ADCP in Gopalpur Port: Ocean Current Measurement

1. Location and Overview of Gopalpur Port

Geographical Location

Gopalpur Port is situated in the district of Ganjam, Odisha, India. It is located on the east coast of the country, along the Bay of Bengal. This strategic coastal position provides it with access to important shipping routes and trade opportunities.

Significance of the Port

It thus happens to be one of the vital ports in the regional maritime trade. The nature of cargo handled is very diversified and includes bulk commodities of coal, iron ore, and agri-products, amongst others. It also deals in containerized cargo. The Gopalpur Port becomes a lifeline for many industries within Odisha and the neighboring states as far as importation of much-required raw material is concerned and, likewise, export of finished products is concerned.

The management of the port is highly efficient and oriented towards modernization and optimization. There are well-organized teams responsible for different functions, including vessel traffic management, cargo handling, and security. Advanced technologies such as automated cargo-handling equipment and digital communication systems are being used to enhance the productivity and smooth operation of the port.

Port Facilities

Berths

The port has several berths, which were designed for various vessel types. Some of the berths at the port include those meant for medium-sized container ships and bulk carriers. The berths are fitted with modern mooring and docking facilities to ensure the safe arrival and departure of ships. The utilization of high-quality fenders and bollards works to minimize the impact during the process of docking.

Cargo-handling Equipment

It also has conveyor systems and grabs of suitable capacity for bulk cargo handling. The conveyor systems transport the materials efficiently from the ships to the storage areas. In the case of container handling, there are gantry cranes which load and unload containers with precision and speed.

Storage Facilities

There are vast warehousing facilities for various cargo types: well-organized stockpiles with adequate drainage and dust-suppression systems for bulk commodity; container yards with effective storage and retrieval systems in the case of containers. Then there is also other general cargo and facilities to address liquid cargo, if and when required.

Channel and Navigation Aids

The depth and width of the channel of this port are maintained properly, allowing safe passage. The dredging activities are regularly performed to maintain the channel and make it usable for ships with varying drafts. Buoys, beacons, and radar systems are all part of the navigation aid to enable vessels to come and leave the port safely. The radar systems provide real - time information about the position and movement of other vessels in the vicinity of the port.

2. Importance of Measuring Ocean Currents in Gopalpur Port

Safety of Vessel Navigation

The measurement of ocean currents is important for safe navigation of ships. Knowledge of the speed and direction of the current is very important for captains of ships while approaching berths or navigating through the channel in the port. A strong cross-current near a berth can make docking an extremely difficult and dangerous task. An example is that a vessel approaching a berth against the current may need to reduce speed and alter its course to ensure a safe landing. Accurate current measurement enables captains to make the best decisions, avoiding danger from collisions and other kinds of accidents.

Optimization of Port Operations

Current data is vital for optimizing the port's operations. By understanding the tidal currents and other regular flow patterns, port authorities can schedule the arrival and departure of ships more effectively. This allows for better utilization of berths and other resources. For instance, ships can be timed to arrive during periods of favorable currents, which can speed up the loading and unloading process. Knowledge of current patterns also helps in planning cargo - handling operations more efficiently and thereby increasing productivity.

Environmental Considerations

From an environmental perspective, knowledge of ocean currents is important for the eventuality of an accidental spill of pollutants. Due to the nature of the cargo handled in the port - such as petroleum products or chemicals - it is relevant to predict the spread of a spill. The current data can be used to implement containment and mitigation measures rapidly to minimize environmental damage.

3. Working Principle of ADCPs (Acoustic Doppler Current Profiler)

Principle of Doppler

ADCPs work on the principle of the Doppler effect. When an acoustic signal is transmitted by the ADCP meter into the water, it scatters off the moving water particles. Since the water particles are moving due to the ocean current, they shift the frequency of the reflected acoustic signal received back by the ADCP profiler. By the Doppler effect, this frequency shift is proportional to the velocity of the flow.

Current Speed and Direction Calculation 

The magnitude and direction of this Doppler shift are used by the ADCP current profiler to derive the current speed and direction at various points within the water column. Due to the fact that signals can be transmitted at different angles and at multiple levels in the water column, the ADCP current meter is able to profile the ocean current to show how the current changes with depth.

