ADCP's Application to Ocean Current Measurement in Stavanger Port

1. Where is Stavanger Port?

Stavanger Port is situated in the city of Stavanger on the southwestern coast of Norway, facing the North Sea. The port constitutes a vital passage in both domestic and international shipping. The city is strategically placed in relation to major shipping lanes and close to the rich oil and gas fields of the North Sea, contributing to the development and importance of the port.

Port Scale and Throughput

The Port of Stavanger is one of the largest and busiest in Norway; it boasts a quite high annual throughput in handling a wide range of cargo, including general cargo such as consumer goods, industrial products, and construction materials. Considering that Norway has the largest oil and gas industry, the port also plays an important role in the handling of oil-related products, equipment for the offshore oil and gas platforms, and bulk commodities such as grains and minerals. It annually handles a high volume of vessels, from small-scale fishing boats to giant oil tankers and container ships.

Routes and Business

The port has an extensive network of ferry routes. There are regular ferry connections with other major Norwegian cities such as Bergen and Kristiansand, which allow for passenger traffic and the transportation of cars and cargo. Besides, Stavanger Port has international ferry routes from its ports to Denmark, Sweden, and the UK. From a shipping perspective, the port is an important center for container shipping lines, with vessels traveling to various parts of the world. Moreover, the port forms a base from which the off-shore supply industry is regulated, including a logistical supply role and point of departure for offshore platforms for manpower and equipment alike.

Inset: Management and Operation

Stavanger Port is competently managed in a very correct and safe environment by the appropriate port authorities themselves. Management itself is responsible for the maintenance in the port pertaining to berthing, quays, and any storage facilities pertaining to it. They ensure that international shipping regulations, safety standards, and environmental protection measures are complied with. The port authorities are in close contact with shipping companies, oil and gas operators, freight forwarders, and other players for the optimization of operations, reduction of vessel turnaround times, and enhancement of the overall competitiveness of the port.

Port Facilities

Stavanger Port features modern and well-maintained facilities. It has several berths of varying lengths and draft capabilities to handle different vessel types. The port is also equipped with modern cargo-handling equipment, including large-capacity cranes, forklifts, and conveyor systems that ensure goods handling is very efficient. In addition, there is an extended storage facility in the form of warehouses for general cargo, temperature-controlled storage houses for perishable goods, and open-air storages for bulk commodities and oversized equipment.

Waterways and Direct Navigation

The waterways to Stavanger Port are well-maintained and dredged on a regular basis to ensure safe passage for vessels. The port has direct navigation links to major ports in Europe and around the world, making it a crucial node in the global shipping network. The entrance channels are well-marked, and navigational aids such as buoys and lighthouses are in place to assist vessels, especially during adverse weather conditions or at night.

2. Why is it important for us to measure the ocean currents in Stavanger Port?

Navigation Safety

Precise knowledge of the ocean currents at Stavanger Port is an important aspect in safe navigation. The complicated coastline and features of the North Sea create variable conditions of currents. These could highly influence the speed and course of vessels, especially during berthing, unberthing, and navigation along channels of the port. Such a measurement would help captains to make informed decisions to alter their course so as to avoid any probable collision or grounding.

Optimizing Port Operations

Ocean current data is important in optimizing port operations. In berthing or unberthing vessels, the direction and strength of the current must be put into consideration. A strong current will make these operations a bit more challenging and time-consuming. Current measurements allow port operators to plan the most favorable times for vessel maneuvers, better allocate resources, and optimize the efficiency of the cargo handling operations altogether. Currents also have a bearing on the movement of floating cranes and other port-related equipment; in fact, comprehension of the said factors does boost operational safety and productivity.

Environmental Protection

Measurement of the ocean currents helps in the protection of the environment in the port area. Currents are a very significant media for the dispersive process of pollutants. In situations involving an oil spill or other hazardous substances, knowledge about the current pattern allows environmental managers to forecast pollutant spread. This enables them to take timely preventive and cleaning measures that minimize damage to the sensitive North Sea and surrounding coastal area ecosystem.

Therefore, this present measurement being so critical, ADCP or Acoustic Doppler Current Profiler has become one of the most efficient tools that are used in measuring currents of the ocean and more specifically in the Stavanger Port. These also provide very high-precision and real-time data.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

ADCPs operate based on the Doppler effect. When an ADCP profiler transmits an acoustic signal into the water column, the sound waves encounter suspended particles in the water, such as sediment, plankton, or small organisms. As these particles move with the water current, the frequency of the sound waves reflected back to the ADCP is different from the original transmitted frequency. The ADCP measures this frequency shift, known as the Doppler shift. Using the Doppler equation, the instrument calculates the current water velocity at various levels within the water column.

Particular Techniques of Currents Measurement in a Port

• Ship-borne ADCP: A ship-borne ADCP is mounted on a vessel in motion. During the movement of this vessel through the waters off Stavanger Port, for example, the ADCP meter will measure current velocities at several depths along the route traveled by the ship. This method is very useful for a broad-scale view of the conditions in the port. For example, it will be able to map out in general the pattern of currents within different parts of the port, which is a very useful function for large-scale navigation planning and for understanding overall flow characteristics of the water in the North Sea near the port.
• Fixed ADCP: These are installed in fixed locations within the port, such as on the seabed or on fixed structures like piers or buoys. Such ADCPs can continuously monitor the current condition at a point for a long period. That will be helpful to understand the long-term trends and local variations of the currents, for example, near the berths, in narrow channels, or at critical navigation points in Stavanger Port.

4. What's needed for high-quality measurement of Stavanger Port currents?

Equipment Reliability

The ADCP flow meter has provided very reliable equipment for current measurement of high quality in Stavanger Port. Because of the salty seawater, strong winds, waves, and fluctuating temperatures around the North Sea, the ADCP is supposed to resist these factors without frequent breakdowns. Reliable equipment provides consistent data collection that is imperative for accurate analysis and decision-making.

Size, Weight, and Power Consumption

First of all, an ADCP current profiler is desired to be compact and not too heavy in weight.

That would mean lesser hassle to mount, particularly under circumstances of constricted spaces for mounting in a small-size fishing vessel or smaller, closed ports. And this means using it for extended lengths of time-which indeed must be applied especially for the fixed-mounted current meter types with electric supply obtained by batteries or even solar. In Stavanger Port, where continuous measurement is often a requirement, an ADCP capable of low-power consumption can execute its operation with minimal need to recharge or substitute power sources regularly.

Cost-effectiveness

This would be able to realize large-scale measurement in the port area at a reasonable cost for the ADCP. The cost-efficient ADCP will enable multiple units to be deployed if necessary, for comprehensive current data to be obtained from different parts of the port area. This is important in acquiring a full picture of current conditions at Stavanger Port, information of great use in various applications such as in navigation safety to environmental protection.

Material Selection

The casing of the ADCP current meter should be fabricated from titanium alloy. Titanium alloy is highly resistant to corrosion and thus appropriate for long-term exposure in the saline conditions of the sea at Stavanger Port. It would not be subject to the corrosion of saltwater over a long period, so it would guarantee the durability of the ADCP. Besides, titanium alloy has strength and is lightweight, so it satisfies both structural strength and ease of installation.

5. How to Choose Appropriate Equipment to Measure Currents?

Depending on the Use

• Ship-borne ADCP : It acts as a special tool for undertaking large-scale surveillance of the entire port area. When a quick assessment of flow conditions is taken over an open area by ship, then there is no suitable alternative other than the ship borne ADCP version. It could be placed at Stavanger Port and serve vessels with higher draughts, like container ships or oil tankers, and collect data while in transit through the port and deliver current conditions along their route paths in real time.
• Sit-on-bottom ADCP: This type is used for long - term monitoring of specific locations in the port. For example, at the entrance of the port, in a channel where the current may be critical for navigation, or close to a berth where the current is important for vessel berthing operations, a sit-on-bottom ADCP can be placed on the seabed and record current data continuously.
• Buoy-mounted ADCP: useful where water surface data is wanted. It will be also applied if fixed bottom mounting is not possible. In general, there can be locations that may include conditions with possibly very strong tidal currents or unfavorable bottom conditions around the North Sea, off the coast of Stavanger. Under such conditions, the buoy-mounted type of ADCP will be launched.

It can drift with the current and hence yield information about surface-layer currents.

Depending on Frequency

With water depth up to 70m, it is recommended to use an ADCP operating at a frequency of 600kHz. Many places in Stavanger Port are within this range, including shores and parts of inner-port channels. Such an ADCP device would, therefore, give highly resolved data from these shallow water areas for high-resolution current analyses.

A 300kHz ADCP is generally appropriate for water depths up to 110m. It may be used for areas with moderate depth in the port, as some of the main shipping channels have a reasonable depth that would not be classified as very deep but require precise current measurement. - In case of deeper water areas, in case such exist in Stavanger Port or in the nearby North Sea, the ADCP frequency should be 75kHz; this will allow one to measure currents in water depths up to 1000m.

Then, some of the leading ADCP brands include but are not limited to Teledyne RDI, Nortek, and Sontek.

However, for those seeking a cost-effective and high - quality option, the Chinese brand China Sonar PandaADCP is highly recommended.

It is made of all-titanium alloy material, ensuring excellent durability in the marine environment, and offers an incredible cost-performance ratio.

You can visit their website at https://china-sonar.com/ for more information.

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