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

1. Where is Cochin Port?

Overview of Cochin Port

Cochin Port, popularly known, is a major maritime hub on India's south - west coast. It is one of the finest natural harbours in the world and has a strategic location that has played an important role in the country's maritime trade since time immemorial. The port boasts large-scale infrastructure with a very high throughput. Cochin has a broad diversity in its range of cargoes moving in and out, spanning from containers, petroleum products, chemicals to agricultural goods. The shipping routes of Cochin Port connect it to various ports in the Middle East, Europe, and Asia-Pacific regions.

Management and operation in Cochin Port are efficient and well-organized. A team is dedicatedly deputed for vessel traffic management, cargo handling, and other port-related services. Advanced technologies such as automated cargo-handling systems and real-time vessel-tracking software are run to optimize its operations. For example, the cargo-handling systems can load and unload containers rapidly, which reduces the turnaround time of ships.

Port Facilities The port is well and fully equipped with various modern facilities. It has different depth berths for accommodating vessels of varying sizes. There are modern cranes and other loading and unloading machinery lining the quay for handling different types of cargoes efficiently. Storage facilities include vast warehouses for dry cargo and special tanks for liquid cargo. There are also facilities for ship repair and maintenance, providing services like engine overhauls and hull cleaning.

Channel and Direct Shipping

The channel of the port is well-maintained to ensure safe passage for ships. It has an appropriate depth and width, with regular dredging operations taking place to maintain it as navigable for large vessels. Cochin Port has direct shipping connections with many important ports. These direct links provide huge advantages to the enterprises to reduce their transport costs and time, making it an attractive option for shipping companies and those businesses engaged in international trade.

2. Why measure the ocean currents in Cochin Port?

Importance to Port Operation and Management

Cochin Port should take ocean current measurements for a number of reasons. First of these is vessel navigation safety. Knowledge of current directions and speeds assists ship captains in making better decisions when approaching berths or maneuvering through narrow channels. A strong cross-current off a berth can sometimes turn the act of docking into an ordeal. Precise current measurements enable captains to adjust their angles and speeds of approach with a view to smooth and safe docking, avoiding collision risks.

It is also crucial for the optimization of port operations. Present information allows for more effective planning of the arrival and departure of ships. With knowledge regarding the tidal currents and other recurring flow patterns, the management can make better management of the berthing facilities and plan the loading and unloading activities accordingly. This results in increased productivity since it allows the better coordination of cargo-handling operations.

Besides that, from an environmental point of view, the knowledge of ocean currents is useful in drawing trajectories of pollutants, in the event of an accidental spill, thus enabling immediate action to be initiated to contain and lessen the environmental damage. In this context, a correct and easy measurement method such as ADCP-Acoustic Doppler Current Profiler is much desired for the measurement of ocean current at Cochin Port.

3. How do Doppler Principle ADCPs Work?

Measurement Principle

The ADCPs work according to the Doppler principle. When the Acoustic Doppler Current Profiler (ADCP) sends out an acoustic signal into the water, it scatters off of moving particles in the water. Due to the ocean current, the water particles are in motion, and the frequency of the reflected acoustic signal that returns to the ADCP current profiler is shifted by them. According to the Doppler effect, this frequency shift is proportional to the velocity of the water flow. By analyzing the frequency shift, the ADCP profiler calculates the speed and direction of the water flow. The ADCP current profiler emits signals at multiple angles with different depths to produce a profile of the ocean current, showing how the current varies with depth.

Methods for ADCP in Port Ocean Current Measurement

The shipborne ADCPs were installed on the ships operating around the area of Cochin Port. When the ship moves around the port area, it continuously emits acoustic signals into the water below it. The movement of the ship thus provides the ADCPs with a wide view for covering more areas and collecting current data from different locations. For instance, in the normal survey of the port by a research or inspection ship installed with a shipborne ADCP, it can acquire data on current patterns across different parts of the port and offer an overall idea about the condition of the water flow.

