ADCP in Antirrio Port: Ocean Current Measurement

1. Where is Antirrio Port?

Overview of Antirrio Port

Antirrio Port is situated in Greece. It is a port with a considerable role in the local and regional maritime transportation network. It has a medium size and throughput. The port is involved in the transportation of a wide range of goods including agricultural products, building materials, and industrial goods.

It is well-linked with the mainland by all kinds of transport links, allowing for the easy and swift transfer of cargo to and from the port. Antirrio Port Authority is mainly responsible for providing a hassle-free operation in the port, besides vessel traffic management, cargo operations, and infrastructure maintenance by the authorities.

Facilities

Berths: The port has a number of berths designed to handle different types of vessels. There are berths for medium - sized cargo ships and ferries. These berths are equipped with modern mooring and docking facilities to ensure the safe arrival and departure of ships. High - quality fenders and bollards are used to protect the ships and the berths during docking and undocking.

Cargo-handling Equipment: Along the quay, there is a range of cargo-handling equipment. For handling bulk materials like building materials, there are conveyor systems and grabs. General cargo and containers are handled with forklifts and gantry cranes. The equipment is designed to efficiently move goods between the ships and the storage areas.

Storage Facilities: There are storage areas for different types of cargo. For bulk materials, there are stockpiles with proper containment and drainage systems. For containers and general cargo, there are container yards and warehouses. There are also cold - storage facilities for perishable goods.

Channel and Navigation Aids: The channel is maintained to a suitable depth and width to allow the safe passage of ships. Dredging is carried out quite regularly to keep it navigable for vessels of different drafts. The channel is adequately provided with buoys, beacons, and radar systems to help guide the ships into and from the port. In fact, the radar system gives in real time the position and movement of other vessels in the vicinity of the port.

2. Why measure the ocean currents of Antirrio Port?

Importance for Operation and Management of the Port

There is great importance in the measurement of ocean currents within Antirrio Port. Firstly, regarding safety vessel navigation, knowledge of speed and direction of the currents is important to ship captains who are approaching berths or navigating through the channel. A strong cross - current in the surroundings of a berth can easily turn docking into a risky process. As an example, the ship would have to strongly adjust the speed of its approach against the current while entering a berth in order for a smooth approach and safe docking to occur. Precise current measurements permit captains to make informed decisions that minimize the risk of collision and other accidents.

It is also crucial for the optimization of the port's operations. Current data facilitates the scheduling of the arrival and departure of ships. By understanding the tidal currents and other regular flow patterns, port authorities can better allocate berthing resources and plan loading and unloading activities. This leads to improved productivity as it enables more effective coordination of cargo-handling operations.

From an environmental point of view, ocean currents are useful in knowing the spread of pollutants, such as oil or chemicals, in case of an accident. Since the port deals with such cargo, it is important to determine the spread of a spill as quickly as possible. In this regard, the current data can be used to speedily implement containment and mitigation measures to minimize environmental damage.

They represent an advanced and more convenient method for the measurement of these currents than those methods using more traditional approaches.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

The working of ADCPs is based on the Doppler principle. When an Acoustic Doppler Current Profiler (ADCP) sends an acoustic signal into the water, it scatters with the moving water particles. As these particles of water move due to ocean current, there is a Doppler shift in the frequency of the reflected acoustic signal that comes back to the ADCP meter. This frequency shift, as the Doppler effect says, is related to the water flow velocity.

Current Speed and Direction Calculation

The ADCP current meter estimates the speed and direction of the ocean current at various depths in the water column by analyzing the magnitude and direction of this frequency shift. The signal is transmitted at different angles and at various depths to develop a profile of the ocean current, indicating how the current changes with depth.

ADCP Deployment in the Port

Shipborne ADCP

One ADCP flow meter is installed on ships operating in the Antirrio Port area. While the ship moves around the port, the ADCP current profiler continuously emits acoustic signals into the water underneath. The movement of the ship allows the ADCP profiler to survey a wide area and take current data from different locations. For instance, a research or inspection ship with a shipborne ADCP could conduct a routine survey of the port and collect data on current patterns over different areas of the port, thus giving a good overview of the water flow conditions.

