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

1. Where is Muuga Port?

Overview of Muuga Port

Muuga Port is located in Estonia, near the capital city Tallinn. It is a major port in the Baltic Sea region with a significant scale and high throughput. The port serves as a crucial link for Estonia's international trade and handles a wide range of cargo including bulk commodities like coal, oil products, and various types of ores, as well as containerized goods.

The shipping connections of the port are extensive, with routes to several European and other international ports. It is a very important factor in the economic development of Estonia and the surrounding region. Muuga Port is well managed, and advanced technologies have been adopted for the management of vessel traffic, cargo handling, and other operations. The port has well-organized teams that are assigned different functions to ensure goods and ships move in and out of the port smoothly.

Port Facilities

Berths: Muuga Port features several berth facilities catering for a diverse range of vessel types, from deep water to standard-sized tankers and bulk carriers. Each is outfitted with the most updated mooring and docking machinery to facilitate safety upon arriving and departing in port waters. Strong bollards and fenders absorb much force when ships proceed with normal docking and undocking maneuvers.

The different types of cargo-handling equipment found along the quay include the pumping and transfer systems used to handle oil products and other liquid cargo, the conveyor systems and grabs to handle bulk cargo such as coal and ores, and for the handling of containers, the gantry cranes accomplish the loading and unloading efficiently.

Storage Facilities: Huge storage facilities of various cargo are present. For oil products, large-scale storage tanks with safety features such as spill-containment and fire-protection systems can be found. For bulk materials, well-organized stockpiles with proper drainage and containment systems are maintained. There are also container yards for storing containers.

Channel and Navigation Aids: The channel is dredged regularly to a depth and width that can accommodate safe passage. Such regular dredging operations keep it usable by vessels with large drafts. Navigation aids include buoys, beacons, and radar systems that are installed to guide ships in and out of the port. The radar systems provide real-time information about the position and movement of other vessels in the vicinity of the port.

2. Why should we measure the ocean currents in the Muuga Port?

Importance for Port Operation and Management

The measurement of ocean currents in Muuga Port is very important. First of all, it is important from the viewpoint of vessel safety navigation. It is of paramount importance for the captains to know the current speed and direction while approaching the berths or negotiating the channel. A strong cross-current at a berth can render the operation of docking difficult and dangerous. For instance, if the ship is approaching the berth against the strong current, the captain will have to adjust his speed and angle of approach for smooth and safe docking. Accurate current measurements enable captains to make the right decisions and minimize their chances of collisions and other accidents.

This again, helps optimize the operational activities at the port. With current information on weather, it can optimally plan the arrival and departure of ships. It will be easier to know and estimate tidal currents and other regular flow patterns. These estimates can help in good allocation of berthing and loading and unloading of goods, hence enhanced productivity through coordination of cargo-handling operations.

Besides, the knowledge of ocean currents is important from an environmental point of view in case there is an accidental spill of pollutants. Since the cargo handled at the port is of nature, such as oil products and chemicals, it becomes imperative to be able to predict the spread of a spill. The current data will be helpful in quickly containing the spread and mitigating measures to reduce environmental damage.

3. How do ADCPs using the principle of the Doppler effect work?

Principle of Measurement

The working of ADCPs is based on the principle of the Doppler effect. When an acoustic signal is emitted from an ADCP into the water, the moving particles of the water interact with the transmitted acoustic signal. Since these particles of water are moved due to ocean current, the frequency of the reflected received acoustic signal is shifted by those moving particles of water, and this is related, by the Doppler effect, to the velocity of the water flow.

Calculation of Current Speed and Direction

By analyzing the magnitude and direction of this frequency shift, the Acoustic Doppler Current Profiler (ADCP) can calculate the speed and direction of the ocean current at different depths in the water column. By emitting signals at multiple angles and different depths, it can create a profile of the ocean current, showing how the current varies with depth.

ADCP Deployment in the Port

Shipborne ADCP

One ADCP current profiler is installed on ships operating in the Muuga Port area. While the ship moves around the port, the ADCP continuously sends acoustic signals into the water beneath it. Because of the movement of the ship, the ADCP covers a wide area and collects current data from different locations. For instance, a research or inspection ship with a shipborne ADCP that is conducting a routine survey of the port can collect data from the current patterns across many parts of the port for a comprehensive understanding of the water flow situation.

Fixed ADCP

Fixed ADCPs are installed at selected fixed positions within the terminal, like on the ocean floor at places where most navigation is done or in front of the entrance or exit. These continuously view the currents of the ocean in the fixed positions over long durations. This information becomes helpful for finding out the regular pattern of currents in specific areas in the terminal. For example, a bottom-mounted ADCP flow meter at the port entrance can measure the inflow and outflow currents so that the tidal and general flow features of this site can be known.

4. What's required for good-quality measurement of Muuga port currents?

Equipment Requirements

First, a number of equipment characteristics will be important for high - quality measurement of the currents in Muuga port: material reliability, an ability to resist the harsh effects of the marine environment, in particular, salts and other chemical components in seawater cause destruction of materials in it. All equipment should bear pressure changes at different depths of water and mechanical forces from waves and currents.

Second, it should be of a smaller size, lower weight, and reduced power consumption. The compact size can be easily installed anywhere at the port, either on ships, fixed structure pier, or seabed ground. The lighter weight eases the installation and transportation procedures. Lower power consumption ensures that the equipment can operate continuously for long periods without the need for frequent battery replacements or excessive power supply, especially in long-term monitoring applications.

Cost is another important factor. A lower-cost option allows the port to deploy more measuring devices for wider current monitoring across different areas of the port.

The Advantage of Titanium Alloy for ADCP Casing

This is where the casing is preferably made of titanium alloy. Being able to develop excellent corrosion resistance, thus maintaining the structural integrity with functionality when subjected to seawater for extended periods, its ratio of strength-to-weight is high such that the construction of this casing results in durability coupled with light weight. However, if the instrument has a case made from titanium alloy, then such pressures could well be tolerated by an ADCP profiler operating in deeper areas of Muuga port with higher water pressures. Results obtained from such instruments can be fairly accurate in that context.

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

Selection Based on Usage

Shipborne ADCP: Where the intention is to carry out wide-area surveys of the port waters while the ship is operational, shipborne ADCP will be suitable. In this case, it can cover different sections of the port as the ship moves around, collecting a large amount of data for a comprehensive understanding of the overall current situation in the port. That will be useful for mapping the general patterns of flow and variations across different areas of the port waters.

Sitting - bottom ADCP: Long-term and fixed-point monitoring of certain locations in the port, especially those near important infrastructure or areas with complex current behaviors, is more appropriately carried out with sitting-bottom ADCPs. They can record the continuous current data at those fixed positions with valuable insights into the local current characteristics and changes over time.

Buoy-mounted ADCP: In conditions when it is not feasible or appropriate to install fixed equipment on the seabed or vessels, buoy-mounted ADCPs can be deployed. They float on the water surface and can measure the currents in the upper layers of the water column. Relatively easy to deploy and re-deploy, they can be used to monitor specific dynamic or difficult-to-reach areas inside the port.

Selection Based on Frequency

The choice of frequency for ADCPs depends on the water depth in Muuga port. For areas with a water depth of up to 70 meters, an ADCP with a frequency of 600 kHz is usually a good choice as it can provide accurate current measurements in this relatively shallow depth range. In waters as deep as about 110 meters, it is more advisable to use an ADCP with a frequency of 300 kHz. Where the sections of the port are extremely deep and attain a water depth of up to 1000 meters, then an ADCP with a frequency of 75 kHz should be used for valid profiling of the ocean currents at such great depth.

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.