D&C contract value $96m
BHP identified a requirement to increase towage services to support operations in Port Hedland including:
- Planned future expansion of iron export capacity through Port Hedland
- Mitigation of the significant risk of a vessel running aground and blocking the Port Hedland departure channel which is 42km in length, tidally constrained and uni-directional
The development at Hunt Point involved the excavation of a new harbour within the existing dredge material management area, construction of four (4) pontoons providing cyclone berths for up to eight (8) new RAstar 85 Escort tugs (1065t displacement) as well as a fifth pontoon providing four (4) berths for small boats. Piled seawalls either side of the entrance channel reduce cyclone wave penetration and batters around the perimeter of the harbour are rock protected. The existing tug harbour at Nelson Point has also been upgraded with two (2) new pontoons installed adjacent to the existing service jetty to provide bunkering services to the tugs. A davit crane capable of lifting 3.6t at 12.5m radius has also been installed to support maintenance operations.
Madsen Giersing (MG) was engaged by the principal contractor Lendlease to provide the detailed design and technical support services for the project. MG’s scope was the design of the marine structures and coastal protection structures for the new Hunt Point development and the new structures for the Nelson Point harbour upgrade.
The tug pontoons are 52m long and 5.85m wide steel pontoons restrained by 8 tubular steel piles and 37m long steel gangways with a maximum slope of 1:4 across the 7.5m tidal range with two dual Yokohama ABF-P fenders for each berth. The design included detailed dynamic mooring simulations of the cyclone mooring arrangement by a sub-consultant International Maritime Consultants (IMC).
Mooring line hangers, mooring line reels, bollards, snap back guards and rotating access brows have been provided on the deck of the pontoons. Day-night leading marks and navigation aids atop the piled seawalls have been installed to guide vessels entering the harbour.
Port Hedland, Western Australia