- 30 Oct 2017
That is true. And those would need addressing too. It all comes down to cost. Clearly the immediate aim must be to make the best use of HST performance without having to spend huge amounts on the infrastructure. From an alignment point of view 85 to 90mph is possible for close to 10 miles on the climb northbound to Drumochter summit. The current northbound limit is only 60mph or 70mph for sprinters. Ironically the Sprinters can just about manage to reach 60mph on the climb - short HST's would easily do 85mph. The limit changes to 85mph on the downhill sections - mainly because that is the only place the sprinters could achieve it!I've only used the line a few times but have got the impression that the reason that the journey times are so slow is the low line speeds because of the curvature and because of the number of speed restrictions over bridges and culverts rather than the passing moves.
Where would you add more loops and how long would they be? Operationally they seem to slow things up because one train has to arrive and wait for a lengthy period of time in order for the second to pass through fast. But if either is delayed that creates more delay. Examining the timetable quite a few services cross at Moy/Tomatin..and it looks as though much of that south of culloden was singled - so the perfect stretch to redual. But as so many services cross at station loops such as Aviemore Dunkeld and Pitlochry, punctuality is essential.I entirely agree, but this thread is about Scotrail HSTs in the here and now and not the Highland Main Line of the imagination. The reality is that we have high powered trains constrained by limitations to the infrastructure, and the only improvements to hand are those that have been made to signalling at Pitlochry and Aviemore. The very least required to maintain resilience is the restoration of three loops, but we don't even have that, never mind dualling.