ADCP's Application to Ocean Current Measurement in the Port of Rosslare

1. Where is the Port of Rosslare

The Port of Rosslare is situated in County Wexford, Ireland. It is one of the major ports on the south-east coast of Ireland and a vital link for the nation's domestic and international maritime trade.

Port Scale and Throughput

The port is of a moderate scale and has well-developed infrastructure for handling a wide range of cargo. Its annual throughput includes containers, Ro-Ro cargo such as vehicles, and bulk cargo like agricultural products and building materials. The port is being upgraded continuously to be able to meet the demands of expanding trade volumes.

It has several berths of diverse characteristics, allowing it to welcome ships of all sizes. From the small ferries that provide connections to nearby islands and the UK, to greater cargo vessels involved in international trade.

Routes Business

Rosslare port is a very important part of the Irish transportation network. It has regular ferry services to UK ports such as Fishguard and Pembroke, crucial for passenger and vehicle transport. It is connected with various European ports in the case of international trade, dealing with a wide range of import and export items.

Business operations span a broad spectrum, which includes the container terminal in the port, that handles cargo that forms part of international supply chains, Ro - Ro services in vehicle transport, that is quite substantial given Ireland's decent trade in automobiles and associated accessories, as well as supporting the local agricultural industry exporting produce and importing building materials.

Port Management and Operation

The port has a professional management team responsible for all aspects of the day-to-day running of the facility. This covers berth allocation, planning of ships' load and discharge, and the implementation of safety and security matters within the port area.

This will, on one hand, involve close collaboration with shipping companies, customs, and other services that surround and relate to the operation of the port. Management will be concerned with environmental and sustainability matters, such as waste management and reduction of emissions that result from port activities.

Facilities at the Port

It is equipped with modern port facilities. It has berths with appropriate depths for various vessels and advanced cargo-handling equipment, including cranes for handling containers and ramps for Ro-Ro operations. The port has storage areas for different types of cargo, including a container yard and warehouses for general cargo.

Facilities for refueling and light maintenance of ships can be done. Besides, for passengers, there are waiting rooms, cafes, and shops available in the terminal buildings.

Channel and Direct Navigation

The port has a well-maintained channel that allows the safe entrance and exit of ships. Regular dredging is done in the channel to ensure that ships of different drafts can enter, based on their requirement for depth. Adequate buoys, lights, and radar systems have been set up to guide ships during both arrival and departure. This makes direct navigation for vessels possible from different directions across the Irish Sea and other connected waterways.

2. Importance of Ocean Current Measurements in the Port of Rosslare

Navigation Safety

The measurement of ocean currents in the Port of Rosslare is of high importance for the safety of ships. Currents in the Irish Sea can be highly variable and strong at particular times of weather. This helps the ships to navigate with much better accuracy and thus to avoid risks such as collisions and running aground.

For instance, ferry captains have to consider the current while docking or undocking the vessel for the safety of passengers and vehicles aboard. Precise current information enables them to make accurate speed and course corrections in order to align smoothly with the berth.

Efficient Port Operations

It helps in understanding the ocean currents for the smooth functioning of the port. Understanding the current patterns aids the port authorities in better scheduling the arrival and departure of ships. The ships can avail the benefit of favorable currents, thereby saving on fuel during docking and undocking.

This also assists in optimizing the utilization of port facilities. For example, if the current is in a direction to assist the movement of ships to a particular berth, the process of loading and unloading can be speeded up, thereby making better use of the berths and other facilities.

Environmental Protection

Currents play a vital role in the dispersion of pollutants in the port area. In the event of an oil spill or other chemical release, knowledge of the current patterns is crucial for the effective containment and clean-up measures.

It can also utilize real-time data in managing wastewater and other discharges more efficiently, in order to mitigate their impacts on the marine environment. This is especially true since the port is within a sensitive coastal ecosystem.

Infrastructure Maintenance

The forces exerted by ocean currents over time can affect the structural integrity of port infrastructure such as breakwaters and quay walls. Measuring the currents provides valuable data for the long - term planning and maintenance of these structures.

For example, if the currents are consistently strong in a particular area, additional reinforcement may be needed to prevent erosion and damage to the quay walls. ADCP (Acoustic Doppler Current Profiler) provides a more advanced and convenient way to measure ocean currents compared to traditional methods.

3. Working Principle of ADCPs Using the Doppler Principle

ADCPs work on the basis of the Doppler principle. They send acoustic signals into the water. The acoustic waves scatter off the moving particles in the water, such as sediment, plankton, or other small organisms carried by the ocean current. When these waves bounce back, the frequency of the reflected waves changes.