Fixed ADCP

Fixed ADCPs are installed in specific, fixed locations within the port, such as on the seabed near important navigational areas or at the entrance/exit of the port. These ADCPs continuously monitor the ocean currents at their fixed positions over a long period. The data collected is useful for analyzing the regular current patterns in specific areas of the port. For example, a bottom-moored ADCP placed at the entrance of the port could measure the in-flow and out-flow currents, which could provide the understanding of the tidal effects and other consistent flow characteristics in that area.

4. What's needed for high - quality measurement of Antirrio port currents?

Equipment Requirements

For high - quality measurement of the currents in Antirrio port, some of the key equipment characteristics are as follows. First of all, material reliability is important. The equipment has to resist the aggressiveness of the marine environment. Seawater contains salts and other chemicals that may destroy in time some materials. The equipment also has to resist the pressure variations that take place at different water depth and the mechanical action of waves and currents.

The second desirable feature is a size as small as possible, lower weight, and power consumption. A compact size means that it will be easy to install anywhere around the port, whether on ships, fixed structures like piers, or on the seabed. A lighter weight makes transport and installation easier. Lower power consumption can mean that the equipment can remain online for a long duration of time without needing heavy-duty battery replacement or excessive power supply. In particular, this is also relevant to applications involving long-term monitoring. Another important aspect is that cost is an important factor; this lower cost will then allow the port to deploy even more measuring devices for complete coverage of current monitoring on wider areas of the port.

The Advantage of Titanium Alloy for ADCP Casing

ADCP current profiler casings are best made from titanium alloy. It has very good corrosion resistance, which means it will not lose its structural integrity and functionality even if it has been in seawater for a long time. Its high strength-to-weight ratio allows for the construction of a durable yet relatively lightweight casing. For example, in the deeper parts of the Antirrio port where higher water pressures are present, an ADCP current meter with a titanium alloy casing can effectively withstand these pressures and continue to provide accurate current measurements.

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

Selection Based on Usage

Shipborne ADCP: In case the goal is to carry out wide-area surveys of the port waters during vessel operation, then shipborne ADCP will be a good choice. It can cover different sections of the port as the ship moves around, collecting a large amount of data for an overview of the overall current situation in the port. It allows one to obtain a mapping of general patterns of flow and their variation over different areas of port waters.

Sitting - bottom ADCP: In long-term and fixed-point monitoring of some specific positions inside the port, like those with important infrastructures or complex current behaviors, a sitting-bottom ADCP is more suitable. They can record the current data continuously at fixed positions, which provides much valuable information about the local current characteristics and their variations with time.

Buoy-mounted ADCP: These can be used when it is not convenient to install fixed equipment on the seabed or on ships. They float on the water surface and can measure the currents in the upper layers of the water column. They are relatively easy to deploy and can be relocated if needed, thus becoming suitable for monitoring certain dynamic or hard-to-reach areas within the port.

Selection Based on Frequency

The ADCPs for Antirrio port depend on the choice of frequency. An ADCP profiler with 600 kHz in frequency generally would be adequate for an area with a water depth of up to 70 meters, in which, under normal weather conditions, current measurements can easily be produced in this rather shallow depth range. For deeper waters of up to about 110 meters, the 300 kHz frequency is more advisable. In those very deep sections of the port with a water depth reaching as high as 1000 meters, an ADCP current profiler at a frequency of 75 kHz would be recommended to ensure reliable profiling of the ocean currents at such great depths.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, there is also an excellent Chinese ADCP brand-China Sonar ​PandaADCP. It is made entirely of titanium alloy material, which not only ensures its durability in the marine environment but also offers an excellent cost-performance ratio. For more information, you can visit its official website: (​https://china-sonar.com/).

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