I was planning to travel from Kenton to Watford Junction early this morning
on the Overground, returning after 21:00 tonight. There weren't any
scheduled engineering works, but this morning, all the Overground trains on
the line were cancelled, first because of "emergency engineering" work at
Willesden Junction, then because of "signal failure" at Willesden Junction.
In the meantime, Bakerloo trains continued to run, apparently unaffected by
the mysterious problem on the shared tracks.

When I got to Watford this evening, I assumed the problem would have been
solved hours earlier, but was amazed that, not only hadn't it been fixed,
but the problem had turned into "scheduled engineering" work, and the
absent Overground trains were bustituted to Harrow and Wealsden, where the
Bakerloo awaited. Despite these supposedly tough-to-fix problems at
Willeseden Junction, the Bakerloo continued to run normally.

So does anyone know what the actual problem with the Overground was?

On 2013\08\17 23:26, Recliner wrote:
I was planning to travel from Kenton to Watford Junction early this morning
on the Overground, returning after 21:00 tonight. There weren't any
scheduled engineering works, but this morning, all the Overground trains on
the line were cancelled, first because of "emergency engineering" work at
Willesden Junction, then because of "signal failure" at Willesden Junction.
In the meantime, Bakerloo trains continued to run, apparently unaffected by
the mysterious problem on the shared tracks.

Maybe a signal had fallen down and was fouling the Overground loading
gauge? ;-)