Vertech recently worked on a world first Derrick Deconstruction project in collaboration with an engineering firm, an EPC and the operator. The aim of this challenging project was to isolate, make safe and remove the North Rankin derrick structure.
The project was completed by utilising the derrick’s own top-drive rails and a HIAB crane with a bespoke frame, which was used to run up and down the derrick to lower structural steel to the deck. The upper modules were ‘stick-deconstructed’ using this methodology and thereafter dual crane lifts were used to remove the lower modules.
This innovative approach was a world first in the deconstruction of a drilling derrick and came with significant cost, time and safety efficiencies. Indeed, the client was so impressed with the execution of this project that they produced a video that demonstrates the power of collaboration and sets the bar for future projects.
The design and successful implementation of the project was largely attributed to not only the professionalism of the onsite teams, but to the detailed planning and collaboration of all parties and the comprehensive mock up trials prior to mobilisation.
As demonstrated in the video, a mounted crane and multi-skilled IRATA rope access tradesmen (including electrical, mechanical, rigging, NDT and scaffolding personnel) were used to complete all isolations, steel cutting and rigging on the project. Custom dropped object protection and netting allowed simultaneous work fronts at various levels of the structure.
The implementation of the knuckle-mounted crane was a world first, significantly reducing the estimated man hours expected using traditional methods. The hazard controls and prevention methods used on this project were considered sufficient to allow the facility to continue to operate throughout the project.