Application of ADCP to Ocean Current Measurement in Manila Port

1. Where is Manila Port?

Manila Port is located in the capital city of the Philippines, Manila. It is a major international and domestic maritime hub in Southeast Asia.

Port Scale and Throughput

Manila Port is one of the biggest in the country. It has an extensive scale with a high throughput that handles a wide variety of cargo. The port deals in several millions of tons cargo annually, from containers of consumer goods and industrial raw materials of steel, chemicals, and agricultural products like rice and fruits, to great bulk cargo like coal and petroleum products. The container terminals of the port are capable of handling huge amounts of TEUs, or Twenty - foot Equivalent Units, thus serving the purpose of international trade with almost any country around the world.

Routes and Business

It is an important link in the shipping routes of the world. It has links with major ports in Asia, Europe, the Americas, and Oceania. Domestically, it serves as a redistributive hub with the integrated system of feeder routes crisscrossing the various regions in the Philippines. The firms involved in the port operation are varied and cover an enormous range of activities: shipping lines dealing in containers, stevedoring companies concerned with loading and unloading cargo, and freight forwarders arranging the transport of merchandise. The port also supports a thriving trade in cars, electronics, and other high-value items.

Port Management and Operation

The management of the facility is controlled by a highly involved multi-level system with several layers of port authority and governing bodies. This body operates several aspects of running the ports. They are also responsible for vessel traffic management to maintain order in ship arrivals and departures in and out of the ports. Berthing arrangements are carefully drawn in order to make maximum utilization of the extended quay space. Cargo handling in the port is efficiently handled and safety and security procedures strictly followed. The port invests in modern technologies and infrastructures that raise its overall performance and competitiveness.

Facilities

The facilities of Manila Port are modern. It means it is also equipped with various container terminals with modern gantry cranes and other handling gear that move containers in and out rapidly. Besides this, the special terminals for bulk cargo, liquid cargo (oil and chemical carriers), and Ro-Ro cargo are assigned to carrying vehicles. The port has vast storage facilities in the form of container yards and warehouses. It also has facilities for the maintenance and repair of ships, alongside bunkering stations for fuel supply and other ancillary services like fresh water supply and garbage disposal.

Channel and Direct Navigation

The port has a well-maintained deep-water channel allowing big vessels to navigate through safely. The channel is dredged regularly to maintain the draft necessary for modern container ships and other large-capacity vessels. The channel is also fully endowed with a set of navigational aids, including buoys, beacons, and radar systems. These aids enable the mariners to navigate correctly through the channel, even under adverse weather and tidal conditions, directly into the various terminals of the port.

2. Why should we measure the ocean currents in the Manila port?

Improved Vessel Operations

Ocean currents in the Manila Port have to be measured for improving the operation of vessels. To berth and moor precisely, knowledge of direction and speed of the current is critical. By understanding the currents, port operators are able to guide the ships to their berths with more assurance and minimal possibility of collision, hence keeping the vessels and port infrastructures safe. This enables the ships to take advantage of the favorable currents during entry and exit, hence large savings in fuel and also saving on the time taken during transit.

Efficient Trade and Logistics

For the efficient flow of trade and logistics, accurate current measurements are vital. Currents can impact the scheduling of ship arrivals and departures. Shipping companies can plan their voyages more effectively, taking into account the current conditions to ensure timely deliveries and avoid demurrage charges. Additionally, understanding the currents helps in predicting any potential disruptions in the transportation of goods, allowing for better supply chain management and reducing the impact of delays on businesses.

Infrastructure Protection and Planning

From the infrastructure point of view, current measurements give relevant data at present for maintenance and future planning of port structures. Hydrodynamic forces caused by currents may have impacts on the stability and durability of quay walls, piers, and other port facilities with time. With proper current data, port authorities are able to design more robust infrastructure and plan preventive maintenance activities to extend the life span of the structures and guarantee continuity in their operation.

Environmental Considerations

In the modern context of growing ecological concern, the measurement of currents is important from the point of view of environmental protection. Currents are a substantial factor in the distribution of contaminants within the waters of the port. In cases of oil or other spills, knowledge of current patterns aids in the adoption of effective containment and cleaning strategies. It also assists in monitoring the impact of port activities on the surrounding marine ecosystem and in formulating sustainable development plans.

