We'll probably see C4Ks on this route before we see 22Ks at IE's pace
edit: If IE used 90mph capable stock rather than, let's say, 70mph 29000s, then based on existing Enterprise timings from Newry-Drogheda the train could leave at about 0652 - and hey, maybe even offer Dundalk or Drogheda people a chance to make the 0650 departure to Belfast. But hey, who needs to make Belfast before 0945, right? Would this exemption even allow northbound carriage of passengers even if IE made time to stop on the way north?