Case Study

QuikDeck®: removal of underdeck structures for decommisioning

Fixed Platform in the North Sea
AquaTerra’s client, Allseas, is in the process of decommissioning the topside structures on a North Sea platform, as well as preparing the asset for topsides removal.

AquaTerra has been tasked with removal of underdeck structures that would obstruct with lifting yokes due to be installed.

Structures to be removed include:
- Monkradle transverse beams
- Underdeck runway beams
- Floodlight platforms
- Mooring platforms
- Underdeck Guides

Key Summary
  • Removal of underdeck structures to facilitate topsides removal including: Monkradle beams, runway beams, floodlight platforms, mooring platforms, underdeck guides
  • Underdeck work scopes posed scheduling and productivity risks from weather restrictions and simultaneous operations
  • Significant quantity of uncertified steel requiring structural checks
  • QuikDeck® implemented in five key underdeck locations (150m2 each) to provide fall-back opportunities and reduce required standby cover
  • Uncertified steelwork checks integrated into engineering and design
  • Multidisciplined approach with the installation team reduces personnel and cost
  • QuikDeck® has lower self-weight than traditional scaffolding, making transportation and handling easier


All of the work scopes required for this scope are underdeck, which if executed by rope access pose a significant risk to schedule and productivity due to weather restrictions, simultaneous operations, and the need for outboard safety support.

Because of the age and condition of the underdeck, including the quantity of uncertified steel, particular attention was needed when designing and engineering a solution. Structural checks were required for each lifting point utilising uncertified steel.

The Solution

AquaTerra Group has implemented the use of QuikDeck® in five key locations under the deck. Each platform gives around 150m2 of workspace. These QuikDeck® platforms will create ‘fall back opportunities’ to allow work to continue without standby cover.

Uncertified steelwork checks were executed throughout the entire workspace, taking into account existing utilisation and any major loads on top of the deck. This information was used in the engineering and design of the QuikDeck® solution.

Where normally scaffold teams and project teams would be separate groups of personnel, AquaTerra Group’s multidisciplined approach means that the installation team also carry out the work in the further parts of the scope. This reduces personnel on board and brings down the overall cost and duration of the scope.

As each platform has been built, the AquaTerra Group team has commenced work in that area, removing the identified structures to clear the way for the lifting yokes. QuikDeck has a lower self weight than traditional scaffolding, so it has been easier to transport, handle and store on the asset.

The Result

QuikDeck® platforms are now complete in 3 of 5 locations, with work on the underdeck scope now in progress.

The system has a lower self-weight than traditional scaffolding, so it has been easier to transport, handle and store on the asset.

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