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

1. Where is Pipavav Port?

Overview of Pipavav Port

The port, also a key one, of Pipavav is sited in the Amreli district of Gujarat in India and is of large scale with massive throughput. Pipavav Port is properly connected through important domestic and international trade routes that handle a varied range of cargoes, from automobiles, containers, and bulk cargo related to coal and iron ore transportation to other general cargo cargo vessels.

The port is vital to the development of the regional economy. Industries rely on the port for the importation of raw materials and the exportation of finished products. Pipavav Port is well managed, adopting modern technologies that make every operation run smoothly. It has a vessel traffic management team, cargo handling team, and every other team necessary for the successful running of activities within the port. Productivity is enhanced, and the general operations of the whole port are smoothened through the use of automated cargo-handling systems and digital communication channels.

Port Facilities

Berths: The port has several berths that are built to accommodate various vessels. There are deep-water berths for large-sized container ships and bulk carriers. These berths are equipped with modern mooring and docking facilities to ensure the safe arrival and departure of ships. The use of strong bollards and fenders helps in withstanding the forces exerted during the docking and undocking processes.

Cargo - handling Equipment: Along the quay, there is a wide range of cargo - handling equipment. For container handling, gantry cranes with high - speed and precision - loading capabilities are in place. For bulk cargo, there are conveyor systems and grabs to efficiently transfer materials from the ships to the storage areas. In the case of automobiles, there are specialized ramps and handling equipment to load and unload vehicles.

Storage Facilities: The storage facilities are large and exist for different types of cargo. For containers, there are well-organized container yards, while bulk materials are stacked in large stockpiles with proper drainage and containment systems. Automobiles have covered storage areas to protect them from the elements. The port also has storage tanks for liquid cargo, such as petroleum products, which are fitted out with safety features like spill-containment barriers and fire-protection systems.

Channel and Navigation Aids: The channel of the port is dredged to a sufficient depth and width to accommodate the safe passage of ships. Regular dredging operations are carried out to keep it navigable for large-draft vessels. Navigation aids like buoys, beacons, and radar systems guide the ships in and out of the port. The radar systems provide real - time information about the position and movement of other vessels in the vicinity of the port.

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

Importance for Port Operation and Management

Measurement of ocean currents is very significant in Pipavav Port. First of all, it is very important from the point of view of safety of vessel navigation. Knowledge of current speed and direction is crucial for ship captains while approaching berths or navigating through the channel. A strong cross-current near a berth can make the docking process challenging and risky. For example, a ship approaching a berth against a strong current would have to adjust speed and angle of approach to ensure a smooth and safe docking. Accurate current measurements allow captains to make informed decisions, reducing the risk of collisions and other accidents.

This helps to optimize the operationalization at the port, whereby scheduling for arrival and departure at the port would be appropriately achieved. Accurate interpretation of the tidal current and regular flow pattern provides better facilities to berth allocation planning, scheduling for loading and unloading of goods. It implies better productivity as cargo handling operations would then be better coordinated.

Moreover, from an environmental perspective, knowledge of ocean currents is valuable in case of an accidental spill of pollutants. Given the nature of the cargo handled in the port, such as petroleum products and chemicals, predicting the spread of a spill is crucial. The current data can help in quickly implementing containment and mitigation measures to minimize environmental damage.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

ADCPs work on the principle of the Doppler effect. When an ADCP sends out an acoustic signal into the water, the moving water particles scatter this signal. Due to the ocean current, the water particles will be in motion and result in a frequency shift of the reflected acoustic signal received by the Acoustic Doppler Current Profiler (ADCP). This shift is related to the velocity of the water flow according to the Doppler effect.

Current Speed and Direction Calculation The acoustic doppler velocity meter can also determine the current speed and direction at various points within the water column by using both the magnitude and direction of this frequency shift. Transmitting at several angles and different depths allows the creation of a profile of the ocean current, which indicates how the current changes with depth.

ADCP Deployment in the Port

Shipborne ADCP

A shipborne ADCP is installed on ships operating within the Pipavav Port area. As the ship moves around the port, the ADCP current profiler continuously emits acoustic signals into the water below. The movement of the ship allows the ADCP to cover a wide area and collect current data from different locations. For example, during a routine survey of the port by a research or inspection ship equipped with a shipborne ADCP, it can gather data on the current patterns across various parts of the port, providing a comprehensive understanding of the water flow situation.

Fixed ADCP

Fixed ADCPs are installed in stationary positions around the port, such as on the seafloor where navigation is very important, or at the entrance or exit of the port. Each ADCP measures the water current at a fixed position, continuously over long periods of time. These records can be used to define the average regular currents at selected areas within the facility. For example, a bottom-mounted ADCP profiler at the entrance of the port can measure the currents entering and leaving the port, which will give an idea about the tidal effects and other steady flow features in that area.

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

Equipment Requirements

For high - quality measurement of the currents in Pipavav port, certain equipment characteristics are crucial. First is the reliability of the materials. The equipment has to endure the harsh marine environment. Seawater has salts and other chemicals that will corrode materials over time. The equipment also needs to endure pressure changes at different water depths and mechanical forces by waves and currents.

Second, it should be smaller in size, lighter in weight, and have low power consumption. Compact size is for easy installation in several locations within the port, either on ships, on fixed structures like piers, or on the seabed. The lighter weight makes it easier to install and transport. The use of low power ensures that the equipment operates for long periods of time without necessarily needing replacement of batteries or a large supply of power. This becomes of great essence in cases that involve long-term monitoring applications.

Cost is another crucial consideration: The lower the cost, the larger the number of measuring devices that can be deployed at any given time to perform the same current monitoring task on the various areas of the port.

The Advantage of Titanium Alloy for ADCP Casing

The casing of ADCPs is preferably made of titanium alloy. It has excellent corrosion resistance, meaning it can maintain its structural integrity and functionality even when 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, the higher water pressures experienced in the deeper parts of Pipavav port would easily be withstood by an ADCP that has a casing made from titanium alloy, continuing to deliver current measurements accurately.

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

Selection Based on Usage

Shipborne ADCP: Where wide-area surveys of the port waters are to be conducted along with the operation of a ship, shipborne ADCP is quite adequate. That would cover different sections in the port as the ship meanders around, collecting extensive amounts of data for a comprehensive look into the overall current situation of the port. This is useful in mapping the general flow patterns and variations across different areas of the port waters.

Sitting - bottom ADCP: They are appropriate for long-term and fixed-point monitoring in some given places within the port, such as near some important infrastructure or areas where current behavior is complex. It can continuously record the current data at fixed positions, providing detailed information about the local characteristics of the current and changes with time.

Buoy-mounted ADCP: In cases when it is not convenient to install fixed equipment on the seabed or on ships, buoy-mounted ADCPs can be used. They float on the water surface and are capable of measuring the currents in the upper layers of the water column. Being relatively easy to deploy and allowing redeployment when necessary, they may be useful in monitoring certain dynamic or hard-to-reach areas within the port.

Selection Based on Frequency

As mentioned earlier, the selection of frequency for ADCPs will depend on the water depth at Pipavav port. In areas where the water depth is up to 70 meters, an ADCP of 600 kHz is usually the best choice as it can yield very good current measurements in this relatively shallow depth range. In waters up to about 110 meters deep, it is better to use an ADCP with a frequency of 300 kHz. In very deep parts of the port, when the depth reaches as much as 1000 meters, one should use an ADCP with a frequency of 75 kHz to ensure reliable profiling of ocean currents at such great depths.

There are several well - known ADCP 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.