On Jun 10, 6:22*pm, "Paul Scott"
wrote:

Axle bearing faults apparently,

Seems bearings was a duff rumour

No ... axle bearings are the traction return earth path. Think about
it ... there is no other point of contact for the earth path.

Ah I see. So where does brush gear come into it? I thought that would be
used to bypass the bearings to avoid heating effects. Might be thinking of
something else though...

Actually I wrote that so fast I am in error ... bearings by virtue of
being metal are conductors, there is some kind of brush that AFAIK
provides the electrical path to avoid arcing in the roller bearing.
IIMU there is a brush within the bearing housing - maybe thats the
issue.

As I surmised on another forum, I suggest bearings size is the cause,
earth path issues the effect

--
Nick