.... got an alarm at night on the lub oil purifier for the main engine.
Opened the strainer
and found it clogged with white metal debris (almost powder type)
This was early morning and we were due to stop and drift anyway
that morning to wait for high tide in the S'Pore strait.
Once we opened [the crankcase],
we clearly observed a lot of quite large pieces of white metal
half-way sticking out from the bearings,
and a lot resting on the on the coarse sump filters.
Cleaned it out, measured all bearings
whilst the C/E made calls around the world.
We were advised by superint and B and W to proceed,
which we did (with a sky-high bloodpressure).
After discharging we got repair teams onboard to:
a) change the bearings and
b) modify the bottom frame of the engine.
On the inside on the lower part of the cranckcase
they welded support brackets, and also a few of the 90º "corners"
at the level of the cranckcase doors were rounded off.
And off we went.
We had failure later also on these bearings, but only minor ones,
and we changed the bearings ourselves.