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

1. Where is Bitung port?

Bitung port is located in the city of Bitung, which is on the northern tip of Sulawesi Island in Indonesia. It is one of the major ports in the region and an important maritime hub.

Port Scale and Throughput

The port has seen quite a large growth over the years and is of significant size to handle a wide array of vessels. It operates a substantial volume of cargo yearly, both domestic and international. The throughput includes, fishery products, as Bitung is famous for the vibrant fishing industry, besides general merchandise, industrial raw materials, and manufactured goods. It plays a significant role in trade exchange, not only internally within the Indonesian archipelago but also with international partners, especially those from the Asia-Pacific region.

Routes and Business

Bitung port has an extensive network of shipping routes. Domestically, it connects with numerous other ports in Indonesia, thus enabling the distribution of goods across different islands. Internationally, it is at important trade routes that link it with countries in Southeast Asia, Northeast Asia, and Oceania. Business operations at the port range from handling containers for efficient cargo transport to dealing with bulk cargo such as coal and agricultural products. It also has facilities to process and export fishery resources, turning the port into a vital axis for the fishing industry in this region.

Port Management and Operation

The port is directed by a professional team of port authorities with relevant departments behind them. They are responsible for the smooth operation, management of vessel traffic, berthing space allocation for ships, handling cargo activities, and maintaining overall security and safety in the port area. The operation is complex, needing coordination at all levels to guarantee efficient goods and vessel flow, stevedoring companies, customs officials, port engineers, and other stakeholders alike.

Facilities: The port is bestowed with very modern facilities. The berths vary in number, length, and depth for accommodating ships ranging from tiny fishing boats to quite large cargo ships. Modern equipment for the handling of cargo, including cranes, forklifts, and conveyor belts, to handle many kinds of cargo and expedite the processes of loading and unloading are available in the port. In addition, it has cold storage facilities for fishery products, general goods warehousing, and workshops for ship maintenance and repair. Facilities to refuel ships to support their continuous operation are also provided.

Channel and Direct Navigation

The port is provided with a well-maintained channel that allows safe access to and from the facility. This channel is dredged from time to time to keep the depth at the right levels for vessels of various drafts. It has a line of navigation aids like buoys, lighthouses, and sophisticated radar that assist ships in keeping their track accurately, thus allowing direct and smooth navigation for both incoming and outgoing traffic.

2. Why measure the ocean currents in the Bitung port?

Measuring ocean currents in the Bitung port is very vital in regard to its functioning and management effectively. The main reasons for this measurement include optimization of ship movement within the port. With good knowledge of the current speeds and directions, the port authority will be in a position to schedule vessel arrival and departure times with better precision. This allows ships to come up to the berths more smoothly, reducing time and fuel consumption during docking and undocking processes. For example, if there is a strong current in a certain area, it can guide the ships in such a way as to take advantage of the flow without using too much power from the engines.

Second, it is essential to the safety of maritime activities in the port. Unpredictable or strong currents can be hazardous for ships, especially where the waterways are relatively narrow or there are underwater structures. With accurate current measurements, timely navigational warnings could be issued, and the ships would be able to take corrective courses to avert collisions with other vessels or running aground.

Moreover, understanding the ocean currents is beneficial for environmental protection in the port area. Currents can affect the dispersion of pollutants such as oil spills or wastewater discharges. By knowing the current patterns, appropriate measures can be taken to contain and clean up any potential pollution incidents more effectively.

Moreover, current data is an important input for the long-term planning and maintenance of port facilities such as quay walls and breakwaters. The forces exerted by ocean currents over time may affect the structural integrity of these facilities, and accurate measurements allow for better design and maintenance strategies to ensure their durability.

ADCP-technique provides a more advanced and feasible alternative in measuring ocean currents without having to revert to former, laborious methods of measuring it. It can furnish highly detailed and real-time information of the current profiles across various depths, thus encapsulating comprehensive hydrodynamic conditions within the port.

