There’s many reasons why proper ballast water treatment can’t take place onboard a vessel coming into port. Whether it’s a malfunctioning system, an impossibility to (economically) install a retrofitted system onboard an existing vessel or a local authority with ballast water requirements exceeding expectations. In recognition of this, Damen has developed its unique InvaSave Mobile Ballast Water Discharge technology, enabling in-port ballast water processing and discharge.

The InvaSave is designed to make ballast water treatment easy, fast and reliable. The unit is completely autonomous with a built-in generator and integrated hosereel, and comes in a CSC-certified standard-size shipping container, making it easily transportable by road and sea. The best part about it however, is that it does away with required holding times. This means that whatever ballast water passes through the unit, it comes out D-2 certified in a single pass, without delays of any kind! The InvaSave is the only ballast water treatment system currently on the market that’s IMO certified to operate this way.


  • Contingency measure in ports in case onboard BWT units fail or are insufficient
  • Can be placed on deck of barges/pontoons, enabling even unmanned vessels to comply with BWT regulations
  • Self-sufficient – independent of external power supply and pumping capacity
  • No holding times required, single-step treatment of all ballast water upon discharge
  • Better compliance monitoring for local authorities and port control
  • IMO-certified BWT independent of space-, pressure drop- and power reserves found on board vessels
  • Reliable solution for both ports and operators – designed for low maintenance
  • Suitable for salt, fresh and brackish water
  • No chemicals are deployed
  • Deals with extremely turbid waters: down to 20% UV-Transmissibility!
  • Gravity ballasting for ballast intake still possible
  • Enables contingency measures in ports in case onboard BWT units fail


    Highly Mobile

    Highly Mobile

    The InvaSave is a standard-sized container. It can be transported like any other shipping container and be put on any floating vessel, truck or simply on land. This ensures maximum flexibility: the container can be used as a mobile contingency unit where ever you need it to be, and thanks to an optional built-in generator, you don’t have to worry about local power supplies or other infrastructure.

    Bigger ships, bigger capacity

    Bigger ships, bigger capacity

    For the biggest ships, more capacity is required. The InvaSave is designed to run in parallel with other units, correspondingly multiplying the standard 300 m3/hour capacity of a single container. Depicted is a design with eight containers and an integrated bunker-type crane to deliver the reception hose on deck of big ships. Another alternative is to make good use of an old barge: convert it to a floating storage (‘buffer’) unit and let one or two InvaSaves work their magic in their own time.

    Sit tight, the InvaSave is coming to you!

    Sit tight, the InvaSave is coming to you!

    Putting a pair of InvaSaves on a fast vessel (Damen FCS 4008 depicted) makes for a highly mobile ballast water treatment vessel. Ideal for smaller ports looking to share resources, or big ports looking for increased mobility.



    The InvaSave can be transported by road on a flat-bed truck, enabling cost-effective access to virtually anywhere. The (optional) integrated hosereel enables an ‘InvaSave’ truck to start operating right from the quayside after arrival of the vessel. This ensures the shortest possible turn-around time. The water leaving the container is ‘D-2 certified’ and can simply be pumped into the harbour basin.



    The InvaSave is specifically certified to both receive raw ballast water from an incoming vessel and supply clean ballast water to a departing vessel. The latter is extremely useful should an onboard BWMS fail during ballast water intake. As an on-board system has to perform both during intake and during expulsion of ballast water, this situation would usually result in ballasting operations having to cease. By taking on InvaSave-treated water, the vessel can still sail with its tanks filled. During the voyage, the crew have time to fix the on-board BWMS and discharge in the usual manner upon arrival in the next port.


    Dimensions container 45’ x 8’ x 9,6’ (LxWxH) High cube
    Treatment capacity
    10 – 300 m³/h
    Power consumption 70-140 kW
    Effectiveness Designed for waters with low UV transmission, fresh, brackish and sea water
    Ballast Water processing Fully automated and monitored
    Generator US/EPA Tier 3/EU Stage 3A 160 kWe
    Design pressure 10 bar
    Noise level Meets highest standards



    As a contingency measure, isn’t it allowed to treat (potentially raw) ballast water from incoming ships with a regular BWMS that’s installed in the harbour?

    Unfortunately not, for a number of different reasons:

  • The type approval certificate of a ballast water treatment (BWT) system describes how it can be used. Normally, for a conventional BWT system, the IMO type approval certificate specifies whether the ballast water is treated before it enters or after it leaves the ballast tank. In case a BWT system is used to treat only at discharge it should be written in the IMO type approval certificate that this is also tested.
    The InvaSave is certified and tested specifically for use at the point of discharge. This will also be written in the IMO type approval certificate.
  • A conventional on board (UV based) BWT system uses a filter during ballast water uptake. Filtration is the critical first step in organism removal. It clears larger organisms while simultaneously removing sediments in the water. The automatic backwash cleans this filter and is discharged overboard. This is permitted since the backwash discharge contains the same organisms as the surface water. In the case that this filter is used (only) at discharge, the backwash will contains different organisms since it is taken in from a different area. Therefore, it cannot be discharged to the surface water.
    In the InvaSave container a secondary filtration train is installed, to clean the filter backwash from organisms. Therefore it is permitted to discharge the filter backwash to the surface water with the InvaSave in the case that the ballast water is not from the same area.
  • A conventional on board (UV based) BWT system is certified according to a standard IMO protocol. This protocol includes the requirement that the ballast water is stored for 5 days (land based tests) in the ballast tanks to allow time for the organisms to respond to the UV treatment. After 5 days the ballast water from the tanks is sampled and the number of organisms are counted. If the numbers are within the limits of the IMO Ballast Water management Convention, a BWT system receives its IMO approval. In the situation that a conventional on board (UV based) BWT system is used only at discharge there is no delay effect for to allow the organisms to die in the tank and the discharged ballast water will probably not meet the IMO standard.
    The InvaSave will be IMO certified without the need for storage time of ballast water in the ballast tanks for the die-off of the organisms.
  • What does the IMO Ballast Water Management Convention (BWMC) mean for my company’s operations?

