Coordinating Onboard & Workshop Repairs
A dry-dock repair programme brings together equipment with different inspection, machining and assembly requirements. For this project, INJEGOV’s scope extended from the main engine to cargo and auxiliary pumps, governors, electric motors, heat exchangers, deck machinery and an intermediate shaft bearing. Components were transferred to the workshop where required, while selected equipment was serviced in situ because of its size and restricted removal access.
MAN B&W 6G60ME-C9.2 Main Engine Overhaul
The main engine scope covered all six cylinder units. Cylinder covers, exhaust valve assemblies, piston-and-rod assemblies, cooling jackets and stuffing boxes were dismantled for servicing. Workshop work included cleaning, visual and dimensional inspection, dye penetrant checks and hydraulic pressure testing of the relevant components. Cooling passages were cleaned, seals and O-rings renewed, and the units prepared for onboard reassembly with owner-supplied piston rings and other specified spares.
Cylinder liner work and dimensional checks formed part of the programme. The report records liner diameters within the stated maker’s limits. Onboard work also included bearing and guide shoe clearance measurements and crankshaft deflection readings after overhauling.
Main Engine Cylinder Liner Measurement
Cylinder liner dimensional inspection during main engine overhauling
MAN B&W Main Engine Cylinder Unit Dismantling
Onboard dismantling of MAN B&W main engine cylinder units
Cylinder Cover Inspection & Injector Hole Repairs
Six cylinder covers were transferred to the workshop for disassembly, carbon removal, visual and dimensional inspection, dye penetrant inspection and hydraulic pressure testing. Targeted repairs addressed eight injector holes across five covers.
The affected areas were ground to remove corroded material and checked again by dye penetrant inspection. Repair work combined preheating and Inconel 625 welding, controlled annealing and final grinding or machining to standard dimensions, followed by lapping. This brought local surface restoration into the wider cylinder cover service.
Cylinder cover surface inspection during workshop servicing
Exhaust Valve Overhaul & Surface Reconditioning
Six exhaust valve assemblies underwent workshop overhauling, including cleaning, dimensional checks, dye penetrant inspection and reassembly. The component repair scope included four exhaust valve spindles and three exhaust valve seats.
Spindle reconditioning involved removal of damaged material, preheating, NIMONIC welding in an automatic welding unit and machining to standard dimensions, followed by finishing of the landing surfaces. Seat reconditioning used laser cladding to rebuild the specified landing surfaces and diameter, followed by machining, final measurements and cleaning of the cooling holes.
Exhaust Valve Housing Surface Inspection
Inspection of the exhaust valve housing seating area
Exhaust Valve Seat Machining
Workshop machining within the exhaust valve seat reconditioning scope
Exhaust Valve Spindle Welding
Automated welding during exhaust valve spindle reconditioning
Piston Crown Reconditioning & Assembly
Four piston crowns received reconditioning of their grooves and diameter using submerged arc welding, followed by controlled annealing and CNC machining to the original dimensions. The ring grooves were hard chrome plated, with hardness checks, grinding and final dimensional verification using OEM gauges.
The crown top surfaces were rebuilt with Inconel 625 by MIG welding and finish-machined by CNC. Piston-and-rod servicing also included cleaning, dimensional inspection, dye penetrant checks and hydraulic pressure testing. The workshop photographs document the piston assemblies during the broader servicing and reassembly sequence.
Piston assemblies during workshop servicing within the dry-dock overhaul
Cargo Pump Overhaul & Shaft Restoration
Cargo pump work combined dismantling and inspection with impeller, shaft and wear ring repairs. For three cargo pumps, the scope included machining the impellers at the wear ring locations, fabricating and fitting brass rings, and setting the clearances against the mating pump wear rings.
Shaft reconditioning addressed bearing and labyrinth seal journals through pre-machining, automatic GMAW rebuilding with stainless wire and final machining to nominal dimensions. Additional work included fabrication of a throttle bush and flinger for one pump and restoration of the cargo pump wear rings.
Cargo Pump Onboard Dismantling
Cargo pump dismantling as part of the dry-dock repair programme
Cargo Pump Impeller and Shaft Machining
Machining of a cargo pump assembly during component restoration
Auxiliary Pump Overhaul & Machining
The pump programme extended to ballast, lubricating oil, boiler feed, sea water cooling, fresh water cooling, EGCS, fire and general service, condenser and scrubber systems. Work included disassembly, cleaning, inspection, shaft and impeller checks, impeller balancing, reassembly and installation, with running tests included in the service scope.
