Jackets are a popular choice of fixed wind foundation in water depths of 30m-70m due to their maturity and use of smaller piles which are easier to install than monopiles. Jacket foundation piles are usually pre-installed for efficiency and installation is done using a pre-piling template to ensure that they are installed in the correct place and within the appropriate tolerances. As a result, pre-piling templates require a precise and intelligent design process to ensure they are fit for purpose. 

Full EPCI capabilities 

2H provides complete design and engineering services for pre-piling templates. Our global footprint and partnerships with local supply chains and fabrication yards around the world mean that we can also undertake the full engineering, procurement, construction and installation scope.  

Design Considerations for Pre-Piling Templates 

The installation of jacket piles is a precise operation and depends on the quality of the pre-installed piling operation. Pre-piling templates therefore generally need a number of secondary features: 

• A hydraulic levelling system to ensure that the template is orientated horizontally for accurate positioning of the piles.  

• Hydraulic pile guides to accurately position piles during installation process.  These tend to be retractable to allow passage of the piling hammer.

• Active controls functionality to aid the above. 

• Survey systems to ensure the templated is orientated and positioned correctly at the turbine location.

• Project-specific features such as noise suppression to reduce the acoustic effects of the hammer and mudmat breakout mitigation systems to ensure that the structure can be retrieved in a variety of soil conditions. 

Pre-piling template configurations can vary significantly as the design needs to suit the size of the jackets being installed, the number of piles associated with each jacket, and the installation method used by the vessel selected for the project. There are also options around whether the pre-piling template is standardised for specific applications, or whether the structure is designed to be adjustable for use on multiple projects with different specifications. 

2H understands there is a range of options that could be considered in terms of template size, shape, design and functionality and we work with our clients’ specific requirements to develop the most appropriate template design for the project. 

 Key Services 

• Structural modelling 

• In-place structural analysis and design

• Geotechnical design (inc. mudmat sizing) 

• Controls and hydraulics systems design 

• Lifting and installation analysis 

 Project Experience 

• Offshore WindForce – Wikinger – design, supply of specialist equipment, commissioning and operation of a pre-piling template for 70 4-legged jackets and larger diameter OSS piles

• DEME – Moray East – detailed design and engineering support for a pre-piling template for 103 3-legged jackets

• HMC – Greater Changhua – detailed design of a pre-piling template for 111 3-legged jackets