ADCP in Semayang Port: Ocean Current Measurement

1. Where is Semayang port

The Semayang port is located in Indonesia. It is a key port in the region that serves various maritime activities such as cargo transportation and fishing.

Port Scale and Throughput

The port is of considerable size and has substantial throughput. It deals with various types of cargo, such as agricultural products, which are in plenty in the surrounding areas. For instance, it may handle palm oil, coffee, and spices. It also handles construction materials and general cargo. The throughput depends on factors such as the local agricultural harvest seasons and demand for construction materials in the area.

The port can accommodate a range of vessels. Medium-sized cargo ships are a common sight, along with numerous fishing boats.

Routes and Business

The Semayang port is well-connected with other local and regional ports. Domestically, the port is an important link in the carriage of goods to various parts of the country. On the business side, it exports local agricultural produce and imports machinery and consumer goods for the local community and industries.

Shipping routes are very important in the economic activities of the area. They support the movement of goods from the hinterland to the port and vice - versa.

Port Management and Operation

The port management is committed to efficient and smooth operations. The port authority manages various activities that range from vessel docking, cargo handling, and storage. They have strategies to enhance the utilization of port facilities and resources.

Safety and security are paramount. The port has established measures to respond to emergencies and protect the infrastructure and cargo from theft, among other natural calamities.

Port Facilities

Different facilities are provided at the port. The berths are made for various vessel types. It also contains cranes and forklifts, among other equipment for loading and unloading the cargo efficiently.

Storage areas are given accordingly. It contains warehouses for dry goods, cold storage for perishable items, and even the basic ship repair and maintenance facility for the local fleet.

Channels and Direct Routes

The Semayang port has well-maintained channels. Dredging operations are carried out to give the channels appropriate depth for safe navigation of ships.

The port has direct routes to other significant ports in the region. These direct routes enhance the transportation of goods and contribute to the overall trade activities of the port.

2. Importance of Measuring Ocean Currents in Semayang Port

Vessel Safety: The safety of vessels is paramount. With a mix of fishing boats and cargo ships, the understanding of ocean currents becomes relevant. Currents have an impact on the stability and navigation of ships both during docking and undocking, and while at sea. With the correct measurement of the currents, the port can give real-time information to captains, reducing the risk of accidents such as collisions and groundings.

Efficient Port Operations: Knowledge of current patterns is useful in optimizing port facilities. For instance, it helps in determining the most efficient locations for cargo handling and storage. If the currents flow in a particular direction, it might be more efficient to locate storage areas or loading docks accordingly. This can lead to more efficient loading and unloading of goods, reduced waiting times for vessels, and lower operational costs.

Environmental Considerations: The actual measurements will be useful as an environmental tool to study the dispersion of pollutants and sediments within the port area. To plan for dredging and other works in coastal engineering, such information is important in maintaining a healthy marine environment. ADCP current meter is a more sophisticated and convenient way of measuring these currents compared to the traditional methods.

3. Working Principle of ADCPs Using the Doppler Principle

ADCPs work by the principle of the Doppler effect. They send acoustic signals out into the water. These acoustic signals are reflected back by the particles in the water, and these particles are moving due to the current. Movement of the particles causes a Doppler shift in the frequency of the reflected signal.

Ship-borne ADCP: Ship-borne ADCP is installed on a vessel when it is deployed at Semayang port. The ADCP current profiler emits an acoustic pulse in either a downward or a side-looking direction while the ship moves through the water column. The reflected signals from the water column are received and analyzed. These signals are Doppler shifted, and from the magnitude of the frequency shift, the water current's velocity at various depths is obtained. This serves to profile the structure of the current as the vessel travels through the area.

Fixed ADCP: Fixed ADCPs can be installed on structures like piers or buoys. They continuously send acoustic signals always in a downward-looking direction. Then, reflected signals are analyzed for the Doppler shift. Since fixed ADCPs can monitor current continuously in a certain location, it can provide a long record of the current velocity and direction over a long period, which can be helpful in understanding the current behavior near the port entrance or other critical areas.

4. Requirements for High-Quality Current Measurement in Semayang Port

Equipment Design: The equipment should be made of reliable materials for high-quality current measurement in the Semayang port. Considering the nature of vessels operating from this port, a small-sized and lightweight design would be appropriate for easy installation on ships and fixed structures.

Power Consumption: The power consumption should be low, especially for fixed ADCPs that have to operate continuously. This ensures that the equipment can function for long periods without the need for frequent battery replacement or power source maintenance.

Cost-effectiveness: Cost-effectiveness is another important consideration, given the economic scale of the port and the number of measurement points. The equipment must be able to provide accurate results without the cost of deployment and maintenance being too high.

Corrosion Resistance: The casing of ADCP flow meter is preferably made of titanium alloy. Titanium alloy has excellent corrosion resistance, which is very important in a marine environment. Corrosion can take place in ordinary metals if exposed to saltwater in a port. Seawater can pose corroding effects, and using this alloy will mean durability in the long term of such equipment. Its high strength-to-weight ratio provides additional reduction of general device weight when considering structural integrity.

5. Selecting an Appropriate Equipment for the Measurement of Current

With Regards to Application

Ship-borne ADCP: This is suitable for when you want to measure currents during the movement of a vessel. In the Semayang port, it can be used by fishing boats and cargo ships to measure the current along their path, helping in navigation and operational decisions.

Sedimentation ADCP: it is ideal for long term and fixed point monitoring in the current near the seabed. Its use in the port is for real-time monitoring of current behavior within the port at selected locations that are near the berths or, generally, around the underwater body.

Buoy-based ADCP: This is applicable when the goals are to monitor currents within a particular area over a prolonged period and have some flexibility in the location. In the Semayang port, it can be placed in areas where ships do not frequently pass but it is important for the comprehensive understanding of the current patterns of the area.

Frequency-Based

In general, for waters up to 70m deep, an ADCP profiler with a frequency of 600kHz would be appropriate. For depths around 110m, a 300kHz frequency is more suitable. And for very deep waters up to 1000m, a 75kHz ADCP is the better option.

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

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