Measurement of Ocean Current Using ADCP Application in Trieste Port

1. Where is Trieste Port?

Trieste Port is located on the northeastern coast of the Adriatic Sea, in the city of Trieste, Italy. Situated at the junction between Central Europe, the Balkans, and the Mediterranean, this port has a strategic position in transportation. It is widely regarded as a strategic gateway for Italy toward the rest of Europe and several international markets. It is suitably linked to the main shipping lanes of the Adriatic Sea.

Port Scale and Throughput

The Port of Trieste is a large and capable port. It is well equipped with an extended system of berths, in which large ships-like container vessels, bulk carriers, and Ro-Ro vessels-can be readily accommodated. The annual throughput of the port is very great, and such large throughput embraces a wide variety of cargo moved. It provides an essential gateway for import and export of general cargo, such as consumer goods, industrial machinery, as well as construction material. Due to its position, it acts as a vital trans-shipment hub of cargo for goods that arrive in Central and Eastern Europe.

Directions and Business

There is an established network of shipping routes serving the port. It has a direct connection with the most important Mediterranean ports: Marseille in France, Barcelona in Spain, Piraeus in Greece, etc. There are also regular shipping lines to Black Sea ports enabling trade exchange with countries like Romania and Bulgaria. Trieste Port is very important for the landlocked countries of Central Europe since it gives them access to the sea. The services where it is involved in business operations include general cargo handling, container trans - shipment, and Ro - Ro operations. It further contributes to cruise industries where many cruise ships annually visit the port.

Port Management and Operation

The Trieste Port Authority runs the port in the name of efficiency, safety, and environmental sustainability. This includes maintenance infrastructure such as the berths, quays, and storage facilities of the port. They apply international shipping regulations, safety, and environmental protection measures. In this respect, it coordinates the shipping companies, freight forwarders, and other stakeholders to develop further the competitiveness of the port.

Port Facilities

Modern and efficient facilities are provided at the Trieste Port. There are large-capacity container cranes that can efficiently load and unload containers from ships. In addition, it has dedicated ramps and handling areas for Ro-Ro vessels. The port also includes storage areas, with warehouses for general cargo and open-air yards for bulk commodities. Besides that, it has modern ship-repair and maintenance yards, offering comprehensive services to the shipping industry.

Waterways-Direct Navigation

The waterways to Trieste Port are maintained and, at regular periods, dredged for safe passage. There is a well-marked channel in the port, with navigational aids such as buoys and lighthouses that assist during the approaches of vessels to the port. It has direct access to the Adriatic Sea, meaning vessels can have easy access to the global shipping network.

2. Why are ocean current measurements necessary in the Trieste Port?

Navigation Safety

Knowledge of the ocean currents at Trieste Port is essential for safe navigation. Currents in the Adriatic Sea are caused by tides, wind, and the exchange of water masses with the Mediterranean Sea. These can have a significant impact on the movement of vessels, especially during berthing, unberthing, and navigation within the port's channels. By measuring the ocean currents, ship captains can make informed decisions, adjust their courses, and avoid potential collisions or groundings.

Optimization of Port Operations

Ocean currents are important in the optimization of port operations. In the berthing of vessels, for example, it is always put into great consideration the direction and strength of the current. A strong current makes the berthing processes tougher and time-consuming. With the correct measurement of current, the port operators are able to plan the most feasible time for vessel maneuvers, better allocate resources, and enhance the efficiency of cargo-handling operations. Currents also have a bearing on the movements of port-related craft, including tugboats and floating cranes, while an understanding of such factors could further advance both operational safety and productivity.

Environmental Protection

The measurement of currents is very useful for environmental protection in the area of the port. Currents are one of the most determining factors in pollutant dispersion. In cases of oil spills or other dangerous substance releases, current patterns allow forecasts of the contaminants' spread. This will give environmental managers time to take all preventive measures to clean up, thus protecting the sensitive marine ecosystem of the Adriatic Sea and the surrounding coasts.

