ADCP Applied to the Measurement of Ocean Current in Hirtshals Port

1. Location of Hirtshals Port

Hirtshals Port is situated in the northern part of Denmark on the Jutland Peninsula. It is a major port with diversified characteristics and functions.

Port Scale and Throughput: Large in scale, Hirtshals Port is an important facility in processing different types of cargo. It also has an impressive annual throughput of bulk and containerized cargo. For example, it has sizeable volumes of fish products given the proximity to rich fishing grounds. In addition to this, it also handles general cargo such as construction materials, machinery, and consumer goods. Its throughputs have been increasing over the years as its role in regional and international trade has been on an upward trend.

Route and Trade: It is linked with almost all domestic and international shipping routes. It serves as a vital link for trade between Denmark and other countries in Scandinavia, as well as with countries across the North Sea and the Baltic Sea regions. A large number of fishing vessels come to this port to offload their catches. It has also developed a considerable ferry business, which involves taking passengers and vehicles to various destinations, such as Norway and the Faroe Islands.

Port Management and Operation: The port is managed and controlled by professional management, ensuring the smooth running of port operations. The port management looks after berth allocation, planning with shipping companies in co-ordinating vessel arrivals and departures, as well as trying to ensure cargo handling operations are handled efficiently. Regular maintenance and upgrading of port facilities are done in order to meet the growing demands for load handling while standards of safety and efficiency are upheld.

Facility: Hirtshals Harbor has modern, all-inclusive facilities. It has multiple berths of different sizes that accommodate the various crafts, ranging from small fishing boats through to large cargo ships and ferries. It has on-site fish processing plants fitted with advanced technology to process the just-caught fish. Cranes of different lifting capacities are also provided on-site for loading and unloading containers and other heavy cargo. Warehousing facilities are available to store goods before they are transported further.

Channel and Direct Shipping: The port contains a well-maintained and dredged channel that allows ships to enter and leave safely and smoothly. It has direct shipping connections with many important ports in the neighboring countries, making trade and transportation of goods and passengers quicker and more efficient.

2. Why should we measure the ocean currents in the Hirtshals Port?

Ocean currents are of utmost importance in the operational and managing aspect of Hirtshals Port. Firstly, to navigate ships safely, the pattern of ocean currents needs to be known in advance. The current speed and direction while a ship enters or leaves the port gives a better overview to the captain for decision-making on course and speed adjustment. For instance, if the entrance of the port has strong cross-currents, then ships have to consider such forces as well to prevent collisions or challenges during docking. On the other hand, with actual measurements of currents, the hazards of mishaps at the time of ship maneuvering become considerably minimized.

This helps in the effectiveness of the functions of the ports. Ocean currents can give interference to the time of berthing or unloading of ships. When ships can make use of favorable currents when approaching the berths, this may expedite the process and cut down on fuel consumption. The long-term action of ocean currents is also essential for long-term planning in terms of infrastructure expansion and maintenance in the form of piers and breakwaters. With time, currents can cause erosion in such facilities or affect the stability of the structure; hence, the accurate current data permits early maintenance and suitable design modifications.

For such cases, the ADCP current profiler has become one of the preferred choices because of the advanced capabilities it offers. In that, it will be able to provide factual and real-time data on current velocities and directions at varied depths, thus availing the flow conditions of water in much more detail than from conventional measurement methods.

3. How does the Doppler Principle work in ADCPs?

The working of ADCPs is based on the principle of Doppler. They emit acoustic signals into the water column. These acoustic waves interact with moving particles in the water, which could be suspended sediments, small organisms, or other debris. In this case, the acoustic waves bounce back after hitting these moving particles, a situation where the frequency of the reflected waves, because of the Doppler effect, changes. By properly detecting and analyzing this frequency shift, it is possible to determine the velocity of the water relative to the ADCP flow meter.

