ADCP in Rauma Port: Ocean Current Measurement

1. Introduction to Rauma Port

Location and Importance

Rauma Port is located in the city of Rauma, Finland. This is a very important and active port in the Baltic Sea area, playing an important role in both internal and international trade. The favorable location of the port makes it have good access to different shipping routes, which link it to all other European ports and beyond.

Scale and Throughput

The port is on a large scale with high throughputs. The cargo handled within the port encompasses containers, forest products such as timber and pulp, as well as industrial and bulk goods. The trade volumes passing through the Rauma Port significantly contribute to the local and regional economies.

Management and Operations

Rauma Port management is extremely effective. There are well-organized teams for separate port operations, such as vessel traffic management, cargo handling and storage. Advanced technologies, enabling the optimization of these, result in smooth and safe operations.

2. Port Facilities

Berths

Rauma Port has several types of berths that provide facilities for different vessel types. Deepwater berths accommodate the largest container ships and bulk carriers. The modern mooring and docking facilities at these berths include high-strength bollards and fenders to handle the safe arrival and departure of ships in bad weather.

Cargo-handling Equipment

Along the quay, an array of cargo-handling equipment is available. State-of-the-art gantry cranes, which can load and unload containers with high precision and a great deal of efficiency, are deployed for container handling. For forest products, there are specialized cranes and conveyor systems to handle logs and pulp. In the case of bulk cargo, the materials are transferred from the ships to the storage areas with the help of conveyor belts and grabs.

Storage Facilities

The port has big facilities for storage. The port facilities also include well-organized container yards, which are designed efficiently for receipt, storage and retrieval. To take care of the forest products at the port facility, it has large-scale stockpiles with proper coverage and protection from different weather elements. The bulk and other general cargo is taken care of by the appropriate warehouses, storage areas with necessary containment and security features.

Channel and Navigation Aids

The channel of the port is kept at a depth and width to allow for the safe passage of ships. Regular dredging operations are carried out to keep it navigable for vessels with different drafts. Navigation aids include buoys, beacons, and advanced radar systems that guide ships into and out of the port. The radar systems also give real-time information on the position and movement of other vessels around the port.

3. Importance of Measuring Ocean Currents in Rauma Port

Navigation Safety

Measurement of ocean currents is an issue of vessel navigation safety. The captains of ships should be aware of the velocity and direction of the currents in approaches to berths and also when navigating in the channel of the port. A strong cross-current near a berth can make the process of docking difficult and dangerous. For instance, if a ship is approaching a berth against a significant current, he may have to adjust the speed and angle of approach so that the docking is smooth and safe. Precise current measurements allow captains to make informed decisions and minimize the possibility of collisions and other accidents.

Operational Optimization

Current data is needed to optimize port operations. With knowledge of the tidal currents and other regularly occurring flow conditions, port personnel can more efficiently manage their berthing and scheduling of loading or unloading operations. This leads to an increase in productivity by offering better coordination of cargo - handling operations. For example, if the port is aware that during a specific period there will be favorable currents for vessels of a certain type, it can schedule the arrival and departure of vessels of that type during those periods to reduce delays.

Environmental Considerations

From an environmental standpoint, knowledge of ocean currents plays an important role in the eventuality of an accidental spill of crude oil or chemicals. On the basis of the nature of cargo handled, there is a need to realize an early prediction of spreading that could take place in the event of a spill. The current data can swiftly put into place containment and mitigations to reduce environmental effects.

4. Working Principle of ADCPs Using the Doppler Principle

Measurement Principle

The Doppler principle is used in the operation of the Acoustic Doppler Current Profilers (ADCPs). Whenever an ADCP current meter transmits an acoustic signal into the water, the moving particles in the water interact with that signal. Since these particles of water are in motion due to the ocean current, they induce a shift in the frequency of the reflected acoustic signal that comes back to the ADCP meter. According to the Doppler effect, this frequency shift is related to the water flow's velocity.

Calculation of Current Speed and Direction

By analyzing the magnitude and direction of this frequency shift, the ADCP current meter 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 profiler is installed on ships operating in the Rauma Port area. During the ship's movement around the port, the ADCP flow meter sends acoustic signals into the water with constant intensity. The ship movements enable the ADCP current meter to monitor large areas and acquire current data at different locations. For instance, a research or inspection ship with a shipborne ADCP that is on a routine survey of the port can collect data from different parts of the port on the current patterns and thus give an overview of the water flow situation.

Fixed ADCP

Fixed ADCPs are placed at certain fixed positions within the port, like on the seabed near important areas of navigation 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 to analyze the regular current patterns in specific areas of the port. For example, a bottom-moored ADCP installed near the port entrance can measure the currents flowing in and out and provide insight into the tidal effects and other steady-state flow features of that area.

5. Requirements for High - Quality Measurement of Rauma Port Currents

Equipment Requirements

In the measurement of the currents in Rauma port, some equipment characteristics are important for high - quality measurement. First of all, the material reliability is very important. The equipment should be able to tolerate the harsh marine environment. The salts and other chemicals in seawater make the materials deteriorate in a long period of time. The equipment also needs to bear the pressure changes caused by different water depth and mechanical forces caused by waves and currents.

The second is a smaller size, lighter weight, and lower power consumption. A smaller size allows for easy installation at any location in the port, whether on ships, on fixed structures like piers, or on the seabed. The lighter weight makes the installation and transportation processes easier. Lower power consumption ensures that the equipment can operate continuously for long periods without the need for frequent battery replacements or excessive power supply, which is especially important for long-term monitoring applications.

Cost is another important factor: A lower-cost option enables the port to deploy a larger number of measuring devices for more comprehensive current monitoring across different areas of the port.

The Advantage of Titanium Alloy for ADCP Casing

ADCP profiler casings are preferred to be made from titanium alloy. It has excellent corrosion resistance; it is able to keep up its structural integrity and functionality even in seawater for a long time. The high strength-to-weight ratio enables one to build a tough yet relatively lightweight casing. For example, in the deeper parts of the Rauma port where higher water pressures are present, an ADCP flow meter with a titanium alloy casing can effectively withstand these pressures and continue to provide accurate current measurements.

6. How to Choose the Right Equipment for Current Measurement

Selection Based on Usage

Shipborne ADCP: Where wide-area surveys of the port waters during the ship's operation are the target, then this is suitable. It can provide data on different sections of the port as the ship goes around and collates large data for an overview of the current situation in the port as a whole. That would be useful for mapping the general flow patterns and variations across different areas of the port waters.

Sitting-bottom ADCP: This is good for long-term and fixed-point observation of certain areas in a port, including those where there is some very important infrastructure or areas of complex currents. They can record continuously the data of current at those fixed positions, and that provides much-valued insight into the characteristics of local currents and possible changes of them 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 can measure the currents in the upper layers of the water column. Being relatively easy to deploy and allowing for repositioning, they are suitable for monitoring certain dynamic or hard-to-reach areas within the port.

Frequency Selection

To select the ADCPs in Rauma port, different water depths determine the type to use: When up to a certain depth of 70 m in area, normally, an appropriate option is the frequency of an ADCP-600 kHz providing current measurements rather accurately over a relatively shallow depth range. For deeper waters of up to about 110 meters, it would be more advisable to have an ADCP with a frequency of 300 kHz. For very deep parts of the port with water up to 1000 meters deep, an ADCP with a frequency of 75 kHz is desirable for dependable profiling of the currents at such great depth.

There are several well - known ADCP current meter 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.