7RTA58T-B
The Sulzer 7RTA58T-B is a low‑speed, two‑stroke marine diesel engine with seven large cylinders (580 mm bore) delivering up to 15 120 kW at 105 rpm, designed for heavy fuel oil or marine diesel oil operation.
Engine Specifications
Inspector Detail
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Designation decoded
Sulzer 7RTA58T-B – 7-Zylinder, 580 mm Bohrung, 2416 mm Hub, Zweitakt-Kreuzkopfmotor mit zahnradgetriebenem Nockenwellen-Antrieb, T=Tanker-Variante, B=verbesserte Ausführung
Background
The 7RTA58T-B is the improved version of the RTA58T tanker engine. The B designation marks improvements to combustion space, piston ring package, running gear design and combustion optimization compared to the previous version. With 580 mm bore and 2416 mm stroke (S/B 4.17), the engine offers a high stroke ratio for low speed and high efficiency. Equipped with VIT, pulse lubrication and CLU. The B improvements include optimized piston ring geometry, improved running gear materials and adapted lubricating oil distribution. As a 7-cylinder engine it requires special torsional vibration monitoring.
Calculated metrics
Inspector checklist
- Measure gear flank clearance and compare with wear limits
- Zahnradkontaktbilder auf gleichmäßige Lastverteilung prüfen
- Check lubricating oil supply and oil temperature at gear drive
- Document camshaft bearing condition and bearing clearance
- Kolbenringe auf korrekte B-Version-Spezifikation prüfen (optimierte Geometrie)
- Verify running gear material and design of B version
- Verbesserte Schmierölverteilung an den Quills kontrollieren
- Combustion chamber geometry changes to be observed during piston crown inspection
- VIT-Funktion über den gesamten Lastbereich prüfen
- Pmax-Gleichmäßigkeit zwischen allen 7 Zylindern kontrollieren
- Test fuel injection nozzles for spray pattern and opening pressure
- Fuel pump timing and delivery start to be verified
- Measure cylinder oil dosage per stroke and per cylinder
- Verify CLU control and load-dependent dosage
- Lubrication quills to be checked for patency and correct spray pattern
- Drain oil analysis for neutralization performance and wear particles to be performed
- Torsional vibration damper to be checked for condition, silicone oil level and tightness
- Barred speed range documentation and compliance to be verified
- Kurbelwellendurchbiegung an allen Lagerstellen messen
- Schwingungsmesswerte mit Referenzdaten vergleichen
- Laufbuchsenverschleiß an allen Messebenen dokumentieren
- Piston rings to be checked for wear, end gap and correct B-version
- Crosshead guide and piston rod to be inspected
- Piston crown to be examined for thermal damage and crack formation
Logbook reference values
| Parameter | Expected | Deviation means |
|---|---|---|
| Zylinder-Abgastemperatur | 325–385 °C at rated load | Scatter >30 °C between cylinders indicates combustion or injection problems |
| Spülluftdruck | 2.6–3.4 bar at rated load | Low pressure indicates turbocharger or charge air cooler fouling |
| Kühlwasser-Austrittstemperatur | 78–85 °C | Elevated temperature indicates deposits in cooling system or defective thermostats |
| Kreuzkopfführungstemperatur | 50–65 °C | Increase indicates lubrication deficiency or wear |
| Kurbelwellendurchbiegung | ±0,05 mm | Exceeding indicates bearing wear or foundation deformation |
| Cylinder liner wear | ≤0,04 mm/1000 Bh (B-Version typisch verbessert) | Increased wear despite B-upgrade indicates lubrication or fuel problems |
| Maximaler Zünddruck (Pmax) | Herstellervorgabe ±3 bar | Deviation indicates VIT error or compression problems |
Common Failure Modes
Expert tips
- 💡 For the B-version, be sure to ensure uniform equipment of all cylinders with B-specification piston rings and liners – mixed equipment can lead to uneven wear and power differences.
- 💡 The improved liner wear of the B-version (typical ≤0.04 mm/1000 Bh) should be used as the new reference value in drain oil analysis.
- 💡 Bei Tanker-Einsatz mit häufigem Teillastbetrieb die VIT-Kalibrierung auch im unteren Lastbereich verifizieren – die B-Version bietet hier verbesserte Optimierungsmöglichkeiten.
Related components
Classification & regulatory
For the 7RTA58T-B, the same torsional vibration proofs apply as for the standard T-version. When converting from standard to B-version, the class surveyor must be informed and the change must be noted in the class documentation. Tanker-specific SOLAS requirements regarding emergency shutdown and overspeed protection remain unchanged. MARPOL requirements for stuffing box leakage monitoring must be observed.
Reference content for inspector orientation. Always verify against manufacturer's manual, latest service letters and class society requirements.
Other Cylinder Configurations 50
Components & Design
Component data being added…
Technical Data
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Maritime Network →Manuals
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operating
Sulzer RTA Operating ManualWärtsilä Switzerland (historical Sulzer)
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maintenance
Sulzer RTA Maintenance ManualWärtsilä Switzerland (historical Sulzer)
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spare_parts
Sulzer RTA Spare Parts CatalogueWärtsilä Switzerland (historical Sulzer)