Component-specific repairs addressed worn impeller surfaces and pump body wear ring locations. INJEGOV fabricated and fitted brass rings and inserts, machined mating surfaces and adjusted clearances. Gaskets, seals and other required parts were supplied or fabricated within the wider project, alongside owner-supplied spares.
Marine Auxiliary Pump Workshop Overhaul
Auxiliary pump servicing across multiple vessel systems
Marine Pump Workshop Servicing
Hands-on workshop servicing within the auxiliary pump overhaul programme
Electric Motor, Fan & Blower Servicing
Electric motor servicing covered equipment associated with pumps, IGS blowers, boiler forced-draft fans and main engine auxiliary blowers. The scope included disassembly, cleaning, inspection, bearing renewal with the specified spares, drying and insulation resistance testing. Selected motors were serviced in situ where size and access restricted workshop removal.
Workshop machining restored worn bearing pockets in motor end covers through machining, sleeve fabrication and fitting, followed by finishing to standard dimensions. Additional work included shaft journal polishing, IGS blower bearing housing servicing and fan dynamic balancing.
Electric Motor Bearing Pocket Machining
Machining of an electric motor end cover bearing location
Marine Fan and Blower Impellers
Fan and blower components within the electric motor and ventilation equipment service scope
Windlass & Mooring Winch Reconditioning
Deck machinery work included removal of a windlass/mooring winch assembly for workshop dismantling and inspection of its shaft, drums, gearing, brake and clutch components. Repairs combined bush renewal, phosphor bronze bearing fabrication, shaft checks and journal restoration.
The machining scope included rebuilding shaft journals by automatic GMAW, finishing to standard dimensions, alignment checks and dye penetrant inspection. Drum brake landing surfaces were machined to remove corrosion, and bearing housings were machined to correct ovality. Bearing inspections and jack-up tests were also included, with clearances recorded in the service report.
Mooring Winch Shaft Machining
Shaft machining during windlass and mooring winch reconditioning
Windlass and Mooring Winch Workshop Assembly
Deck machinery assembly during workshop overhauling
Mooring Winch Crane Lifting During Dry-Dock Repairs
Crane handling of the mooring winch assembly during the dry-dock repair programme
Intermediate Shaft Bearing Inspection
The intermediate shaft bearing was opened for inspection, including removal of the lower bearing part, cleaning and reassembly. The photographic record shows the exposed shaft journal and the removed bearing shell, documenting a separate propulsion shafting task within the dry-dock programme.
Onboard inspection of the intermediate shaft bearing
Governor Overhaul & Bench Testing
Three WOODWARD cargo oil pump turbine governors and three YANMAR diesel generator governors were removed for workshop servicing. Work included complete disassembly, cleaning, visual and dimensional inspection, repair parts replacement and reassembly, followed by running tests and adjustments on a test bench according to manufacturer standards and specifications.
The governors were transported back for onboard installation. The report also records an operating-oil observation, illustrating the role of workshop inspection in identifying service requirements beyond the mechanical repair itself.
YANMAR Governor Workshop Testing
YANMAR governor servicing and workshop testing within the dry-dock programme
WOODWARD Governor Overhaul
WOODWARD governor disassembly and inspection during workshop overhauling
Heat Exchanger Cleaning & Starting Valve Service
The wider scope included in-situ chemical cleaning by recirculation of two central fresh water coolers. Condenser and drain cooler work included opening covers, mechanically cleaning tubes with brushes and reassembling the units. The ejector condenser was also listed within the heat exchanger programme.
The main engine starting valve was included for removal, workshop disassembly, cleaning, inspection and seal renewal using the specified ship-supplied parts, followed by reassembly and reinstatement.
Fuel Valve Servicing & Final Mechanical Checks
Eighteen main engine fuel valves were included for disassembly, chemical cleaning, inspection, polishing and reassembly, with working-pressure adjustment and test bench checks. The scope also covered spindle guide servicing and needle-and-seat grinding.
Recorded crankpin, main bearing, crosshead bearing and guide shoe clearances were reported within the maker’s stated limits, as were the crankshaft deflection readings after overhauling. Sea-trial attendance by service engineers was included in the project scope; the report does not provide separate sea-trial performance results.
