ADCP Applied to Ocean Current Measurement in the Port of Helsinki

1. Where is Helsinki Port?

Overview of Helsinki Port

Helsinki Port is located in the capital city of Finland, Helsinki. It is a giant port in the Baltic Sea and enjoys a large scale and high throughput. The facility is an important transportation junction that links Finland with other countries through different shipping routes. It handles a wide range of cargo including containers, bulk cargo such as forest products (timber, pulp), and industrial products. It is also an important passenger port, with numerous ferry connections to other Baltic destinations.

The port is well run with modern systems in place to guide vessel traffic, handle cargoes, and attend to passenger services. Similarly, dedicated teams handle functions such as berthing operations, storage and distribution of cargo, and custom clearance. The engagement of modern technologies such as automated cargo-handling equipment and electronic communication channels increases productivity and promotes smoothness in the conduct of port activities.

Port Facilities

Berths: The port has several berths designed to handle various kinds of vessels. Deep water berths are there in order to handle big size container ships and cruise ships. These berths facilitate state-of-the-art mooring and docking facilities with a view to ensuring safety during the arrival and departure of ships. The high quality of fenders and bollards used can resist high forces during docking and undocking.

Cargo-handling Equipment: Along the quay is an array of cargo-handling equipment. For the handling of containers, modern gantry cranes featuring high speeds and precision in loading are deployed. To handle bulk cargo, conveyor systems and grabs exist for proper transfer of materials from ships onto storage. For the handling of forest products, specialized equipment deals in logs and pulp.

Storage Facilities: It has large-scale storage areas for different types of cargo. The container yards are well-organized, with an efficient storage and retrieval system. For bulk cargo like timber and pulp, there are stockpiles that have proper drainage and containment systems. The port has warehouses for other general cargo and cold-storage facilities for perishable goods.

Channel and Navigation Aids: The channel is dredged to a depth and width that will allow the safe passage of vessels. Regular dredging operations are carried out to keep it navigable for vessels with large drafts. Navigation aids include buoys, beacons, and radar systems that guide vessels into and from the port. The radar systems provide real - time information concerning the position and movement of other vessels in the near proximity to the port.

2. Why would it be useful to have the measurement of ocean currents in Helsinki Port?

Significance to Port Management

Ocean currents should highly be measured in Helsinki Port for many important reasons, but mostly for vessel safety while navigating through the channels of Helsinki Port. Current speed and direction are vital pieces of information for captains in approach to berths or while in the channel. A berth may be subject to strong cross - current that renders a docking difficult and dangerous. For instance, the vessel approaching the berth while being against the strong current might need changes in its approach speed and angle so as to provide smooth and safe docking. With valid current measurements, captains can make informed decisions and avoid collisions or any other accidents.

This helps to further optimize port operations. Current data aids in proper scheduling of arrival and departure of ships. Knowledge of tidal currents and other regular flow patterns allows for a more efficient allocation of the berthing resource by port authorities and better planning of the loading and unloading activity. Productivity consequently increases since this is necessary to coordinate cargo-handling operations more effectively.

Additionally, due to environmental concerns, accidental discharges of oil and other chemical pollutants require knowledge about the currents in the ocean. Predictions based on the type of cargo handled in this port become imperative in such an instance. The current data are thus utilized in rapidly mounting containment and mitigation procedures to mitigate damage to the environment.

3. How do ADCPs using the principle of the Doppler work?

Principle of Measurement

The working of ADCPs is based on the Doppler principle. An acoustic signal emitted into the water by the ADCP meter bounces back after interaction with the moving particles of water. Due to the ocean current, these particles are in motion and produce a frequency shift in the reflected acoustic signal received back by the ADCP profiler. From the Doppler effect, it follows that this frequency shift depends on the velocity of the flow.

Current Speed and Direction Calculation By observing the magnitude and direction of this frequency shift, the ADCP flow meter is able to compute the speed and direction of the ocean current at various points in the water column. It emits signals at several angles and different depths, allowing it to build a profile of the ocean current and showing how the current changes with depth.

