Damen Shipyards Group has announced a new line of Trailing Suction Hopper Dredgers (TSHD) comprising of the Marine Aggregate Dredger (MAD) 4000 and 5600 vessels.
The MAD vessels, designed for in collaboration with engineering company Maritime Design and Engineering Services (MD&ES), will aid offshore aggregate operations and are able to work in North Sea conditions up to depths of -60 meters.
These capabilities will allow operators to mine sand and gravel in deeper waters, farther from shore than preceding models. Damen have observed an increase in demand for civil construction supplies and developed the technology to be well suited for existing ports and delivering more uptime at sea.
“We’ve tailored the technical specifications of the designs in line with the port infrastructure in the region in which the dredgers will operate,” said Olivier Marcus, Damen’s Product Director Dredging. “Furthermore, we’ve paid close attention to seakeeping behaviour in order to ensure the vessels can operate comfortably and safely, even in harsh weather conditions.”
The bow shape of the MAD vessels allows operations in adverse weather conditions and is based on a proven Damen design used by the Damen Offshore Carrier (DOC) and Platform Supply Vessel (PSV) which protects the sand and gravel cargo from green water ingress.
“These vessels are future proof,” added Marcus. “Featuring Tier III engines and, requiring no ballast water, fully compliant with the latest IMO regulations, these dredgers are looking forwards. On top of that the design also takes into account the possible future requirement for advanced automation.”
A submerged, wear-resistant Damen dredge pump facilitates the loading of sand and gravel aboard the vessel, passing the aggregate through the heavy-duty dredgers’ screening towers, where sieves assess and class the mined material. It is then stored and de-watered in the vessel’s hopper which has a capacity of either 4,000 or 5,600 m3 depending on the category of MAD. The operation is supported by optimised instrumentation that facilitates feedback throughout the entire process.
The vessels’ fully automated clamshell system unloads the material onto a conveyer belt and is suitable for use in varying locations.
“With a single vessel you can do almost everything,” stated Marcus. “You can go out, get the material, classify it, dry it and deliver it to location. It is the first standardised design in the world with such a scope.”
The Standardised design is also versatile and takes into account the need for customisation and multi-role functionality.
“A number of options exist in order to cater to differing client needs,” added Marcus. “The vessel can be supplied with bottom doors if required – which will offer additional versatility in case it is required to perform differing operations. It can also receive spud poles, for example. And, should the client wish to scale up at any point, the MAD 4,000 can easily be converted into a MAD 5,600 with a simple section addition.
“The MAD concept is one that tackles not only the needs of today, but of tomorrow also. We have developed a vessel that represents the lowest possible euro to cubic metre ratio. It is lightweight, with an optimised, efficient propulsion train, minimised hydraulic usage and offers both low and easy maintenance. We are very much looking forward to seeing it in action.”