For an industry familiar with in-line systems, persuading shipowners to consider an alternative is a hurdle, writes Giles Candy
Before installing a ballast water management system (BWMS) an owner must decide which one to use. After 10 years of seeing an endless stream of in-line BWMSs being presented, technical departments no longer have questions about the ballast water management rules or if BWMSs will even be required. They have refined much of the conversation to the consistent parameters by which most in-line systems operate: ballast pump flow rate, filter size, power consumption, discharge treatment/neutralisation and footprint. They know the metrics they are looking for.
So introducing a completely different type of BWMS can be a challenge in itself – yet an in-tank BWMS offers many advantages for many vessels. Its metrics are very different from other systems, though. The factors they are familiar with are removed from the equation. Total ballast volume and time are the new metrics, and time can be on a sliding scale – more time can allow smaller, cheaper, equipment.
To answer the question “how much time is needed?” with “it depends” does not sound like a great reply. But if an owner will hear out the reasoning, an in-tank system can open the door to a completely new way of looking at ballast water management. Potentially smaller equipment operating at sea for a longer time means no impact on port activities and increased confidence in technical and biological compliance. Ballast water treatment still has to be done, but its impact on vessel operations is minimised and confidence in compliance is maximised.
One owner that quickly saw the opportunity is CMB/Bocimar. Talking to Envirocleanse about its patented inTank BWMS, the potential advantages were clear to see, particularly for Bocimar’s fleet of larger vessels. In late 2017, after an initial engineering feasibility was completed, a pilot study agreement was signed to install a small inTank BWMS aboard the Capesize bulk carrier Mineral New York. The first step, completed during Q1 2018, was to install the hardware for the unit.
While the operating differences of an in-tank BWMS minimise the impact on vessel operations, many of the installation challenges are similar to those of an in-line system. Its lack of filters certainly helps, as does the relatively small size of the three skids – an electrochlorination cell with power supplies, a dosing unit with circulation pump and a De-Chlor neutralising unit. It was decided to install this equipment in the machinery space but, with no filters required, it could be fitted in a deckhouse. A containerised installation is also possible, even for a Capesize.
Despite the skids’ relatively small footprints, getting each to its intended location required careful planning and some short-term relocation of other equipment in their paths. Moving this equipment, just temporarily, was a particular challenge in this installation because it was being completed at sea.
The largest hurdle for an inTank installation is its circulation piping. In this case some stripping lines could be used, and installation of some prefabricated sections was completed. Fitters and welders are generally very good at relatively straight runs of small pipe, but it was an achievement to complete this at sea, including to the cargo ballast hold.
Differences between in-line and in-tank solutions disappear when it comes to integrating the new BWMS’s control with the existing ballast water control system. For both types, integration with the ballast control system should lead to ballast treatment control that is as seamless as possible.
For newbuild installations this can be engineered into the system from the beginning, but aboard Mineral New York we were faced with an older control system. The Envirocleanse team, which included the marine engineer Glosten with help from CMB/Bocimar, developed a new panel that allows the vessel to switch into treatment control at will. This helps support the pilot nature of this installation.
At the time of writing in early April, work is just beginning on the study – but so far inTank has successfully mixed a 25,000 m3 cargo ballast hold. At Envirocleanse, we believe this demonstrates the efficiency of its patented solid-state mixing nozzles and answers many valid questions regarding scaling of the system. Meanwhile, inTank has successfully completed all the tests for IMO’s revised G8 testing requirements and for US Coast Guard (USCG) type-approval. It will be submitted to the USCG for type-approval once DNV GL has reviewed the documentation.
*Giles Candy is business development director at Envirocleanse