This frequency shift, commonly known as the Doppler shift, has a direct relationship with the velocity of the moving particles and, hence, the velocity of the ocean current. Most ADCPs are equipped with multiple transducers that emit and receive these acoustic signals in different directions. By measuring the Doppler shift from multiple directions, usually in a three-dimensional or two-dimensional configuration, the ADCP current meter can calculate the speed and direction of the ocean current at different depths.

Shipborne ADCP

Shipborne ADCPs are installed on vessels. While the ship is on motion through the water, the ADCP flow meter continuously sends acoustic signals downwards and around. It records the current velocity as the ship navigates across different areas of the port.

The advantage of this method is its mobility. It enables a wide range of measurements within the port waters. Again, it is necessary to take into consideration the ship's own motion, in order to get valid results. Calibration and compensation methods correct for any erroneous movements by the ship itself.

Fixed ADCP

Fixed ADCPs are positioned at fixed points within the port, either on the bottom of the ocean or affixed to fixed structures such as piers or buoys. They constantly monitor the ocean current at that one fixed point over an extended period.

This provides long-term and consistent data for understanding the regular current patterns in a specific area of the port. The disadvantage is that they only cover a limited area around their installation location, but they are very useful for establishing reference current data for particular regions within the port.

4. Requirements for High-Quality Measurement of Currents in the Port of Rosslare

Equipment Materials

For high-quality measurement of ocean currents in the Port of Rosslare, the equipment materials should be reliable. Since seawater is corrosive and there is a possibility of impacts from floating debris, the material should be strong enough.

The equipment must resist the marine environment of the Irish Sea without degradation of performance. An excellent choice for the casing material of ADCPs is titanium alloy as it offers very good corrosion resistance in seawater.

Compact and Lightweight Design

The size of the equipment should be small to facilitate easy installation, especially in areas that have limited space such as on small buoys or in regions with complex underwater structures.

The lightweight design is also quite helpful as it simplifies the installation and maintenance process. This is quite helpful for those instruments that are deployed and retrieved very frequently.

Low Power Consumption

Low power consumption is necessary for at least a few reasons including possible long-term monitoring. Low power supply can prohibit operation over an extended period or expensive frequent replacement of batteries as sometimes the possibility of powering up machinery in the port area itself can be rare.

This holds quite true in case of fixed ADCPs as these instruments operate continuously for long duration without/with least disturbance.

Cost Effectiveness

Cost-effectiveness too plays a role. For full current measurement in the port, less costly equipment enables wider deployment so that the current situation can be closely monitored across the waters of the port.

This will be useful for a small port like Rosslare to plan its resources and arrive at an informed decision on what current measurement strategies are the best.

5. How to Choose the Right Equipment for Current Measurement

Based on Usage Purpose

Shipborne ADCP: Where the idea is to obtain current data for a wide area of the port while the ship is in operation-for example, during regular port surveys or when collecting data for navigational chart updates. Shipborne ADCPs, therefore, will be handy to cover different parts of the port as the ship moves around.

Bottom-mounted (Sitting) ADCP: In cases where the monitoring of certain points within the port has to be long-term and fixed, say near the critical infrastructure of breakwaters or at the entrance of the port channel, bottom-mounted ADCPs are suitable. They provide stable and continuous data for understanding the local current characteristics.

Buoy-mounted ADCP: For areas where it is not convenient to install fixed equipment on the seabed or on structures, or when a floating monitoring point is needed to capture surface and near-surface current conditions, buoy - mounted ADCPs are the way to go.

Based on Different Frequencies

For water depths within 70m, a 600kHz ADCP will often be a good option. It can provide a fairly high-resolution current profile in shallower areas, suitable for many parts of the port that are not extremely deep, like near the quay walls or in the inner harbor.

When the water depths reach as high as 110m, a 300kHz ADCP is more applicable since it can effectively penetrate at these depth levels and give current velocity results.

For much deeper areas, such as in the approach channel of the port, with water depths over 1000m, a 75kHz ADCP is recommended, seeing as its lower frequency makes it capable of attaining greater depths while still picking up useful current information.

Several known brands for ADCP profiler exist, such as Teledyne RDI, Nortek, and Sontek. On the other hand, the China Sonar PandaADCP is the one worth choosing by people seeking a cost-effective option with excellent quality. It uses an all-titanium alloy material that meets both durability and good performance. With this incredible cost-performance ratio, it becomes a great choice for ocean current measurement in the Port of Rosslare. You can learn more about it on its official website: https://china-sonar.com/.

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