The RT-flex system was first applied to a full-size research engine in
June 1998 at Wärtsilä’s facilities in Switzerland and represented the
third generation of electronically-controlled Sulzer diesel engines.
The first RT-flex engine, a six-cylinder RT-flex58T-B model, was tested
in January 2001 and later installed as the propulsion plant of a 47 950
dwt bulk carrier, which was handed over in September that year. The
engine’s slow-running capability was demonstrated by steady operation
at speeds down to 12 rev/min. Subsequent orders called for sevencylinder
RT-flex60C models, the first Sulzer low speed engine designed
from the bedplate up with electronically-controlled common rail systems
(Figure 12.35). The RT-flex option was extended to all bore sizes in