Application of ADCP to Ocean Current Measurement in Mariveles Port

1. Where is Mariveles Port?

Mariveles Port is located within the municipality of Mariveles in the province of Bataan, Philippines. It is a strategic port in the region, whose location accesses the important shipping lanes and trade routes.

Port Scale and Throughput

Large scale and throughput. It is a major facility for various types of cargo: bulk cargo, including coal and grains to containerized goods. Because of the strategic location near industrial areas and a transportation network, the volume is high. The annual throughput is very large, with the number growing every year along with the rising number of ships coming into port to load and discharge cargoes. It has played an important role in the local and regional economy, in that it contributes to transporting raw materials to industries and finished products to various areas of distribution.

Routes and Business

Mariveles Port has easy access to various domestic and international shipping routes. Domestically, these connect it to other major ports within the Philippines for efficient movement of goods across the archipelago. It has international trade links with countries in Asia and other regions. The major businesses found in the port include shipping companies dealing in container and bulk cargo movement, stevedoring services for loading and unloading activities, and warehousing for storage of goods. It also supports industries such as power generation, by handling fuel imports, and manufacturing, by providing raw materials.

Port Management and Operation

The port is managed by a team comprising port authorities and other connected organizations. Their role at the port involves the smooth movement of vessel traffic, quick berthing arrangements, and total adherence to safety and security. They provide overall supervision of cargo handling to meet high standards of efficiency and quality. Besides this, infrastructural development and maintenance works are under way to keep the port on par with others and prepare it to handle growing trade volumes.

Facilities at Port

It is a modern facility with several berths of variable size that can handle anything from medium-sized cargo ships to large bulk carriers. The port has vast areas for storage that include container yards and warehouses for different types of goods. Besides, it also includes specialized facilities in handling hazardous and bulk materials, such as coal-handling equipment and liquid storage tanks. Loading and unloading equipment, such as cranes and conveyor belts, are available to guarantee the orderly and efficient transfer of cargo to and from ships and onto and from onshore storage facilities.

Channel and Direct Navigation

The channel of Mariveles Port has proper dredging, enabling the safe navigation of ships through the area. Tides and vessel sizes are factored in for regular dredging at the channel area. It has a set of navigational aids such as buoys, beacons, and radar systems. The aids enable the mariners to head directly and safely into the port without possible hazards such as shallow areas or underwater obstacles.

2. Why do we need to measure ocean currents in Mariveles port?

Optimizing Vessel Operations

Measuring currents is crucial to optimize vessel operations in the waterway of Mariveles Port. Current direction and speed knowledge will be useful in exact berthing and mooring. Understanding such currents will also enable the operators to position vessels in suitable dockings during operations without leading to possible collisions of vessels and damage to either vessels or port infrastructures. By doing so, ships could also utilize this advantageous current in their favor and save on fuel, wasting less time during entries and exits in the port.

Support for Trade and Logistics

Accurate current measurements are essential within the context of efficient trade and logistics. Currents are capable of delaying shipping schedules. Current information, if updated, will help the shipping company to plan their arrival and departure more systematically so as to assure timely deliveries and thus avoid the cost of demurrage. This becomes all the more important since a wide range of time-sensitive cargo such as perishable goods and industrial supplies is moved through the port.

Infrastructure Maintenance and Planning

From an infrastructural viewpoint, the measurements today contribute much to the maintenance and development of port structures for the future. Hydro-dynamic forces of currents can have their devastating effects on the stability and durability of quay walls and piers over time. By contrast, it would also allow port authorities to design infrastructure for better resistance and to schedule preventive activities to extend its lifetime.

Environmental Considerations

Measuring ocean currents is also important from an environmental protection point of view. Currents act to disperse pollutants within the waters of the port. Knowledge of the patterns of current flow in the event of a discharge of oil or other contaminant assists in implementing effective containment and cleanup. It also serves to assist in monitoring the impact of port activities on the surrounding marine ecosystem and in formulating sustainable development plans.

The Acoustic Doppler Current Profiler (ADCP) is a more sophisticated, more convenient method of measuring ocean currents than traditional methods. It can deliver, in real time and in detail, information on the profile of the current and hence offer better accuracy and efficiency in monitoring ocean currents around the port area.

