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

1. Where is Makassar port?

The Makassar port is located within the city of Makassar on the southwest coast of Sulawesi Island, Indonesia, and it is an important maritime hub for the area.

Scale of the port and throughput

It has been growing steadily for some time. The area has been bestowed upon this purpose, offering a vast handling area for numerous port activities. Therefore, cargo traffic flow is enormous; the various types of commodities range from agricultural produce and minerals to manufactured goods in large throughputs. It is a vital link for both domestic trade within Indonesia, providing access to various parts of the archipelago, and international trade, connecting Indonesia with countries in Asia, Oceania, and beyond.

Routes and Business

The Makassar port has numerous shipping routes. Domestically, the port has regular connections with major ports on other islands such as Java, Sumatra, and Kalimantan. Internationally, it is on the routes that link Southeast Asia with Australia and parts of the Indian Ocean region. Its businesses in the port include handling containerized cargo, bulk cargo of coal and grains, and general cargo. The port also has facilities for loading and unloading vehicles and other specialized shipments.

Port Management and Operation

Professional port authorities manage the facility to ensure that day-to-day operations run smoothly. They will manage the berthing arrangements of vessels, cargo handling processes, the overall security, and infrastructures involved. The operation hence requires a well-coordinated approach between the stevedoring companies, customs officials, and the port maintenance crews to facilitate quick and efficient handling of the vessels and cargo in good time.

Port Facilities

The port is fitted with modern facilities. It has a number of berths of varying lengths and depths to accommodate different types of ships, from small coastal vessels to large ocean-going cargo ships. Advanced cargo handling equipment such as cranes, forklifts, and conveyor belts facilitate the loading and unloading of goods. There are warehousing facilities for storage of different types of cargo before they are transported further. In addition, there are facilities for refueling and maintenance of ships.

Channel and Direct Navigation

The port has a well-maintained channel allowing the ships to enter and leave safely. The channel is dredged frequently to retain the depth the ships of various drafts require. Similarly, it provides all the navigational facilities like buoys, lighthouses, and radar to guide the ship during its approach and departure so that the vessels can directly navigate, coming from any direction.

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

Precise measurement of ocean currents is very crucial for the operations and management of the Makassar port. First of all, knowledge of the current pattern helps in optimizing ship berthing and unberthing. The information on current direction and speed helps the port authorities schedule vessel arrivals and departures by knowing the right timing of these vessels. Also, knowledge of currents in ports enables the guiding of ships to berth along the current to minimize lateral forces during docking.

Second, this is important for the safety of ships moving in and out of the port. Strong or unpredictable currents can pose risks to vessels, especially those with larger drafts or those carrying hazardous cargo. With precise current data, appropriate navigational warnings can be issued, and ships can adjust their speed and course accordingly to avoid accidents like collisions with other vessels or running aground.

The knowledge of ocean currents is also useful for pollutant dispersion in the port area. In case of any accidental spill of oil or other harmful pollutants, the flowing current helps in assessing the spreading of pollutants so that timely measures of containment and cleaning-up can be done.

Besides that, current data is highly important in planning and maintaining port infrastructures like breakwaters and quay walls. Currents are capable of exerting huge forces on these structures over time, and with more accurate measurements, better design and maintenance strategies can be implemented to ensure durability.

The ADCP flow meter has come to be more advanced and convenient for the measurement of ocean currents compared to the traditional methods. It could provide very detailed and real-time information on current profiles at different depths and thus enabled a comprehensive understanding of the hydrodynamic conditions in the port area.

3. How do ADCPs using the Doppler principle work?

ADCPs apply the basic principle of the Doppler effect. They emit acoustic signals into the water. When these acoustic waves encounter moving particles in the water, such as sediment particles or small organisms that are carried by the ocean current, the frequency of the reflected waves changes. The frequency shift, known as the Doppler shift, is directly related to the velocity of the moving particles and thus to the velocity of the ocean current. By measuring this frequency shift from multiple directions-usually in a three-dimensional or at least two-dimensional configuration-ADCPs can calculate the speed and direction of the ocean current at different depths.