    The BWMC was finally ratified on September 8th, 2016. This means, that as of September 8th, 2017, the convention will come into effect in full force for all participating nations (please see the IMO website for an up-to-date list of participants). All vessels >400 GT must from this day onwards carry an approved Ballast Water Management Plan and a Ballast Water Record Book. Furthermore, you are required to perform ballast water exchange to the IMO ‘D-1’ standard and keep track in writing of such operations up until the date of your next IOPP-certificate renewal. After this date, you are required to perform ballast water treatment, rather than exchange, using a certified ballast water management system. The corresponding IMO standard for ballast water treatment is called the ‘D-2’ standard.

    Why is there a market for the InvaSave technology?

    There are many scenarios for which an external treatment process makes sense. Take for example ship owners that cannot justify the costs of retrofitting vessels due to their age. Perhaps your vessel usually operates in areas where the Ballast Water Convention is not enforced (yet) but would now by chance like to visit a country where management is required. Or perhaps your vessels operate exclusively between a small number of ports; making available port-based ballast water management services could save you the costs of retrofitting. Sometimes, external treatment is the only option. Think of failure of your onboard ballast water management equipment, which at the moment unfortunately is a headache occurring often and of course always at the wrong moments. What happens to barges that don’t even have their own ballast water pumps? Or ballast water from drydocks? There are many, many possible reasons why your vessel is unable to comply with the required ballast water management scheme. No matter what the reason, however, the InvaSave offers the solution!

    Why is the InvaSave unique?

    The InvaSave is the world’s first, and only, mobile and stand-alone ballast water treatment system certified to the applicable IMO D-2 standard. There are no required holding times or pre-treatment steps, nor are any noxious chemicals used. Whatever ballast water goes in comes out certified compliant to the IMO D-2 standard in a single pass. This makes it unique; all our competitor’s products are certified merely for on-board treatment and require treatment at intake and discharge.

    Can the InvaSave be used for retrofitting?

    It is not intended for retrofitting. But, if it makes sense, then yes it can be used in that way. The InvaSave has been tested in rough, real-life scenarios on-board ships to certify its rigidity and survivability under actual working conditions.

    Does the InvaSave treat all salinities and water qualities?

    Yes, it does. The InvaSave has been tested and certified to work with fresh, salt and brackish waters and down to extremely low UV-transmission (UVT) values of 20%.

    What is the power consumption?

    Power consumption is in the range of 70 to 140 kW, depending on throughput. The InvaSave can be delivered with a built-in generator set (making it truly stand-alone) or alternatively be hooked up to a shore power connection.

    Can the InvaSave also be used to supply treated ballast water?

    Yes, it can. Water generated by the InvaSave is certified to the IMO D-2 standard. If this water is subsequently loaded as ballast onboard vessels, it is considered ‘treated’ as would be the case if a certified on-board system had treated the same water. Upon arriving at your destination, discharging the ballast via your onboard treatment system is considered fully complying with the Ballast Water Convention. This is a useful feature if, for example, your on-board treatment system breaks down when taking in water in port as ballast water. Simply take on board InvaSave-treated water instead of raw seawater and fix your onboard treatment system on the way to your next destination. This way, you can avoid having to wait in port for your ballast water system to be fixed!

    Is the installation of an on-board ballast water treatment system economically viable for my vessel(s)?

    For vessels with few ballast water discharges per year and for older vessels, fitting an onboard unit may not be economically efficient. Against this background Damen has developed its unique InvaSave Mobile Ballast Water Discharge Technology, enabling port-based ballast water management for routine service and emergency measures. This new technology broadens significantly the range of total ballast water solutions for ballast water compliance that Damen offers to its customers. Damen is always happy to think about the most commercially interesting solutions for our partners and clients. Contact us if you have any doubts!

    What about ballast water treatment on barges?

    Barges oftentimes do not have a pump room or even space to fit a Ballast Water Management System. As such, they especially will be in potential, immediate, trouble as of the 8th of September 2017, the date on which the Convention will come into effect. After all, performing an offshore ballast water exchange (to the required IMO D-1 standard) without ballast pumps is an impossibility. The InvaSave can help. I can travel with the barge on deck or remain on dry land and take care of ballast water treatment when necessary.

    How to comply to the BWMC at a dock or scrapyard or when carrying out salvage operations?

    When a vessel is in dock, it can’t always use its own Ballast water treatment installation to discharge ballast water directly into the dock. Ballast water has to be drained from the dock yard and treated or collected as waste. The same has to happen when a vessel is being scrapped or salvaged. Here the self-sufficient InvaSave with its capacity to treat ballast water at discharge only is the answer to be in full compliance with the BWMC.

    Can I discharge my ballast water when I have a failure in my ballast water treatment system?

    No, ballast water cannot legally be discharged when a vessel has a failure in its ballast water treatment system.
    These vessels can safely discharge their ballast water through the Damen InvaSave. Operators in Ports can have InvaSave systems available in order to provide emergency assistance and the required redundancy for ship owners to stay compliant with the BWMC at any time and without incurring costly delays.


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