Navatech Ltd was contracted by Rever Offshore to perform the seafastening of the equipments (chute, winch, MDL Reel Drive system etc) used for the Fairfield Dunlin decomissioning project.

The project took decommissioned product onto three reels (8.6m to 9.6m diameter up to 280Te each) over three trips. The product has been recovered over a chute on the stern of the Normand Clipper sequentially onto the forward, middle and aft reels using the towers to power the reels up to a tension of around 30Te.

Navatech has been involved in the seafastening & design/check of the following items:
– 30Te overboarding chute above the aft bulwark. This involved the design of the supporting steel frame with its access platform;
– A&R Winch;
– 5Te deck handling winch;
– 8in Pull head design;
– Mattress lifting beam design.

The Rever RDS grillage was upgraded and optimised. This fourth Revision of the grillage has seen the following additions:
– Two stb/port bolted tubulars frame allowing the reels seafastening chains to be basketed around;
– Existing grillage has been extended to incorporate a third reel;
– Roller box. A roller box was needed onto the RDS grillage in order to deviate the winch wire to avoid clashing with the reels;
– 30Te hang off padeyes required on the RDS to perform the recovery work.

Only six double cleats per reels were used, allowing a quick multi reel drive system installation

(Photos courtesy Rever Offshore)
Mattress lifting beam:

Reel Drive system (RDS):

30Te SWL Stern chute: