ADCP Application to the Ocean Current Measurement in the Port of Pori

1. Location of the Pori Port

Description of Pori Port

Pori is a sea port located in the city of Pori, Finland. It was a medium - sized Finnish port that played a significant part in the local and regional commerce. The port had good connection with other Finnish ports. Besides, it had connections with international routes of shipping.

It handles a variety of cargo that includes forestry products, such as timber and pulp, agricultural products, and general industrial cargo. Besides these, it also has facilities to handle containers, though the container traffic may not be as high-volume as that handled by some of the bigger ports. The management at Pori Port focuses on efficiency in operations and a good level of service for shipping companies and local industries.

Facilities at the Port

Berths: The port has a number of berths designed to handle various vessels. It contains berths for medium-sized cargo ships and barges. These berths have modern mooring and docking facilities that make the coming and going of ships very safe. The use of fenders and bollards serves to protect both the ships and the berths in question during the time of docking and undocking.

Cargo - handling Equipment: There are different cargo-handling pieces of equipment along the quay. The cranes and conveyor systems for the movement of the logs and pulp are required in the case of forestry products, and fork lift and other handling equipment for agricultural and general cargo and in the case of container handling, the gantry cranes will load and discharge the containers.

Storage Facilities: There are warehouses of storage for various types of cargo. For forestry products, stockpiles are made that have protection against the elements of weather. For agricultural products, warehouses with suitable climate and storage conditions are available. There are also container yards and general-cargo storage areas.

Channel and Navigation Aids: The channel in the port is kept at a sufficient draft and width to accommodate tides for the safe passage of ships. It is under regular dredging to keep it suitable for vessels with various drafts. Navigation aids include buoys, beacons, and radar systems to guide the ships into and out of the port. The radar systems provide real-time information on the position and movement of other vessels in the vicinity of the port.

2. Why measure the ocean currents in Pori Port?

Importance for Port Operation and Management

The measurement of ocean currents in Pori Port is very important. To begin with, this was done for the safety of vessel navigation. The knowledge of current speed and direction is quite essential for captains of ships in approaching the berths or navigating through the channel. A strong cross-current near a berth could make the process of docking difficult and risky. For instance, if a ship approaches a berth against a strong current, the speed and angle of approach must be adjusted accordingly to ensure smooth and safe docking. Accurate current measurements allow captains to make informed decisions and reduce the risk of collisions and other accidents.

This would not only improve the operation at the port but also help in fine-tuning arrival and departure timings of ships with increased accuracy. In the process, understanding tidal currents and other regular flow patterns allows the port authorities to better allocate the berthing resources and plan loading and unloading activities, leading to gains in productivity as more effective coordination of cargo-handling operations is possible.

Also, from an environmental point of view, in the case of accidental spills of pollutants such as oil or chemicals, ocean current knowledge is useful. Based on the kind of cargo handled at the port, it is important to know how a spill will spread. The current data can be used to quickly contain and mitigate the situation in order to minimize environmental damage.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

ADCPs rely on the principle of the Doppler effect. An ADCP current profiler sends out an acoustic signal into the water, which scatters from the moving water particles. Because the water particles are in motion due to the ocean current, the frequency of the reflected acoustic signal that bounces back to the ADCP meter shifts. The Doppler effect now comes into play to relate this shift in frequency to the velocity of the water flow.

Current Speed and Direction Calculation

The Acoustic Doppler Current Profiler (ADCP) computes the current speed and its direction at different layers within the water column from the magnitude and direction of this frequency shift. With these multiple-angle emissions at a number of different depths, a profile of the ocean current is achieved that depicts variations of the current with depth.

ADCP Deployment in the Port

Shipborne ADCP

A shipborne ADCP is installed on ships operating in the Pori Port area. While the ship moves around the port, the ADCP current profiler continuously sends acoustic signals into the water from underneath. The movement of the ship enables the ADCP flow meter to cover a wide area and collect current data from various locations. As such, in the case of a routine survey of the port by a research or inspection ship fitted with a shipborne ADCP, for instance, it can collate data of the current patterns across many parts of the port to give a holistic view of the water flow situation.

Fixed ADCP

Fixed ADCPs are installed in certain fixed positions within the port, such as on the seabed near important navigational areas or at the entrance/exit of the port. These ADCPs will continuously monitor the ocean currents at their fixed positions over a long period. The collected data is useful for analyzing the regular current patterns in specific areas of the port. For example, a bottom-moored ADCP installed at the port entrance can measure the incoming and outgoing currents to quantify the tidal effects and other consistent flow features of that area.

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

Equipment Requirements

For high-quality measurement of the currents in Pori port, some equipment characteristics are most relevant. First, the material reliability is very important. The equipment should be resistant to the harsh marine environment. Seawater includes salts and other chemicals which can destroy the materials over time. The equipment should also resist pressure changes at different water depths and mechanical forces by waves and currents.

This also pertains to the preferred minimal size, lighter weight, and lower power consumption. Thus, a compact size facilitates easy installation at every opportune location in a port, either in water on ships or in fixed positions on piers or on the seabed floor. A lighter weight eases the installation and transport of it. This means that lower power consumption can make the equipment work uninterruptedly for long hours, which is highly important for long-term monitoring applications without the necessity of changing batteries or an excessive power supply.

Cost is also an important aspect. The lower cost will enable a port to deploy more measuring devices and conduct current monitoring over a more significant area of the port for better monitoring.

The Advantage of Titanium Alloy for ADCP Casing

The casing of ADCPs is preferably made from titanium alloy. It features excellent corrosion resistance; hence, it remains functional with no deterioration of its structural integrity in seawater even for a very long time. Because of the high strength-to-weight ratio of this metal, it would be able to construct an extremely strong yet comparably lightweight casing. For example, in deeper parts of the Pori port with higher water pressures, an ADCP current meter with a casing of titanium alloy can withstand such pressures without breaking down and provide continued current measurements.

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

Selection Based on Usage

Shipborne ADCP: If the aim is to conduct wide-area surveys of the port waters while the ship is in operation, the shipborne ADCP shall be ideal for the same. In that case, it covers the different sections of the port that the ship moves to capture much data to give a total concept of the overall current state in the port area. This will be useful for mapping the general flow patterns and variations across different areas of the port waters.

Sitting - bottom ADCP: These are more appropriate for the long-term and fixed-point monitoring of specific locations within the port, such as near important infrastructure or areas with complex current behaviors. They can continuously record the current data at those fixed positions, providing valuable insights into the local current characteristics and any changes over time.

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

Selection Based on Frequency

The water depth in Pori port is the basis for the choice of frequency for ADCPs. In general, areas with a water depth of up to 70 meters require an ADCP flow meter with a frequency of 600 kHz, as it can provide quite accurate current measurements in this relatively shallow depth range. For deeper waters up to about 110 meters, it is better to use an ADCP profiler of 300 kHz. And for extremely deep sections of the port with a water depth reaching up to 1000 meters, it is recommended to use an ADCP with a frequency of 75 kHz to make sure reliable profiling of the ocean currents at such great depth is obtained.

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.