ADCPs Deployed within the Port

Shipborne ADCP

One ADCP profiler is installed on ships operating in the Gopalpur Port area. As the ship moves around the port, the ADCP flow meter continuously sends acoustic signals into the water below. The movement of the ship enables the ADCP current profiler to cover a wide area and collect current data from different locations. For instance, it can be used during the normal survey of the port by a research or inspection ship equipped with a shipborne ADCP to collect data regarding the current patterns across multiple parts of the port to provide a full understanding of the water flow situation.

Fixed ADCP

Fixed ADCPs are installed in stationary positions within the port, 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 data collected is useful for analyzing the regular current patterns in specific areas of the port. For example, one bottom-mounted ADCP installed near the entrance can measure the ingoing and outgoing currents, which give valuable information about the tidal effects and other steady flow features in that area.

4. Requirements for High - Quality Measurement of Currents in Gopalpur Port

Equipment Requirements

Material Reliability

The equipment has to be capable of withstanding the harsh marine environment for high-quality measurement. Seawater contains salts and other chemicals that can cause corrosion over time. The equipment also needs to endure pressure changes at different water depths and mechanical forces caused by waves and currents. Therefore, the materials used in the construction of current-measuring equipment should have high resistance to corrosion and mechanical stress.

Size, Weight, and Power Consumption Smaller size, lighter weight, and lower power consumption are preferred. With a compact size, it will be relatively easy to install anywhere around the port, whether on the ships, fixed structures such as piers, or even underwater. A lighter weight would reduce the complexity of installation and transportation. Consuming less power, on the other hand, makes the device run continuously for extended hours without replacing batteries frequently, which may be necessary in long-term monitoring applications.

Cost-effectiveness

Cost is another critical aspect. With a lower price, it will be much easier for the port to deploy a greater number of measuring devices for an extensive current monitoring at every different area in the port.

The Advantage of Titanium Alloy for ADCP Casing

In most ADCPs, the casing is made of titanium alloy. The use of such an alloy allows for superior corrosion resistance, ensuring that its structural integrity and functionality remain uncompromised even in seawater over a prolonged period. Its high strength-to-weight ratio enables a durable yet relatively lightweight casing. For example, at the deeper parts of Gopalpur port, where the water pressures are higher, an Acoustic Doppler Current Profiler (ADCP) with a casing made from a titanium alloy can resist these pressures without loss of its performance to measure currents with the required accuracy.

5. Selection of Equipment for Current Measurement

Based on Application

Shipborne ADCP

If the aim is to conduct wide-area surveys of the port waters while the ship is in operation, then a shipborne ADCP is suitable. It can cover different sections of the port as the ship moves around, collecting a large amount of data to provide a comprehensive understanding of the overall current situation in the port. This will be useful to delineate the general patterns and variations in flow within the different regions of the port waters.

Bottom ADCP sitting

In cases where there is a need for long-term and fixed-point monitoring of certain locations within the port, especially near important infrastructure or where complex current behaviors are found, bottom-sitting ADCPs are more appropriate. 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

They may be used in situations when it is inconvenient to install fixed equipment on either the seabed or the ships themselves. Buoy-mounted ADCPs float in the water and are capable of measuring the currents in the upper layers of the water column. Relatively simple to deploy and to redeploy in case of necessity, they can service some areas with dynamic conditions, which would be hard or impossible to reach otherwise.

Selection Based on Frequency

ADCPs will be selected based on the frequency of water depth in Gopalpur port. An ADCP current meter frequency of 600 kHz would normally be a good choice for an area like Gopalpur port with water depth up to 70 meters, because it can give fairly accurate current measurements in this relatively shallow depth range. When dealing with deeper waters up to around 110 meters, an ADCP with a frequency of 300 kHz is more advisable. And for extremely deep sections of the port with a water depth reaching up to 1000 meters, an ADCP with a frequency of 75 kHz is recommended to ensure reliable profiling of the 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.