Pioneering Spirit has safely removed the 15,300-tonne Heather Alpha topsides from the UK northern North Sea in a single, seamless lift.

Completed on 11 August, the operation marked the culmination of three years of detailed engineering, meticulous planning and offshore preparation, delivered in close collaboration with operator EnQuest and specialist contractors.

Located 460 kilometres northeast of Aberdeen, Heather Alpha has been a fixture of the North Sea for nearly 50 years. Its removal represents the penultimate offshore lift in a packed 2025 campaign for Pioneering Spirit.

The topsides was lifted using the vessel’s unique motion-compensated system, capable of removing entire structures in a matter of seconds. This method minimises offshore exposure, reduces man-hours and enhances safety – all while delivering major project cost savings.

“This project is a textbook example of what our single-lift technology was designed for – removing large, ageing structures safely, quickly and efficiently,” says Project Manager Krijn van Eeten. “Meticulous preparation, innovative thinking, keeping solutions simple, and seamless teamwork between our onshore engineers, offshore crews and EnQuest made this another project to remember.”

Years in the making

Preparations began in 2024 with the installation of custom-made lift points, structural strengthening, caisson works and separation cuts – much of it carried out while the platform remained manned. Returning in early 2025, offshore teams finalised underdeck scopes tied to leg cutting and separation.

The campaign highlighted the versatility of Allseas’ integrated in-house teams, who worked alongside specialist rope access crews to overcome challenging weather and operational constraints. This collaborative approach kept the project on schedule and reinforced the value of maintaining core preparation expertise in-house.

Following removal, the topsides will be transferred to Allseas’ cargo barge Iron Lady for tow to the M.A.R.S. disposal yard in Frederikshavn, Denmark, where the structure will be dismantled and more than 95% recycled and repurposed, ensuring maximum material recovery.

About Allseas

Allseas is a family-owned global offshore contractor specializing in pipelay, subsea construction, and ultra-heavy lift. Since 1985, they have led the offshore energy market through bold innovation, consistently pushing technical boundaries to deliver pioneering, responsible solutions that evolve with the changing energy industry. By delivering cutting-edge solutions to the industry's toughest challenges, learning fast and sharing knowledge, Allseas redefines what is possible above and below the water’s surface, and seizes market opportunities that drive sustainable growth, leveraging engineering expertise to develop technologies that will play a key role in accelerating the energy transition.

About EnQuest

EnQuest is providing creative solutions through the energy transition. As an independent energy company with operations in the UK North Sea and South East Asia, the Group's strategic vision is to be the partner of choice for the responsible management of existing energy assets, applying its core capabilities to create value through the transition.