ADCP for Ocean Current Measurement at Port Rossaveal

1. Location of Port Rossaveal

Port Rossaveal is on Ireland's west coast. For the most part, this is a major port with several ferry services and fisheries in that area.

Scale and Throughput of the Port

The scale of the port is moderately sized. Its throughput is significant in terms of passenger and vehicle transport via ferry services to the Aran Islands and other destinations. In addition to ferry traffic, it also handles a considerable amount of fishing - related activities. The fishing vessels based here contribute to a steady flow of fish catches and associated cargo. The port's operations are of significant relevance in the local economy, serving both tourism and the fishing industry.

Routes and Business

Rossaveal port is well-connected through ferry routes to the Aran Islands, which is a major tourist attraction. These ferry services form a vital part of its business, facilitating the movement of people and vehicles. For fishing purposes, it is connected with other fishing ports, through which it trades equipment and supplies for fishing as well as transportation of catches. It also provides ancillary services for the fleet, like boat repair and maintenance.

Port Management and Operation

The port management focuses on the efficient running of ferry services and fishing operations. Berthing arrangements are carefully coordinated in order to ensure smooth docking of both ferries and fishing vessels. Safety regulations are very strict, especially considering the large number of passengers using the ferry services. For fishing activities, there are measures in place for handling the catches hygienically and ensuring the safety of the fishermen.

Port Facilities

These complement facilities matching dual-purpose operations of the port, with berths designed for large ferries and fishing boats, waiting areas for passengers, a ticket office, and even areas for loading and unloading vehicles onto the ferries. For fishing, facilities have a place for handling fish, storages for fishing gear, and cold storage for fresh catches. The port also has equipment to assist in cargo loading and unloading, like cranes and forklifts.

Channel and Direct Shipping

The channel of the port is maintained for safe passage of vessels. Regular dredging is carried out to provide depth necessary for ferries and fishing boats. It enjoys direct shipping connections by its ferry services to the Aran Islands and other coastal ports for fishing-related trade.

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

It is important to measure ocean currents in the Port of Rossaveal for several reasons: this is crucial for safe vessel navigation. The ferry services, carrying a large number of passengers and vehicles, have to navigate safely in and out of the port. Currents can affect the maneuverability of the ferries especially during docking and undocking. The same goes with fishing vessels, as their ultimate hope is to sail back home safely with all their catch. Accurate current measures can further help in giving better navigation aid that will reduce the chances of disasters.

Current measurements are also important for efficient port operations. Currents can affect the speed and accuracy of loading and unloading operations. For instance, when a ferry or fishing boat is being brought into a dock, a strong current may make it hard to place the vessel in the correct position. With accurate current data, the port can optimize these operations, reduce waiting times, and make the best use of its berthing facilities.

Finally, from an environmental point of view, knowledge of the ocean currents is relevant to the management of any potential pollution incidents. Currents will determine the spread of pollutants, such as oil spills or other hazardous materials. By measuring the currents, the port can take proactive measures to minimize the environmental impact and protect the local marine ecosystem. Acoustic Doppler Current Profiler (ADCP) provides a more advanced and convenient way to measure these currents compared to traditional methods.

3. How do ADCPs using the Doppler principle work?

The principle of operation for ADCPs is based on the Doppler principle. They send out acoustic signals into the water. These signals interact with moving particles in the water, such as suspended sediments or small organisms. The acoustic signals reflected back to the ADCP current meter suffer a frequency shift owing to the Doppler effect. This frequency shift is measured by the ADCP current profiler and gives the velocity of the water particles, which, in turn, provides the velocity of the ocean current.

Ship-borne ADCP

On this platform, ship-borne ADCPs can be installed on the ferries or fishing boats. In this vessel, as it travels through exercises around the port and adjacent waters, the ADCP flow meter sends pulses of sound in various directions usually downward and sideways. With every vessel movement, this measures current velocity at several depths; hence, a very elaborate profile of the current condition is mapped out along that arc over which the vessel has gone.

Fixed ADCP

Fixed ADCPs can be installed at selected locations in the port, like on the seabed near the berths or at the entrance of the channel. These ADCPs continuously observe the current at a single point over an extended period. The data collected over time is necessary to understand the long-term current characteristics in key areas of the port, for example, the entrance of the channel or near the berths.

4.What is required for high-quality measurement of Rossaveal port currents?

For high-quality measurement of the ocean currents in the Port of Rossaveal, the equipment should be manufactured from reliable materials. Since seawater is corrosive and there is a chance of physical damage from the marine environment, the device should be able to bear these situations. Small size, light weight, and low power consumption are also favorable. A compact and lightweight ADCP is easier to install and operate, whether on a boat or at a fixed location. Low power consumption allows for continuous operation without frequent battery replacement or high energy demands. Cost-effectiveness is also a key factor to enable wide-scale deployment in the port.

ADCP profiler is preferably housed in casing made from a titanium alloy. In this regard, titanium alloy provides excellent corrosion resistance in sea water, which ensures that it protects the device for years without much hassle. It has an exceptionally high strength-to-weight ratio; it may be strong and durable enough to serve its purpose and can keep its weight rather low. Besides, this will result in a reduced environmental impact due to the biocompatibility of the titanium alloy.

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

The choice of the right equipment for current measurement in the Port of Rossaveal depends on the particular requirements.

Ship-borne ADCP

This is adequate for a wide-ranging view of the prevailing conditions around the port. By the vessel sailing in various areas around the port, the ship-borne ADCP can obtain information over an extensive coverage to give an overall wide-range representation of the current systems within the waters of the port.

Bottom-mounted (Sitting on the seabed) ADCP

This type of ADCP meter is ideal for long-term fixed-point monitoring. It can be installed at strategic points in the port, for instance, at the entrance of the channel or near the berths to continuously monitor the current condition in those specific areas.

Buoy-mounted ADCP

Buoy-mounted ADCPs provide valuable current information in situations where the installation of fixed bottom-mounted or boat-mounted units is not practical. They may be deployed in open water areas inside the port to measure currents at a series of depths.

Regarding frequency selection, different frequencies are applicable for different water depths: a 600 kHz ADCP is suitable for water depths up to 70 meters, a 300 kHz ADCP for depths up to 110 meters, and a 75 kHz ADCP for much deeper waters up to 1000 meters.

There are well-known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, there is also a Chinese ADCP brand, China Sonar PandaADCP. It is made of all-titanium alloy material, which ensures its durability in the marine environment 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 ADCP instrument brands and models.