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MAN Energy Solutions

5G80ME-GI9.5

Name: MAN Energy Solutions 5G80ME-GI9.5
Brand: MAN Energy Solutions
SKU: OSE-38335

The MAN 5G80ME-GI9.5 is a 5‑cylinder, low‑speed 2‑stroke dual‑fuel main engine delivering up to 24 950 kW at 78 rpm, capable of running on HFO/MDO or LNG with near‑zero methane slip.

24950.0 kW

Power

950,000 kg

Weight

Engine Specifications

Cylinders

800 mm

Bore

3720 mm

Stroke

24,950 kW

MCR Power

78.0 rpm

MCR RPM

21.0 bar

MEP

159.0 g/kWh

SFC

2-stroke

Stroke Type

Family: MAN Energy Solutions ME-GI · Tier: IMO Tier III (gas mode) · Fuel: HFO, VLSFO, MDO, LNG

Inspector Detail

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Designation decoded

5 stands for 5 cylinders, G for Green Ultra-Long-Stroke, 80 for 800 mm bore, ME-GI for high-pressure gas injection (LNG), 9.5 for Mark 9.5. MEP 21.0 bar.

Background

The G80ME-GI9.5 is a large engine with 800 mm bore, 3720 mm stroke, and the extremely high S/B ratio of 4.65. MEP 21.0 bar indicates high specific loading. For the largest LNG carriers. Mark 9.5 as the current generation.

Calculated metrics

Stroke To Bore Ratio

4.65

Mean Effective Pressure Bar

21.0

Inspector checklist

Running Gear & Tribology

Cylinder liners: S/B 4.65 at 800 mm and MEP 21.0 bar — the most extreme loading combination, wear measurement at 12+ positions
Piston rings: Highest side pressure under gas conditions and high MEP
Cylinder lubrication: BN25 at MEP 21.0 bar — precise feed rate decisive

High-Pressure Gas Injection System

Gas injection valves: 300 bar at 800 mm — large valves, tightness critical
HP compressor: Condition and redundancy — most critical component
Gas detectors: Methane lighter than air — at the top

Crosshead & Stuffing Box

Crosshead bearing: 3720 mm stroke! — most extreme inertia forces in the ME-GI series
Stuffing box: S/B 4.65 at 3720 mm stroke — highest relative movement
Piston rod: Deflection

Electronic Control

ME control: FIVA, HPS/HCU, EICU
Gas/diesel changeover
Safety logic

Cooling System

Piston cooling: Extreme heat load at 800 mm and MEP 21.0 bar
Bore cooling for blockage
Cylinder head: NDT for cracks

Logbook reference values

Parameter	Expected	Deviation means
Exhaust temperature by cylinder	310–370 °C (LNG); 350–420 °C (diesel)	Spread >15 °C → investigate immediately
MEP	~21.0 bar	Deviation >1 bar → analyze combustion
Gas injection pressure	280–320 bar	Deviation → HP compressor
Crosshead bearing temperature	55–65 °C	Rise >3 °C → immediately
Pmax	±2 bar	Deviation → control system

Common Failure Modes

Extreme liner wear at S/B 4.65, MEP 21.0 bar and LNG

Symptoms: High wear rate

Causes: Most extreme side forces in the ME-GI series, MEP 21.0 bar with gas without ash film, BN/feed rate not optimized

Preventive: BN25 oil, calibrate Alpha Lubricator precisely, check wear rate at every piston withdrawal

Crosshead bearing overload at 3720 mm stroke

Symptoms: Temperature rise, bearing clearance

Causes: 3720 mm stroke — most extreme inertia forces, Insufficient oil supply

Preventive: Monitor temperature closely, verify oil supply

HP compressor failure

Symptoms: Diesel fallback

Causes: Wear at 300 bar

Preventive: Ensure redundancy

Expert tips

💡 G80ME-GI9.5 with 3720 mm stroke is one of the most stretched large engines in the world — the crosshead loading is extreme, temperature monitoring has absolute priority
💡 MEP 21.0 bar at S/B 4.65 and gas: This combination places the highest demands on cylinder oil management — coordination with MAN specialists recommended
💡 Stuffing box at 3720 mm stroke: The relative movement is maximal — set the inspection interval to 1000 running hours or shorter