Client: BHP Billiton & Monadelphous Group
Location: Port Hedland iron ore car dumper
Due to the increase in demand for iron ore, the rail car dumper at the BHP Billiton Port Hedland Iron Ore Loading Wharf required upgrading.
Each carriage has a capacity of about 100 tonnes of ore.
KEY CHALLENGES
Steel I-beams encased 400mm deep in concrete had to be left in place while the structure was strengthed, and then cut by wire saw for removal at 25 separate locations.
The cut concrete surface had to be coated with a moisture inhibiter and the newly exposed reinforcing steel had to be cut back 50mm and painted with an anti-rusting agent before filling over the hole.
Work was carried out in extreme conditions during the summer months where the outside temperature regularly reached 45°C, making it considerably hotter inside the dumper. This necessitated the cutting of over 50 openings for ventilation in floors that were up to 3m thick.
Two 12 man shifts, which included supervisors and mechanics, operated day and night with monitoring fluid intake a critical part of the working day.
The project required significant plant resources to be deployed including:
- 3 three phase generators;
- 6 wire saws;
- 2 wall saws; and
- 20 drill rigs;
“Blind” recesses had to be formed in sloping walls to accommodate the stabilizers for the new dumper, requiring the bottom to be formed first to enable the back and sides to be cut.
As the removed concrete had to be transported by road, most of the concrete was cut into 20 tonne pieces.
PROJECT SUCCESSES
In total about 500 square metres of wire sawing was completed with over 700m of drilling for wire and lifting holes.
As part of the upgrade over, 700 tonnes of concrete was successfully cut and removed from the dumper.