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New water injection dredger designs gain ground

2022-11-28 Bert Visser
Van der Kamp, Jan De Nul, Van Oord and Penang Port Commission are among companies expanding their fleets with the latest generation of water injection dredgers.

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Photo Credit: Bert Visser

Throughout 2022 several companies have commissioned the building of water injection dredgers (WIDs). These dredgers - most suited for dredging silts, clay particles and fine sands - are a cost-effective and environmentally friendly option, with their high work rate meaning faster completion of projects and a lower carbon footprint compared to conventional dredging. 

WIDs dilute sediment by injecting water into the subsoil, creating a density current which naturally moves the sediment away from the dredged area to deeper areas. This eliminates the need for traditional excavation techniques and the subsequent transportation of sediment material. It is an efficient and environmentally sound way of maintaining the depth of navigation channels, rivers and ports. 

Van der Kamp’s Aquadelta

Earlier this year Dutch dredging and contracting company Van der Kamp commissioned the building of a WID, later named Aquadelta. Conoship International designed the vessel in close cooperation with Van der Kamp’s engineers. The vessels was built at Scheepswerf Bijlsma shipyard in Wartena. 

Van der Kamp has a long tradition of using WIDs in Western Europe, mainly The Netherlands, Germany and the UK. At present, it owns four units of this type, with two being managed and operated by the German affiliate company Meyer & Van der Kamp; Akke, in service since 1984, and Jan, which was converted from a mussel dredger in 2012. The other two, Maasmond and the new Aquadelta, are both managed by the main company.

The engineers of Van der Kamp have, with substantial input from the crew, used their wide experience of WID operations to make an optimal design for the new dredger, taking into account dredging efficiency, ability to work under a variety of conditions and capability for quick mobilisation to new projects. The vessel is over 48m long, has a breadth of 12m, a design draught of 2.3m and a gross tonnage of 497. 

Aquadelta has a diesel-electric propulsion arrangement that includes five Paccar-DAF MX-13 390kW engines driving two 450kW thrusters to propel the dredger to a speed of 10 knots. The vessel is equipped with two 320kW electric-driven water injection pumps which can reach a dredging depth of 27m, while a dynamic positioning system and an unlimited sailing area allow for versatile operations spanning large seaports to shallow waterways.  

Much attention has been given to the vessel's interior to make it user-friendly and comfortable, with accommodations available for a crew of six. Conoship designed the vessel with future-proofing in mind, keeping plenty of room in both the layout and the deadweight for future conversions, including the future installation of alternative fuels or battery systems. 

Having accurate and up-to-date survey data at your disposal is essential for an efficient water injection dredging operation. With this in mind, Aquadelta has been fitted out with its own survey equipment, including a multi-beam echo-sounder. This equipment enables the vessel to conduct its own seabed assessment activities prior to dredging meaning that it doesn’t have to rely on any other survey-dedicated vessels. 

Aquadelta was christened on 25 August 2022 at the Port of Rotterdam, where it had been carrying out its first dredging operations, cleaning the berth of the Cruise Terminal Rotterdam in view of the arrival of Queen Mary 2. After the name-giving ceremony and further dredging operations in the port of Rotterdam, Aquadelta sailed to Germany to begin work in the Jade estuary near Wilhelmshaven.

Jan De Nul’s Cosette

Jan De Nul launched their new WID, Cosette, on 12 October 2022 at the Neptune Marine shipyard near Dordrecht in the Netherlands. Cosette is a sister vessel to Pancho, a WID vessel which Jan De Nul received earlier this year, also from Neptune Marine. Both vessels have a length of about 27.5 metres and a total installed power of 2,376 kW.

The dredgers are of the Ultra-Low Emission Vessel (ULEV) type, meaning that they are equipped with an advanced dual exhaust gas filtration system that filters up to 99% of polluting nano-particles from the exhaust gases. This system consists of a diesel particulate filter (DPF) and a selective catalytic reduction system (SCR) that reduces NOx emissions.

Jan De Nul Group now has a wide range of ULEVs in its fleet, ranging from trailing suction hopper dredgers and water injection dredgers to offshore installation vessels. At the time of print, Jan De Nul’s fleet has five WID vessels. 

Van Oord WIDs on order

In July 2022, Van Oord ordered the construction of two WIDs from Kooiman Marine Group after the successful operation of sister vessels Maas and Mersey in 2021. The new vessels will have the same specifications, including a hybrid energy management system that allows energy to be stored in batteries for later use in propulsion and other purposes. Diesel-electric engines will reduce carbon emissions and the vessels will comply with IMO Tier III legislation for reducing harmful NOx emissions and will also consider EU Stage V legislation. 

The new dredgers will feature the latest heave compensation and dynamic positioning technologies, enabling a largely automated dredging process. The vessels offer mass flow and power jetting systems as well as water injection, making them particularly versatile. The scheduled commission for the first unit of the order is set for the first half of 2024. 

Expansion of WID fleets has also occurred outside Europe. In May 2022, Dutch company MOTAS Dredging Solutions announced that it had been contracted by Penang Port Commission to design, construct, deliver and commission an equipment package for a WID in Malaysia. Vessel construction will occur in Malaysia by JICORE Group Inc. Commercial trials will commence in 2023, and after completion ownership of the equipment will belong to the Penang Port. 

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