Owners would be advised to think hard about the ballast water management systems they choose, as type approval alone is no guarantee it will do the job, writes Coldharbour chief executive Andrew Marshall
There is a perception that US Coast Guard-type approval for a ballast water management system (BWMS) is a sort of gold standard. All too often, shipowners are being lulled into a false sense of security that by specifying a USCG-approved BWMS, they can fit and forget.
From a manufacturers’ point of view, we all need to have USCG approval because otherwise the market is limited. The Coldharbour BWMS already has IMO-type approval, USCG AMS and is currently working through the full USGC TA process.
The 2013-built 158,513 dwt Suezmax tanker Bordeira, owned and operated by TMS Tankers, was fitted with the Coldharbour BWT system in May 2018. Bordeira is being used to carry out USCG-type approval tests for the Coldharbour system, supervised by Lloyd’s Register (LR). LR has already overseen IMO-type approval for the Coldharbour system, validated by the UK’s Maritime and Coastguard Agency.
But a BWMS can have a USCG certificate, an IMO certificate, a revised IMO certificate, an LR certificate, a BV certificate, a UK MCA certificate, even a cycling proficiency certificate, and still not work on a given ship. Rather, the system needs to be the correct one for the type of ship and the trade the ship is undertaking.
There are currently two main groups of systems and one smaller sub-group. The two larger groups are filter plus ultraviolet light (UV), and filter plus electro-chlorination, or variations of some sort. These two groups account for about 85% of the market.
The third group is what I call ‘freaks and weirdos’, of which I count Coldharbour as one.
By and large, all the systems in the first two categories work during ballast water uptake. The ballast water comes up through the pumps, into the treatment plant and then on into the ballast tanks – and that is perfectly fine.
In my opinion, this is perfectly good technology for about 85% of vessels. However, problems arise among the very largest vessels, where efficacy and operational suitability begin to fall away, and this occurs for three reasons.
First, a large ship, say a VLCC of 300,000 dwt, is typically required to pump ballast water at 6,000 m3 per hour, and being able to force that flow through a 40-microns filter - regardless of intake water condition, mud levels or ice levels - is a bit far-fetched.
I am not saying it is impossible; it depends on how much kit is installed. But can the pressure/flow be maintained under all conditions? I don’t think so.
The second challenge is that on a VLCC there can be 100,000 tonnes of ballast water. Not only does this mean processing 6,000 m3 per hour, it means doing so reliably for 18 hours non-stop during loading. Anything that causes a disruption will cause a delay.
The third challenge is that the larger ships generally have the longest ballast and there is no BWMS from any manufacturer, approved or not approved, that can kill all invasive species under all operating conditions 100% of the time.
The problem here is that some live species will be left in the ballast water, feeding on lots of dead organisms for weeks on end. Remember, the system has to be compliant at the point of discharge, not intake; it does not take many organisms to start re-growing to breach the limit.
Our system is developed for large vessels, Aframax, Suezmax, VLCC, VLOC, Capesize bulkers and so on. We don’t do anything smaller. Our system does not undertake any treatment during intake.
The Coldharbour system treats the ballast water during part of the ballast voyage with inert gas, a system already familiar to tanker crews. The idea is to treat the ballast water during the voyage and so arrive with the ballast water fully treated. That way, the economic model of the ship is retained and there is no delay during loading or discharge.
Snapshot biography - Andrew Marshall
Andrew Marshall is the chief executive officer of Coldharbour Marine Limited (CHM). Mr Marshall has held his current position since 2010, having spent the previous three and a half years as a technical and market advisor to the company. He is Secretary of the newly formed Ballastwater Manufacturers Equipment Association. Elected as a Fellow of the Institute of Marine Engineering, Science and Technology (ImarEST) in 2012, Mr Marshall is a regular contributor to the IMarEST Ballast Water Expert Group that meets to provide guidance to IMO on ballast water issues.