The Contract for the transportation and installation of the Shearwater Development Alliance facilities was awarded to Heerema Marine Contractors UK Ltd as a subcontract from Heerema Hartlepool in February 1997.

The SDA was an Alliance comprising Shell, Heerema and Amec. Design of the Jacket was performed by HMC in Leiden with fabrication by HHB in Vlissingen. Design of the topsides was performed by Amec in London with fabrication by Amec, Wallsend and Heerema Hartlepool.

Phase 1 of the installation was completed in May 1999 and comprised the SWR 'C' Jacket and the Wellhead Deck (on the previously installed SWR 'A' jacket as a separate project.)

Phase 2 was completed in April 2000 and required the dual lift capacity of the Thialf to be upgraded to the largest HLV in the world. It comprised the Integrated Deck (a world record lift), a Cabins Module, Incinerator, Bridge and Flare. A period of hook-up support by the Thialf was the subject of a contract variation. The duration of this support was reduced by the amount of waiting on weather time incurred prior to the lift of the Integrated Deck.

Main Characteristics

Milestones
Offshore Start Date: 2000-Q1
Offshore End Date: 2000-Q4
Main Spread
Vessel: --
Transport Vessel(s): Thialf
Hamers: MHU-2100, S-2300 back-up

Main Technical Data - Phase 1

Jacket: Dual Crane / Lift Upend - 5,718t
Skirt Piles (8 off): Diameter 108"
Wellhead Deck: 1,200t

Main Technical Data - Phase 2
Deck Type: Dual Crane Lift - 11,800t
Cabins Module: 850t
Incinerator: 520t
Bridge: 250t
Flare Type: Dual Crane Upend - 190t