The Acoustic Doppler Current Profiler (ADCP) allows the ocean current measurement to be done relatively in a more modern and much more handy way than was used in older, more traditional approaches. It has the ability to provide real-time, high-resolution current profile information that allows the monitoring of ocean currents at the port area more precisely and efficiently.

3. How do the ADCPs using the principle of Doppler work?

ADCPs rely on the principle of the Doppler effect. They transmit acoustic signals into the water. The acoustic waves interact with the moving particles in the water, such as suspended sediments or small organisms, by interacting with them. The frequency of the reflected waves, due to the Doppler effect, changes as acoustic waves encounter these moving particles.

It measures the frequency shift in the reflected signals. Depending on a series of algorithmic interpretations and calibration, this device then calculates the speed of moving particles. Since these are moved, for the large part, by the ocean current itself, this enables the ADCP meter to find its velocity of the current.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs were mounted in vessels operating at the port area. The ADCP current meter continuously sends out acoustic pulses in different directions, usually downwards and sideways, while the ship is moving. It measures the current velocities at different depths along the path of the ship. Data collected during the movement of the ship can be used to create a comprehensive map of the current field in the port area, providing detailed information on the current patterns during the voyage of the ship.

Fixed ADCP

Fixed ADCPs are installed at fixed locations in the port, for instance, on the seabed or attached to fixed structures such as piers or breakwaters. These ADCPs will continuously monitor the ocean currents at that particular location over time. Data from fixed ADCPs is of importance to understand the long-term and consistent current conditions at key points in the port. This can serve as reference data for port operations, studies, and infrastructure planning.

4. What does it take to make high-quality measurements of currents in the Manila port?

Material and Design Requirements of the Equipment

Accurate measurement of the ocean current in Manila Port requires a specific quality of equipment. These have to be made from durable material that will be able to withstand the unforgiving marine environment: the corrosion brought about by seawater, pressure that also fluctuates with depth, and any impact from floating debris, for instance.

Besides that, the small size and light weight are preferable in several respects. This can easily be installed on vessels or fixed structures in the port due to space limitation in some areas. The low power consumption will help operate the ADCPs longer, since changing the battery may not be as frequently possible, nor energy supply in huge amounts be always possible; this is much true in the case of fixed ADCPs where continuous feeding through electricity might not be practical or feasible.

Advantages of Titanium Alloy Casing

ADOPs with casing made from titanium alloy are highly recommended. The material of the titanium alloy has several outstanding advantages. First, it has excellent corrosion resistance that allows the ADCP profiler to resist the corrosive nature of seawater for a long period, enabling it to maintain its performance and accuracy. It also has a favorable strength-to-weight ratio that allows for a durable yet lightweight design. Moreover, it is resistant to high pressures at greater depths, which is quite useful for its application in various water depth conditions of the port area.

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

Based on Usage

Shipborne ADCP: Where the overview of the current patterns across different areas of the port during vessel movements is to be attained, shipborne ADCP would be appropriate. It will cover a wide area given the ship navigating around the port and provides quite useful data for the overall analysis of the current situation.

Bottom-mounted (Sitting on the seabed) ADCP: In cases requiring the monitoring of the current condition over a long period of time uninterruptedly at certain fixed locations, such as near main port structures, or if one needs data of a continued current, either for research purposes or for operational reference, bottom-mounted ADCPs are more fitting, and they can give much stabler and consistent data over a longer period of time.

Buoy-mounted ADCP: When the currents have to be measured in areas inaccessible for fixed installations or even ship operations, buoy-mounted ADCPs are applied. These ADCPs while gathering the data can drift with the currents to some extent and hence provide information on the current variations in those areas.

Based on Frequency

 600 kHz is normally a good choice for water depths within 70 meters and can give detailed and accurate current measurements in relatively shallow areas of the port.

For water up to 110 meters deep, a 300 kHz ADCP is more appropriate since it can effectively penetrate the water column to obtain reliable current data at those depths.

For deeper areas, with water depths up to 1000 meters, the 75 kHz frequency should be used because it is capable of covering such a large depth range and still measure the ocean currents with acceptable accuracy.

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

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