ADCP's Application to Ocean Current Measurement in Ventspils Port

1. Where is Ventspils Port?

Ventspils Port is located on the western coast of Latvia, on the Baltic Sea. It is one of the major ports in the Baltic region.

Port Scale and Throughput

The Ventspils Port is a major Latvian port, with quite a big area. It is highly capacitated with much quay and a large port area. The annual throughput is high, involving a wide range of cargo: crude oil and petroleum products, LNG, and bulk goods such as grains and fertilizers. The Port of Gdansk is one of the critical transit points of energy resources in the Baltic Sea area, with the volume of oil and gas being transshipped at the port being quite high.

Due to its strategic location, it has become an important link in trade between Latvia with other Baltic countries and Western and Northern Europe. It connects to different transportation networks and acts as a gate for the transportation of goods coming to, and from, the Latvian hinterland.

Routes and Business

The port is attached to most international shipping routes, particularly in the Baltic Sea. It acts as one of the vital arms of the regional shipping industry, where shipping lines carry out transporting oil, gas, and other bulk cargo. Shipping services, freight forwarding, and logistics represent an enormous area of activities undertaken by this firm. Importing and exporting of energy-related products and agricultural goods is included within its realm.

Besides, Ventspils Port allows for the processing and storage of LNG-a great part that will be of higher importance in the future when the demand for cleaner sources of energy will grow.

Port Management and Operation

The port is governed by a mixture of public and private bodies. The Port of Ventspils Authority coordinates the development and maintenance of infrastructure and general operation. It also works with the terminal operators, shipping companies, and other service providers to guarantee efficient and seamless port operations.

This operation is a complex process involving vessel traffic management, cargo handling, and customs procedures. Various types of advanced technologies are used in flow management, both for goods and vessels, which enhance safety and productivity of the operation.

Port Facilities

Ventspils Port is modernly equipped. Infrastructure includes specialized terminals for the handling of liquid cargo, such as oil and LNG, with storage tanks and appropriate equipment for loading/unloading. There are also terminals for bulk goods handling, with corresponding storage silos and conveyor systems. Warehousing and distribution services at the port are available for different types of cargo.

Safety for hazardous material handling in oil and LNG requires a strict safety and emergency response plan in place in the port.

Channels and Direct Navigation

The channels of the port are well-maintained and dredged to the necessary depths, which allows the passage of different vessels, mainly big tankers and LNG carriers. It has direct access to the Baltic Sea, by which ships can connect with other major ports in the region and along the European coast.

2. Why should we measure the ocean currents in the Ventspils port?

Navigation Safety

In Ventspils Port, the correct measurement of ocean currents is very important from the point of view of navigation safety. Currents can get so complicated in the Baltic Sea around the port because of tides, winds, and the local topography of the seabed. By knowing the current velocities and directions, ship captains can better plan their approach and departure from the port.

Currents can have a major impact on vessel manoeuvrability, especially during critical operations of berthing and un­berthing. This information is of great importance due to the high volumes of traffic passing through, including big tankers and cargo vessels, to avoid collisions and other accidents.

Port Operations and Efficiency

Knowledge of present patterns is also quite essential for the efficient functioning of the port. Currents interfere with the activities of docking or undocking of ships. In case the current velocity is not correctly accounted for in the process of keeping the ship aligned with the berth adequately, it would cause delays at the port in cargo handling as well as other activities of the port.

The currents also, indirectly, affect the movement of tugs and other support vessels within the port area. By measuring the currents, the port authorities are able to optimize the scheduling of these operations, thereby improving the overall productivity of the port. ADCP current meter provides a more advanced and convenient way of measuring currents compared to traditional methods, as it is able to provide current real-time data for better decision-making during port operations.

3. How do the ADCPs, based on the Doppler principle, work?

ADCPs would make use of the Doppler principle by producing acoustic pulses out into the water column; when this interacts with moving particles or anything else in the water flowing with the current, then some shift in frequency of the reflected sound waves will occur.

Ship-borne ADCP

This is usually installed on the hull of a boat.

The ADCP measures the relative velocity of the current with respect to the ship's motion as the ship moves through the water. It continuously records the Doppler-shifted frequencies of the reflected acoustic signals. With the use of advanced signal-processing algorithms, the relative velocity of the current is calculated. By adding the vessel's own speed, which can be derived from other navigation systems, it is possible to calculate the current velocity absolutely at the location being studied.

Fixed ADCP

A fixed ADCP is a permanent installation at strategically selected locations around the port, either directly on the seafloor or attached to a pier.

Fixed ADCPs

Fixed ADCPs constantly send acoustic pulses into the water and measure the Doppler shift of the frequency reflected back.

They can only supply a point-velocity view of the current at a single location. Such data may be useful for long-term studies of current regime, for example, to investigate how currents vary with tidal cycle or season.

4. What would be required for good-quality current measurements in the Ventspils port?

Nature of the Measuring Instrument

The equipment should be made of reliable materials to provide high-quality current measurement in Ventspils Port. It should be resistant to the corrosion effect of saltwater and other possible aggressive media due to the marine environment. Smaller size and weight are advantageous because these features make the equipment easier to install and service, especially on buoys or in confined spaces on ships.

It should have low power consumption, particularly during long-duration deployment where any alternative sources of power are scant. The cost should also be affordable, as it enables more equipment deployment to provide current measurement over the port.

The Case in Making the ADCP Casing of Titanium Alloy

ADCP current profiler casing should preferably be made using a titanium alloy.

It is for this reason that the titanium alloy owns excellent corrosion-resistant properties, very important in the conditions of Ventspils. The continuous attack of seawater at high salinity and other aggressive agents means a piece of equipment using less-resistant material would deteriorate shortly. Besides, the titanium alloy is strong to resist pressure exerted by water or potential mechanical impacts.

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

Depending on Installation Type

Ship-borne ADCP: This is used for ships that need to measure currents in their transit into and out of the port. It is a mobile means of acquiring current data and is good for ships such as tankers and cargo vessels that are constantly on the move.

Sitting-bottom ADCP: It is very effective for fixed-point monitoring in one location, such as at the entrance of a channel or near a berth. It provides a stable, continuous measurement of the current at that particular point.

Buoy-type ADCP: These can be installed in areas where a floating platform would be more apt, like in the open water areas of the port or those with less defined boundaries. Buoy-type ADCPs are very helpful in monitoring a much larger area and therefore can be useful in collecting data on general current patterns across the entire port.

Based on Frequency

Up to 70m of water depth, an ADCP profiler with a frequency of 600kHz will usually suffice. The higher frequency allows for better resolution in shallower water current measurements.

For a depth of approximately 110m, a 300kHz ADCP is more adequate. It is a balance between depth penetration and resolution.

ADCPs in waters of a depth to 1000m will want to use 75kHz because the lower frequency can get deeper into the water column, thus allowing the currents at a deeper depth. There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, the Chinese brand China Sonar ​PandaADCP is also a great option. It is made of all-titanium alloy material, providing excellent durability and corrosion resistance. It also offers an incredible cost-performance ratio. You can find more information about it on their website: (​https://china-sonar.com/).

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