ADCP's Application to Ocean Current Measurement in Bremerhaven Port

1. Where is Bremerhaven Port?

Bremerhaven Port is located on the North Sea coast in the state of Bremen, Germany. Lying at the mouth of the Weser River, the seaport connects Germany with the rest of the world. As such, it provides easy access to major shipping lanes in the North Atlantic and has grown as an important center for international trade.

Port Scale and Throughput

Bremerhaven Port is a large-scale port with huge capacity. It has a large number of berths that are designed to accommodate a wide range of vessel types, from large container vessels and bulk carriers to Ro-Ro vessels. The annual throughput is relatively high, handling all types of cargo. It plays a very important role in the imports and exports of products such as automobiles, machinery, and consumer goods. Besides, it is also a major hub for the processing of break-bulk cargo, project cargo, and forest products.

Routes and Business

The port has an extensive network of shipping routes. It is directly linked to the major European harbors such as Rotterdam of the Netherlands and Antwerp of Belgium thus allowing intra-European trade. Shipping lines frequently reach North American harbors facilitating trade between Europe and the Americas. Based on business activities, Bremerhaven Port performs general cargo handling, container trans-shipment, and Ro-Ro operations. It also serves as a major hub for the automotive industry, housing large-scale vehicle processing centers within the port area.

Port Management and Operation

The Bremenports operate this port under their umbrella with the motto of safety, efficiency, and environmental sustainability in mind. Management is responsible for maintaining berth, quay, and storage facilities within the port. It ensures that there is a due tendency to international shipping regulation, safety, and environmental protection. The port authority engages with shipping companies, freight forwarders, and other stakeholders to align operations for maximum efficiency to increase competitiveness at the port.

Port Facilities

Bremerhaven also has modernly and effectively provided several facilities inside the port, such as highly capable container cranes for rapidly loading/unloading containers to/on vessels and saving time, Ro-Ro ramps, and areas for handling purposes. Inland, the port has provided extensive storage facilities consisting of general goods warehouses and yards for bulk commodities. Equally important, in addition to having state-of-the-art ship repair and maintenance facilities, this ensures full service coverage for shipping industries in every way.

Inland Waterways and Direct Navigation

The waterways to Bremerhaven Port are good and always dredged for the safe passage of vessels. The port has a well-marked channel, and during its approach, there are navigational aids in the form of buoys and lighthouses. It has direct access to the North Sea, where vessels can easily connect to the global shipping network.

2.Why is it necessary to measure the ocean currents in Bremerhaven Port?

Navigation Safety

Precise knowledge of the ocean currents at Bremerhaven Port is decisive in navigation safety. Tides, wind, and the movement of water masses are modifying factors that generally affect the patterns of currents in the North Sea. These currents, consequently, may have important effects on the movement of vessels, mainly during berthing, unberthing, and navigation along the channels of this port. Measuring these ocean currents allows ship captains to make informed decisions and adjustments to their course to avert possible collisions or groundings.

Optimization of Port Operations

Ocean currents are very fundamental in optimizing the operations of any port. Upon berthing vessels, the directions and strength of the current will have to be put into full consideration. With a strong current, berthing may be slower and more problematic. With good current measurements, port operators would be able to plan the timing of vessel maneuvers, manage resources better, and enhance the general efficiency of the cargo-handling operation. Currents also impact the operational movement of port-related equipment, such as tugboats and floating cranes; being able to understand these can reduce risk, enhancing safety and productivity at the same time.

Environmental Protection

Measurement of ocean currents is important for environmental protection in the port area. Currents are very significant in the dispersion of pollutants. In the event of an oil spill or other harmful substances, knowledge of the current patterns can help predict the spread of the contaminants. This enables environmental managers to take timely preventive and cleanup measures, protecting the sensitive marine ecosystem of the North Sea and the surrounding coastal areas.

