Fuel-injection system where pressurised fuel is held in a high-pressure rail and injected per-cylinder via electronically controlled injectors.
Regulatory detail & full definition
Replaces the older jerk-pump system on modern slow-speed marine diesels (MAN ME and Wartsila RT-flex). Allows precise injection timing, multiple injection events per stroke, and lower NOx + soot. Pressure typically 1,000-1,500 bar; control via the engine's electronic governor (ECS).