Primero have worked alongside Dampier Salt’s Sustaining Capital team to safely deliver upgrades to both Lake Macleod and Karratha operations.
Scope of Work
The Lake Macleod Radial Stacker Replacement Project was to be completed during a shutdown of salt harvesting activity with a five-week window of opportunity to undertake the change out. The replacement stacker was supplied by an international OEM with DSL / Primero jointly providing QA support. The stacker was supplied in prefabricated sections transported to site in six 12m sea containers comprising approximately 100t of loose material and mechanical equipment.
Primero partially removed the existing foundation and stacker runway, replacing the long travel and end stop buffer foundation as to allow preassembly of the inbound stacker to commence while production ensued, reducing turnaround impact.
Safe and controlled deconstruction of the highly corroded in situ stacker was the most critical risk present. Planning, detailed deconstruction procedures, modelling and contingencies were all developed to mitigate the risk of the fragile structure behaving unpredictably on the way down. The superstructure was strategically weakened at several points to bring further certainly to predictable removal.
The machine was removed by attaching 80t mooring rope to designated points on the A-frame and towing with a D11 dozer. Upon removal of the existing stacker the balance of long travel and storm lock foundations were placed.
Primero implemented a precast concrete solution for the long travel radial foundations, installing thirteen 12.3m segments each weighing 18t. This reduced onsite manning and ensuring that concrete processing could occur concurrently to production only further reducing the impact to production. A new slew pivot foundation was placed and included a precast centre block with accurately set hold down bolts for the centre slew pivot assembly mount.
With foundations in place critical lifts during erection included:
- Two bogie assemblies at 18T ea;
- Lower boom section approx. 40m long weighing 36T;
- Upper boom section approx. 40m long weighing 27T; and
- Six sets of pendant stays comprising multiple articulated / pinned tubular sections.
Once erected scope included completion of mechanical alignments of conveyor idlers and pulleys, installation of conveyor belt (via subcontractor), installation of guards and complete safe access along the structures.