while also offering excellent product reliability, which is essential for the kind of offshore applications we specialise in. We specified Wärtsilä transverse thrusters for the De Jian because of their environmentally friendly design, compact footprint and low weight, all of which are important features for jack-up vessels. We have cooperated with Wärtsilä many times in the past and look forward to continuing our relationship in the future.
- Mr. Xu Yong Qi, Director of Planning and Construction Department, China Yantai Salvage
“Wärtsilä provided high-quality service and equipment. We experienced a fast response and good support from Wärtsilä through the project execution, which is typical of our cooperation with the company and always appreciated. The thrusters were delivered on time and the installation and commissioning process went smoothly and quickly. Their operation is very stable and they are easy to maintain. It is easy to see why they are a popular choice for vessels in this market, especially with the support during construction and operation that Wärtsilä provide.
- Mr. Sun Xiao Ming, Project Manager, Yantai CIMC Raffles
To find out more about Wärtsilä thrusters visit https://www.wartsila.com/marine/build/propulsors-and-gears/thrusters