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Sulzer
9RTA84C
The Sulzer 9RTA84C is a low‑speed, two‑stroke main propulsion engine delivering 34 380 kW at 102 rpm, distinguished by its large 840 mm bore and proven RTA family reliability.
34380.0 kW
Power
Engine Specifications
9
Cylinders
840 mm
Bore
2400 mm
Stroke
34,380 kW
MCR Power
102.0 rpm
MCR RPM
2-stroke
Stroke Type
Family: Sulzer RTA
· Tier: IMO Tier I
· Fuel: HFO, MDO
Inspector Detail
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Designation decoded
9RTA84C: 9 Zylinder, Sulzer RTA-Baureihe, 84 cm Bohrung, C=Containerschiff-Optimierung. Zweitakt-Kreuzkopf-Langsamläufer mit zahnradgetriebenem Nockenwellenantrieb. Für Containerschiffbetrieb mit variablen Lastprofilen optimiert.
Background
The 9RTA84C is optimized for the container ship market with 840 mm bore and 2400 mm stroke. The C designation stands for Container and reflects the design for the demanding operating conditions of container ships with frequently changing loads, slow-steaming requirements and high availability demands. At 840 mm bore, the engine falls within the range of mandatory dry-dock inspection (820–960 mm). The 9-cylinder configuration remains the most critical variant with regard to engine length and alignment. VIT, Pulse Lubrication and CLU standard equipment.
Calculated metrics
Stroke To Bore Ratio
2.857
Inspector checklist
Containerschiff-Betriebsprofil
- Motor auf Slow-Steaming-Tauglichkeit prüfen (Containerschiff-typisch)
- Evaluate part-load operating hours and their effects on wear
- Lastwechselhäufigkeit dokumentieren (Container-Liniendienst)
- Evaluate turbocharger surging risk at part load
Cylinders and cylinder liners (dry-dock mandatory 840 mm)
- Zylinderlaufbuchsen systematisch vermessen (mindestens 6 Ebenen)
- Examine cylinder liner surface for bore polishing at part-load operation
- Inspect CLU condition at docking
- Check cooling water spaces for corrosion and deposits
Motorausrichtung (9-Zylinder-kritisch)
- Kurbelwellen-Deflexion an allen Lagerstellen messen
- Document foundation bolts and chock condition
- Containerschiff-spezifische Belastungsverteilung berücksichtigen
- Monitor thermal expansion with varying load profiles
VIT and injection system
- Test VIT function at various load points (Container: frequent load changes)
- Inspect fuel injection nozzles for wear and coking
- Kraftstoffpumpen-Index kontrollieren
- Align fuel injection timing across all 9 cylinders
Pulse Lubrication System
- Dosierrate an Betriebsprofil anpassen (Slow-Steaming berücksichtigen)
- Check oil supply channels for deposit formation at part load
- BN-Management für wechselnde Lastprofile optimieren
- Dosierventile an allen 9 Zylindern funktionsprüfen
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Maximaler Zünddruck (Pmax) | 138–155 bar | Scatter >5 bar between cylinders indicates VIT or fuel injection problems |
| Exhaust gas temperature per cylinder | 345–420 °C | Bei Slow-Steaming niedrigere Werte akzeptabel – Streuung >20 °C untersuchen |
| Cylinder liner wear | 0,05–0,15 mm/1000 Bh | 840 mm bore: dry-dock inspection prescribed – monitor bore polishing at part load particularly |
| Kurbelwellen-Deflexion | Herstellervorgabe ±0,05 mm kalt | 9-Zylinder-Konfiguration erfordert engmaschige Überwachung |
| Spülluftdruck | 2,3–3,7 bar (lastabhängig) | Bei Slow-Steaming auf ausreichenden Spülluftdruck achten – Turbolader-Cut-out prüfen |
| Turbolader-Drehzahl | Lastabhängig gemäß Herstellervorgabe | Speed reduction may indicate turbocharger fouling – more frequent in container operation |
| Zylinderöl-Dosierrate | 0,8–1,2 g/kWh | Bei Slow-Steaming ggf. Anpassung erforderlich – zu niedrige Rate verstärkt Bore-Polishing |
| Kompressionsdruckkurve | 118–138 bar | Falling compression pressure indicates piston ring or valve problems |
Common Failure Modes
Bore polishing by slow steaming
Symptoms: ['Glänzende Laufbuchsenoberfläche', 'Erhöhter Ölverbrauch', 'Blow-by-Zunahme']
Causes: Dauerhafter Teillastbetrieb im Containerdienst, Insufficient cylinder oil dosing at low load, Piston rings do not achieve optimal contact pressure at part load
Preventive: Adjust cylinder oil dosage for slow steaming, perform regular full-load runs (load-up), assess liner surface during piston withdrawal
Turbocharger surging at part load
Symptoms: ['Pulsierendes Geräusch vom Turbolader', 'Instabiler Ladedruck', 'Abgastemperatur-Schwankungen']
Causes: Teillastbetrieb nahe Surging-Grenze, Turbolader-Verschmutzung reduziert Wirkungsgrad, Falsche Turbolader-Kombination für Slow-Steaming
Preventive: Set turbocharger cut-out system correctly, perform regular turbocharger wet cleaning, observe operating limits at part load
9-Zylinder-Ausrichtungsprobleme
Symptoms: ['Steigende Deflexionswerte', 'Ungleicher Lagerverschleiß', 'Vibrationsänderungen']
Causes: Extreme engine length with 9 cylinders, Containerschiff-Strukturverformung, Fundamentermüdung
Preventive: Regelmäßige Deflexionsmessungen, Lagertemperatur-Monitoring, Fundamentschrauben-Kontrolle
Einspritzdüsen-Verkokung
Symptoms: ['Schlechtes Strahlbild', 'Kraftstoffverbrauchsanstieg', 'Abgastemperatur-Streuung']
Causes: Häufige Lastwechsel im Containerdienst, Schwerölqualität, Unzureichende Kraftstoffaufbereitung
Preventive: Düsenwechsel-Intervalle verkürzen, Kraftstoffaufbereitung optimieren, Einspritzdruck kontrollieren
Zylinderlaufbuchsenrisse (840 mm Bereich)
Symptoms: ['Kühlwasserverlust', 'Wasser im Spülluftkasten', 'Druckabfall Kühlsystem']
Causes: Thermal cyclic stress from load changes, Kavitationskorrosion, CLU-Dichtungsversagen
Preventive: Trockendock-Inspektion gemäß Klassifikation für 840 mm, Kühlwasserchemie kontrollieren, Druckprüfungen durchführen
Expert tips
- 💡 Container ship operation with slow steaming is the greatest challenge for the 9RTA84C: bore polishing and insufficient cylinder oil supply at low load must be actively managed. Plan load-up runs according to manufacturer recommendations.
