Swedish owner Stena Bulk has firmed up plans to install scrubbers on 16 tankers.
The company said the "major investment" will costs $55m and the work will take place before the IMO 2020 January deadline.
The shipowner had revealed a plan last year to fit the open-loop hybrid systems to 15 ships, with options for six more.
Now it has decided to retrofit 10 IMOIIMAXes, five suezmaxes and a standard MR.
