VANCOUVER (miningweekly.com) – Testing of the fleet of underwater machines that marine mining pioneer Nautilus Minerals will use to mine the Solwara 1 gold/copper project, offshore Papua New Guinea (PNG), has, so far, delivered results meeting or exceeding design parameters, the company recently reported.

Headquartered in Toronto, Nautilus completed submerged trials of the collecting machine and auxiliary cutter late last year.

To date, the bulk cutter has completed commissioning of the power and control system, on-shore functions testing, submerged function testing and submerged endurance trials. The remaining trials will focus on overall cutting performance – a key criteria for this machine, the company noted in a recent press release.

According to Nautilus, an ongoing analysis of the results to date indicates that the seafloor production tools can perform to design specifications with the machine components all functioning as designed in submerged conditions.

The cutting performance of the auxiliary cutter has been particularly positive, the company said, having cut about 770 t of material during trials, with the Nautilus site team commenting that the material appears at least three times harder than the mineralised material at Solwara 1 – even after allowing for the hyperbaric effect on material located at seafloor depths of the Solwara 1 project, which are far greater than the depths at which the trials were conducted.

The company intends to provide a comprehensive analysis once all testwork and data analysis is complete.

"The results of the trials to date indicate that the machines have been meeting and/or exceeding their key design specifications. The performance of these machines is critical to our seafloor production system, and the results to date significantly de-risk the project," CEO Mike Johnston said.