- 💡 At 840 mm bore do not forget the dry dock inspection requirement – particularly examine the liner surface for bore polishing damage, which is typical for container ship part-load operation.
- 💡 The 9-cylinder configuration in combination with frequent load changes of container service places above-average stress on the gear-driven camshaft drive – prioritize torsional vibration measurements and tooth flank inspection.
Related components
Turbocharger (surging limit at part load)
Ladeluftkühler
Crankshaft bearing and main bearing
Fuel treatment and separators
Exhaust gas boiler and economizer
Wellengenerator (falls installiert)
Classification & regulatory
MARPOL Annex VI emission regulations. EEDI/EEXI requirements relevant for container ships in slow steaming operation. 840 mm bore requires dry dock inspection of cylinder liners in accordance with classification society rules. NOx Technical Code compliance to be ensured by VIT. CII rating for container ships can influence engine operating profile.
Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.
Other Cylinder Configurations 50
5RTA48T
5 cyl
· 6,600 kW
5RTA48T-B
5 cyl
· 7,150 kW
5RTA52
5 cyl
· 7,350 kW
5RTA52U
5 cyl
· 7,850 kW
5RTA58T
5 cyl
· 10,150 kW
5RTA58T-B
5 cyl
· 10,800 kW
5RTA62
5 cyl
· 10,100 kW
5RTA62U
5 cyl
· 11,000 kW
5RTA62U-B
5 cyl
· 12,000 kW
5RTA72
5 cyl
· 16,000 kW
5RTA72U
5 cyl
· 17,000 kW
5RTA72U-B
5 cyl
· 18,000 kW
5RTA82T
5 cyl
· 16,600 kW
5RTA84T
5 cyl
· 19,100 kW
5RTA84T-D
5 cyl
· 22,600 kW
6RTA48T
6 cyl
· 7,920 kW
6RTA48T-B
6 cyl
· 7,920 kW
6RTA52
6 cyl
· 8,820 kW
6RTA52U
6 cyl
· 9,420 kW
6RTA58T
6 cyl
· 12,180 kW
6RTA58T-B
6 cyl
· 12,960 kW
6RTA62
6 cyl
· 12,120 kW
6RTA62U
6 cyl
· 13,200 kW
6RTA62U-B
6 cyl
· 14,400 kW
6RTA72
6 cyl
· 19,200 kW
6RTA72U
6 cyl
· 20,400 kW
6RTA72U-B
6 cyl
· 21,600 kW
6RTA82T
6 cyl
· 19,920 kW
6RTA84C
6 cyl
· 22,920 kW
6RTA84T
6 cyl
· 22,920 kW
6RTA84T-D
6 cyl
· 27,120 kW
6RTA96C
6 cyl
· 32,940 kW
6RTA96C-B
6 cyl
· 34,320 kW
7RTA48T
7 cyl
· 9,240 kW
7RTA48T-B
7 cyl
· 10,010 kW
7RTA52
7 cyl
· 10,290 kW
7RTA52U
7 cyl
· 10,990 kW
7RTA58T
7 cyl
· 14,210 kW
7RTA58T-B
7 cyl
· 15,120 kW
7RTA62
7 cyl
· 14,140 kW
7RTA62U
7 cyl
· 15,400 kW
7RTA62U-B
7 cyl
· 16,800 kW
7RTA72
7 cyl
· 22,890 kW
7RTA72U
7 cyl
· 23,800 kW
7RTA72U-B
7 cyl
· 25,200 kW
7RTA82T
7 cyl
· 23,240 kW
7RTA84C
7 cyl
· 26,740 kW
7RTA84T
7 cyl
· 26,740 kW
7RTA84T-D
7 cyl
· 31,640 kW
7RTA96C
7 cyl
· 38,430 kW
Components & Design
Component data being added…
Technical Data
unified from engine model
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Maritime Network →Manuals
-
operating
Sulzer RTA Operating ManualWärtsilä Switzerland (historical Sulzer)
-
maintenance
Sulzer RTA Maintenance ManualWärtsilä Switzerland (historical Sulzer)
-
spare_parts
Sulzer RTA Spare Parts CatalogueWärtsilä Switzerland (historical Sulzer)
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Equipment Model #38695
· ✓ still in production