The Acoustic Doppler Current Profiler (ADCP) is meanwhile a valid and efficient tool for measuring ocean currents in Trieste Port, while providing high-precision and real-time data.

3. How do ADCPs Using the Doppler Principle Work?

Principle of Measurement

The ADCPs operate on the principle of the Doppler effect. Each time an ADCP sends an acoustic signal into the water column, the sound waves encounter suspended particles in the water, such as sediment or small organisms. Since the particles are moving with the current, the frequency of the reflected sound waves returned to the ADCP current meter is different from the frequency of the sound waves originally transmitted. It is this that the ADCP measures, and this shift in frequency is called the Doppler shift. With the use of the Doppler equation, the instrument will determine the speed of the water current at different levels inside the water column.

Particular Methods in the Measurement of Currents at a Port

• Ship-borne ADCP: A ship-borne ADCP is installed on a moving vessel. In this context, with the ship sailing in the water in Trieste Port, the ADCP measures the current velocity over the track traveled by the ship and at various depths. This is useful in obtaining a broad-scale view of the current conditions within the port, which is useful for large-scale navigation planning.
• Fixed ADCP: Fixed ADCPs are installed at some fixed places within the port area, which may be at the seabed or fixed structures such as piers or buoys. These ADCPs can continuously measure current conditions at a particular point over a long period of time and provide information on the long-term tendencies and anomalies of the currents.

4. What is needed for good-quality measurement of Trieste Port Currents?

Reliability in Equipment

The ADCP current profiler equipment should be very reliable to provide high-quality current measurement in Trieste Port. The Adriatic Sea has high salinity, variable weather conditions, and can be subject to strong winds-all of which demand that the ADCP can work under such harsh conditions with no frequent breakdowns. The dependability ensures a continuous acquisition of data required for analysis with the best level of accuracy that would lead to sound decisions.

Size, Weight, and Power Consumption

It should be small in size and lightweight to make installation easy, especially in the many instances it is supposed to fit into a small area such as on the small vessels of local watercraft or enclosed in the ports. Similarly, power consumption is intended to be low to allow its use over extended periods, specifically on fixed-install ADCPs, which work based on battery-powered or solar-powered systems.

Cost-effectiveness

For large-scale measurements in the port area, the ADCP should not be too expensive. A moderately inexpensive ADCP will allow the deployment of as many units as may be required to obtain extensive current data from different parts of the port.

Material Selection

Preferably, the ADCP flow meter casing shall be of a titanium alloy. It offers superior resistance to corrosion for extended periods in salty sea conditions like that of the Adriatic Sea. The metal alloy is strong but light and will suit the twin requirements of being long-lasting as well as easily installable.

5. How to Choose the Right Equipment for Current Measurement?

Based on Usage

• Ship-borne ADCP: Good for extensive regional surveys of the port area. When the times require that a ship covers as many wide areas as possible and in an urgent manner, a ship-borne ADCP would be your best choice.
• Sit-on-bottom ADCP: Applied for time series observation at fixed positions such as general vicinity near entrance and berth approaches inside the port.
• Buoy-mounted ADCP: This is very helpful when data is required at the water surface, or fixed - bottom installation is not possible.

Based on Frequency

• When the water depth is up to 70m, the ADCP should be 600kHz.
• When the water depth is up to 110m, then an ADCP with a frequency of 300kHz will work appropriately.
• A 75kHz ADCP will be used when dealing with water bodies that have greater depths.

There are some well-known ADCP brands in the market, including Teledyne RDI, Nortek, and Sontek. However, for those seeking a cost-effective and high-quality option, the Chinese brand China Sonar PandaADCP is highly recommended. It is made of all-titanium alloy material, ensuring excellent durability in the marine environment, and offers an incredible cost-performance ratio. More details can be viewed on their website at https://china-sonar.com/.

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