The bottoms of our oceans are scattered with precious metals: polymetallic nodules in form of small metallic lumps, containing manganese, iron, and other precious elements like cobalt, nickel, platinum and vanadium. The nodules are spread in fields, found in quiet areas of our oceans. Nowadays scarcity of raw materials makes that deep-sea mining is becoming a realistic option for extracting these valuable materials.

A number of renowned companies prepare to collect these so-called polymetallic nodules at great depths (up to 4.5 kilometers deep) with ultramodern Remotely Operated Vehicles (ROV). Expensive High-Tech tools that will harvest the minerals, while driving on the deep sea beds.  However, the sea beds on which the ROV will operate are soft, making it extremely important to design these structures being as light as possible. Thus, more than logical to consider an alternative: a lighter version in aluminum next to the obvious initial choice for steel. But is aluminum able to cope with the unique challenges encountered at 4.5 km depth?

Highrise Design proudly contributed to this venture, being an aluminum specialist. A complete aluminum structure was designed and structurally verified. All relevant design aspects have been incorporated, such as the prevailing water pressure, required corrosion resistance and the required strength and fatigue resistance. Our team delivered a complete design of the aluminum load-bearing structure. Thanks to this joint design conversion, now there is a possibility to choose the most optimal solution for picking up the polymetallic nodules at a water depth of 4.5 km!