SD 66SD

Common issues

• Bearing wear (thrust and journal bearings) due to high loads, oil contamination, or insufficient lubrication.
• Fouling of nozzle ring and turbine blades, leading to reduced efficiency and increased exhaust gas temperatures.
• Erosion or corrosion of turbine blades and nozzle ring, particularly with high sulfur fuels or poor combustion.
• Compressor impeller fouling or erosion, reducing charge air pressure and engine performance.
• Oil leakage from bearing housing seals (labyrinth or mechanical seals), leading to oil consumption and potential contamination of charge air/exhaust.
• Rotor imbalance causing excessive vibration, which can lead to premature bearing failure or structural damage.
• Exhaust gas leakage from casing joints, expansion bellows, or manifold connections, posing a safety hazard and reducing efficiency.
• Surging, often indicated by fluctuating boost pressure and a characteristic 'whooshing' sound, typically caused by engine issues, severe fouling, or incorrect operation.

Inspection checklist

• Monitor and record turbocharger speed, bearing oil inlet/outlet temperatures, oil pressures, and exhaust gas temperatures (before/after turbine) against manufacturer's specifications and historical trends.
• Check for abnormal noise, vibration, or surging during operation; use a vibration meter if available.
• Inspect for oil leaks around bearing housings, drain lines, and casing joints. Check for exhaust gas leaks from casing joints and expansion bellows.
• Visually inspect the compressor and turbine sides (via inspection ports) for signs of fouling, erosion, foreign object damage (FOD), or oil carry-over.
• Inspect the condition of the air filter elements and check the differential pressure across the filter.
• Verify the proper operation and effectiveness of the water and/or chemical washing systems for both compressor and turbine.
• Check the tightness of all casing bolts, foundation bolts, and connections to the engine and exhaust system.
• Inspect the charge air cooler for cleanliness, signs of leakage, and differential pressure across the cooler.
• Confirm the functionality of the overspeed trip mechanism (if fitted) and low lubricating oil pressure alarms.

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Complete bearing cartridge assembly (thrust and journal bearings)
• Oil seals (labyrinth or mechanical type, as per design)
• Gasket and O-ring set for overhaul
• Nozzle ring segments (partial or full set)
• Impeller nut and locking washer
• Washing nozzles (for water and chemical washing systems)
• Air filter elements
• Special tools for disassembly and assembly

Safety

• High Temperatures: Exhaust gas (up to 500°C) and casing surfaces pose severe burn risks. Ensure proper insulation and caution during inspection.
• High Rotational Speed: The rotor operates at extremely high speeds (10,000-15,000 RPM). Catastrophic failure (bursting) can cause severe injury or death. Adhere strictly to maintenance procedures and wear limits.
• High Pressure: Exhaust gas and charge air are under high pressure. Leaks can cause injury or damage. Ensure all connections are secure.
• Hot Oil: Lubricating oil is under pressure and hot. Leaks can cause fire hazards or burns.
• Noise Levels: Turbochargers generate extremely high noise levels during operation. Hearing protection is mandatory in the vicinity.

Class survey

The class surveyor will typically review the vessel's Planned Maintenance System (PMS) records for the turbocharger, including running hours, overhaul history, and spare parts consumption. An external visual inspection will be conducted for signs of oil leaks, exhaust gas leaks, corrosion, or physical damage to the casing, insulation, and piping. Operational parameters (temperatures, pressures, speed) will be verified against manufacturer's specifications. The functionality of safety devices, such as the overspeed trip and low lubricating oil pressure alarms, will be confirmed. During major overhauls, the surveyor may witness the inspection of critical components (bearings, rotor, nozzle ring, diffuser) and verify measurements against wear limits. The condition and cleaning records of the charge air cooler and exhaust gas expansion bellows will also be checked.

Estimated lifetime: 80,000 to 120,000 running hours (with regular maintenance and component replacement as per overhaul schedules)