ADCP Deployment in the Port

Shipborne ADCP

A shipborne ADCP installed on ships operating in the Helsinki Port area, while moving around the port, continuously sends acoustic signals to the water underneath. Movement of the ship enables the ADCP current meter to cover an area and collect current data from different locations. For instance, it can be used in a routine survey of the port by a research or inspection ship fitted with a shipborne ADCP to collect data over the current patterns across the many parts of the port for a complete understanding of the water flow situation.

Fixed ADCP

Fixed ADCPs are deployed in targeted, fixed locations in a port, such as on the seabed near important navigational areas or at the entrance/exit of the port. When deployed, these ADCPs continuously monitor the ocean currents at their fixed positions over long period. The data obtained could be useful in analyzing regular patterns of current in certain areas in the port. For example, a bottom-moored ADCP installed near the entrance can measure the in- and out-going currents, thus enabling the study of the tidal effects and other regular features of the flow in that area.

4. What's needed for high - quality measurement of Helsinki port currents?

Equipment Requirements

Certain equipment characteristics are essential for high-quality measurement of currents in Helsinki port. The first important factor is reliability of the materials. This is because the equipment is exposed to a harsh marine environment. Seawater contains salts and other chemicals which may cause material corrosion over time. The equipment should be able to withstand the changes in pressure at different levels of water depth and mechanical forces due to waves and currents.

Besides that, a smaller size and lighter weight with low power consumption are preferred. This is because a compact size allows for easy installation at any location in the port, whether on ships, fixed structures like piers, or on the seabed. A lighter weight would reduce the complication in installation and transportation. Lower power consumption allows the device to operate for extended lengths of time without frequent replacements of batteries or high-power feeding, especially in the case of long-term monitoring applications.

Cost is also a significant factor. The lower the cost, the larger the number of measuring devices the port can deploy for current monitoring across various areas in the port.

Advantage of Titanium Alloy for ADCP Casing 

The casing in ADCPs is made mostly of titanium alloy. An extremely good corrosion resistance includes a long structural and functional endurance in seawater exposure of the titanium alloy. Having a high strength-to-weight ratio, it is allowable to build a durable yet considerably lightweight casing. For example, in deeper parts of the Helsinki port where higher water pressures exist, an ADCP current profiler with a casing made of titanium alloy can easily bear such pressures and still give correct current measurements.

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

Selection Based on Usage

Shipborne ADCP: Where the objective is to carry out wide-area surveys of the port waters while the ship is in operation, shipborne ADCP will be suitable. It can cover different sections of the port as the ship moves around, collecting a large amount of data to provide a comprehensive understanding of the overall current situation in the port. This can be useful for mapping the general flow patterns and variations across different areas of the port waters.

Sitting - bottom ADCP: These are more suited to the long-term, fixed-point monitoring of specific locations in the port, for instance, near important infrastructure or areas with complex current behavior. They can continuously record current data at those fixed positions, providing valuable insight into the local current characteristics and any changes over time.

Buoy-mounted ADCP: In cases when it is not convenient to install fixed equipment on the seabed or on ships, buoy-mounted ADCPs can be used. They float on the water surface and can measure the currents in the upper layers of the water column. They are relatively easy to deploy and can be relocated if needed, making them suitable for monitoring certain dynamic or hard-to-reach areas within the port.

Selection Based on Frequency

The choice of frequency for ADCPs depends on the water depth in Helsinki port. For areas with a water depth of up to 70 meters, an ADCP flow meter with a frequency of 600 kHz is usually a good choice as it can provide accurate current measurements in this relatively shallow depth range. Where the water is deeper, up to about 110 meters, it is more advisable to use an ADCP profiler with a frequency of 300 kHz. In very deep sections of the port, where the water can be as deep as 1000 meters, it is recommended to use an ADCP with a frequency of 75 kHz to reliably profile the ocean currents at such great depth.

There are several well - known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, there is also an excellent Chinese ADCP brand-China Sonar PandaADCP. It is made entirely of titanium alloy material, which not only ensures its durability in the marine environment but also offers an excellent cost - performance ratio. For more information, you can visit its official website: (https://china-sonar.com/).

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