The Australian Maritime College, a specialist institute of the University of Tasmania is carrying out important research that could help save billions of dollars in port infrastructure, dredging and transhipping costs.
Traditional transhipment involves an export vessel such as a Capesize bulk carrier mooring as close to the mining operation as its draught allows and being loaded by smaller feeder vessels. This project looks at using a floating harbour transhipper (FHT) as an ‘offshore warehouse’ to meet the growing demands for coastal transhipment in the mining sector and commercial port operations.
PhD candidates Nick Johnson and Lauchlan Clarke are working with industry partner Sea Transport Corporation (STC) to refine and test the FHT concept. The three-year project has received an $A420,000 Linkage grant from the Australian Research Council and STC.
Nick explains that transhipping is about transferring large volumes of cargo as quickly and cheaply as possible from remote areas with limited infrastructure in a diverse range of weather conditions. Traditionally, the transfer of bulk ore cargo takes place over a couple of weeks, with the feeder vessels running back and forth between a small port and the moored export vessel. However, the new FHT concept will act as an offshore warehouse, allowing the feeder vessels and export vessel to work on their own continuous schedules.
The FHT will be able to carry about 60 per cent of the capacity of a Capesize export vessel, so when the export vessel comes in and moors to the FHT, it can immediately start transferring goods. While this is happening, the feeder vessels can be discharged either to the FHT stockpile or directly to the export vessel reducing downtime and increasing cost-efficiencies.
Estimated to be worth around US$90 million, the FHT is approximately 315 metres long and features an enclosed conveyor system to facilitate the transfer of the bulk product from the feeder vessel into its own stockpile and from this stockpile to the export vessel. Using an enclosed conveyor system eliminates spillage and allows for dust-free transhipment, reducing impact on the surrounding environment and any nearby residential areas.
The FHT system aims to significantly reduce transhipment delays caused by inclement weather by greatly reducing the relative motions between the FHT and the feeder vessel. This is achieved by mooring the feeder vessel inside a well dock at the aft end of the FHT, rather than the side-by-side method used in traditional transhipping.
The scenario-modelling work will be completed on the computer in tandem with rigorous physical experimental testing in AMC’s model test basin.
Lauchlan’s area of research focuses on the water flow that is produced when the feeder vessel enters or exits the FHT well dock.
According to Lauchlan, the well dock is always open to the ocean, and when the feeder vessel enters, the majority of the water in the well dock has to be displaced. He will be examining innovative solutions to minimise any negative effects on the manoeuvrability of the feeder vessel, such as using vents to allow the water to escape the well dock as the feeder vessel enters.
The project has huge potential to minimise the environmental impact of bulk product export (such as iron ore, bauxite, coal and grain) and save billions of dollars in onshore infrastructure costs thanks to offshore warehousing.
It eliminates the need for major dredging and earthworks to enable access to coastal ports, and has generated a great deal of interest among mining companies around the world.
Lauchlan and Nick join the team of AMC Chief Investigators Dr Jonathan Duffy, Dr Irene Penesis, Dr Shinsuke Matsubara, Professor Neil Bose and Project Lead, Dr Gregor Macfarlane, who will all work closely with their collaborators at STC.
The FHT design has already won two awards, including the Lloyd’s List award for innovation in 2012; last year a paper co-authored by STC and AMC won the Australian Division of the Royal Institution of Naval Architects Walter Atkinson Award.