On 2015\06\21 02:45, Recliner wrote:
Basil Jet wrote:

IIRC Drayton Park has both fourth rail and overhead,
although obviously not for much distance.

The fourth rail isn't operational. It was disconnected when the overhead
was installed. It does have a short length of third rail and overhead, but
that's not uncommon.

This seems to imply that overhead + 4th rail is in some way harder to do
than overhead + 3rd rail... I would have thought it would be the other
way around.