I'm assuming you mean WRT (Warton) not WTN (Waddington) and it begs the question why use WRT not BLK?
Thanks for the correction, I did indeed mean Warton and not Waddington.
As to why we don’t use Blackpool, it’s not long enough.
Teeside is still usable for 300’s, but again, it’s not long enough for our requirements for 800’s.