The floating harbour transhipper: New-generation transhipment of bulk ore products

• Published in: Volume 7: Ocean Engineering
• Main Authors: MacFarlane, GJ, Johnson, N, Clarke, L, Ballantyne, R, McTaggart, K
• Format: Conference Object
• Language: English
• Published: American Society of Mechanical Engineers 2015
• Subjects: Engineering; Maritime Engineering; Ship and Platform Hydrodynamics; Arctic
• Online Access: http://proceedings.asmedigitalcollection.asme.org/proceedingbrowse.aspx#Conference; https://doi.org/10.1115/OMAE2015-41337; http://ecite.utas.edu.au/101689

Bulk products such as iron ore and coal are usually shippeddirectly from shore facilities using large bulk carriers. Thisoften involves significant cost due to major dredgingoperations, long jetties, large storage sheds and the acquisitionof large tracts of coastal land. The costs of direct shore to anocean-going export vessel (OGV) loading often run intobillions of dollars prohibitive for small- to medium-scalemining operations, particularly in remote regions with onlydistant access to deep water ports. The current industry standardfor mitigating these issues is transhipping; the bulk cargo istransported from a smaller shore based facility to the exportvessel moored in deep water by a small feeder vessel.Transhipment, while mitigating many of these issues, doesintroduce other concerns with respect to limiting seastate,environmentally harmful dust and potential spillage duringmaterials transfer.The Australian company Sea Transport Corporation andthe Australian Maritime College at the University of Tasmaniaare developing new technology for bulk ore transhipment: thefloating harbour transhipper (FHT). The FHT is essentially alarge floating warehouse with an aft well dock to supportmaterial transfer operations from the feeder vessel.The major advantages to the mining export industry are inthe form of environmental and economic improvements, insome cases completely avoiding expensive dredging whileminimising the environmentally invasive onshoreinfrastructure. In addition, the whole process is enclosed,therefore eliminating grab spillage and dust transport issuescommon to other transhipping methods.This paper presents an overview of the main hydrodynamicissues currently being investigated: primarily the interactionbetween multiple floating bodies close to one another in aseaway. The two primary ship-to-ship interactions that arebeing investigated are the effects experienced by the feedervessel when it is docking or undocking within the FHT welldock and the interactions between the three vessels whenoperating in close proximity in an open seaway.A combination of physical scale model experiments andnumerical techniques is employed, with a significant portion ofthe experimental program dedicated to the validation of thenumerical simulation codes used to investigate the behaviour ofthe vessels.ShipMo3D is an object based library developed by DRDCfor the purpose of analysing the seakeeping performance ofvessels operating in a seaway in either the frequency or timedomain. The capabilities of ShipMo3D are applied to this novelapplication in an attempt to provide realistic simulations of theinteraction between the vessels of the FHT system.DualSPHysics, an open source Smoothed ParticleHydrodynamics (SPH) code, is being applied to the domainwithin the very restricted water environment of the FHT welldock to investigate the fluid flow behaviour and the effect thatthis has on the feeder vessel when entering/exiting.