(28 Jul 2014, 9:51 am)DaveyBowyer wrote I would've chosen out of 7514 to 7521 for the X15 (3) and X14 (4).
I still don't see why Arriva didn't put an order in for B9TL's before the deadline for Euro 6 for the X15 and X18. I rate Enviros well for mid distance work like the X21 and X22 but for long distances, the B9TL is far better. I know 6071 and the B7 spares have been making several appearences on the TTX but if they had've bought 10, they could've used them in rotation with one day on the X15 / X18 then swapping the following day. They are only unreliable when constantly thrashed like what they are on the A19 and that would cause problems for the X15 but if rotated properly, they'd be quite reliable particularly on the X18.
Simply put, I think it'll be down to the cost.
Go North East's Volvo B9TLs cost near enough £200k each, to the Arriva equivalent of Sapphire specification. ADL E400s on the other hand, will cost £10k-£20k or so less.
I don't think it's a coincidence that GNE purchased so many (34) last year, given that the vehicle would no longer be manufactured, after those orders.