Shipborne ADCP: In Hirtshals Port, a shipborne ADCP brings the vessel into a cruise whereby, at places around the port area, certain zigzag and/or circular courses are promptly followed. The ADCP current profiler mounted on the ship emits acoustic signals continuously in different directions, down, sideward, etc. During its movement, it measures the current velocity of the ocean in various depths and positions along its path. Its movement will enable a broad survey of the water currents throughout different parts of the port during the operation.

Fixed ADCPs are generally installed at strategic locations within the port, such as on underwater structures near the entrance or along the sides of the port basin. They stay at their fixed point of placement and provide continuous monitoring of ocean currents. This gives good and long-term data about the current conditions at those specific points, and such information is valuable for an understanding of regular patterns and variation in the currents in important areas of the port.

4. What is required for high-quality measurement of the current in Hirtshals Harbour?

High-quality measurement of the currents in Hirtshals Port requires several aspects in relation to the measuring equipment.

First and foremost, material reliability is of utmost importance. Material reliability such that the casing of the ADCP flow meter is made of titanium alloy. Titanium alloy has several outstanding advantages. It has excellent corrosion resistance, hence it can stand for a long time in sea water without disintegration from its corrosive nature. This high strength-to-weight ratio allows providing robust protection to the internal components of the ADCP meter while keeping the overall weight of the device relatively low, therefore facilitating the installation in both ship and fixed underwater locations. Additionally, titanium alloy has good thermal stability, which is important because equipment is exposed to variable temperature conditions in the marine environment.

The size of the equipment should be small and lightweight. A compact, lightweight ADCP flow meter can minimize the complexity and impact on measurement that a huge one could create. Installation is also simplified on ships or at fixed positions within the port.

Another important requirement is low power consumption. In applications involving long-term monitoring, especially for fixed ADCPs that require continuous operation, low power consumption ensures that the equipment can operate without frequent battery replacements or disruptions in power supply. This becomes important to ensure consistent and reliable current measurement over extended periods.

Besides, large-scale measurement must be at a low cost. If the cost of the ADCP current profiler is too high, it will limit the number of devices installed in the port. This would result in incomplete coverage of the current measurements. With a cost-effective solution, one could get a more comprehensive understanding of the ocean currents throughout the port area.

5. How to choose the right equipment for current measurement?

The specific usage and requirements will determine the choice of equipment for current measurement in Hirtshals Port.

Shipborne ADCP: If the intention is to make extensive current measurements while the ship navigates within the port area, shipborne ADCP is a suitable option. It can cover a relatively large area, as the ship moves around the port, giving an overview of the current conditions in different parts of the port.

Bottom-mounted ADCP (Sitting on the seabed): For fixed-point monitoring of specific locations within the port, such as areas near critical infrastructure or where there are particular current characteristics that need continuous observation, bottom-mounted ADCP is the right choice. It remains stationary at the selected position, continuously recording current conditions there and hence providing useful data concerning the long-term behavior of the currents.

ADCP mounted on buoys: These can be used when monitoring of the currents in a specified surface area or in open waters within the port needs to be carried out. The buoy-mounted ADCP floats on the water surface, measuring the currents in its immediate vicinity, and gives a good indication of the surface current patterns.

Besides, it is necessary to choose different frequencies of ADCPs according to the water depth. For water depths within 70m, 600kHz ADCPs are suggested for accurate current measurement in relatively shallow areas. For depths up to 110m, the 300kHz is better, while for deeper areas with water depths reaching 1000m, 75kHz is appropriate.

There are some famous ADCP profiler brands in the market, like Teledyne RDI, Nortek, and Sontek. However, a Chinese brand stands out with very good characteristics, China Sonar PandaADCP . Material: all-titanium alloy is used to ensure very high durability and reliability in the marine environment. Besides, an incredible cost-performance ratio makes this ADCP flow meterquite attractive for its users. You can learn more about it through its official website: https://china-sonar.com/.

Here is a table with some well known ADCP instrument brands and models.