ADCP's Application to Ocean Current Measurement in Port of Long Beach

1. Where is Port of Long Beach?

The Port of Long Beach is in Southern California and neighbors the city of Long Beach. It is one of the busiest and most important ports in the United States and a crucial part of the global supply chain.

Port Scale and Throughput The facility has a very large port area with extensive terminal facilities and a large number of berths. It handles very large cargo throughput, especially in containerized cargo. It is considered a major gateway for both imports and exports, as it helps in the facilitation of numerous types of goods such as electronics, apparel, furniture, and automotive parts. The port can be ranked among those that have the biggest capacities of handling containers around the world, where it processes thousands of containers per day.

Routes and Business It acts as a crucial link between Asia and the United States. There are so many shipping lines from this port to major Asian ports in China, Japan, and South Korea. The nature of business activities ranges from consumer goods, raw materials to finished industrial products. For instance, it imports a large amount of electronic components and sends agricultural products and high-tech manufactured goods.

Port Management and Operation The management of the port involves an in-depth administrative and operational setup. A managing team ensures smooth functioning and guides vessel traffic flow, handling operations of cargo, and also oversees the issues concerning security. That includes efficient berthing and unloading/loading of vessels with the help of modern technologies and well-trained staff. Stringent environmental and safety regulations are followed to preserve the surroundings and the employees working in those areas.

Port Facilities It is fully equipped with state-of-the-art facilities. It has modern container terminals with high-capacity cranes, ensuring efficient handling of containers. Furthermore, there are vast storage areas comprising a container yard and warehouses to store any kind of goods. Other services include ship repair and maintenance, bunkering, and logistics support for hassle-free cargo movement.

Channel and Direct Shipping The channels of the port are dredged to proper depth in order to receive big container ships and other vessels. It provides line hauls to many international ports directly. Its location on the Pacific coast provides a clear route to the major lanes, hence access and shipment across the Pacific Ocean can be well facilitated.

2. Why should we measure the ocean currents in the Port of Long Beach?

Measurement of ocean currents is indispensable in the Port of Long Beach for a number of reasons: firstly, regarding the safety of shipping operations, the ocean currents in the area can affect the maneuverability of ships. By accurately measuring the current patterns, the port authorities can provide better guidance to ships during entry and exit from the port. It will prevent accidents related to collisions with quay walls or other vessels in cases of strong or variable currents.

It is also good for optimizing the operations at ports. Knowing the current velocities will enable the ships to adjust their speeds and courses, hence cutting down on fuel consumption. A case in it is that ships can use a favorable current when entering or leaving a port quickly for better productivity at the port and elimination of queues in vessels.

It is also for the long-term maintenance of the port structure. Sediment deposition around the facility can also be influenced by ocean currents. With this knowledge, management could plan dredging work more effectively, along with taking other measures to ensure the integrity of the port channels and berths. The measurement of current conditions using Acoustic Doppler Current Profiler(ADCP) is more sophisticated and efficient than in previous methods.

3. How do ADCPs using the Doppler principle work?

They depend on the Doppler principle of operation. These recorders emit their acoustic signals in water. Consequently, when they reflect upon moving particles, such as the suspended sediments or small organisms in the flow of water, the frequency reflected waves shift accordingly due to the effect created by the Doppler effects.

Ship - borne ADCP In the Port of Long Beach, a ship-borne ADCP can be installed on various vessels such as survey ships or port-service vessels. During the movement of the ship, the ADCP sends acoustic pulses downwards and sideways. The frequency shifts of the reflected pulses from different depths are measured. By analyzing these frequency shifts, the speed of the ocean current at different depths can be calculated. The data collected can be used for real - time navigation or stored for further analysis.

Fixed ADCP Fixed ADCPs can be mounted on the seabed, on the side of piers, or other fixed structures. These ADCPs continuously emit and receive acoustic signals. They provide a long-term record of the current velocities and directions at a specific location. This information proves useful for understanding the local current patterns and changes over time.

4. What is required for the measurement of high-quality Port of Long Beach currents?

For high-quality, current measurement to be achieved in the Port of Long Beach, the following characteristics should be met within the equipment used. The materials of equipment should be guaranteed. For instance, the casing in ADCP preferably consists of a Titanium alloy. There is excellent corrosion resistance in this Titanium alloy which is needed in this marine environment to withstand the corrosive action of saltwater, which would mean durability or stability over time.

The size of the equipment should be small and the weight light. A small and lightweight ADCP is easy to install either on a ship or at a fixed location. It reduces the load and space that it will occupy, making it convenient to use.

The other important factor is low power consumption. Since equipment working in a port environment needs to be running all the time, with low power consumption, it will keep running for longer periods of time without requiring replacement of batteries frequently or without higher energy supply costs. The cost of the equipment also needs to be reasonable to make large-scale deployment feasible for current measurement.

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

The selection of adequate equipment for measuring current at the Port of Long Beach is done based on the intended use.

By Installation Type

• Ship - borne ADCP: If it is desired to measure the current during the movement of the ship or to perform surveys across varied areas of the port, the ship-borne ADCP may be considered as an appropriate system.
• Bottom - mounted ADCP: For long - term and fixed - point monitoring of current conditions, especially near critical port structures such as channels and berths, bottom - mounted ADCP is the better option.
• Buoy - mounted ADCP: When the focus is on the surface and upper - layer current patterns in the open water area of the port, buoy - mounted ADCP can be considered.

Based on Frequency The choice of frequency depends on the water depth. A 600 kHz ADCP will be able to work in water depths up to about 70m and can therefore be deployed in the shallower areas of the port. For water depths up to about 110m a 300 kHz ADCP will be appropriate and covers a larger part of the main port area. A 75 kHz ADCP is designed for much deeper waters, up to 1000m, and can be used in areas with significant water depth such as near the port entrance.

There are well - known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, a Chinese brand, China Sonar PandaADCP, is also worth noting. It is made of all - titanium alloy material and offers an excellent cost - performance ratio. You can find more information on its website: (https://china-sonar.com/).

Here is a table with some well known Acoustic Doppler Current Profiler(ADCP)  instrument brands and models.