(23 Sep 2022, 8:47 am)streetdeckfan wrote Is there a reason the X21 wasn't transferred to Washington with the drivers?
Efficiency and cost. It's more efficient to run the X21 from Riverside (with reliefs at Gateshead).
The remote reliefs are presumably factored into the tender price of the 25 and 28/29, and the 58 is a short-term thing (will eventually return to Riverside) until the staffing situation improves at Riverside.