Ballast Water Exchange Bwe Construction Essay

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This report reviews the studies and related literatures on the ballast water management which is about the engineering aspects of the ballast water and different method of the ballast water treatment. The purpose for doing this is that the ballast water treatment on-board will be mandatory after 12 months after its ratification by 30 states representing at least 35% of the world shipping tonnage. In the report, I will show all the different categories of the ballast water treatment system for different sizes and types of the vessel. With the most optimised technology, the ship owner and ship builder will choose the best suitable system for the ships.



Sea water has been used as ballast to stabilize the vessels at sea around 120 years ago. Ballast water is pumped-in to maintain safe operating conditions through the voyage. The ballast water issue was recognized as a problem as early as 1982 UN Convention on the Law of the Sea and the 1992 Convention on Biological Diversity. The ballast water and segments carried by modern vessels contain a variety of organisms including bacteria and viruses at the larval stages of the many marine animals. Also, as the conditions of the ballast tanks and piping system are harsh , the organism survive to compete with the native species in the port of discharge .Moreover , they are able to thrive in the new environment due to the lack of the nature predator in the waters. Thus, the species can have a serious ecological, economic and public health impact on the receiving environment.

To prevent the transfer of the invasive species and coordinate a timely and effective response to invasion, the International Marine Organization (IMO) has developed the regulation to set the constrains about the discharge s of the ballast water and reduce the risk of introducing new species from ships' ballast water. Most of the method s that are used initially to discharge ballast water into the open have been found not effective in preventing new species .The Ballast Water Management (BMW) Convention applies to all ships that are designed to carry dischargeable ballast water. It applies to to ships flying the flag of Parties to the Convention and also the ships operating under the authority of Parties. In addition, discharge to approved on-shore reception facility can be used as an alternative to ballast water management. The convention defines two basic method of managing the ballast water:

Ballast Water Exchange (BWE)

As the name implies, ships are required to ballast and de-ballast in the deep open ocean. It is not required in some exceptional circumstances, such as where it will endanger the ship.

Ballast Water Treatment (BWT)

BWT is more robust method than the BWE in preventing the spreading of the invasive organisms. The BWM Convention provides for its use to become mandatory over time and defines a schedule of BWT implementation deadlines foe ships of different sizes and ages. Based on the technology now, there are 3 methods mainly dealing with the BWT and they are the namely: mechanical, physical and chemical. Every BWT system will treat the ballast water by one or more method.

In the report, the ballast water management is mainly focusing on the BWT part. In order to be a best BWT system for the ship, the system must be of the lowest cost as the BWT system will not produce ant profits for the owner but only to follow the regulations from the convention. Moreover, the system must be efficient enough to deal with the ballast water. Last but not least, all the system must be approved by the classifications and the convention. I will evaluate the current BWT system based on the cost, efficiency and classification and optimise for certain types of ships.


2.1 Motivation

I have been working at Jurong Shipyard as commissioning engineer for over one year, and just that time I have been working on the ballast water system .I begin to realize problems of the ballast water as the ballast water problem occur also at the early stage of the ship building. As the environment at shipyard is not so good but some the species will compete and evolve which will become a danger to the native animals. To follow and comply with the international regulation, we need to always take attention of the ballast water problem at anyplace.

2.2 Research Capability

With the help my supervisor Dr .Ivan CK Tam, I am able to decide a detailed topic and working direction in my project. At the project work, I may face some difficulties and Dr .Ivan Tam has given plenty of suggestion and led me to a better result. Besides, all the latest ballast water regulations can be found at the IMO website [1], which will help me in the regulations part of my project report. Also, a lot of the articles, journals and books can be found at the Newcastle University Library. Thus, I can find plenty of the information on the current ballast water management technology and methods, which are the second part of my report. In addition, more information needs to be gathered to compare the advantage and disadvantages of all the ballast water management systems. This information can be found at the "Google Scholar" or "Google Books" rather than the methods mentioned above.


The aim of the final year report is to the let people to realise the importance of having the ballast water management system on-board vessels and optimise the ballast water system for the ship owner and ship builders. It is not only following the regulations of the international convention but also need to maintain and create a better environment for the marine animals. As we human are at the top of the biologic chain, so if the marine life is not managed well, they will definitely affect us life one day.


The objectives of this final year project are:

1) Familiar with the latest ballast water regulation.

2) Analyses of the current ballast water management technology.

3) Develop optimised ballast water system for vessel.


