ADCP's Application to Ocean Current Measurement in Luanda Port

1. Where is Luanda Port?

Luanda Port is located in Luanda, the capital of Angola on the western coast of Africa. It is an important part in the economic activities of Angola with large-scale and high-volume throughput.

Port Scale and Throughput

Different berths in the port are available to receive vessels of large capacity, both container ships and bulk carriers. During the last couple of years, with the improvement in the Angolan economy-especially regarding oil and gas, mining, and agriculture-the traffic in the port has developed an upward trend. It handles considerable imports that range from consumer goods to industrial equipment and construction material. The main cargoes exported include crude oil, diamonds, and agricultural products. The port's handling capacity has been on a gradual increase to meet the rising demands for trade.

Routes and Services

Luanda Port is well connected in terms of international shipping routes. There are regular services via major European ports like Rotterdam and Hamburg, which allow the importation of goods made in Europe and the exportation of Angolan resources. It is also connected with Asian ports, such as Singapore and Shanghai, by which a wide variety of products, including electronics and textiles, are traded. The port provides a full range of services, from cargo handling and storage to customs clearance and ship repair. It has different terminals for different types of cargo, ensuring efficient operations.

Management and Operation of the Port

The port is operated both by the government affiliated port authorities and private-sector operators. The attention of the management is focused on high-quality services, safety, and security with sustainable development. There is modern management to optimize the flow of vessel traffic, processes for handling cargo, and resource allocation. On-the-job training programs are provided regularly for workers in the various ports to improve their skills and efficiency.

Port Facilities

The Luanda Port is a modern facility with state-of-the-art infrastructure. These involve various types of cranes, such as gantry cranes and mobile harbor cranes, which have great lifting capacities to handle jumbo containers and heavy-lift cargo. Storage areas are well organized, with separate areas for the storage of goods that require silos for dry-bulk storage or refrigerated containers to hold perishable goods. Besides, it is equipped with modern communication systems and navigation aids to assist in its operations.

Waterways and Direct Navigation

The waterways around Luanda Port are deep and wide enough to enable big draft vessels to pass through it. Besides, it has direct access to the Atlantic Ocean, which is a key ingredient in international trade. Continuous efforts have been made regarding the waterways: maintenance and dredging operations are constantly carried out to keep the waterways at optimum depth for ships of all sizes.

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

Ocean current measurement in Luanda Port is important in a number of aspects involving port operations and management.

Instructions Ensuring Vessel Safety

Knowledge of the real features of ocean currents is useful in safe navigation. Strong or irregular currents pose a great risk to vessels during entry, exit, and berthing. The masters of the vessels can plan in this regard about the speed, course, and timing of the operation based on the current pattern. This reduces the chance of collision, grounding, and other maritime casualties, which saves lives of crew and maintains vessel integrity.

Cargo Handling Optimization

Ocean currents may also impact the effectiveness of cargo handling operations. For example, if the current is too strong, then the exact positioning of a vessel at the berth could be difficult to achieve. Measuring currents enables port operators to plan cargo operations during times when the current conditions are most favorable, hence increasing the general productivity of the port.

Infrastructure Planning and Maintenance

Current data is important for long-term planning and maintenance of port infrastructures. The ocean currents can cause erosion and sedimentation, affecting the stability of the berths, breakwaters, and other structures. By monitoring the currents, engineers can design robust and sustainable infrastructure and thus have a foreseen schedule for timely maintenance and repair work.

Environmental Protection

Understanding ocean currents is crucial for environmental protection in the port area. Currents can influence the dispersion of pollutants, such as oil spills or chemical waste. By measuring the currents, port authorities can better predict the spread of pollutants and take appropriate preventive and mitigation measures to protect the marine ecosystem.

Acoustic Doppler Current Profilers have emerged as a very modern and convenient tool for measuring ocean currents in Luanda Port. They possess high resolution and accurate data that best suits current measurements of the port.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

The ADCPs operate based on the principle of the Doppler. An Acoustic Doppler Current Profiler(ADCP) that sends an acoustic signal into the water-the signal travels through the water column. Due to moving water particles, the frequency of the reflected acoustic waves shifts. This frequency shift, called the Doppler shift, is proportional to the velocity of the water particles relative to the ADCP. By measuring this Doppler shift, the ADCP can compute the velocity of the water in the direction of the acoustic beam.