Fixed ADCPs are deployed at fixed locations within the port, such as on the seabed near important navigational areas or at the entrance/exit of the port. These ADCPs continuously monitor the ocean currents at their fixed positions over a long period. The collected data is helpful in analyzing the regular current patterns in the specific areas of the port. For example, a fixed ADCP installed near the port entrance can record the currents coming in and going out of the port, thus helping to understand the tidal effects and other consistent flow characteristics in that region.

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

Equipment Requirements

The measurement of currents in Cochin port requires certain equipment characteristics for high-quality measurement. Preeminently, the reliability of the materials used in the equipment is very important. The equipment has to bear the harsh marine conditions, particularly the salinity in seawater, that can cause corrosion to the equipment. Seawater is composed of different salts and other chemicals that can easily corrode materials in the equipment over time. The equipment must also bear the pressure changes at various water depths mechanical forces by waves and currents.

Secondly, a smaller size, lighter weight, and lower power consumption are desirable. A compact size allows for easier installation in various locations within the port, whether on ships, on fixed structures like piers, or underwater. A lighter weight simplifies the installation and transportation processes. The lower power consumption ensures that it will operate continuously for extended periods without needing a number of frequent battery replacements or excessive power supplies, which is especially important for long-term monitoring applications.

Cost is another factor. The lower the cost, the greater the number of measuring devices the port can deploy for more comprehensive current monitoring in different areas of the port.

The Advantage of Titanium Alloy for ADCP Casing

The casing of ADCPs is preferably made of titanium alloy. The excellent corrosion resistance of titanium alloy allows the material to retain both its structural integrity and functionality even when it is exposed to seawater for a long time. Its high strength - to - weight ratio allows for the construction of a durable yet relatively lightweight casing. For example, in the deeper parts of the Cochin port where higher water pressures are present, an ADCP current meter with a casing made of a titanium alloy can effectively withstand these pressures and continue to provide accurate current measurements.

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

Selection Based on Usage

Shipborne ADCP: If the aim is to conduct broad surveys of the port waters while the ship is in operation, then shipborne ADCP is quite suitable. It can cover different sections of the port as the ship sails along its routes, collecting a large amount of data to provide a comprehensive understanding of the overall current situation in the port. This will be useful in mapping the general flow patterns and variations across different areas of the waters.

Sitting Bottom ADCP: When the monitoring of long-term and fixed point in some place within the port becomes necessary, like near important infrastructure or the areas with the complex behaviors of the current, sitting bottom ADCPs become more suitable. They can continuously record the current data at those fixed positions, providing valuable insights into the local current characteristics and any changes over time.

Buoy-mounted ADCP: In locations where the installation of fixed equipment on the seabed is not convenient, nor on ships, buoy-mounted ADCPs are an option. They float on the water surface, measuring the currents in the upper layers of the water column. They are relatively easy to deploy and can be relocated if needed, hence they become suitable to observe certain dynamic or hard-to-reach areas within the port.

Selection Based on Frequency

The choice of frequency for ADCPs depends on the water depth in Cochin port. A particular choice for waters up to 70 meters deep is an ADCP current profiler of frequency 600 kHz, as that would give very accurate current measurements within this quite shallow depth. When working in waters as deep as about 110 meters, a lower frequency should be advisable, such as 300 kHz. Whereas for very deep parts of a port, where the water depth can go as high as 1000 meters, it is recommended that the ADCP meter be with a frequency of 75 kHz to ensure very reliable profiling of the ocean currents to such great depths.

There are several well - known ADCP profiler brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, there is also an excellent Chinese ADCP brand - China Sonar ​PandaADCP. It is made entirely of titanium alloy material, which not only ensures its durability in the marine environment but also offers an excellent cost - performance ratio. For more information, you can visit its official website: (​https://china-sonar.com/).

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