The machine is Turbo Generator , the Gas turbine is GE Frame 1.
Fire incident happened in GT side due to Lube Oil leakage either internal or external not confirmed yet. Upon inspection , the Babbitt material loss found in bearing#3 (see attached crossection ) at LP rotor. Also coke or tar found at LP bucket. All relevant pics and GT crossection dwg attached .
The questions are:
1) what’s the origin of lube oil leakage external or internal ? Is it split from bearing housing or lube oil supply pipe leakages ?
2) what’s the root cause of lube oil leakage ?
3) What’s the root cause of Babbit materials loss at Lower part of Brg#3? Pics attached
4) how the coke or tar formed at LP buckets ? Pic attached