ADPCP - There are typically a number of acoustic beams-an arrangement of usually 3 or 4 beams set at different angles. With this kind of setup, a multi-beam ADCP finds out three-dimensional velocity vector of the water flow based on several combined velocity measurements; hence, one can completely describe the water movement in the measurement area.

Methods to Measure Current in Ports

Ship-borne ADCP

Ship-borne ADCPs are installed on the hull of a moving vessel. While the ship is sailing in the port area, the ADCP flow meter continuously measures the ocean currents along the path the ship covers. This method is useful for quickly getting a huge amount of current data over a relatively wide area and may give an idea about the general current patterns in the port, which helps in initial surveys and route planning.

Fixed ADCPs

These are installed on the seabed or on fixed constructions in the port, like piers or buoys. These ADCPs enable the continuous, long-term monitoring of the currents of the ocean at a specific location. They are especially efficient in studying local current variations, such as near a berth or in an area with complex hydrodynamics. Fixed ADCPs shall provide valuable information on long-term trends and short-term fluctuations of the current, which are important for optimization in port operations.

4. What's needed for high-quality measurement of Luanda Port currents?

Material Reliability

The instruments for such current measurements in Luanda Port need to be made from very reliable materials. The casing of an ADCP current meter shall therefore be preferably made from a Titanium alloy since marine conditions comprise saltwater corrosion, high-pressure conditions, and mechanical stress. Titanium alloy constitutes a very good corrosion resistance that has the ability to extend equipment life in seawater. It offers a very good resistance against the corrosion by saltwater during an extended period.

Small in Size, Light Weight

It also shall be compact with low mass. In situations such as having very small places available in general and in the limited size of space-from small research vessels up to fixed structures that generally bear the dimension limit, which requires easiness of the device to get installed and puts lower load while installing the measurement target environment. For example, a small and lightweight ADCP would hardly interfere with natural water flow on installation from a buoy.

Low Power Consumption

Low power consumption is of great importance. In a marine environment, power supply is difficult, especially in long - term monitoring applications. With low power consumption ADCPs, this can be operable for a longer period by just using battery power or small - scale renewable sources such as solar panels. This reduces the need for frequent battery replacements or complex power - supply infrastructure.

Low Cost

In order to enable the large-scale current measurement in the port area, the cost of the equipment should be as low as possible. A low-cost ADCP makes deployment of multiple units possible, providing a better overview of current patterns. It also provides an opportunity for regular current measurements by port authorities on limited budgets.

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

Determined by Usage

Ship - borne ADCP

An ADCP on a ship is the preferred option if one needs a general overview of the existing conditions over a large area of the port in the shortest time. For example, in a port expansion project, if one wants to get an initial idea of the current patterns in the proposed new areas, a shipborne ADCP can be used to cover a large expanse of water in relatively short time.

Bottom-mounted ADCP

When long-term, continuous monitoring of the current at a specific location needs to be carried out, such as near a critical berth or in an area where sedimentation problems may occur, a bottom-mounted ADCP is more appropriate. It can provide detailed data on the local current variations over an extended period, useful for infrastructure design and operational management.

Buoy-mounted ADCP

An ADCP mounted on a buoy will be suitable for the measurement of current in areas where the depth of water changes or in open-water areas next to the port. The buoy can float with the water to measure the dynamic changes in the current at different locations.

Determined by Frequency

The frequency of an ADCP is determined by water depth. For the depth of water within 70m, a broadband 600kHz ADCP would be ideal. This frequency gives high resolution over shallow waters. Where the water is about 110m deep, a 300kHz would be better since it will penetrate deeper and still maintain quite a reasonable level of accuracy. The best choice when measuring into water depths up to 1000m is a 75kHz ADCP because it can reach deeper.

There are several well - known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, for those seeking high - quality and cost - effective solutions, the China Sonar PandaADCP is highly recommended. Made entirely of titanium alloy, it offers excellent performance and an incredible cost - performance ratio. For more information, you can visit [https://china-sonar.com].

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