Europort - November 7-10 2023, Rotterdam Ahoy-News & Media

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Dredger technology puts safety first

Dredger technology puts safety first

03 November 2021
Dredger technology puts safety first

The Central Dredging Association (CEDA), in close collaboration with their corporate members, organised the 'CEDA Europort Innovation Event’. During two afternoons 24 companies presented their innovations in 15-minutes- pitch talks. We selected three of them.

Ensuring dredging equipment is located away from areas associated with risk is a significant consideration for the first Trailer Suction Hopper Dredger to be built featuring a hydrogen fuel cell as part of its power plant.

The 70m length ship, which will be homeported at Sète in the south of France on delivery by Brittany-based shipbuilder Piriou in Q3, 2023, has been designed in collaboration with LMG Marin. Fuel cell integration is expected to save up to 20% in the amount of fuel oil consumed by the 1500m3 dredger, which will be able to pump sand from depths of up to 32m.

An artist’s impression of the new ship formed part of a presentation from Jan Willem de Wit, Managing Director at Holland Marine Technologies covering innovation in Trailer Suction Hopper Dredger design as part of his 'CEDA Pitch Talk’ at Europort 2021, Rotterdam on 3 November. HollandMT is a key dredge systems supplier for the project.

"As with any ship, it is necessary to locate all of the dredging equipment away from any area posing an explosion risk, but considerations where hydrogen as a new alternative marine fuel require special attention,”

Safety was also the focus as de Wit acknowledged the way the vessel Yed Prior has been operating beyond expectations one year after being converted from container ship to 5300m3 sand & gravel TSHD by Royal Niestern Sander for owner Spaansen Marine Aggregates. The vessel’s distinguishing features include innovative moon-shaped gantries with all-electric drag-arm winches from HollandMT, developed to limit motion for a ship providing efficient dredging at water depths of 40m.

According to de Wit, Yed Prior has been making exceptional use of its 2000 kW submerged dredge-pumps over the period, with the moon-shaped gantry profile contributing to vessel stability making it possible to increase vessel payload from 8,000 tonnes to 10,500 tonnes.

Non-nuclear slurry density meter
The Enschede-based Alia Instruments presented a non-nuclear slurry density meter. The Alia Density Meter (ADM) offers accurate real-time data, allowing clients to truly optimize their production while eliminating the costs of special certifications and the disposal of hazardous materials.

Measuring the density of slurries is traditionally done with gamma meters. "The radioactive source however is the cause of a lot of practical drawbacks with regards to licenses, training, shipment and operators who have their reservations about using such technology”, Jan Peters explained. "Furthermore it has an impact on the business management of companies who have to answer to society’s pressure to reduce nuclear waste, and to operate in a sustainable manner. The Alia Density Meter is an electromechanical alternative without these drawbacks.”

The ADMis positioned in-line in the slurry pipeline. The density, defined as the slurry mass per volume unit, is measured under dynamic conditions , i.e. when the slurry is flowing. Inside the density meter, an actuator exerts a force with a known value and frequency onto the slurry, while an accelerometer measures its resulting acceleration. Newton’s second law of motion F = m x a, which relates the force F to the acceleration a via the mass m, is utilized to determine the mass of the slurry . The slurry volume is a known factor in the measuring tube of the meter. This means that the measured slurry density is nearly immediate and accurate, regardless of pipe diameter or slurry composition.

 

Sustainable Energy Powerplant
Improving vessel performance and lowering emissions are two main drivers for ship owners. To equip a vessel with batteries is often presented as a method of increasing sustainability. For Bakker Sliedrecht this is only the starting point, Remco Ammerlaan explained. "The true value is created in the dynamic collaboration of all energy generators and storage solutions. Our philosophy is to optimize the grid with various functionalities, which combined can improve the efficiency of conventional sources, and enable the grid for the use of more sustainable options. All solutions are optimized for the vessel's characteristics and operational profile, both for existing and new-build vessels.”

The modular Energy Storage Solution enables existing ships to be made ready for the (temporary) use of sustainable energy carriers and generators with only limited modifications. The Energy Storage Solution is packaged in a 20-40ft container which can be directly connected to the on-board energy network.

At the moment battery containers and solutions are the go-to solution to store energy and optimize existing power plants. Ammerlaan: "An increasing number of dredging and offshore operators start to explore the opportunities provided with supercaps and LNG generators. Once new power storage technologies such as hydrogen have been developed, they can be integrated to the ESS in a 'plug & play’ way.”