Andreas Wiesmann, general manager of strategy and business development for 2-stroke engine services at Wärtsilä Marine, explores how radical derating can support growing ship efficiency demands.

In 2022, Wärtsilä concluded one of its most significant vessel conversion projects to date; the pilot project for a radical derating solution designed to keep mid-life two-stroke engine powered vessels in compliant service for longer. The conversion involved reducing the bore size of a 12RT-flex96C-B engine to become a 12RT-flex72R. That is a 25% reduction on one of the biggest engines in the market.