3. How Do Doppler Principle ADCPs Work?

Working of ADCPs is based on the Doppler principle. Transducers installed in the water emit acoustic signals. Acoustic waves, while entering the water, get scattered due to the moving particles present in water because of the suspended sediments or small organisms. The reflected waves from the moving particles change the frequency because of the Doppler effect.

It measures the frequency shift of the reflected signals from an ADCP meter. By subjecting these signals to appropriate algorithms and calibration, the device derives the velocity of the moving particles. In turn, as these moving particles are principally the components of the ocean current, this sensor can determine the speed of the ocean current.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are fitted in vessels operating in the area of the port. While the ship is in motion, the ADCP current profiler sends acoustic pulses continuously in several directions, usually downwards and sideways. It measures the current velocities at different depths along the path of the ship. Data collected during the movement of the ship can be combined to give a detailed mapping of the current field in the port area, hence a good understanding of the current patterns during the voyage of the ship.

Fixed ADCP

Fixed ADCPs are deployed at specific locations in the port, either on the seabed or fixed to fixed structures such as piers or breakwaters. These ADCPs continuously monitor the ocean currents at that particular location over time. The data obtained from fixed ADCPs is valuable for understanding the long - term and consistent current conditions at key points in the port. This can then be used as a reference for port operations, research, and infrastructure planning.

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

Equipment Requirements

For high-quality measurement of the ocean currents in Mariveles Port, the equipment needs to have reliable materials. It must be able to withstand the harsh marine environment, including the corrosive effects of seawater, high pressures at different water depths, and potential impacts from floating debris.

Other important aspects are the size and weight of the equipment; the smaller the size, the lighter the weight is, and hence it would be better, especially in vessels or space-limited areas of fixed structures. This allows more flexibility in the placement of the equipment.

Another important factor is the power consumption. A low-power consuming device is desirable for the reason that it can be operated for longer hours without frequent battery replacements or excessive energy supply. This will be very important for the fixed ADCPs, in which access to a continuous power source may not be so easy.

Titanium Alloy Casing Advantage

ADCPs with casing made from titanium alloy are the best options. It has very good resistance to the corrosion caused by seawater; therefore, it can put up with such conditions over a long period of time. This will result in the protection of integrity and performance of the ADCP profiler. It has a very high strength-to-weight ratio: this means it can realize a durable but light design at the same time. And this is useful both at installation and operation. Besides, titanium alloy withstands high pressures at greater depths, making it suitable for use in different water depth conditions in the port area.

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

Based on Usage

Shipborne ADCP: If the purpose involves a broader understanding of current patterns in the port while vessels are in motion, then shipborne ADCP will be quite appropriate; it can cover enlarged areas of the port when the ship is sailing, thus giving an extensive current situation.

Bottom mounted ADCP: It would be more applicable to relatively long-term continuous monitoring at fixed locations where changes in current condition are critical, near fundamental structures and vital areas where the characteristics of currents should be of particular interest for reference or research and operational considerations. They are also suitable because they can provide stable information with continuity for an extended period of time.

Buoy-mounted ADCP: Where these currents have to be measured at locations inaccessible by fixed installations or by ships carrying out operations, buoy-mounted ADCPs could be employed. Drifting with currents to some extent while collecting data, many varieties of these types of ADCPs are in use for studies over the variations in currents in those regions.

Based on Frequency

Water depth within 70 meters, a frequency of 600 kHz is generally good to go for an ADCP current profiler. It provides high-resolution and very accurate current measurements in the relatively shallow parts of the port.

For water as deep as up to 110 meters, one would want a 300 kHz ADCP since such a frequency would penetrate through to that depth range effectively, where reliable current data is obtained.

The depths can be as large as 1000 meters or even more, with quite adequate coverage using a 75 kHz frequency ADCP, and yet the ocean currents are well measured within acceptable accuracy.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, it's worth mentioning a cost-effective Chinese ADCP brand-China Sonar PandaADCP. It is made of all-titanium alloy material and offers an impressive price-performance ratio. You can visit its website at (https://china-sonar.com/) for more information.

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