Application of ADCP to Ocean Current Measurement in the Port of Biak

1. Where is the Port of Biak?

The Port of Biak is located on the island of Biak in Papua, Indonesia, and is a large, active maritime hub within the region.

Scale of Port and Throughput

It is a pretty large-scale port with huge coverage of space for different port functions. It has a significant throughput that includes a wide variety of commodities such as fishery products, considering the importance of fishing in the area, and also minerals and agricultural products from the surrounding regions. It is an important link for both domestic trade within Indonesia and international trade, connecting the region to other countries in the Asia - Pacific.

Routes and Business

Biak Port is connected to various shipping routes: domestically, it has regular connections with major ports in Java, Sumatra, and other islands; internationally, it is located on important trade routes linking it with countries like Australia and some Pacific Island nations. The business operations of the port cover container handling for efficient cargo transport, bulk cargo operations such as loading and unloading of coal and ores, and processing and export of fishery resources.

Port Management and Operation

The port is run by a professional team of port authorities and related departments: controlling day-to-day operations, from the berthing arrangement of vessels of various sizes to coordinating cargo operation loading and unloading and keeping the port area safe and secure. Such an operation can only be efficiently run with close coordination among stevedoring companies, customs officials, and other port-related personnel for the smooth and efficient handling of vessels and cargo.

Port Facilities

The port is an efficient one with modern facilities. The berths within the harbor are of unequal length and depth, facilitating vessels ranging from small fishing boats to large ocean going cargo vessels. Advanced handling equipment in the form of cranes, forklifts, and conveyor belts expedite loading and unloading. There are also warehousing facilities for storing different types of cargo before they are transported further. In addition, the port is equipped with ship refueling and maintenance facilities that ensure constant vessel activity.

Channel and Direct Navigation

The port has a well-maintained channel through which ships can easily enter and leave the harbor. The channel is usually dredged at regular time intervals to ensure that a required depth of ships in various drafts may be secured. It has a channel fitted with buoys, lighthouses, and radar systems so that ships coming from every direction may approach or leave with direct navigation.

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

For Safe Navigation

Measuring ocean currents in the Port of Biak is indispensable for safety reasons regarding vessels. This knowledge contributes to the safe and secure conduct of vessels in and out of the port. Strong or unpredictable currents are a danger to the ships, more so with vessels of great draft or hazardous cargo. With current data available, ships would be able to adjust course and speed appropriately to avoid potential accidents that include collision or running ashore.

It is also advantageous to the efficient running of the port. Knowledge of the ocean currents facilitates the berthing and unberthing of ships. For instance, favorable currents may be utilized by ships to reduce time and fuel consumption in the berthing and unberthing process. This will eventually enhance the port's efficiency and minimize waiting times among ships.

For Environmental Protection

From an environmental point of view, ocean current measurement is very important. Currents can affect the dispersion of pollutants such as oil spills or wastewater discharges. Knowing the pattern of currents, the port can better plan and implement measures to contain and clean up any potential incidents of pollution, minimizing the impact on the marine environment.

For Infrastructure Maintenance

Current data is an important input for long-term planning and maintenance of port infrastructures like breakwaters and quay walls, since the forces exerted by ocean currents over time may highly affect the structural integrity of such facilities. Acoustic Doppler Current Profiler (ADCP) provides a more advanced and convenient way of measuring ocean currents compared to traditional methods. It can provide detailed and real - time information concerning current profiles at different depths.

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

ADCPs work on the principle of Doppler. They send acoustic signals into the water. When the acoustic waves detect moving particles in the water-sediment particles, plankton, or any other small organisms carried by the ocean current-the frequency of the reflected waves changes. This change in frequency is related to the velocity of the moving particles and thus to the velocity of the ocean current, which is known as Doppler shift.

ADCPs normally have several transducers, which send and receive these acoustic signals in various directions. By measuring this Doppler shift from different directions, usually in a three - or two - dimensional configuration, the ADCP current meter 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. The ADCP current profiler continuously sends acoustic signals downward and around as the ship moves through the water. It takes measurements of the current velocity while the ship is crossing over different areas of the port. The obvious advantage of this method is its mobility, allowing for a wide range of locations within the port waters where measurements can be taken. However, to get accurate results, it would be necessary to account for the ship's own motion. Calibration and compensation methods are applied to reduce any errors due to ship movement.

Fixed ADCP

Fixed ADCPs are deployed at specific locations in the port, which may be on the seabed or fixed structures such as piers or buoys. They monitor continuously at that fixed point over a longer period. This provides long-term and consistent data for understanding the regular current patterns in a specific area of the port. The disadvantage is that they only cover a small area around their installation site, but they are very useful in establishing reference current data for particular regions within the port.

4. What is required for high-quality measurement of Biak Port currents?

The equipment should have the following characteristics for high - quality measurement of ocean currents in the Port of Biak.

Reliable Materials

Reliable materials are required in making the equipment. Because it is used in the sea, there is corrosion from sea water, pressure at various depth, and possible impacts by floating debris; a durable material must be used.

Compact and Lightweight Design

The size of the equipment should be small to allow for easy installation, particularly in locations with very limited space, such as on small buoys or in areas with complex underwater structures. The equipment design should also be lightweight to simplify the deployment and retrieval operations.

Low Power Consumption

Low power consumption is especially important for long-term monitoring applications. Equipment with high power requirements can hardly maintain continuous operation if the power supply options are limited in the port area or frequent battery replacement/recharging is required.

Cost-Effectiveness

Cost-effectiveness is another important factor. In large-scale measurement efforts in the port, affordable equipment can be deployed more extensively, thus enabling a more comprehensive understanding of the current conditions throughout the waters of the port.

The casing of ADCP flow meter is preferably made of titanium alloy. Titanium alloy has excellent corrosion resistance in seawater, ensuring the longevity of the equipment. It is relatively strong yet lightweight and, therefore, able to bear high pressures at greater depths without adding excessive weight to the overall device. In addition, its biocompatibility means that it will have less adverse effects on the marine environment or interfere with the acoustic signals used by the ADCP profiler.

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: These will be applicable in cases when monitoring over a long period in specific locations within the port and also at fixed points becomes necessary, for instance, at locations with critical infrastructures such as breakwaters, or at the entrance of the port channel. These offer very stable and continuous data for understanding the characteristics of the local current.
• Buoy-mounted ADCP: These are best for use where the installation of fixed equipment on the seabed or on structures is inconvenient or when a floating monitoring point is needed to capture the surface and near-surface current conditions. They are relatively easy to deploy and can be moved as needed, if required.

Based on Different Frequencies

For water depths up to 70 meters, an ADCP of 600 kHz is a very good option; it would give a high resolution current profile in relatively shallower waters, which may be fitting for most of the areas in the port where the water depth is not particularly deep, such as near the quay walls or in the inner harbor.

• A 300 kHz ADCP is more suitable for water depths up to 110 meters. It can easily penetrate the water column at this depth and provide good accuracy in current velocity measurement.
• To access the deeper areas, such as within the approach channel of the port whose bottom features can be in excess of 1000 meters, there should be a 75 kHz. ADCP. The lower frequency can reach deeper and will return useful current information.

ADCP brands well known in the market include Teledyne RDI, Nortek, and Sontek. However, for those who want a cost-effective option with excellent quality, the China Sonar PandaADCP is the one to consider. The all-titanium alloy material combines durability and good performance. With its incredible cost-performance ratio, it provides a great choice for ocean current measurement in the Port of Biak. You can learn more about it on its official website: (https://china-sonar.com/).

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