Darwin Port Benefits from Dredging
Darwin Port Corporation has identified the need to significantly improve shipping access to accommodate larger and more numerous vessels. This came as a part of its strategic planning to support major projects and diverse Port users, including fully loaded LNG tankers, dry bulk carriers and new cruise liners such as the Queen Mary 2, which is now a regular visitor to Darwin.
A $3.8M dredging project has removed approximately 105,000 m³ of sand and sediments from a 450 m wide and approximately 2 km long section of the channel at Middle Pass, adjacent to Charles Point Patches. Dredge spoils were deposited approximately 200 m away from the channel to minimize environmental impact.
So far, this section had restricted access for larger ships at low tide. Now, the improved shipping access delivers greater efficiencies by reducing turnaround times which results in considerable cost savings for Port users.
The increased access is bringing heavier post-Panamax sized vessels that can enter and leave the harbor every day of the year, whereas in the past the number of available sailing days was around 220 per year.
Previously, these vessels had to wait for a suitable tidal sailing window, requiring sometimes up to five days to load the ship. It is expected that most loads will now be accomplished within three days.
Capitalizing on available resources
The Corporation was able to move quickly on the project by contracting existing dredging vessel Eastern Aurora which was already working within the harbor to create the access channels for the new Marine Supply Base. Extending the stay of a dredger already in Darwin harbor negated the need and cost of a separate mobilization.
These factors created significant efficiencies as well as time savings and the dredging contractor, Hall Contracting Pty Ltd, was able to commence the work in late March and completed the majority of dredging works on 17 May.
The whole project was achieved in a remarkably short period of time commencing with community consultations, including engagement with the Environment Center and the Amateur Fishermen’s Association, followed by environmental approvals prior to dredging work and final surveys.
The channel remained open to larger vessels during dredging, with arrangements in place to ensure that the contractor cleared the channel, resulting in minimal disruption to Port users and no delays to shipping. The dredging project proceeded very smoothly without any environmental incidents and turbidity levels were generally very low and well within the limits set by environment regulators.
Levelling of remaining high spots has since taken place and the post dredging hydrographical surveys indicate that the target of 14 m has been achieved.
Improved access to Port of Darwin
Larger vessels which regularly call on the Port now have extended tidal access to Darwin Harbor following a successful dredging operation by the Darwin Port Corporation which has increased the depth of the main shipping approach from 10.1 to 14.0 meters below the lowest astronomical tide.
This allows for 98% all tide access which is a 30% improvement for 12 m+ deeper draft vessels including mega cruise ships and carriers of LNG, dry bulk, petroleum and liquid bulk, which were previously restricted to a smaller tidal window.
Darwin Port Corporation CEO, Terry O’Connor, said the Corporation’s dredging program has produced significant productivity gains for commercial shipping.
“Wider transit tidal windows improve overall flexibility for Port operations and reduce vessel turnaround times. In turn, this delivers increased cargo loading capacity and cost benefits for shipping operators and the Corporation,” Terry O’Connor said.
Supporting the development of northern Australia
There have been many significant access improvements within Darwin harbor including new channels to the Marine Supply Base and from East Arm Wharf to the INPEX Bladin Point loading jetty and the Module Offload Facility. The success of these projects was dependent on effective community and stakeholder engagement and extensive forward planning.
The Northern Territory’s economic activity is leading the nation with the Port’s second LNG plant under construction at Bladin Point, the newly opened world class Marine Supply Base at East Arm Wharf dedicated to servicing the region’s expanding oil & gas industry, and planning already underway for a future dry bulk facility.
With improved channel access and ongoing investments in infrastructure, the Port of Darwin has the capacity to safely accommodate the volume and scale of shipping needed to support the development of northern Australia.