ADCP's Application to Ocean Current Measurement in Vejle Port

1. Where is Vejle Port?

Vejle Port is located in the eastern part of Jutland, Denmark. It stands out as a multi-functional port and a key element in regional maritime infrastructure.

Port Scale and Throughput

Large-scale port with substantial cargo throughput for a variety of different cargoes. Its annual throughput comprises a large quantity of bulk cargo: coals, grains, and construction materials; it also handles a growing volume of container traffic. The strategic location and efficient operations have ensured a steady rise in the port's throughput over the years, as it acts as an important link in the supply chain for both domestic and international trade.

Routes and Business

Vejle Port is connected to an extensive network of domestic and international shipping routes. It is involved in a wide range of businesses. For example, it exports local industrial products and agricultural produce, including furniture and dairy products. Imports mainly consist of raw materials for local manufacturing and consumer goods. Additionally, it provides ferry services that connect to nearby islands and coastal regions, facilitating the transportation of passengers and vehicles.

Port Management and Operation

The port is managed by a professional team committed to the efficient running of the port. This encompasses berth allocation, coordination with shipping companies for effective vessel schedule management, right through to the actual loading and unloading process. Regular maintenance and upgrading of port facilities have been undertaken to boost productivity and safety.

Port Facilities

The port is coupled with modern facilities. There are several berths of different sizes, basically accommodating ships that range from small fishing boats to larger cargo vessels. Advanced cranes of various lifting capacities are available for the manipulation of containers and heavy bulk cargo. The warehousing facilities are well designed in terms of storing different types of goods under the right conditions.

Channel and Direct Shipping

Vejle Port has a well-maintained channel allowing ships to enter and leave smoothly. It has direct shipping connections with important ports in the Baltic Sea region and along the Danish coast. Those direct connections are of paramount importance for the success of the port and its contribution to local and regional economies.

2. Why should we measure the ocean currents in the Vejle Port?

Navigation Safety

The measurement of ocean currents in Vejle Port is important for the safety of ships. Currents can have a strong impact on a ship's navigation. Imagine a ship when it approaches the port to dock; a strong lateral current could drag it off-course. With accurate current measurements, ship captains can make precise adjustments in their approach speed and angle to minimize any risk of collision with other vessels or structures of the port.

Operational Efficiency

Knowledge of ocean currents benefits the operational efficiency in the port as well. The ships can then use this knowledge of favorable currents to schedule their entry and departure times accordingly. Through assistance provided by these currents for propulsion, the ships can reduce fuel consumption and time taken. For instance, a ship leaving the port with the help of a following current will reach its destination faster and more cost-effectively. Infrastructure Maintenance and Planning

Understanding ocean currents is key in the long-term maintenance and planning of port infrastructure. Currents, through time, erode and generally affect the stability of structures like piers and breakwaters. By monitoring, port authorities can anticipate such damage and schedule appropriate maintenance. This is also helpful in designing more resilient infrastructure. Being more sophisticated and handier, ADCP current meter refers to Acoustic Doppler Current Profiler. This method of current measurement provides detailed information on the velocity and direction of currents at different depths in real time, thereby showing in great detail the water flow conditions of the port, which is beyond the capability of the traditional methods.

3. How do ADCPs using the Doppler principle work?

ADCPs operate on the principle of Doppler. They transmit acoustic signals into the water. These signals reflect back, interacting with moving particles in water, such as suspended sediments or even small organisms that might be in the way. Due to the Doppler effect, when the acoustic waves are reflected back from such moving particles, the frequency of the reflected waves changes.

Shipborne ADCP

A shipborne ADCP installed on a vessel operates within Vejle Port. During the operation, when the ship cruises along different paths in this area, the ADCP current profiler constantly sends acoustic signals both downwards and sideways. Consequently, the movement of the ship enables the ADCP flow meter to measure ocean current velocity at different locations and depths, thus mapping water currents over a wide area during its operation.

Fixed ADCP

Fixed ADCPs are installed at discrete points in the port, such as on underwater structures near the entrance or along the quay walls. These ADCPs are fixed in one position and constantly measure the currents of the ocean. Long - term and consistent data regarding the current situation at this exact location is provided. This is important to understand how the regular patterns and variations of currents work in key areas of the port.

4. What’s needed for high - quality measurement of Vejle Port currents?

Material Reliability

The equipment used for current measurement, especially the casing of ADCP meter, should be made of reliable materials. Titanium alloy is a preferred material for the casing. Titanium alloy has excellent corrosion resistance, which is essential for withstanding the harsh marine environment. The corrosive effect of seawater can quickly damage equipment with less - resistant materials. The high strength-to-weight ratio of the titanium alloy provides strong protection to internal components of the ADCP profiler and keeps equipment relatively lightweight, consequently easy to install both on a ship or at a fixed underwater location. Also, it possesses good thermal stability, useful in marine conditions variable in temperature. In fact, very few modern oceanographic instruments are made of pure metals.

Size, Weight, and Power Consumption

The equipment has to be small in size and lightweight. The smaller and lighter an ADCP current meter, the easier it is to install; also, due to its compact size, it will interfere less with water flow during measurement. Installation would be more straightforward on either a moving vessel or from a fixed position at the port. A low power consumption rate is a must. With fixed ADCPs, low power consumption ensures that the equipment operates continuously with less frequency of battery replacement or problems in power supply. This is especially important for long-term monitoring.

Cost-Effectiveness

Cost is one of the important factors for large-scale measurement. As in, if the equipment is very costly, it will limit how many ADCPs can be deployed in a port. A cost-effective solution means more comprehensive coverage in current measurements, which helps in understanding the ocean currents throughout the port area more efficiently.

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

Based on Usage

Shipborne ADCP: Where the primary intent is to perform current measurements while the ship is in motion within the port area, shipborne ADCP shall be applicable. It can cover relatively large areas as the ship moves around the port, thus giving a wide view of current conditions over many parts of the port.

Bottom - mounted ADCP: For fixed - point monitoring of specific locations in the port, such as near critical infrastructure or areas with unique current characteristics, bottom - mounted ADCP is the right option. It remains stationary at a selected position and continuously records the current conditions there, which is valuable for understanding the long - term behavior of the currents. 

Buoy-mounted ADCP: When it's necessary to monitor the currents in some surface area or in open waters within the port, buoy-mounted ADCP can be used. It floats on the water surface and measures the currents in its vicinity, useful for getting an idea about the surface current patterns.

Based on Frequency and Depth

Different ADCP flow meter frequencies shall be selected based on the water depth. For water depth within 70m, ADCPs of 600kHz are recommended that can provide accurate current measurements in a relatively shallow area. For a depth up to 110m, 300kHz ADCPs are more suitable. And for areas where the water is much deeper with a depth of 1000m, 75kHz ADCPs shall be used.

There are well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese brand, China Sonar PandaADCP, stands out. It is made of all - titanium alloy material, ensuring high durability and reliability in the marine environment. Moreover, it offers an incredible cost - performance ratio. You can learn more about it through its official website: https://china - ​sonar.com/.

Acoustic Doppler Current Profiler (ADCP), therefore, plays an important role in the measurement of ocean currents in Vejle A. The selection of correct equipment, depending on specific needs, should be aimed at receiving accurate and useful current data to support efficient operation and management of a port.

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