ADCP's Application to Ocean Current Measurement in Trincomalee Port

1. Where is Trincomalee Port?

Trincomalee Port is located on the northeastern coast of Sri Lanka. It is a natural deep - water harbor and one of the most important ports in the Indian Ocean region.

• Port Scale and Throughput: It has a large-scale infrastructure, including extensive quay facilities and a number of berths. The size of cargo it can handle is enormous, ranging from containers to petroleum products to dry bulk cargo. The port's throughput is increasing year by year due to its strategic location and excellent harbor conditions.
• Routes and Business: The port of Trincomalee plays a vital linkage in the maritime trade route between South Asia, Southeast Asia, and the Middle East. It is also involved in various business activities, such as the import of crude oil and refined petroleum products on behalf of the domestic market, in addition to the export of Sri Lankan produce of tea, rubber, and spices. Shipping lines utilize the port as a stop-over point for re-fueling and cargo transshipment.
• Port Management and Operation: The port is managed by a team of professionals who oversee day-to-day operations. They ensure that vessels berth efficiently, cargo handling is quick through modern equipment and well-trained staff. The management also focuses on security and safety measures to protect the port and the ships using it.
• Port Facilities: It is a facility that has been fully equipped with state-of-the-art facilities. It has deepwater berths fitted for large-scale tankers and container ships. The port has storage tanks for petroleum products and warehouses for general cargo. In addition, there are facilities for the repair and maintenance of ships; these include dry docks and workshops.
• Channel and Direct Shipping: The natural harbor offers a well-sheltered and deep-water channel. The strategic location of the port gives way to direct shipping connections with major ports around the world. Thus, it allows efficient transportation, reducing transit times, which makes it favorable for shipping companies.

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

It is very important that the measurement of ocean currents in Trincomalee Port is accurate. Firstly, for the safety of shipping operations: ocean currents may considerably affect the ship's maneuverability. By knowing the current patterns, the port can provide better guidance to ships during berthing and unberthing processes. This helps in preventing collisions and other accidents that could occur due to the influence of strong or unpredictable currents.

It is also useful for the optimization of port operations. The knowledge of the present velocities and directions will help in planning the best routes for vessels that enter and leave the port. This may be of great importance in fuel consumption and general productivity. For instance, ships may adjust their speeds and courses to meet up with their destinations faster with the current.

Current measurements are also needed in long-term planning and maintenance of the port. Currents can affect the sedimentation process around the port. The measurement of currents shall help the port authorities to plan dredging well in advance with predictions. This ensures the channels and berths of the port remain at required depth and stability. ADCP flow meter is more advanced and convenient for current measurement compared to the traditional methods.

3. How do ADCPs using the Doppler principle work?

The basic operation of ADCPs relies on the Doppler effect. The instruments send acoustic signals down into the water. When acoustic waves are reflected back from moving particles in the water, suspended sediments, or small organisms, the Doppler effect changes the frequency of the reflected waves.

• Ship-borne ADCP: In Trincomalee Port, a ship-borne ADCP can be mounted on different vessels. While the ship is in motion through the water, the ADCP current meter sends pulses of sound downwards and sideways. The frequency shifts of the reflected pulses coming from different depths are measured. By processing these frequency shifts, the velocity of the ocean current at different depths can be calculated. The data obtained can be utilized either for real-time navigation or stored for further analysis.
• Fixed ADCP: Fixed ADCPs can be deployed on the sea floor, from the side of piers, or other fixed platforms. These ADCPs continuously transmit and receive acoustic signals. They provide a long-term record of the current velocities and directions at a specific location. This data is useful for understanding the local current patterns and any changes that occur over time.

4. What does a good measurement of Trincomalee port currents call for?

Several aspects related to the equipment should be required to perform the current measurement of high quality at Trincomalee Port. Materials of equipment are in demand, in which titanium alloy casing should be great for ADCPs. Because of its outstanding corrosion resistance, therefore it is ideal to be utilized at a sea area. The capacity to face sea water and corrosive nature will surely result in longevity of equipment stability and reliability.

The size of the equipment should be small and the weight lightweight. A compact and lightweight ADCP current profiler would be easier to install either on a ship or in a fixed location. Besides, it reduces the load and space needed, hence making it easy to use.

The other essential factor is that of low power consumption. Since operation should be continuous in the port environment, equipment with low power consumption can operate for extended periods without frequent battery replacements or excessive energy supply requirements. Also, the cost of the equipment should be moderate to allow large-scale deployment for current measurement comprehensively.

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

The type of equipment selected for current measurement at Trincomalee Port would be based upon its intended use.

Installation Type

• Ship-borne ADCP: It would serve well in cases where the objectives of measurement would encompass monitoring during the movement of the ship or making surveys over larger areas of the port.
• Bottom-mounted ADCP: For long - term and fixed - point monitoring of current conditions, especially near critical port structures such as channels and berths, bottom - mounted ADCP is the better option.
• Buoy-mounted ADCP: When the focus is on the surface and upper - layer current patterns in the open water area of the port, buoy-mounted ADCP can be considered.

Based on Frequency

Frequency choice is a function of the water depth. A 600 kHz ADCP will work well in water depths to about 70m and could be deployed in shallower areas of the port. A 300 kHz ADCP will operate well in water depths to around 110m and hence it would serve the deeper part of the main port area. It could show the 75 kHz ADCP working within much deeper water, up to 1000m, even in areas near a port entrance where big water depth variation is common.

There are well-known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, a Chinese brand, China Sonar PandaADCP, is also worth noting. It is made of all - titanium alloy material and offers an excellent cost-performance ratio. You can find more information on its website: (https://china-sonar.com/).

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