TCT 18

Common issues

• Bearing wear (journal and thrust bearings) leading to excessive rotor play and vibration
• Compressor side fouling (dirt, oil mist) reducing efficiency and causing surging
• Turbine side fouling (soot, unburnt fuel) reducing efficiency and increasing exhaust back pressure
• Exhaust gas leaks from casing joints, expansion bellows, or gas inlet/outlet pipes
• Damage to nozzle ring or turbine blades (erosion, corrosion, foreign object damage)
• Oil leakage from bearing housing seals or oil supply/drain connections
• Cracks in turbine or compressor casings due to thermal stress or vibration
• Malfunction of speed sensor or associated monitoring system

Inspection checklist

• Check rotor axial and radial clearances (free play) against OEM limits using a dial gauge.
• Inspect compressor impeller and diffuser for fouling, erosion, and damage. Clean as necessary.
• Inspect turbine blades, nozzle ring, and gas inlet casing for fouling, erosion, corrosion, and cracks.
• Verify integrity of all casing joints, expansion bellows, and pipe connections for exhaust gas and oil leaks.
• Check condition of air filter elements and ensure proper sealing.
• Examine bearing housing for oil leaks and check oil level/condition in gravity tank (if applicable).
• Monitor turbocharger speed, exhaust gas temperatures (in/out), and boost pressure for abnormal readings.
• Listen for unusual noises (whining, grinding, rubbing) during operation and run-down.
• Inspect securing arrangements and anti-vibration mounts for tightness and condition.

Service intervals

Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.

Typical wear limits

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

Critical spares

• Complete set of journal and thrust bearings (including sleeves and pads)
• O-ring and gasket kit for casing joints and service openings
• Speed sensor (magnetic pick-up or eddy current type)
• Oil pump (if externally driven or critical for lubrication system)
• Air filter elements (if applicable)
• Nozzle ring segments (if modular design and prone to damage)
• Special tools for dismantling and assembly (rotor lifting gear, bearing pullers)

Safety

• Hot Surfaces: Turbocharger casings and exhaust pipes operate at very high temperatures (300-600°C). Ensure proper insulation and warning signs.
• Rotating Machinery: The rotor operates at extremely high speeds (e.g., 8,000-15,000 RPM for TCT 18). Never attempt to open casings or work near the rotor while in operation or during run-down.
• High Pressure Exhaust Gas: Leaks can cause severe burns and create hazardous conditions in the engine room.
• Confined Space Entry: Inspection or maintenance inside exhaust gas ducts connected to the turbocharger may require confined space entry procedures.
• Sudden Failure: Catastrophic failure of the turbocharger can lead to engine shutdown, loss of propulsion, and potential damage from flying debris.

Class survey

Class surveyors typically verify the general condition of the turbocharger, absence of excessive vibration, leaks (exhaust gas, oil), and proper functioning of safety devices (e.g., overspeed trip, alarm systems). They will review maintenance records, especially for bearing replacements and major overhauls. They may request a performance check or witness a run-up/run-down test. The integrity of insulation, securing arrangements, and compliance with SOLAS requirements for hot surface protection are also checked. Any signs of casing cracks or severe fouling will be noted.

Estimated lifetime: For major overhaul: 12,000 - 24,000 running hours. Total operational lifetime with proper maintenance and component replacement can exceed 100,000 hours.