Many ports located on rivers have a sediment level significantly higher than the level that ships’ onboard ballast water treatment systems are tested against.
In response, Damen Shipyards Group has developed a ballast water prefiltration barge (BWPF) to assist vessels ballasting in such ports in complying with the IMO’s Ballast Water Management Convention.
“The level to which onboard systems are tested demonstrates an ability to handle sediment levels up to 50 mg per liter,” says Damen Green Solutions product portfolio manager Matthijs Schuiten. “However, at some terminals, this level is exceeded – sometimes considerably. We recently ran tests on a waterway in the U.S., close to a harbor, for example, and found sediment levels 30 times above this.”
Notable cases of important waterways that exceed the level to which onboard systems are tested include the Huangpu Jiang in Shanghai, the River Thames in London and the Red and Mississippi rivers in the U.S.
“Such high levels of sediment can cause ballast water filter blockage,” Schuiten continues. “This can make for huge operational challenges, preventing cargo unloading or ballast water intake.”
Damen’s answer is the new BWPF barge, designed to go alongside a vessel at terminal and filter the sediment before ballast water is taken aboard.
“Pre-filtering the water in this manner ensures the ballast water system onboard is not blocked due to sediment,” says Schuiten. “Having such capabilities enables terminals to add value with an additional service for calling vessels. With the IMO legislation’s passage into law, we expect to see demand for such services in the near future. Developing the BWPF Barge is Damen’s way of making sure that, when the need arises, we are prepared to respond quickly.”
The BWPF barge can process up to 4,000 cu.m water per hour with a sediment level anything between 50 and 1,500 mg per liter. Filtration is available between 10 and 50 micron, to suit varying sediment sizes. The entire ballast water filtration system fits neatly inside a standard 40’ ft container, making logistics straightforward.