Dredging

VESSEL REVIEW | Krakesandt – Dutch operator takes delivery of 3,000cbm hopper dredger

Baird Maritime

Netherlands-based marine projects company De Hoop Terneuzen has begun operating the second newbuild trailing suction hopper dredger (TSHD) in a series ordered from local shipbuilder Thecla Bodewes. Named after a 14th century sandbank off the coast of the Dutch town of Cadzand, Krakesandt is a sister vessel of Anchorage, which was handed over to the same customer in 2020. The newer TSHD is presently deployed on its initial project for a client in the North Sea.

Built by Thecla Bodewes' Barkmeijer Shipyards division to a design developed by local naval architecture firm Groot Ship Design, Krakesandt has a length of 105.9 metres, a beam of 15.85 metres, a draught of 6.94 metres, and accommodations for 14 crewmembers. Like its sister, it is designed for extracting sand and gravel aggregates at depths of up to 60 metres and is powered by diesel-electric propulsion. De Hoop Terneuzen said that, in addition to ensuring smart power management, the use of electric propulsion increases propeller efficiency while dredging, navigating, manoeuvring, and unloading, hence optimising energy and fuel consumption as well as reducing emissions.

The propulsion setup on the TSHD includes diesel-electric generators from D&A Electric and two VZ-1800 2,100kW rudder propellers and one VT-700 600kW tunnel thruster from Veth Propulsion.

Photo: Alewijnse

The dredging equipment consists of a single suction pipe with a diameter of 0.7 metres and two hoppers with a total capacity of 3,000 cubic metres. The discharging of collected material is accomplished with the aid of a special wet discharge installation and a loading arm that adjusts to the changing depths of the TSHD itself and the barge into which the material will be deposited.

Alewijnse was responsible for the design, building, installation, and commissioning of the TSHD's switchboards, consoles, and the dedicated alarm, monitoring, and control systems. For the control and monitoring of the dredging process, Alewijnse developed an intelligent and integrated bus-driven system. In addition to delivering improved dredging performance, its capabilities mean that a crew of just seven or eight will suffice to manage, load, and unload the vessel.

Other advanced automation systems have also been integrated on board. These include an alarm and monitoring system for fire door monitoring and remote tank sounding, and a bridge operating system  for the control and monitoring of the lighting systems. Also fitted is a dredge control system for the control and monitoring of the remote controlled dredging valves, position indication, and control of the swell compensator, overflow, pumps, screen/hopper loading system and the onboard hydraulics. A ship system control is responsible for control and monitoring of the trim valves.

Krakesandt also boasts a draught and loading system for continuous measurement of the equipment's depth and the calculation of the actual load, trim, and list. The Alewijnse suction tube system (ASTS) combines software and hardware for the measurement, calculation, visualisation, and monitoring of the dredger's suction tube position when underwater.

Photo: Alewijnse
Krakesandt
SPECIFICATIONS
Type of vessel:Trailing suction hopper dredger
Flag:Netherlands
Owner:De Hoop Terneuzen, Netherlands
Designer:Groot Ship Design, Netherlands
Builder:Thecla Bodewes, Netherlands
Length overall:105.9 metres
Beam:15.85 metres
Draught:6.94 metres
Capacity:3,000 cubic metres
Propulsion:2 x Veth Propulsion VZ-1800 rudder propellers, each 2,100 kW; Veth Propulsion VT-700, 600 kW
Generators:D&A Electric
Alarm/monitoring systems:Alewijnse
Other electronics:Alewijnse
Dredging equipment:Suction pipe
Type of fuel:Diesel
Crew:14
Operational area:North Sea