On behalf of the Norwegian Coastal Administration, Scanmatic has delivered a current measurement system for Svelvikstrømmen, located just outside Drammen.
Svelvikstrømmen is a narrow strait that connects the inner and outer parts of the Drammen Fjord. The strait is nearly blocked by the Svelvik moraine, which stretches across the fjord. This narrowing makes Svelvikstrømmen one of Norway’s most powerful tidal currents, where outgoing flows can reach speeds of up to 5 knots. The navigable channel through the strait is approximately 13 meters deep and 180 meters wide.
The strait sees heavy traffic from leisure boats, ferries, and commercial shipping to and from the Port of Drammen. To enhance navigational safety through this critical waterway, the Norwegian Coastal Administration has commissioned Scanmatic to establish continuous current measurements. The data is available to navigators to support safe voyage planning through the strait.
Continuous Measurements with ADCP
An ADCP (Acoustic Doppler Current Profiler) is installed on the seabed approximately in the center of the channel. It measures water speed and direction at each meter throughout the water column, providing a current profile that helps vessels anticipate drift during passage—contributing to safer navigation.
The ADCP operates continuously and is connected to an SM5059 field station, which also collects data from a wind sensor located onshore. This sensor measures both wind speed and direction.
Data Sent to Coastal Administration’s Traffic Center
Time series data from the current and wind measurements are transmitted from the SM5059 to an H2 cloud platform at the Norwegian Coastal Administration’s maritime traffic control center in Brevik. This ensures real-time access to updated environmental data for monitoring and operational purposes.
Technical Information
ADCP
An Acoustic Doppler Current Profiler (ADCP) is an instrument placed on the seabed to measure water currents vertically through the water column. It points upwards and sends out acoustic signals that are reflected back by particles in the water. By analyzing the Doppler shift in the reflected signals, the instrument calculates the velocity and direction of currents in various layers of the water column.
The ADCP used in Svelvikstrømmen is an Aquadopp from the Norwegian manufacturer Nortek.
SM5059 Field Station:
https://www.scanmatic.com/sm5059-hydrological-meteorological-datalogger/
H2 Cloud Platform:
https://www.scanmatic.com/products/h2-cloud/
Live Current Data for Svelvikstrømmen:
https://mobvaer.kystverket.no/svelvikstrommen/
Underwater footage of the ADCP (Acoustic Doppler Current Profiler) installed on the seabed in Svelvikstrømmen. The instrument continuously measures current speed and direction to support safe navigation through one of Norway’s strongest tidal straits.