SELF-DISCHARGER FOR EUROPEAN STONE TRADE

With keel-laying at Chengxi Shipyard foreseen in December, the newbuild is expected to be ready for handover to the Hartmann/CSL partnership by early 2021, for long-term deployment in the distribution traffic of aggregates supplier Mibau-Stema.

The vessel will have main dimensions of 190m length overall, 29m breadth and 16m depth, transporting high-density cargo in seven hoppered holds and equipped to ensure the rapid turnaround, just-in-time deliveries fundamental to the short-sea stone trade, without having to rely on shoreside discharge gear.

To ensure a continuous unloading process, cargo will be gravity fed through gates in the bottom of the holds to a centreline conveyor running to an elevator belt for transfer to a long, boom conveyor pivoted at the forward end of the weatherdeck. The rotatable boom affords the reach and flexibility in placing material ashore, to serve a multitude of delivery points, and manoeuvring at confined berths and in tidal waters will be assisted by tunnel thrusters at bow and stern.

The newbuild’s specified discharge capacity of 5,500t per hour, as well as maximum load deadweight, exceeds that of any of the Hartmann belt self-unloading bulkers currently employed by Mibau-Stema. The present fleet offers throughput rates up to 3,100t/hour and aggregate cargo intakes up to 31,000t.

On-site newbuild supervision at Chengxi’s Jiangyin City yard in Jiangsu province, on the Yangtse, is the responsibility of a team from CSL’s Global Technical Services. It is understood that the CSL/Hartmann joint venture has exercised an option on a second vessel.

Besides its diverse shipping interests, the Hartmann family is co-owner of Mibau-Stema with the HeidelbergCement Group. Mibau-Stema is a leading supplier and major exporter of aggregate for Europe’s construction industry, drawing the material from its four state-of-the-art quarries in southern Norway, at Jelsa, Tau, Dirdal and Larvik, and loaded aboard the beltships for coastal and shortsea transportation.

In the Norwegian deposits, it claims to have “a virtually inexhaustible source” of granodiorite, quartz diorite, syenite, granite and gneiss for aggregate in varying fractions to meet specific application and project requirements. Mibau-Stema also provides armour stone for hydraulic engineering, and blocks for erosion control, breakwaters and piers.

Stone production is in the range of 15-17 million tonnes per annum, primarily for export, direct to site or via more than 40 terminals in the North Sea and Baltic regions using the self-discharger fleet. Mibau-Stema’s ships also distribute sand and gravel from various depots and pits in HeidelbergCement’s network.