QAL Waste Line Replacement

Client: Queensland Alumina Limited

Contract: Design and Construct

Location: Gladstone, Queensland 

 

Project Capabilities

Marine Pipelines

Fast Facts

  • 8.8 km DN 350 above ground pipeline
  • 1400 support structure piles in water
  • Zero lost time injuries
  • Zero environmental incidents
  • Completed 13 weeks ahead of schedule

McConnell Dowell designed, supplied, constructed and commissioned the Bauxite Waste Line 4 Replacement at Queensland Alumnia’s Gladstone refinery. The team successfully completed the works eight weeks ahead of an accelerated schedule and 13 weeks ahead of the original contract completion date. Now completed, the project protects the local waterways and environment. 

Traversing a marine tidal zone, the project drew on McConnell Dowell's leading pipeline and marine expertise and involved the:

  • Design of the new Waste Line 4 and the augmentation design of the support structure
  • Removal of the existing DN350 WL4 pipeline
  • Augmentation of the support structures, including approximately 1400 piles within tidal and marine zones
  • Installation of the new above ground waste piepline - 8.8 km of DN 350 SCH 60 steel pipe.

The McConnell Dowell team constructed the new line while operations continued using the current assets. Approximately 5,000 m of 350 mm dia. mudline was laid parallel to the existing pipe rack that contains four operating line assets.

Once completed, an operational change was made to take the current Line #4 out of operation. The old asset was then cutdown into transportable sections, capped and taken to a disposal site for scrapping. In parallel, civil, structural and diving crews started piling rectifications to extend the life of the existing structure by another 25 years.

New pipe strings were lifted off temporary supports that were used in the welding/ coating operations and placed onto the support foundations or into culverts. The pipe strings in the tidal areas were placed using a specialised push/ pull method to reduce the construction footprint.

After placing the entire pipeline on the existing structure, the pipeline was tested hydrostatically to more than the operating pressure. After testing, the pipeline was de-watered and handed over to QAL Operations.

Over 150,000 hours were worked on site with zero lost time injuries and environmental incidents recorded. The team’s strong focus on quality was also evident with zero weld repairs recorded. The team also contributed to the economic well-being of the region by maximising local industry participation.

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