Why don’t as many crews sign them, and whats the route clearance difference? I thought they were pretty similar in all respects? All utterly awful, mind
144s are a different train to 142s even though they are in the same family, so a train crew signing a 142 doesn't mean they can just work a 144 without any further training and neither does it mean a 142 being cleared for a route automatically means a 144 is cleared. There's 4 times as many 142s in the fleet as 144s and the 144s mainly stay on Yorkshire routes due to former PTE sponsorship, so there's lots of crews who don't sign 144s.