Currently lots of services are double voyagers, extensions are just half of a double voyager going somewhere with the other half going to the usual destination. When they need to divert via the Chiltern route they have low stock demand due to the engineering work so they can run them using voyagers.
They also transfer unused Pendolinos to the Birmingham - Glasgow/Edinburgh route, releasing Voyagers for the Chilterns blockade busters, this is apparently the only time Pendolinos are seen in Edinburgh now...
Paul
Yep, we lost our daily Edinburgh to Euston and return back in December 2007. Recently we had Pendolino's on Edinburgh - Lockerbie shuttles due to work on the
WCML▸ ! Bit of a waste of resources for one stop!