Video: Painstaking effort to offload new dredge
4 July, 2018
Port Otago’s new $8 million backhoe dredge, the renamed Takutai, was carefully lifted off its delivery ship in a three-hour-plus, slow-motion operation in June.
The specialist 143m heavy-lift Fairpartner, from the Netherlands, remained fully buoyant during the unloading at Port Chalmers.
Unlike some similar ships, it did not flood its hold to submerge its deck below the waterline to allow its cargo to float off.
Port Otago marine and infrastructure general manager Sean Bolt said Fairpartner instead used a complex water ballasting system, which worked in conjunction with its cranes, to counterbalance the massive lift.
”It’s simply [achieved with] the lift of the two cranes,” Mr Bolt said.
The 35m Takutai weighs about 650 tonnes and just after 4pm yesterday, it finally sat on harbour waters.
While having no propulsion of its own, Takutai has three 13m legs which will enable it to ”crab” its way across the seafloor so it can load the barge Hapuka with spoil.
Today, its three legs, weighing a combined more than 100 tonnes, will be readied for reassembly with the dredge.
Takutai, capable of dredging to 19m, is set to replace bucket dredge Vulcan, whose hull is understood to be 100 years old.
Once training has been completed for Takutai’s two-person crews, it is expected to be operating by the middle of July.
It will be used for all facets of upper and lower harbour channel work.
Built for a project in France in 2012, the previously named Kostaldea, was initially required for only a year’s work.
It is expected to have a 30-year lifespan with Port Otago.