SS. Ocean Mining: Deep Sea Mining: A New Horizon for Dredging Technology
Authors: Van Bloois Jan Willem , Frumau Jan 
Published: July 2009

The presentation will describe a short outline of important historical developments in the Dredging and Mining Technology. Also the link of Dredging Technology with existing On and Offshore Mining Installations will be highlighted.

New developments and business drivers (for instance: SMS deposits) in the Deep Sea Mining market are most interesting for the Dredging Industry. Extrapolation of existing know how is very useful to develop frontier technology in this new area.

Especially the existing technology for Seafloor Excavation and Vertical Hydraulic Transport of the excavated materials is very important for the development of effective and profitable future Seafloor Mining Equipment. Although the Dredging Industry is approaching deep water projects like Rock Dumping etc., Sea Floor Excavation in remote areas for more then 300 m water depth is not possible with conventional Dredging equipment. New concepts have to be developed to facilitate future Deep Sea Mining. IHC Merwede and Seatools are working on new challenging developments to be launched shortly.

For the development of a total deep sea mining concept it is very important to join forces in the Offshore Market. Riser technology is available. Processing on board of the Mining Vessels is also proven Technology and combined with transshipment experience in the Dredging Market efficient concepts can be developed. To develop Deep Water Excavation and Vertical Hydraulic Transport it is very important to team up with the mining company. To realize the mining company's expectations it is essential to join during the exploration phase to specify exactly the parameters for a suitable mining installation. For an effective and profitable Mining process it is also very important to set up a mining plan with the mining company including the issues of availability and utilization of the installation.

Important issues are: adaptability to seafloor conditions (profile, rock characteristics vs excavation process, distribution of the minerals, water depth, environment & sustainability, etc.), utilization and high availability of the system (weather conditions, maintenance, mining preparation, versatility, reliable production rates, etc.), material handling on board of the vessel and further transportation to land based installations (hydraulic transport, process monitoring, ore conservation, etc.)

The presentation will highlight various excavation tools such as a ROV-grabber, developed by Seatools and a Seafloor Mining Crawler with suitable excavation tools, developed by IHC Merwede. Specific challenges will be explained.

Both principals can be used in all stages of the mining process, from sampling of soil to full-scale production. The grabber can be used for terrain preparation prior to the deployment of crawling excavators and other mining tools. For both systems the deployment systems will be explained.

Besides Deep Sea Mining is this new technology also very interesting for Sea Floor Intervention which is related to the Oil and Gas Industry in deep water areas like the Gulf of Mexico.

The paper will conclude with a brief comparison of the capabilities and limitations of the various excavation methods such as the Grabber and Crawler excavation compared to other methods of sub sea mining.