(19 Dec 2018, 7:57 pm)S830OFT wrote A suggestion to the 8 is to have it run to Spennymoor and back then interwork onto the X21 using Gas Buses.That would be a logistical nightmare, the times would have to match up correctly on the 8, X21 & X22 (plus the 5/5A & 7 between Darlington and Aycliffe) to make that work and in their current forms they do not, if the 8 went standalone a round trip would take 2 and a half hours but the X21 currently takes about 4 hours and X22 takes 3, so only way that would really work is to give X21 & X22 roughly half an hour layover at Peterlee/Sunderland which won't happen due to extra resources needing to be required and driving hours could be a issue especially on the X21 and you would end up with X22 being parked up for around 35 minutes in Middlesbrough as well (alternatively terminate both services at Seaham to allow times to match without long layover excluding Middlesbrough on X22).
If the 8 was to be cut to terminate in Spennymoor, the allocation of EcoCities would be a issue if it was to perform the current Sunday loop within Spennymoor due to a turning issue, although it is actually not impossible to get them round.