(Yesterday, 8:51 am)Retro Nero wrote There was no fast service (X10) to Middlesbrough, it was the X1 which called at Chester, Durham and Sedgefield....
When the X10 ran in the early and mid nineties I seem to remember it being jointly operated by Northern, Tees and United, and buses ran the X10 in one direction and the X1 in the other.