First of all, it is from the literature research and analysis. It is necessary to learn about the latest regulations and rules about the ballast water. Moreover, all the current ballast water management technology needs to be gathered together

Secondly, it is the approach stage. Currently, there are many ballast water treatment system manufacture company, and they have already get approval from the ballast Water management convention. Based on the technology, I can approach to them to have a detailed view of their product on the engineering principle. I will work on the system layout and all the technical details which are for developing the optimised system. However, to have a better view on behalf of the ship owners and ship builders, it is important to compare the advantages and disadvantages of these systems in terms of the cost, efficiency and the classification approval for different kinds of ships.

Thirdly, software will be used in solving the part of the problems. Engineering language is all about the calculation, comparison and theory. To show the efficiency of the ballast water management system, it is useful to simulate by the CFD to show the improvement. It will come out at the final report of my project.


The Ballast Water Convention will enter into force 12 months after its ratification by 30 states representing at least 35% of the world merchant shipping tonnage. Therefore many operators, regarding entry-into-force as inevitable, are planning new ship order s on this basis and managing existing fleets as if the ballast water conventions are in force so as to gain operational experiences. Parties to the ballast water convention will require all ships to carry the ballast water record book, ballast water management plan and the ballast water management certificate which is awarded by the flag state and duty authorised organisation. For the ballast water management system, there are ballast water exchange (BWE) and ballast water treatment (BWM).For BWE, there are there ways of exchanging namely; sequential, flow-through and dilution. Herewith inside this report, the BWT system is mainly referred as the key in the ballast water management as the BWE is still not so effective and may cause danger to ship in some certain conditions. For the current technology, there are mainly three methods for the treatment system.

Physical Method

It is the simpler method compared to other two methods. Engineering principle of centrifugal and filtration will be used. With this method, the particles with a heavy density can be removed from the ballast water and most the solid portion as well. Some more, it can lead to reduction of density of the live organisms as it will damage them during the process .However, it is limited to deal with the lighter density particles and it is difficult to remove the dissolved materials and the small bacteria and viruses. The physical normally need cooperate with other method to have the best efficiency. The technology can be operated at a reasonable cost and it has little impact on the current operation.

Mechanical Method

For the mechanical method, it is mentioned with the generation of the cavitation or super saturation with mechanical principles. Taking the cavitation method for example, as we know cavitation will have effect as the pressure change .It is just the cavitation which will be able to create bubble .When the bubble collapse, it will rupture the cell members of the species and also destroy particles and organisms by forcing them apart. The mechanical method is effective and it can significantly improve the ballast water quality. However, it is complex equipment and need a lot of the maintenance in the operation. Classification also need long time to approve this kind of system as the system based on this method need specialised personnel and equipment to operate. It is effective technology but still need to develop to an optimised stage to meet the requirement of ship owners and builders.

Chemical Method

As the name implies, the chemical method is usually dealt with importing kind of chemicals to the ballast water system for treatment. It is of ease in the operation. Pumps which are for transferring the chemicals will be used and it will be effective in the treatment process. But, the chemicals may have toxic effect on humans. More hazardous environment issue may occur when using the chemicals. So the chemical method need strictly comply with IMO standards as well as the flag state regulations. It is cost effective method and also need attention on handling the chemicals on-board s hips.

All the current treatment systems are based on one or more methods. Ballast water treatment system companies are working hard to research on the technology development and they all have their speciality. I will show different kinds of companies with their system in the final report of my project. I will explain them in terms of the detailed cost; efficiency and classification requirement approval .As the convention will make the ballast water treatment system mandatory over time, so the ship owner and ship builders certainly need consider this issue.

The ballast water treatment system is to be applying to ship new building and retrofitting. Basically, the new building has to follow the latest regulations and it is not a issue for them. But, retrofitting is different as the ships are already in services for years, and the introduction of the new system may affect the ships operation. It will surely increase the operating cost for the ship owner and charters which will drag the whole marine industry. So it is time now and it is important to develop the ballast water management system to every party in the shipping industry.


All the conventions have realized the problem of the ballast water system but people are lacking of professional knowledge to settle the problem. IMO has been working hard on the regulations and BWM convention also cooperates with the system manufacturers to produce better products. In my report, I will summarize the theoretical engineering aspects to clear cost compassion, advantages of the system, cost and efficiency of all existing company products. So the all the related organization will be more familiar with all the regulations and ship owner and ship builders can refer to a professional thesis for their choice of optimised ballast water system for new building or retrofitting ships.