OTC 2024: High-voltage swivel joint offers FPSO, floating wind applications

May 10, 2024
Moog’s high-voltage electrical swivel joint handles greater than 52 kV.
By Ariana Hurtado, Editor and Director of Special Report 
HOUSTON Moog Inc.’s Model 483 high-voltage electrical swivel joint (HVES) was designed to enable developers of floating wind energy platforms to commission structures that vertically pivot, or weathervane.
Models 481 and 483 are both suitable for use in offshore applications including wind platforms.
“For example, the HVES Model 483 provides the yaw axis allowing alignment with the flow of current or air,” Deepak Jagannathan, Moog’s manager of strategic growth and innovation, told Offshore. “Subsea moorings, which connect a rotating wind turbine to the seafloor, can include an IP68-rated subsea swivel for permanent immersion, providing flexibility on the mooring and structure design.”
Moog developed its Model 483, first launched at OTC 2023, from its workhorse MV power swivels for the FPSO market, and it has been installed in more than 60 locations worldwide with an uptime of 99.92%.
“The Moog HVES is an industry first; the first production unit is being built now,” he said. “We have a large install base (200+) of similar situations that are rated for lower voltage. These are successfully operating around the globe.”
The company said the Model 483 HVES is the only high-voltage option on the market that handles greater than 52 kV. It is rated at 72.5 kV (66 kV operating) for pivoting offshore applications. The HVES stands 2,300 mm with a diameter of 2,510 mm and weighs about  5,280 kg.
Jagannathan added, “Existing solutions in the market help transfer high-voltage power up to several tens of kV and currents of up to 2,000 amps in offshore environments, but the Moog HVES can transfer up to 145 kV, which is five to six times higher than what’s currently available on the market. This higher voltage equates to faster charging for example.”
All of Moog’s floating production system swivels are certified for use in hazardous locations.
The company’s designs adhere to IEC codes, and DNV has independently verified the technology.
High-power electrical swivels help power subsea equipment, remote production platforms and transfer power from renewable sources like wind and tidal. The swivels also allow offshore assets (including vessels) to be powered and charged from green power sources offshore.
“Moog swivels enable the transfer of power, signals and fluid across a rotary interface,” Jagannathan said. “For example, swivels are part of a floating production system’s (FPS) turret and help the FPS weathervane around the mooring system and the mooring line. In harsh weather, a turret mooring system is essential. Using the turret, the platform can rotate while moored to the seafloor. As renewable power becomes more important offshore, swivels are critical for construction of wind platforms. Swivels are for any application requiring a product that can withstand harsh marine conditions or requires long life with minimal maintenance intervals.”
So far, the company has completed some engineering studies for the Model 483, but the first case studies are forthcoming with the initial installations on the way.
“Moog’s swivels are used in a variety of floating production systems, including buoys, turret moorings and offshore loading towers,” Jagannathan concluded. “Moog’s swivels permit the continuous delivery of electrical power and signals, hydraulic fluids, and fiber-optic signals, with unlimited freedom of a vessel or wind turbine platform to weathervane about its mooring point.”
About the Author

Ariana Hurtado | Editor and Director of Special Reports

With more than a decade of copy editing, project management and journalism experience, Ariana Hurtado is a seasoned managing editor born and raised in the energy capital of the world—Houston, Texas. Utilizing her editorial expertise, she helps create and oversee new special industry reports and revolutionizes existing supplements, while also contributing content to Offshore magazine, its newsletters and website as a copy editor and writer. In addition, she manages digital media for the Offshore team.