Update 23rd February. By Martin Howard and Ian Robins.

D7017 is undergoing some refurbishment work at the moment over the winter period.
Photos below from the 11th February by Martin, showing the refurbished boiler room in D7017 after initial
painting. On the floor at the left side of the image is one of the newly installed mounts for securing the new
battery rack.
The other photo is of the new battery rack in its first coat of primer. This will provide a much neater storage
option for the batteries on the loco.

D6566 – The loco this week went to BL in conjunction with D9526 for test running between BL and NF top
and tail with a three coach rake of coaches.
A team consisting of Andy, Will, Clive and myself with Martin as driver were on board.
James from WSR Ops was the guard.
After a couple of return trips a problem with the Class 14 meant that it was left at BL for attention by her
support crew and the 33 continued alone.
All went well for two more return trips but on the next run towards NF with full power applied, a momentary
drop in amps was noted combined with a puff of smoke from under the drivers desk in No.1 cab from where
it was being driven.
The train was brought to a halt and Andy who had been travelling in the rear No.2 cab reported having
seen a bright flash accompanied by a bang.

An investigation inside the engine room was performed and the ominous black stains on the grilles
betrayed the cause, a main generator flashover had occurred.
Removal of the brushgear covers revealed arc damage primarily between the positive brush box at the 10
o’clock position and the connection point for the negative brush box above.
Minor arcing had also occurred between other boxes and the edge of the commutator all around the
circumference and a coating of carbon and copper splatter had spread around.

Inside the control cubicle the Power Earth Fault Relay (EFR) flag was showing TRIP and was therefore
Despite the mess around the brushgear no other major damage was apparent so an attempt was made to
take power again and this proved successful.
Curiously, the smoke from under the desk was found to be the Control Earth Fault MCB arcing, the theory
behind this still to be established.
Therefore, with careful driving the loco propelled the three coaches back to BL and parked them in the
sidings without further incident and the EFR remained SET.
To confirm that no damage had also been sustained by the Traction Motors the loco was then put over the
pit at BL and internal examinations performed, this revealed all to be well.
So with some remedial work having also been performed on the Class 14, the two locos were coupled up
and worked in their booked path back to WN.
It was apparent that the some major cleaning up was required inside the generator so on Sunday with
assistance from Thomas the brushgear was rotated and all brush boxes were removed for attention on the

Whilst I dressed out any arc damage with a file as far as was necessary, Thomas gave the brush boxes
and insulators a thorough wash in electrical cleaning fluid and dried them off.
Thomas has also cleaned and re-painted the soot stained grilles.
Attention then turned to the interior of the generator.
The engine was barred around and the v-ring and edges of the commutator segments were cleaned
before coating with Ultimeg Anti-Tracking Paint, luckily we had some in stock.
The brush box insulators have similarly been coated with Anti-Track.

A good fresh arc attachment point was identified on the lower ridge of the brush ring adjacent to one of the
negative brush boxes, this was filed down and coated with Anti-Track.
It was apparent that there have been a good number of arc attachments to the brush ring lower ridge over
the life of the generator, under previous ownership of course!  So that ridge will be coated with Anti-Track
as it is rotated to refit the brush boxes.
A quick insulation check on the armature gave a reading of tens of megohms so will be ok.
The stator side gave a lower value (once the EFR isolation link was removed) but this will be in parallel with
many other items such as the traction motors so needs to be separated to give a definitive reading.

However, no obvious cause of the flashover has so far been identified, it could have been a piece of
debris that has just vaporised.  So next weekend it should be a case of re-assemble and try again!