NAUTILUS Minerals has completed the assembly of the bulk cutter, the first of the seafloor production tools (SPT) for its proposed copper-gold operation in the Bismarck Sea.

Nautilus chief executive Mike Johnston said it was a huge step towards making its ambitions of producing metals from the seafloor a reality.

“This is a major milestone for the company, having the first of the three SPTs assembled,” he said. “This achievement brings the company all the closer to making seafloor mining a reality.”

The bulk cutter is the heaviest of the three SPTs, weighing 310 tonnes when fully assembled. It is designed to be the high productivity machine responsible for the bulk of production.

Subsea vehicle designer and manufacturer, Soil Machine Dynamics (SMD) has been tasked with building the SPTs for Nautilus.

Nautilus gave a mention to some of the companies which had been involved in the design of the SPTs, pointing out Sandvik Australia which had designed and built the cutting drum.

“The designs are based on similar designs used on large continuous miner machines used in underground mining and construction,” Nautilus said.

The track sets for all three SPTs have been designed and built by Caterpillar based on an existing Caterpillar excavator track design. Modification to the track set for subsea operation and required cutting duty was completed by SMD in consultation with Caterpillar and Sandvik.

The dredge pumps for all three SPTs have been supplied by Damen, while hydraulic equipment for all three SPTs was based on existing off-the-shelf Bosch Rexroth hydraulic equipment, with adaptations by SMD.

Companies and institutions involved in the simulations and test work of the bulk cutter include CSIRO, Cellula Robotics, Deltares, Istanbul Technical University, ContiTech Oil & Marine Corp and Paterson & Cooke Consulting.

“We are proud to have such world class companies and institutions involved in the design and testing of these tools,” Mr Johnston said.

The next step for the company will be to carry out commissioning and acceptance testing of the bulk cutter in parallel with assembling the other two production tools, the auxiliary cutter and the collecting machine.

The auxiliary cutter will prepare the rugged sea bed for the more powerful bulk cutter, with the two machines designed to gather the excavated material.

The third vehicle, the collecting machine, will collect the cut material by drawing it in as seawater slurry with internal pumps and push it thought a flexible pipe to the subsea pump and on to the production ship via a riser system.