Keystone Engineering’s Offshore Renewables Division has developed a patented design called the Inward Battered Guide Structure, or “Twisted Jacket” foundation. This innovative offshore foundation reduces both cost and risk compared to traditional offshore foundations.
The company says its experience in fabrication, construction, and installing offshore structures provides a big advantage in the design stage of the IBGS structure by providing a focus on constructability, fabrication efficiency, and reduced install time.
From 3,000 to 32,000 tons, the company has experience with fabrication, loadout, and transport of many of the deep water, topsides, decks, quarter, compliant towers, jackets, and hulls currently installed in the Gulf of Mexico and other regions.
Fabrication: The IBGS has fewer nodes and components compared to a traditional jacket, making it easier to assemble. Fewer welds are required because there are fewer braces. The IBGS lend itself to serial production. Weight redistribution from jacket steel to less expensive pile and caisson steel greatly reduces the fabrication cost. The IBGS footprint in a vertical position takes less space than a tradition jacket for storage at a staging site. The structure is safer and easier to manufacture than tradition jacket because it is fabrication horizontally and the assembly s completed at relatively low heights above ground. The IGBS does not require castings or pile pins while many tradition jackets do.
Installation: No offshore welding and no underwater work is needed, which greatly reduces HSE, commercial, and schedule risks. It is possible to use less expensive vessels to install the vertical caissons and to perform grouting operations. The caisson guide structure and piles can b installed without repositioning the installation vessel. In the U.S. market, the equipment spreads costs are less for an IBGS versus a monopile. The IBGS needs smaller hydraulic or vibratory hammer than those used for monopiles. Also, smaller installation vessels can be used because the IBGS max lift weight is less than monopiles.
For the full brochure: https://www.keystoneengr.com/offshore-renewables