ADCP's Application to Ocean Current Measurement in Botany Port

1. Where is Botany Port?

Botany Port, more commonly known as Port Botany, is located in Sydney, New South Wales, Australia. It is in Botany Bay and is about 10 kilometres south - east of the Sydney central business district.

Scale and Throughput of the Port

Port Botany is considered one of Australia's biggest and busiest ports. It has an integrated design with several berths planned to receive almost every variant of vessel types. The annual throughput recorded in this port is relatively pretty high, and particularly for the containerized cargo items. Million TEUs recorded every year from this port accounts for its prime importance in the links of international trade in Australia. It also records sizeable tonnage of bulk cargo, especially like petroleum products, grains, and minerals. This expansion and modernization have been continuous as the port has sought to meet the rising needs associated with the volume of trade.

Routes and Business

The port has routes that connect Australia to a number of global international marketplaces around the world. The port therefore serves as a key entrance and exit for imported and exported items, enabling trading with Asia, Europe, the Americas, among others. Business: The diverse areas concerned with the supply chain in relation to Port Botany include associated logistics and warehousing/distribution operations to support core cargo handling. The port itself hosts a long list of shipping lines, freight forwarders, and other businesses associated with the maritime field, adding to regional economic development.

Port Management and Operations

The management of Port Botany is vested in the Port Authority of New South Wales. It is responsible for undertaking the strategic development of the port, as well as the day-to-day operations. The authority ensures the smooth operation of the port facilities, vessel traffic management, and enforcement of safety and environmental regulations. It also works for continuous improvement in the port through the addition of new technologies and more infrastructure to increase the competitiveness of the port.

Port Facilities

The facilities at this port are modern and comprehensive. The container terminals are equipped with the most modern cranes, which can efficiently handle jumbo-sized containers. There is a vast container storage yard equipped with highly advanced inventory management systems. The bulk cargo is handled in specific terminals, with respective handling equipment such as pipelines for liquid bulk and conveyor systems for dry bulk. In addition, there are facilities for ship repair and maintenance as well as fueling stations to support the vessels calling at the port.

Channels and Direct Navigation

Approach channels in Port Botany are maintained with the view to making the vessels have safe and easy navigation. The depth of these channels is regularly monitored and dredged when necessary to accommodate large-draft ships. These are supported by a number of navigational aids, which include lighthouses, buoys, and sophisticated radar systems to guide the vessels during its approach and departure. Due to well-marked shipping lanes, vessels can come directly from the open sea into the port. But since the traffic flow is very dense, proper traffic management practices are followed so that the ships move in order and safely.

2. Why measure the ocean currents in the Botany Port?

The reasons for measuring the ocean currents within Botany Port are quite important in relation to some aspects of the port operations and management.

Navigation Safety

The intense traffic volume in Botany Port creates a demand to understand the ocean currents, which is of high importance for ensuring navigation safety. Currents can heavily influence the course, speed, and even maneuverability of a ship. For instance, the strong current can make a ship divert from the original course at some time during berthing, and it results in increasing collision with other vessels, port structure, or even the shore. With proper and correct measurement of the currents, masters of vessels will be able to make proper decisions and change the way they navigate accordingly and take the necessary precautions against possible accidents.

Optimising Port Operations

Ocean currents knowledge is indispensable in optimizing port operations. The current's course and speed are crucial when carrying out any form of berthing or unberthing. A favorable current contributes to easy manipulation of vessels and saves a lot of time in such operations. On the other hand, unexpected or high currents may be one of the prime causes of delaying or making an operation impossible to carry out. Secondly, during load or discharge operations, the ship is said to relate with current about stability. For instance, with real-time current data, port operators are able to plan such operations so that they take place under the most favorable conditions, which then maximizes overall port productivity.

Environmental Protection

Ocean current measurement plays a very important role in the case of an environmental disaster, such as an oil spill or release of pollutants. Currents determine the direction and speed at which pollutants will spread. With the knowledge of the current patterns, port authorities can quickly predict the most probable path that the pollutants will travel and take immediate action to contain and clean up the spill. This helps protect the local marine ecosystem, which is home to a diverse range of marine life. It protects the shores from the adverse effects of contamination because tourism and a clean environment go hand in hand for the good health of the community living there.

Among the different techniques to measure ocean currents, one of the most sophisticated and convenient methods is the Acoustic Doppler Current Profiler (ADCP). It can continuously and with high resolution measure currents at various depths, which will enable thorough understanding of the current structure in the port area.

3. How do ADCPs using the Doppler principle work?

ADCP Measurement Principle

The principle of operation of ADCPs is based on the Doppler effect. An ADCP current meter sends out acoustic signals into the water column. These signals are scattered by small particles in the water, such as plankton, sediment or bubbles. If these particles are moving due to the water current, then the frequency of the scattered acoustic signal received by the ADCP current profiler is different from the frequency of the emitted signal. This frequency shift, known as the Doppler shift, depends upon the particle velocity and therefore the water current. By precisely measuring this Doppler shift, the ADCP calculates the speed and direction of the water current at different depths within the water column.

