Njord R
- Jul 14
- 2 min read
Vessel name
Njord R
Installation date
13-07-2026
Vessel type
Hopper Dredger
Vessel area
Currently the Channel / North Sea
Application
On top of box-coolers
NJORD R is a hopper dredger operated by Rohde Nielsen. The vessel was built in 2011 and is currently sailing under the flag of Denmark. Its gross tonnage is 5189 tons. Its length is 111 meters and beam is 20 meters. The entire vessel is capable of splitting into two to deposit large loads in a matter of minutes.
Shipsonic’s ultrasonic anti-fouling system (USAF) was installed during a dry-docking period in Vlissingen, The Netherlands, following concerns regarding the performance of the vessel's existing ICAF system.
The assignment it was on its way to was preparing the seabed of the channel for a cable or other infrastructure. Its assignment required it to remove sand, gravel and stones where the seabed was too high and depositing it where the seabed was too low.
The vessel had a total of 20 box-coolers, most of them larger than average. On port 9 box-coolers were placed close together and on starboard another 8. In the bow there were one on port and two on starboard.
The ultrasonic anti-fouling system (USAF) installed transducers on all 20 box-coolers. The Shipsonic team worked closely with the welders and electrician company subcontracted by the shipyard Damen.
The system consists of 8 control units (5 x MDP20- and 3 x MDP10- ) and in total 118 transducers (59 x 80Watt/20,5 kHz/IP67, and 59 x 100Watt/28 kHz/IP67).
All control units were visually inspected on working of cooling fans and fans free of obstruction, fuses and LEDs.
The actual signal going to the transducers was tested by connecting the Shipsonic signal tester to each individual outgoing connector (59 x Connector Techno THB.381.A2A (male), 59 x Connector Techno THB.381.B2A (female)).
For each transducer its SPL (sound pressure level) was measured in dB.
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