Mission River Bridge Remediation
KAEFER was engaged by Rio Tinto to undertake structural steel and paint remediation services on the Mission River Bridge near Weipa, QLD.
The works were split across three separable portions of the bridge in alignment with Northern Queensland’s Wet and Dry seasons. The scope comprised provision of an access system to execute the works, structural steel remediation to all ferrous surfaces (including stripping of existing coatings, steel member replacement, welding integrity and corrosion treatment), as well as bolt replacements and protective coatings application.
KAEFER opted to use a jack-up barge to access work areas as a safer and more efficient alternative to other access methods. The jack-up barge offered a number of safety and productivity benefits, including:
- Full deck access to work fronts, resulting in increased productivity
- Platform could be lifted level to work fronts, reducing risk to personnel requiring access via conventional barges (which are susceptible to tidal movements)
- Working platform housed all required equipment and facilities (i.e. offices and ablutions) for execution, increasing productivity
The existing protective coatings on the bridge contained both asbestos and lead materials. This, combined with frequent strong winds over the open water presented significant environmental as well as safety risks. KAEFER utilised full encapsulation for all blasting activities related to removal of the existing coatings, installing a 75 x 30mm timber substructure, 21mm plywood flooring and double-layered BLASTCLAD (200mm thickness) protective sheeting as an enclosure. This allowed the Team to safely capture all hazardous waste for disposal offsite.