Monopiles and Transition Pieces
Sif Group is one of the first manufacturers of monopiles worldwide. With more than 20 years of experience in the offshore wind industry, we have already produced more than 2,500 monopiles at our plants in Roermond and the Second Maasvlakte in Rotterdam.
The Monopile
Over the years, the lengths and diameters of monopiles have grown significantly. Whereas we used to make monopiles of 4 meters in diameter and 40 meters in length, we now produce monopiles with a diameter of 11 meters and a length of up to 120 meters. Our production site at Maasvlakte 2 has been expanded to meet the new requirements. We can now produce up to 500,000 tonnes of steel per year. These ‘XXXL monopiles’ are given a protective coating and form a solid foundation for larger wind turbines at sea, even for farms in remote areas with deep waters.
Sif is known for reliability and high quality. We have never been fined for late delivery for any 2,500 monopiles. With a production rate of 4-5 monopiles per week and a central location in Europe, we are the ideal partner for offshore wind projects.
The technical specifications of a monopile at Sif Group:
- Diameter: 11,0 meters
- Weight: 2500 tonnes (on request higher)
- Length: 120 meters
- Wall thickness: 160 mm
- Production speed: 4-5 per week
Transition pieces
Traditionally, a transition piece connects the monopile to the wind turbine tower. These pieces are usually attached with a flange-bolt connection. Together with Smulders, our partner in Belgium, we have already delivered more than 2,000 transition pieces. Our customers appreciate our experience, which we recognize in in many repeating customers over time..
Sif produces the primary steel of the transition pieces in Roermond. We then transport it to our partner Smulders in Hoboken (Belgium) for further finishing. The final product is then shipped back to Sif to the Second Maasvlakte.
The technical specifications for a transition piece at Sif Group:
- Diameter: 8,45 meters
- Weight: 950 tonnes
- Length: 32 meters
- Wall thickness: 160 mm
- Production speed: 4-5 per week
TP-Less monopile
There is increasing demand for extended monopiles, also known as TP-less monopiles. Worldwide, Sif has produced the most TP-less monopiles. We cooperate with Smulders for welding attachments and the secondary steel package.
The TP-less monopile accommodates innovations such as the Skybox and internal platforms, which can replace boat-landing. These monopiles are often 20 to 30 meters longer than traditional monopiles and save weight by eliminating the ‘skirt’, the overlength required to move a transition piece across the monopile.
Value Engineering
In the early stages of project development, we help our customers think through the ideal foundation solution for wind farms. Our value engineering expertise helps with cost-effective designs. Together with our subsidiary KCI the Engineers, we advise on the optimal layout of cans and cones for efficient production. This results in manufacturable and cost-effective foundations.
Our value engineering allows customers to consider the pros and cons of different options at an early stage. Together with our subsidiary KCI the Engineers, we offer extensive knowledge and experience in the design and calculation of offshore foundations.
Welding Technology
Our technical knowledge enables us to communicate efficiently with customers. We have extensive experience in welding high-quality, super-strength steel alloys for harsh and cold conditions.
What we are proud of at Sif:
- Internal training and qualifications of all welders
- Self-designed welding machines
- Optimised welding techniques
- Years of rolling expertise and the capabilities to cold roll the highest rolling wall thicknesses
- 75 years of experience
Sif's key data production site