3. How Do Doppler Principle ADCPs Operate?

The operation of the ADCPs is based on the Doppler principle. This type of instrument emits acoustic signals into the water column. This produces reflected waves when they run into moving particles in the water, which are transported by the ocean current, with a different frequency than initially present in those acoustic waves. The Doppler shift is related directly to the velocity of these moving particles and thus the velocity of the ocean current. By measuring the Doppler shift from multi-directions-usually in a three-dimensional or two-dimensional configuration, it is possible for ADCPs to calculate the speed and direction of the ocean current at different levels.

ADCP in Port Ocean Current Measurement Shipborne ADCP

Shipborne ADCPs installed on vessels operating in the area of the port. Every time the ship sails, the ADCP flow meter continuously shoots acoustic signals downwards and sidewards. It gathers current velocity information as a vessel traverses over a particular area within the port. The strong point of this approach is mobility, since it is able to give measurements in most locations found within the waters of concern. However, its own movements should be taken into account to accurately derive the sought-after data, and procedures for calibration and correction to remove the ship-generated mistakes are applied accordingly.

Fixed ADCP

The fixed ADCPs are deployed at selected fixed points within the port, either on the seabed or on other fixed installations like piers and buoys. They steadily generate records of the ocean current at that point over extended periods. This will thus provide consistent and long-term data to understand the regular patterns of currents in specific areas of the port. The downside is that they only cover a limited area around their installation site, but they are indispensable in view of establishing reference current data for key locations within the port.

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

Several critical issues with equipment are present for the measurement of the ocean currents in the port of Bitung. The equipment should be made of good, reliable materials, bearing in mind that it may be used in the sea water, under high pressure, sometimes at large depths, or even damaged by the passing of floating objects.

The size of the equipment should be small to allow for easy installation, particularly in areas that are relatively small or have a complex underwater topography. The equipment design must be lightweight for easy deployment and retrieval to minimize manpower and risks during these operations.

It has to be of low power consumption, especially in long-term monitoring applications. High power consumption apparatus may be confronted with certain difficulties in sustaining continuous use, due either to deficiencies in options of power feeding in the port area or problems with frequent replacement and recharging of batteries.

Cost is another consideration. The ability to purchase lower-cost equipment enables wider deployment in measurement efforts on a large scale across the port and allows a better understanding of the current conditions throughout the waters of the facility.

The casing is preferably made from titanium alloy. Titanium alloy has a lot of advantages. For one, it has exceptional resistance to corrosion in seawater. That will help extend the life of the equipment and maintain its performance for longer periods. It is also relatively strong and lightweight, capable of withstanding high pressures at greater depths without adding excessive weight to the device. Furthermore, its biocompatibility means that it has minimal impact on the marine environment and does not interfere with the acoustic signals used by the ADCP current profiler.

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

Based on Usage Purpose

Shipborne ADCP: These are applied when the objective is to obtain current data over a broad area of the port while the ship is operating, such as in regular port surveys or during the collection of data for navigational chart updates. They can cover different regions of the port as the ship moves around.

Bottom-mounted (Sitting) ADCP: For long-term and fixed-point monitoring of specific locations within the port, such as near critical infrastructure like breakwaters or at the entrance of the port channel, bottom-mounted ADCPs are ideal. They provide stable and continuous data for understanding the local current characteristics.

Buoy-mounted ADCP: In situations where the installation of fixed equipment on the seabed or on structures is not convenient, or when a floating monitoring point is required to capture the surface and near-surface current conditions, buoy-mounted ADCPs are suitable. They can be easily deployed and relocated if necessary.

Based on Different Frequencies

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

When the water depth is up to 110 meters, a 300 kHz ADCP would be more appropriate; it can effectively penetrate the water column at these depths and accurately measure the current velocities.

In deeper areas, like the approach channel of the port, where the water depth may be well over 1000 meters, a 75 kHz ADCP would be more suited. Its lower frequency will allow it to reach much greater depths and still obtain useful current information.

Several brands are well known in the ADCP current meter market, such as Teledyne RDI, Nortek, and Sontek. However, if looking to save money but still want a good quality ADCP, then the China Sonar PandaADCP is one of the options. It is made totally of titanium alloy material, making it strong and durable, and performs very well. Having an incredible cost-performance ratio, it offers an alternative in conducting ocean current measurement in ports like Bitung. More details can be obtained from its official website: https://china-sonar.com/.

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