ADCP's Application to Ocean Current Measurement in the Port of Volos

1. Where is Volos port?

Volos port is located in the city of Volos, Greece. This port is a very crucial one on the Pagasetic Gulf.

Port Scale and Throughput The port of Volos enjoys a considerable scale and is relevant in the regional trade. It handles significant cargo every year, mainly from agricultural products, industrial goods, and other types of raw materials. The throughput has seen a gradual increase because it acts as a very key transportation node for domestic and international trade.

Routes and Business It is well-connected through various shipping routes. It has connections with other Greek ports and also with the Mediterranean and Black Sea regions. The business operations involve imports such as machinery and chemicals, and exports of local agricultural produce like fruits and vegetables. The port also facilitates transportation of goods for the local industries, contributing to the economic development of the area.

Port Management and Operation The port management works towards the facilitation of efficient and safe operations. The port authority, under the coordination of vessel arrival and departure, cargo handling, and storage, adopts modern management techniques in the interests of the best utilization of the port facilities and resources. As such, advanced scheduling systems were put in place to reduce waiting times for ships.

Port Facilities The port is further endowed with various facilities. It contains an array of berths, which can accommodate different vessel sizes-from small fishing boats to medium-sized cargo ships. There are cranes and other cargo-handling equipment for loading and unloading goods. In addition, there are storage areas and warehouses for different types of cargo. The port also offers other ancillary services like refueling and the maintenance of ships.

Channels and Direct Ways

The channels in the port of Volos are kept for safe navigation. The port has direct routes to all the major ports of Greece and some neighboring countries, too, which is a route to transportation of goods for economic connectivity of the region. These channels are being surveyed continuously and dredged for the upkeep of the required depth for the ships.

2. Why do we need to measure the ocean currents in the Volos port?

It is very important to measure the ocean currents in the Volos port for several reasons. First of all, this helps optimize the navigation of ships. Understanding the patterns of the currents will help the ships in their route planning. For example, they can avoid areas with strong counter-currents since these would result in higher fuel consumption and longer travel times.

Secondly, current measurement is very important for the safety of port operations. Unpredictable currents may affect the stability of berthed vessels and may lead to accidents such as collisions with the dock or other ships. With proper current data, the port can take measures to secure the vessels properly.

In addition, ocean currents data are useful in dredging and expansion of ports. It helps in showing the areas where sedimentation is likely to take place because of the current patterns and plan the dredging operations accordingly. An Acoustic Doppler Current Profiler (ADCP) provides a more advanced and convenient way of measuring these currents compared to the traditional methods.

3. How do ADCPs using the Doppler principle work?

Principle: ADCPs work on the Doppler principle. They transmit acoustic signals into the water. As these signals come into contact with particles in the water that are moving with the current, the frequency of the reflected signals changes. It is this change in frequency - the Doppler shift - that is used to calculate the velocity of the water current.

Ship - borne ADCP current profiler

The ADCP would be installed on a vessel when a ship-borne ADCP is used. As the ship moves, the ADCP sends out acoustic pulses either directly downwards or sideways. It receives the reflected signals from the water column and analyzes them. The Doppler shift in these signals provides information on the current velocity at different depths. This gives a very fine profile of the current as the ship travels through the water.

Fixed ADCP

Fixed ADCPs are mounted on structures such as piers or buoys. They emit acoustic signals in a specific direction, usually downward. The reflected signals are then analyzed for the Doppler shift. By continuously monitoring these signals, the fixed ADCP flow meter can provide a long-term record of the current velocity and direction at a specific location. This is useful for monitoring the current conditions near the port entrance or around critical infrastructure.

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

Reliable materials are necessary to be equipped for high-quality current measurement in the Volos Port. The design should also be small in size and lightweight. This is because it allows for easy installation and deployment, especially for mobile applications like ship-borne ADCPs.

The other important factor is low power consumption. For fixed-point measurements, it ensures that the equipment can operate continuously without frequent battery replacement or power source maintenance. Cost-effectiveness is also crucial for large-scale deployment in the port area.

The casing of ADCP is preferably made of titanium alloy. Titanium alloy offers excellent corrosion resistance, which is essential in the marine environment. Saltwater in the port causes huge corrosion in other materials, and so the corrosion resistance of titanium alloy contributes a lot to maintaining the performance over a long period. The strength-to-weight ratio is high, hence assisting in bringing down the total weight of the device, while structural integrity can be maintained.

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

Based on Usage

Ship-borne ADCP: It is for the measurement of currents while the vessel is in motion. This it does by profiling currents down the track a ship would travel; in this way, it would be useful in navigation and making an operational decision.

Bottom-moored ADCP: suited for long-term, fixed-point monitoring of currents near the seafloor. It provides full continuous series about the behavior of the current at a given place such as near the port's berths or in places where important structures are installed under water.

Buoy-based ADCP: When the objective is to monitor currents over a long period in a certain area and there is some flexibility in location, a buoy-based ADCP is suitable. It can be placed in areas where ships may not frequently pass but are still important for understanding the overall current patterns in the port.

Based on Frequency

For waters up to 70m deep, a frequency of 600kHz is usually quite appropriate. For depths around 110m, a 300kHz frequency is more suitable. And for very deep waters up to 1000m, a 75kHz ADCP is the better option.

There are well - known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, a recommended Chinese brand is China Sonar PandaADCP. It is made of all - titanium alloy material, providing excellent durability. It also offers an incredible cost - performance ratio. You can find more information about this brand on its website: (https://china-sonar.com/).

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