12VPA4V185

The Pielstick PA4V185 (12VPA4V185) is a 12‑cylinder V‑configured, four‑stroke medium‑speed diesel engine delivering about 1 800 kW at 1 500 rpm, used as main propulsion on a range of commercial ships; source-listed power 1800.0 kW. The supplied category identifies it as Main Engine (4-Stroke Trunk Piston), and it is normally installed in the main engine room as a propulsion prime mover connected directly or through reduction gearing to the propeller or propulsion system. In that role, its primary purpose is to convert fuel energy into mechanical propulsion power using a trunk-piston four-stroke cycle. Compared with a two-stroke crosshead engine, a four-stroke trunk-piston engine combines piston and connecting-rod motion directly at the crankshaft and typically operates at higher rotational speed. Within the supplied list, this entry is distinguished from neighbouring variants by its model designation and the explicitly listed power; no further model-specific difference is stated in the source. No additional performance, approval or construction detail is inferred from the model code beyond the information supplied in the source record. For exact ratings, dimensions, settings, capacities, materials and variant-specific limits, refer to the manufacturer documentation for the exact figure.