At In Situ Machining Solutions, we provide specialist onsite machining services for complex industrial repairs where removing major components is impractical. This recent project involved precision rotor thrust face machining onboard a UK defence marine asset after engineers identified damage during a routine inspection. Working on behalf of a leading global engineering service provider, our team designed a bespoke machining solution that restored the damaged thrust face to original equipment manufacturer requirements without removing the rotor assembly. This onsite machining service significantly reduced downtime and avoided months of additional work.
During a planned inspection, engineers identified damage to the thrust collar on the forward main engine rotor shaft. Contact between the white metal Renk thrust bearing and the rotor shaft thrust face. The resulting damage affected both the flatness and surface finish beyond acceptable OEM tolerances.
The engineering team determined replacing the bearing alone was unviable. Installing a new bearing against the damaged thrust face would result in further wear and increase the risk of seizure during operation. Removing the shaft for repair required a substantial strip down of the propulsion system, introducing the potential need for dry docking. This approach added considerable time to the repair programme and delayed the vessel's return to service. The client required a rotor shaft thrust face repair method completed onboard while maintaining bearing clearances within OEM specification.
Damaged Thrust Face
Damaged Thrust Face
Following an initial survey, our engineering team developed a dedicated machining solution specifically for the restricted working area around the rotor. Because standard equipment could not access the repair location, our workshop designed and manufactured a low clearance orbital machining system with a custom facing slide before mobilisation. The workshop dedicated four days to manufacturing and preparing the specialist equipment before work began on site.
Once onboard, the engineers mounted the orbital machine directly onto the journal diameter and aligned the equipment within 0.01mm of the shaft centreline. This setup ensured the team could machine the thrust face accurately while maintaining the original geometry of the component.
To preserve the bearing clearance, our engineers removed only the minimum amount of material required. The team took fine cuts of just 0.02mm throughout the precision machining process before polishing the thrust face to achieve the required flatness and surface finish. Despite the restricted access, two engineers completed the repair safely by working twelve hour shifts across a six day programme. The team allocated two days to permits and work area preparation, alongside four days carrying out the machining operation itself.
Surface Finish Post Machining and Polishing
The finished repair successfully restored the thrust face within the client required tolerances.
Key project results included:
The completed surface finish exceeded the minimum requirement of 0.4 Ra UM while maintaining the dimensional accuracy needed for reliable operation.
Face Post Machining and Polishing
Face Post Machining and Polishing
Projects like these demonstrate why precision machining directly on the vessel is often preferred for large rotating equipment. By completing the work onboard, the client bypassed extensive dismantling of surrounding equipment. The potential transportation of large components for offsite repair was completely eliminated. The damaged thrust face was restored in place using bespoke portable equipment designed specifically for the application.
The completed industrial machinery repair restored the rotor thrust face to the required condition while preserving the bearing clearances within OEM specification.
The client installed a standard thrust bearing following completion of the machining works, removing the need for replacement shafts or complex offsite refurbishment. Every repair is planned around the individual application, allowing our engineers to deliver accurate marine engineering repairs even where access is severely restricted.
In Situ Machining Solutions supports marine, defence, power generation, and heavy industrial clients worldwide with precision onsite machining services. From rotor shaft machining and crankshaft repairs to journal machining and defence engineering projects, our engineers develop bespoke solutions that minimise downtime while restoring critical components to standard requirements.
Contact our team today to discuss your project requirements and discover how our specialist engineering services provide actionable solutions for critical equipment failures.
