(14 Sep 2015, 5:42 pm)Dan wrote Yeah, it was. Services 22/24 were interworking for the same reason (and don't now).
They've obviously lost their MAX-spec spare (1415) to Stockton, so the appearance of standard-spec vehicles on Durham's allocation on the X12 was bound to increase. We've discussed at length in other areas of the forum the reasons why vehicles can be missing from service - makes a change seeing it on here, although the same comments made previously apply here too.
They should have plenty of Sapphire spares they could have used on the X12 until the 6 launch (as indeed they have used at times).