Hardly express...And how about this one - non-stop Earlsfield to Waterloo:
http://www.realtimetrains.co.uk/train/W35771/2019/06/10/advanced
If this got a clean run it would be doing it in 52, other trains get in the way. If it was clean with no TSRs it would be doing it in 47.At 56 minutes Swindon-Paddington it isn't fast - only about 80mph. When introduced the HST timing was 49 mins non-stop and that was for regular workings rather than anything special.
If this got a clean run it would be doing it in 52, other trains get in the way. If it was clean with no TSRs it would be doing it in 47.