ADCP in Port Ocean Current Measurement Shipborne ADCP

Shipborne ADCPs are installed on vessels. While a ship is underway through the water, the ADCP current profiler continuously sends acoustic signals downward and around. It collects data on the current velocity as it traverses different areas of the port. The advantage of this method is its mobility, allowing for measurements in a wide range of locations within the port waters. However, it may be affected by the ship's own motion to some extent, and proper calibration and compensation methods need to be employed to obtain accurate results.

Fixed ADCP

Fixed ADCPs are mounted at fixed locations in the port, such as on the seabed or on fixed structures like piers or buoys. They continuously monitor the ocean current at that fixed point over an extended period. This provides long-term and consistent data for understanding the regular current patterns in the port. The drawback is that they cover an area only in the immediate vicinity of where they are installed, but they are very useful for establishing reference current data for particular regions within the port.

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

For high-quality measurement of ocean currents in the Makassar port, several factors regarding the equipment are crucial. Firstly, the materials of the equipment need to be reliable. They should be able to withstand the harsh marine environment, including corrosion from seawater, pressure at different depths, and possible impacts from floating debris.

As equipment, it should be of compact size to allow for easy installations even where space is limited, for instance, on small buoys and among the maze of underwater structures. Moreover, its lightweight design would mean better maneuverability with a reduced workload during deployment and recovery operations, thereby reducing some potential risks.

It should be of low power consumption, especially for long-term monitoring applications. High-power equipment may have operational continuity challenges due to either limited options for power supply in the port area or the frequent replacement/recharging of batteries.

Another important factor is cost. In extensive measurement programs in the port, cheaper equipment can be deployed more widely to build up a fine-resolution picture of the present conditions across the waters of the port.

ADCP current meter is preferably housed in a casing made from titanium alloy. Titanium alloy has several remarkable advantages. It has excellent corrosion resistance in seawater, which ensures the longevity of the equipment and maintains its performance over time. It is also relatively strong and lightweight, able to withstand high pressures at greater depths while not adding excessive weight to the overall device. Moreover, its biocompatibility means that it is less likely to cause adverse effects on the marine environment or interfere with the acoustic signals used by the ADCP.

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

Based on Usage Purpose

Shipborne ADCP: If the intention is to obtain current data over a wide area of the port while the ship is in operation-for example, during regular port surveys or when collecting data for navigational chart updates-shipborne ADCPs are a good choice. They can cover different parts of the port as the ship moves around.

Bottom-Mounted (Sitting) ADCP: They are used when long-term and fixed-point monitoring of some places in the port, particularly those that are considered vital, like breakwaters or those points at the entrance of the channel, are required. Bottom-mounted ADCPs give steady and unbroken series of data about local current characteristics.

Buoy-mounted ADCP: In cases when it is not convenient to install fixed equipment on the seabed or on structures, or when there is a need for a floating monitoring point to catch the surface and near-surface current conditions, buoy-mounted ADCPs are ideal. They can be easily deployed and moved if necessary.

Based on Different Frequencies

For water depths within 70 meters, a 600 kHz ADCP is often a good option. It can provide relatively high-resolution current profiles in shallower areas, suitable for many parts of the port where the water depth is not extremely deep, such as near the quay walls or in the inner harbor.

When water depths range up to 110 meters, a 300 kHz ADCP is more appropriate, for this frequency can effectively penetrate the water column at these depths and measure current velocities with much higher precision.

For much deeper areas, such as in the approach channel of the port, where the water depth may be greater than 1000 meters, a 75 kHz ADCP will be more appropriate. Because of its lower frequency, it can reach greater depths yet still obtain useful current information.

Of course, there are more brands in the market for these ADCPs, such as Teledyne RDI, Nortek, and Sontek. However, the China Sonar PandaADCP is a very good option considering cost and quality. The material is all-titanium alloy and can maintain strength with good performance. With its incredible cost-performance ratio, it provides a great choice for ocean current measurement in ports like Makassar. For more information, please access the official website at: https://china-sonar.com/.

Here is a table with some well known ADCP instrument brands and models.