Allseas’s offshore construction vessel Pioneering Spirit has safely removed the 15,300-tonne Heather Alpha topsides from the UK northern North Sea in a single lift. Located 460 km northeast of Aberdeen, Heather Alpha has been a fixture of the North Sea for nearly fifty years.
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. Watch a video of the operation as posted on the Allseas website below.
Motion-compensated lift system
Removal of Heather Alpha 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.’
Also read: Pioneering Spirit delivers offshore wind converter
Preparations from 2024
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.
Allseas’ integrated in-house teams 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.
Also read: Pioneering Spirit performs heaviest offshore lift ever
Disposal in Denmark
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 per cent recycled and repurposed, ensuring maximum material recovery.
Picture: Single-lift removal of the Heather Alpha topsides (photo by Allseas).
Also read: Pioneering Spirit installs French offshore wind substation
