"> MAN Energy Solutions 5S50ME-GI10
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MAN Energy Solutions

5S50ME-GI10

The MAN 5S50ME-GI10 is a 5‑cylinder, low‑speed 2‑stroke dual‑fuel main engine delivering up to 18 650 kW at 127 rpm, notable for its high‑pressure (≈300 bar) gas injection and instant HFO/LNG switch.

MAN Energy Solutions 5S50ME-GI10
18650.0 kW
Power

Engine Specifications

5
Cylinders
500 mm
Bore
2000 mm
Stroke
18,650 kW
MCR Power
127.0 rpm
MCR RPM
2-stroke
Stroke Type
Family: MAN Energy Solutions ME-GI · Tier: Tier III · Fuel: HFO, VLSFO, MDO, LNG

Inspector Detail ✓ verified

Designation decoded

5 stands for 5 cylinders, S for Super-Long-Stroke, 50 for 500 mm bore, ME-GI for high-pressure gas injection (LNG), 10 for Mark 10.

Background

The S50ME-GI10 is the newest Mark 10 version of the 50 series ME-GI. High-pressure gas injection at 300 bar within the diesel cycle. For LNG carriers. Mark 10 as the latest generation with improved electronics.

Calculated metrics

Stroke To Bore Ratio
4.0

Inspector checklist

Running Gear & Tribology
  • Cylinder liners: S/B 4.0 — side forces, LNG cold corrosion wear
  • Piston rings: Gas lubrication conditions
  • Cylinder lubrication: BN25 in gas operation
High-Pressure Gas Injection System
  • Gas injection valves: 300 bar tightness
  • HP compressor: Condition and redundancy
  • Gas detectors: Calibration (methane at the top)
Electronic Control
  • ME control: FIVA, HPS/HCU, EICU
  • Gas/diesel changeover
  • Safety logic
Scavenge Air & Exhaust System
  • Scavenge air box: Clean in LNG operation
  • Turbocharger: Less fouling with gas
  • Exhaust temperature

Logbook reference values

Parameter Expected Deviation means
Exhaust temperature by cylinder 310–370 °C (LNG); 350–420 °C (diesel) Spread >15 °C → check gas/pilot
Gas injection pressure 280–320 bar Deviation → HP compressor/valve
Pmax ±2 bar Deviation → control system
Pilot fuel share 3–8% Deviation → efficiency

Common Failure Modes

HP compressor failure
Symptoms: Pressure drop, diesel fallback
Causes: Wear at 300 bar, Seal failure
Preventive: Maintain HP compressor per instructions, check redundancy
Gas injection valve leakage
Symptoms: Gas alarm
Causes: Wear at 300 bar
Preventive: Inspect valves during piston withdrawal
Cold corrosion wear
Symptoms: Increased wear rate
Causes: Gas temperature, BN
Preventive: BN25, cooling water >65 °C

Expert tips

  • 💡 Mark 10 ME-GI offers improved electronics over Mark 8.5 — check and implement software updates from MAN
  • 💡 5 cylinders on S50: Torsional vibrations at certain speeds — observe Barred Speed Range, especially during gas/diesel changeover
  • 💡 HP compressor redundancy is essential on LNG carriers — regularly test the backup compressor in operation

Related components

FGSS (HP compressor) Gas injection valves Gas detectors Double-wall piping system Turbocharger Pilot fuel system Vibration damper

Classification & regulatory

IMO Tier II/III. IGC Code. SOLAS. MARPOL — LNG nearly SOx-free, CO2 -25%.

Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.

Components & Design

Component data being added…

Technical Data

unified from engine model True

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Equipment Model #38330 · ✓ still in production