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Wärtsilä
12VW34DF-GS-60Hz
The Wärtsilä 12VW34DF-GS-60Hz is a V‑12, 4‑stroke dual‑fuel (LNG/HFO) auxiliary engine coupled to a generator set delivering roughly 4.3 MW at 60 Hz, designed for high‑power hotel and emergency loads on large vessels.
4560.0 kW
Power
Engine Specifications
12
Cylinders
340 mm
Bore
400 mm
Stroke
4-stroke
Stroke Type
Components & Design
Component data being added…
Technical Data
Power per cylinder (main engine 34DF)
500 kW @ 750 rpm
Power per cylinder (auxiliary 34DF)
520 kW @ 720-750 rpm
Mean effective pressure (main)
20.0-19.8 bar
Piston speed
9.6-10.0 m/s
Compression ratio (16V/20V)
12.6:1
Engine type
4-stroke, turbocharged intercooled non-reversible
Swept volume per cylinder
36.3 dm³
34DF Max output (16V main)
8000 kW
34DF/34SG Max output (20V genset)
9800 kW
34SG design
Spark-ignited, lean-burn, pre-chamber
20V34SG dimensions
L:12.7m × W:3.3m × H:4.65m
20V34SG weight
131,500 kg
power kw
4560
rpm
900
fuel type
LNG/HFO (Dual-Fuel)
configuration
V
genset kw
4332
genset kva
5415
frequency hz
60
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Common failures & inspection points
Turbocharger bearing failure - bearing location pins can break, causing the shaft to rotate freely inside housing and potentially damaging the compressor wheel.
Fuel injector tip carbon deposits and clogging - when operating in backup fuel (diesel) mode, liquid fuel deposits on injector tip can thermally decompose ('cra
Gas valve unit (GVU) functionality criticality - GVU valve tightness and proper ventilation during stop sequences essential for safe operation; leakage prevents
Cylinder liner scuffing from insufficient lubrication - mirror polished finish and loss of crosshatch pattern indicate oil starvation; piston rings run dry caus
Load-sharing failures and abnormal shutdown sequences - improper sensor signals or fuel supply irregularities can trigger emergency stops; root causes (fuel sys
Type-general inspection and maintenance points for this equipment category — not model-specific.
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Equipment Model #124677
· ✓ still in production