Project Type
Steel Profiles Used
  • Date of Steelwork Completion
  • Tonnage
  • Hot Rolled Structural Sections
    Universal Beams (I Sections), Universal Columns (H Sections), Equal Angles
  • Plates
    Hot Rolled Sheets
Project Overview

To give a sense of scale of the Project, the Treatment Plant is on board the central section of the MV Benguela Gem Vessel which is Debmarine Namibia’s brand-new purpose-built ship that is 177m long and 27m wide.

Project born out of the need to deliver greater safer and sustainable value for the shareholders of Debmarine Namibia and the people of Namibia, which is home to some of the most sought-after diamonds in the world.

Project size and cost:

“The ~US$420 million custom-built vessel will add an additional 500,000 carats of high value diamonds to Debmarine Namibia’s annual production, an increase of around 35 per cent, while creating 160 high-skilled jobs for Namibians.

Debmarine Namibia is a 50/50 joint venture between the Government of the Republic of Namibia and the De Beers Group. The MV Benguela Gem joins the world-class Debmarine Namibia fleet, which responsibly recovers some of the world’s highest quality diamonds.

The MV Benguela Gem was designed in Norway and Poland, built in Romania and fitted out with its proprietary mission equipment by De Beers Marine South Africa.  Taking two years to construct, it is the most technically advanced diamond recovery vessel in the world, underpinned by high standards of sustainability and safety performance.

”-18 March 2022

PBA Projects was required to design a Treatment Plant to process recovered diamonds mined within the stated bottom and top cut-off figures.

Treatment Plant design to be such that overall vibration in the plant and vessel structures is kept to a level as low as in reasonably possible

Treatment Plant design footprint & weight to fit within vessel defined limits

Project phases/involvement was from conceptualisation to detailed design, implementation, and commissioning.

3C Metal Belmet was required to perform the fabrication, supply, delivery, site assembly and disassembly of the structural, mechanical platework and piping as well as the installation of all free issued mechanical equipment for the Treatment Plant.

The mass of the overall treatment plant components, combined, weighed in at just under 3000 tons with the vast majority of the components all being made from Steel-all of these components were modelled in detail in the 3D environment

PBA Projects Created a fully integrated (live) 3D model:

In-house integration was for all disciplines with everything modelled right down to the nuts and bolts, lights, cameras, instruments, cable racks etc-refreshed in real time

Interfacing with De Beers for their equipment integration

Interfacing with the vessel as direct interface with structures & equipment

From a design perspective, PBA Projects had two main types of structures to design. The first of which was a beam-column braced structure with vertical and horizontal braces. The second of which was a plated structure with stiffeners, that were designed as composite members

The Structures were designed to withstand ships motions, vibratory equipment and reverse loading for rigging

End Connections were generally considered as pinned, but moment connections were considered where required

Structures were welded onto the steel ship

Project Details
From inception of the project, the project methodology was to reduce the duration of final assembly at K&L berth as well as the duration for the vessel integration. 3C Metal Belmet achieved this by performing prefabrication of all structural members, Plated structures, Platework and pipework items 100% complete, fully corrosion protected, C0 commissioned, ready for final assembly. This was only possible by utilizing all of 3C Metal Belmet and their subcontractors' facilities in South Africa as well as Namibia: Fabrication facilities 3C Metal Belmet in Stikland, Cape Town 3C Metal Belmet Namibia’s facilities in Walvis Bay Cinco facilities in the Port of Cape Town Steel Services and Allied Industries workshop in Johannesburg
During design, trying to limit the FEA model sizes while still taking into account enough of the vessel for vibration design. Iterative process of ships motion design and vibration design, and their impact on one another. Having a steel deck as the foundation and trying to reduce the vibration transfer between plants Size of modules for lifting; quayside locating for correct sequencing Focus 30 being here and having an end date to leave, waiting for the ship to arrive (delays due to covid) and then the lifts needing to be revised to save time Availability of materials (first during plant design) & then for lifting frame CHSs changed last minute and needed super-fast incorporation into the design and mass considerations of this for the lifts because bigger sections were available The continued change in design, material availability, environment resulted in multiple change in approach and plan to ensure the schedule is not affected. With the stringent COVID-19 protocols in place during fabrication and assembly we have 3C Metal Belmet implemented various work shift to ensure the work can continue with minimal interruptions as well as to ensure personnel are working in a safe environment.
Benefits of Steel in this Application

Most modern-day ships are made from steel. This vessel is also made from steel. As a result of this it is logical to make the treatment plant from steel. Another reason is because of the interface with the Vessel deck, the steel structures are welded onto the shelter deck

Modular aspects of steel are beneficial, quayside construction and rigging onto vessel

Speed of erection

Weight considerations-this is particularly important on a Vessel as there is a weight limit determined by the naval architect

Important to note that the structures are designed for many more loading and boundary conditions than land-based mining structures, steel is well suited to this as it is versatile and handles variable loads and temperatures well