Pago Pago, AMERICAN SAMOA — The Metals Company spoke out recently saying at the dawn of the deep-sea nodule collection industry nearly fifty years ago, U.S. companies tested a range of nodule-collection technologies. These early pioneers understood the challenges, and their choices reflected the most sensible solutions available at the time. But after decades of innovation, the approach today reflects modern engineering, better data, and far lower operational impact.

Back in 1978, the Ocean Minerals Company (OMCO) worried that heavy tracked vehicles might get bogged down in soft sediment, so they developed an Archimedes-screw-drive system that dug deep into the sediment for traction. Allseas — a key strategic partner, investor, and technology provider for The Metals Company — approached the problem differently, designing its collector with wide snowcat-style tracks and deepwater buoyancy to distribute weight evenly, enabling it to move gently across the seafloor.

This collector now used by the Metals Company leaves only faint ripples — not the deep furrows of OMCO’s ‘Robot Miner’ — significantly reducing disturbance to surface-layer microbial communities that make up the majority of biomass on the abyssal seafloor.

The OMCO system used a rotating collector head that raked the seafloor to gather nodules, but its fixed design also pulled in excess sediment and struggled on uneven terrain. At the front of The Metals Company collector, the Coandă nozzles are optimized for flow characteristics, shape, and pickup efficiency using modern computational fluid dynamics analysis, supported by laboratory prototype testing. Mounted on independently articulated frames, they maintain an optimal height above the seafloor, substantially reducing sediment intake.

To transport nodules to the surface, the Robot Miner crushed them into gravel — but the broken nodules and large volumes of sticky sediment repeatedly clogged the system.

The Metals Company collector is highly efficient at separating nodules from sediment. Allseas’ gravity-based settling hopper and counter-current flow system wash fine sediment from the nodules, allowing heavier nodules to settle while lighter sediment particles remain entrained and exit through rear diffusers.

This gravity-based system ensures 95–98% of entrained sediment is released out the back of the vehicle to settle at the seafloor, dramatically reducing the amount traveling up the riser to the surface vessel.

The water and sediment that comes into the hopper needs to exit the machine. How it exits makes a huge difference.

The unique geometry of the diffusers slows and directs the separated sediment and limits turbulence, enhancing the formation of a gravity-driven sediment flow that settles quickly and stays within meters of the seafloor—helping keep impacts confined to the direct mining area.

With only a nascent understanding of mesopelagic ecosystems, OMCO discharged sediment-laden water overboard, clouding the surface layer of the water column and affecting the photosynthesis that supports much of the life at these depths.

Today, the understanding of where and how life thrives in the eastern Pacific is far more advanced. During TMC’s test-mining preparations, scientists advised that releasing seawater with small amounts of residual sediment higher in the water column could affect fisheries and marine mammals.

Following their advice, Allseas designed the riser for the return water to release at 2,000 meters water depth. Peer-reviewed research has since confirmed this minimizes overlap with key pelagic species.

Deep-sea mining trials first took place nearly half a century ago. Looking back, the work of those early pioneers provides invaluable insights into how different systems interact with abyssal ecosystems—paving the way for everything that has followed.

Fifty years later, Allseas engineered The Metals Company system from the seafloor up for maximum efficiency and minimal environmental impact. As noted in a new peer-reviewed paper published in Nature Ecology & Evolution, this focus on impact-driven design resulted in a far smaller impact footprint than legacy systems, pointing to the potential for rapid recovery with fewer long-term effects.

By refining the technology to further confine plumes and optimize the separation of nodules and mud, the next-generation system will gather more nodules, with less impact.

This is not the 1970s version of deep-sea mining.

It’s a smarter, lighter impact, and more responsible approach — one where engineering precision meets environmental purpose. As Rutger Bosland, The Metals Company Chief Innovation and Offshore Technology Officer, puts it, “we’ve entered an era of impact-driven design.”

In a new Nature paper published in January, independent academics note that integrating technological advancements is "key to more realistic assessments of deep-sea mining impacts."