MARINE FOOD WASTE MANAGEMENT

Background

The Fred Olsen offshore wind focussed firm, Windcarrier, took delivery of it’s second sea borne jack up vessel, the Bold Tern in January 2013. Accompanying its sister vessel the Brave Tern, the 132m vessel set off from its shipbuilders facility in Jebel Ali to work in the north German sea to start installing 80 wind turbines at the newly designated Riffgat offshore wind farm. March 2015 and the Bold is half way through its mission having installed the 40th 3.6MW unit. The vessel equipped with helipad, is staffed by 80 personnel for weeks at a time.

 

Problem

With 80 staff on-board the fully loaded vessel, space is always at a premium. Where weeks might pass by until a service and supply vessel might meet up with the ship, the crew and galley still continue to generate waste that needs dealing with. So what do you do with the putrescible food wastes generated on-board? Many marine vessels store food wastes in refrigerated store rooms, others use macerators and pump the food wastes to a holding tank deep in the bowels of the ship, some store the wastes in sealed barrels on deck, until the next opportunity arises to dispose of them. In the case of the Bold Tern, which generated up to 175kgs of waste per week the storage of the wastes was causing another issue. Rotting foods give off barrel expanding gases. The barrels need to be sealed to store on deck, the barrels expand with heat and become a hazard. As many other vessels, space being a premium on-board, finding a solution that would not require much needed space being taken up in refrigerated store rooms or require room sized waste holding tanks being squeezed into the bowel of the ship was a bonus.

 

Solution

Fred Olsen contacted Tidy Planet and the simplest of solutions to the gassy, space consuming wastes was offered, Gobi drying. Using the G50 Gobi food waste dryer the food wastes could be reduced down in moisture content (MC) to produce a sub 10% MC output material. With such a low MC the food wastes no longer starts to putresce, meaning that the ship could store the wastes in sealed containers without fear of them expanding in the deck warming sun. The knock on effect, 80% less food wastes to store. With the liquid content of the food wastes being driven off as steam, the condensed water content could be disposed of via the ships normal routes, now the solution has a greater benefit in operation, less wastes and less hazardous containers.