Tyra Redevelopment (Decommissioning Phases 3 & 4)

Scope of work 

Phase 3 (2020)  

• Engineering, preparation, removal & disposal (ERPD) of 14,000-tonne TEA processing/accommodation topsides & 7600-tonne TWA processing/accommodation topsides, plus additional modules, support frame, flare jackets & monopile 
• Transfer of topsides & modules to Iron Lady for load-in to M.A.R.S. yard at Frederikshavn, Denmark 
• Transfer of flare jackets to Iron Lady for load-in to Sagro yard at Vlissingen, the Netherlands 
• Pre-lift preparations (incl. removal & separation of under-deck caissons) & leg cutting 
• Design, fabrication & installation of bearing blocks to accommodate horseshoe lifting tools 

Phase 4 (2022)  

• Engineering, preparation, removal & disposal (ERPD) of 5400-tonne TEA jacket & 3100-tonne TWA jacket, plus remaining monopile section 
• Transfer of jackets to Iron Lady for load-in to M.A.R.S. yard at Frederikshavn, Denmark 
• Pre-lift preparations  

Specials & challenges 

• Design & fabrication of bearing block type lift points, (horseshoe) lifting yokes, leg support structures, spreader bars & frames 
• Lift of modules with internal lifting tools (ILTs) 
• Subsea dredging & cutting with internal & external cutting tools 
• Load-in operations by means of hydraulic skidding for topsides & SPMTs for other structures 
• Very limited air gap due to subsidence of both fields (5-7 m) 
• Very narrow span between topsides legs & outreach of TLS beams 
• Close proximity to the other platforms in the field