Up until today, the Acoustic Doppler Current Profiler (ADCP) is a valid and effective tool for measuring ocean currents at Bremerhaven Port because it provides very precise real-time data.

3. How Do the ADCPs Using the Doppler Principle Work?

Measurement Principle

The ADCPs work on the principle of the Doppler effect. An ADCP current meter sends an acoustic signal into the water column, which then encounters the suspended particles in the water, such as sediment or small organisms. Because these particles are moving with the current, the sound waves reflected back to the ADCP have a different frequency than that originally transmitted. The ADCP measures this shift in frequency, known as the Doppler shift. By applying the Doppler equation, the instrument can calculate the velocity of the water current at various depths in the water column.

Specific Methods in Port Current Measurement

• Shipborne ADCP: In this case, the ADCP current profiler is installed on a moving vessel. If the ship sails through the water in the Port of Bremerhaven, it allows the ADCP to measure current velocity at different depths along the track of the ship. It would be useful when one needs a large-scale view of the current condition in the port, which would be helpful in large-scale navigation planning.
• Fixed ADCP: Fixed ADCPs are installed on the seafloor or affixed to moored structures including piers, buoys, and such in specific sites in the harbor. Such fixed ADCPs should be able to monitor continuously or almost so through a single selected point for indefinite periods. Much information can indeed be gleaned from them, especially concerning time series data covering long-term characteristics and local variance of currents in general.

4. What is necessary for accurate current measurement in Bremerhaven Port?

Reliability of Equipment

Highly reliable installed ADCP flow meter equipment will mean a great deal of support for high-quality current measurement in the port of Bremerhaven. The ADCP has to be able to survive the extreme conditions of salinity, changes in weather, and even wind that may cause breakdowns at relatively short intervals within the marine environment of the North Sea. With reliable equipment, consistent data collection is realized, which again means the same for accurate analysis and decision-making.

Size, Weight, and Power Consumption

The size of the ADCP meter should be compact and light in weight. Such a factor would make operating these devices easy, particularly during installation when space is small-for example, on minor local vessels and in restricted structures around the port area. In addition, an important feature related to ADCPs is their low power consumption; this will make them capable of long-term operations, especially in fixed-installed ADCPs which would depend on battery-powered or solar-powered systems.

Cost-effectiveness

This is to enable large-scale measurement in the port area at a reasonable cost for the ADCP. In fact, it can deploy multiple units where necessary, at a rather economical cost to allow comprehensive current data from different parts of the port.

Material Selection

The casing of the ADCP profiler is preferably made of titanium alloy. Because of the long-term use in the salty marine environment, especially in the North Sea, the excellent corrosion resistance of the titanium alloy is a must. Still, it is strong and light enough for tougher demands for durability or ease of installation.

5. How to Choose the Right Equipment for Measuring Currents?

According to Application

• Ship-borne ADCP: Ideal for large-scale surveys of the port area. When a ship needs to quickly assess the current conditions over a wide range, a ship-borne ADCP is the best choice.
• Sit-on-bottom ADCP: This type is suitable for long-term monitoring of specific locations in the port, such as near the entrance or close to berths.
• Buoy-mounted ADCP: Useful for the data of water surface and places where fixed-bottom installation is impossible.

Based on Frequency

• In cases of water depth up to 70m, the ADCP frequency used should be 600kHz.
• In water depth up to 110m, a 300kHz ADCP will be apt.
• A 75kHz ADCP shall be used when the area of operation is even deeper.

There are several popular brands of ADCPs on the market, such as Teledyne RDI, Nortek, and Sontek. However, for those in search of an affordable and good-quality option, the Chinese brand China Sonar PandaADCP is highly recommended. It uses all-titanium alloy material for its body, ensuring the best durability in the marine environment, and providing an incredible cost-performance ratio. You can get more information from their website at https://china-sonar.com/.

Here is a table with some well known Acoustic Doppler Current Profiler(ADCP)  instrument brands and models.