Did these today.The set with 47712+57004 managed to be within 10mins of the shedule most of the day, only been delayed at Seaham due to the long signal section on the up.
However 57009+47802 were delayed on their 1st trip of the day by about 45mins & were behind badly until mid afternoon when 1443 Darlington-Sunderland they worked terminated at Hartlepool so they could get on time.
But a good day anyway & after the 1st round trip, went to York & dropped onto the Pathfinder trip with 67029, so did that back to Hartlepool, then dropping back onto ship-ex's.
Just like the old days with diesel hauled service trains in the north east.