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MAN Energy Solutions

6S70ME-GI10

Name: MAN Energy Solutions 6S70ME-GI10
Brand: MAN Energy Solutions
SKU: OSE-38345

The MAN 6S70ME-GI10 is a low‑speed, six‑cylinder, 2‑stroke dual‑fuel main engine delivering up to 48 480 kW at 91 rpm, notable for its high‑pressure (300 bar) gas injection and instant switch between HFO/VLSFO/MDO and LNG.

48480.0 kW

Power

Engine Specifications

Cylinders

700 mm

Bore

2800 mm

Stroke

48,480 kW

MCR Power

91.0 rpm

MCR RPM

2-stroke

Stroke Type

Family: MAN Energy Solutions ME-GI · Tier: Tier III · Fuel: HFO, VLSFO, MDO, LNG

Inspector Detail

▸

Designation decoded

{'6': 'Number of cylinders: 6', 'S': 'Super-Long-Stroke design', '70': 'Cylinder bore: 700 mm', 'ME': 'Electronically controlled (Man Electronic) two-stroke engine', 'GI': 'Gas Injection – high-pressure gas injection (approx. 300 bar) on the diesel principle', '10': 'Mark 10 – current engine generation'}

Background

The 6S70ME-GI10 is a Super-Long-Stroke dual-fuel engine with a 700 mm bore and 2800 mm stroke in the current Mark 10 generation. It is one of the most widely used ME-GI types and forms the backbone of many LNG carrier newbuild programmes. Compared with the G70 variant, it offers higher rated speeds at the same bore diameter.

Calculated metrics

Stroke To Bore Ratio

4.0

Inspector checklist

Running Gear & Tribology

Check cylinder liner for wear, surface profile and cloverleafing
Check piston rings for wear and gap clearance – 700 mm bore, piston weighs approx. 2–3 tonnes
Inspect piston crown for thermal cracking and deposits
Verify BN25 cylinder oil in gas mode, set feed rate per Alpha Lubricator
Compare wear trend with previous inspections

High-Pressure Gas Injection System (300 bar)

Check GI valves for tightness and wear – Mark 10 valve generation
Comprehensively assess HP compressor: vibration, oil, operating hours
Check double-wall piping system for leakage and annulus monitoring
Verify gas injection pressure 280–320 bar
Test MGFV and quick-closing valves for function

Electronic Control (FIVA, HPS/HCU, EICU)

Check FIVA valves for function and leakage
Check HPS/HCU system pressure and oil quality
Document EICU software status and alarm history
Test gas/diesel mode change and emergency shutdown
Evaluate PMI/CoCoS data for combustion quality

Scavenge Air & Exhaust System

Check turbocharger for condition and efficiency
Inspect scavenge air duct for oil deposits and condensation
Check exhaust gas temperature spread cylinder by cylinder
Check exhaust valves and seats for wear and corrosion
Check EGR/SCR system (if Tier III) for function

Crosshead & Stuffing Box

Check crosshead bearing for wear and bearing clearance
Check stuffing box for gas blow-by and oil loss
Inspect piston rod surface
Analyse scavenge drain and document trend

Logbook reference values

Parameter	Expected	Deviation means
Gas injection pressure	280–320 bar	Pressure drop indicates compressor degradation or valve leakage
Exhaust gas temperature after cylinder (gas mode)	310–370 °C (load-dependent)	Spread >50 °C indicates a gas distribution problem
Exhaust gas temperature after cylinder (diesel mode)	340–410 °C (load-dependent)	Deviation >30 °C indicates injection fault
Pmax (firing pressure)	According to test protocol ±5 bar	Deviation requires root cause analysis and possible adjustment
Pilot fuel share (gas mode)	3–8 % of total energy	Increased consumption shows a gas injection problem
Cylinder oil feed rate (gas mode)	0.6–0.8 g/kWh (BN25)	Over-/under-dosing affects wear and deposits
Scavenge air pressure	2.5–3.5 bar (load-dependent)	Deviation can indicate a turbocharger problem or charge air cooler fouling

Common Failure Modes

HP compressor failure

Symptoms: Gas pressure drop, automatic diesel switchover, compressor vibration and alarms

Causes: B, e, a, r, i, n, g, , w, e, a, r, ,, , l, a, c, k, , o, f, , l, u, b, r, i, c, a, t, i, o, n, ,, , i, n, t, a, k, e, , f, i, l, t, e, r, , c, o, n, t, a, m, i, n, a, t, i, o, n

Preventive: Vibration monitoring, regular oil analysis, adhere to manufacturer maintenance schedule

Gas injection valve leakage

Symptoms: Gas alarm in double-wall space, temperature spread, increased gas consumption

Causes: N, o, z, z, l, e, , e, r, o, s, i, o, n, , a, t, , 3, 0, 0, , b, a, r, , i, n, j, e, c, t, i, o, n, , p, r, e, s, s, u, r, e, ,, , t, h, e, r, m, a, l, , f, a, t, i, g, u, e, ,, , s, e, a, l, , a, g, e, i, n, g

Preventive: Valve replacement per manufacturer interval, regular tightness testing

Cold corrosion in gas mode

Symptoms: Increased liner wear, abnormal scavenge drain analysis

Causes: S, u, l, p, h, u, r, i, c, , a, c, i, d, , c, o, n, d, e, n, s, a, t, i, o, n, , f, r, o, m, , p, i, l, o, t, , f, u, e, l, ,, , w, a, l, l, , t, e, m, p, e, r, a, t, u, r, e, , t, o, o, , l, o, w

Preventive: Cooling water temperature ≥80 °C, BN25 cylinder oil, limit part load

FIVA valve malfunction

Symptoms: Uneven injection, Pmax scatter, rough running

Causes: H, y, d, r, a, u, l, i, c, , o, i, l, , c, o, n, t, a, m, i, n, a, t, i, o, n, ,, , v, a, l, v, e, , w, e, a, r, ,, , e, l, e, c, t, r, i, c, a, l, , a, c, t, u, a, t, i, o, n, , f, a, u, l, t

Preventive: Hydraulic oil filtration and analysis, FIVA test run during inspections

Expert tips

💡 The 6S70ME-GI10 is one of the standard drives for modern LNG carriers – draw on extensive fleet experience from the manufacturer and observe service letters.
💡 At 700 mm bore: pistons and liners weigh several tonnes. Verify onboard crane capacity for running gear replacement. Main bearings and crankshaft require dry dock.
💡 Always verify that methane gas detectors are mounted on the ceiling – methane (density 0.55 relative to air) rises. Function-test all detectors at every inspection.

Related components

FGSS HP compressor Gas injection valves per cylinder Gas detectors (engine room ceiling, double-wall space, compressor room) Double-wall piping system with annulus monitoring Turbocharger (6-cylinder: typically 1–2 turbochargers) Pilot fuel system Master Gas Fuel Valve (MGFV) EICU and safety system Alpha Lubricator (cylinder oil dosing)

Classification & regulatory

IMO Tier II as standard; Tier III with EGR or SCR. IGC Code fully applicable. SOLAS II-1 Reg. 55 for gas fuel installations. MARPOL Annex VI: LNG almost SOx-free, approx. 25 % CO2 reduction compared to HFO. Additional notation from the classification society required (e.g. DNV GF, Lloyd's GF).

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