ADCP in Specific Methods for Measurement of Current in Ports

• Ship-borne ADCP: Ship-borne ADCP is usually mounted on a moving ship. While the ship is sailing around in the port area, continuously measuring current, this can quickly cover large areas of the port and gives the broad-scale view of the current patterns. However, its own motion should be carefully compensated in the processing of the data measured. This is done by the use of supporting sensors, including gyroscopes and GPS that measure the movement of the ship with accuracy in order to subtract the effect from the current data measured.
• Fixed ADCP: A fixed ADCP is installed at some location in the port, for instance, on a pier, a buoy, or a submerged platform.
• This arrangement yields continuous and long-term observation of the current at a particular point. It is useful for studying the long-term trends and variations in the current, besides providing real-time data for port operations in the vicinity of the installation. Fixed ADCPs can be powered by various means, including electricity from the port's grid, solar panels, or batteries.

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

Equipment Reliability

Such ADCP flow meter equipment for current measurement in Botany Port should be highly reliable. That's because the marine conditions of this port involve exposure to saltwater, temperature fluctuations, and possible mechanical stresses as well. It is thus required that the ADCP will be able to put up with such conditions. Above all, reliability depends upon the ADCP materials used for the casing. The ADCP meter would be designed in such a way that it is compact in size, so installation could easily be done at any specific place in the port.

A light design provides advantages, especially for applications on ships, as the ship itself would have minimal impact from stability-affecting forces.

Besides, low power consumption, especially for fixed-mounted ADCPs, is important during long-term operations because other power sources may be resorted to, such as solar panels or batteries. This ensures the ADCP can operate continuously without replacing the batteries often or running out of power.

Cost-effectiveness

These instruments should be reasonably cheap to allow their broad-scale deployment in Botany Port for full current measurements. This will facilitate the installation of a number of units in different areas of the port, thus giving detailed and relatively accurate information about the pattern of the current. Cost-effectiveness could also cover the low maintenance costs that ensure long-term viability.

ADCP Casing Material: Titanium Alloy

The casing of the ADCP is made of a titanium alloy.

There are a number of advantages to using titanium alloy in the marine environment. It has excellent corrosion resistance, which is important for withstanding the corrosive effects of saltwater over long periods. It is also relatively lightweight compared to other corrosion-resistant materials, such as stainless steel, which helps in reducing the overall weight of the ADCP profiler. In addition, titanium alloy has good mechanical strength that can bear the mechanical stresses of ocean current measurement, such as water pressure and impacts from waves or debris.

5. How to Choose the Right Equipment for Current Measurement?

Based on Usage

It has many useful options to get current velocity and its patterns within the port, especially the ones that require very little time consumption and are wide-ranging. Most times, it acts well during initial surveys or for preliminary testing of currents within varied zones around the port area. 

Shipborne ADCP: Shipborne ADCPs have been applied for general analysis on current variation through large ports, enabling the planning of routes and controlling general traffic efficiently.

Sit-on-bottom ADCP: The Sit-on-bottom type of ADCP is suited for fixed-point, long-term monitoring of currents. This type of equipment provides much valuable data regarding long-term trends and variations in the current at a specific location in the port. The Sit-on-bottom ADCPs provide information about the temporal development of the current field that may be useful for infrastructural planning of ports and environmental monitoring.

Buoy-mounted ADCP: Buoy-mounted ADCPs are useful for measuring currents in areas where it is difficult to install fixed-point or ship-borne systems.

They can be deployed in areas with high water flow, in open - water regions near the port, or in areas where access is limited.

ADCPs mounted on buoys can provide current conditions in real time in these areas, which can be of vital importance for navigation and the protection of the environment.

Based on Frequency

A 600kHz ADCP shall be suited for water depths of up to 70m, whereby at Botany Port, which comprises a fair deal of shallow areas-shore and other specific berthing areas-this frequency can be applied for detailed measurement purposes. This higher frequency provides the capability of more accurate measurement of currents within these shallow waters.

A 300kHz ADCP would be appropriate for depths of about 110m. It can be used in areas with slightly deeper water in the port, such as in the main channels or in some of the outer berthing areas. This frequency provides a good balance between depth penetration and measurement resolution.

A 75kHz ADCP is designed for much deeper waters, up to 1000m. Although Botany Port may not have extremely deep waters in its immediate vicinity, if there is a need to measure currents in the adjacent offshore areas or in deeper channels connecting to the port, this frequency can be considered.

The names amongst a few renowned ADCP brands available in the market are Teledyne RDI, Nortek, and Sontek.

However, those who are in quest of value-for-value returns from an ADCP, be it cost or quality, then have a Chinese brand to trust: China Sonar PandaADCP.

The device is fully made of a titanium alloy so that it becomes robust in marine conditions.

It provides an excellent solution for current measurement at Botany Port with an incredible cost-performance ratio. More information is available on their website: (https://china-sonar.com/).

Here is a table with some well known Acoustic Doppler Current Profiler(ADCP)  instrument brands and models.