)
Is that because the High Barnet trains are so packed that passengers downstream can't squeeze on the train in peak hours, such that this arrangement is made to ease congestion?
On the other hand, Chesham and Amersham services at Moor Park don't depart a minute or two before southbound services from Watford now.
The northbound gaps are better than they were before as prior to Norton Bridge the XC was after the Avanti. The gaps were always going to be like that as you were never going to plan anything behind the stopper as you would catch it up between Stoke and Adswood Road.Stoke to Manchester - the pre-Covid timetable had 4 fast services and a stopper each hour.
A brilliant level of service, you might think. Not quite - the departure times were xx05, xx15, xx27 and xx35 off Piccadilly for the fasts, followed by the stopper at xx47. So a half-hour gap in fast services if you were unlucky enough to miss the xx35 (albeit the stopper is 'only' about 15 mins slower than the fast, so is still just about worthwhile taking).
It's similar, if slightly worse in the northbound direction, with fasts at xx20, xx25, xx44 and xx48 followed by the stopper at xx56. So again an effective half-hour wait if you miss the xx48.
As part of Covid timetable reductions, you might have thought that Avanti and XC (the operators of the fast services) would collaborate to ensure that there was still a reasonable service. But no, even today the pattern in most hours is that just the xx44, xx48 (and xx56 stopper) run. Meaning the service is only slightly better than hourly.
Now Stoke to Manchester isn't a huge market, and there are reasons why certain services were removed but not others, but it's just an example of how having lots of trains per hour is useless if they aren't spaced appropriately apart. I'm glad I don't live in Stoke (though that's perhaps not the only reason why!
Not really the case though, is it?
If at least one of the XCs were spaced 20 minutes apart from the London services, you'd have a perfect 20 minute frequency.
No, but it's a bit of a vicious cycle. You're never going to get people relying on the train when poor coordination of service cuts nearly doubles the generalised journey time.
I highlighted above that a 20 minute frequency is already perfectly possible. There is virtually no freight via Macclesfield - just one class 4 and class 6 each day. And the Kidsgrove conflicts really aren't insoluble on a line with a 3 minute headway.
The issue is that the Northern stopper entirely occupies the third of the hour where your desired even-interval fast service would fit. You can't have a perfect even-interval service and an all-stations hourly stopper. They occupy the same space on the graph.
Not if the stopper is overtaken at Adswood Road Jn. See my post above.
...and what about the turnround time of the stopper at Stoke, whose journey time you have just extended by 6 minutes or more?
It's currently 16 minutes in the standard hour. It could manage perfectly fine with 10 minutes; the journey time is only around an hour from end to end.
It's mainly the services that arrive from Bath and Bristol (from Weymouth) in the morning peak that are hourly, and the same for the evening return - presumably that's when the line was busiest on a standard weekday (historically, anyway). The route is exceptionally busy during the summer holidays and on summer weekends - Pre-COVID, the line was managing a half hourly service towards Weymouth for some of the morning on summer Saturdays (Usual services, GWR HST, SWT 159 and I think an additional short working from Westbury), before returning to two-hourly, and then hourly returns in the evening, but as you say - one delay is all it took for things to go wrong. Trains can pass at Castle Cary, Yeovil Pen Mill, Maiden Newton and Dorchester West. Still, in the usual timetable, two hour gaps (with some three hour gaps) in service between Weymouth/Dorchester and the best located station for Yeovil is poor and is never going to entice passengers to use the services if they have other means of travelling.
Sunday's Shipley>Bradford service sees 3 tph, but a 41-minute gap every hour.
I was going to mention the Halifax–Leeds service, the introduction of the Halifax–Hull trains did make it slightly better than the previous timetable, but only by a few minutes.
