HS2 ‘alternative’ examined
The second part of rail analyst William Barter’s post examining 51M’s alternative plans for the West Midlands.
But what could happen if a practical timetabler tried to make something of their plans?
There are now some crucial differences:
- The xx11 from Coventry has been brought forward by about 5 minutes, to resolve the conflict approaching Birmingham International, and get the London Midland train to Birmingham before the new regional runs it down. But:
– It doesn’t quite work, as the regional service has to take pathing time approaching New Street, and arrives there a couple of minutes later than 51M tell us it will.
– Worse than that, as the train now leaves Coventry at the minimum possible interval after the xx03 from London, that doesn’t give passengers time to transfer, and so the connection out of the London train for local stations to Birmingham is effectively broken. Moreover, if the London train arrives a bit late at Coventry it will then have to follow the stopper, losing more time.
– The freight opportunity has been destroyed, as that path used to follow the Virgin from Coventry and now the stopper is having to do that, only just getting to Stechford before the following regional train.
– The revised path doesn’t link with all the current London Midland paths arriving at Coventry from the South. Maybe the new regionals will fill the gap South of Coventry, but as they don’t stop North of Coventry, what is then lost is connectivity between West Midlands local stations and Rugby, Northampton and Milton Keynes, just the sort of places people ought to be able to commute to.
- To avoid the conflict approaching Stechford, the second regional train, leaving Coventry at xx40, has simply been slugged with the train planner’s blunt instrument, pathing time. It now arrives at New Street a good 5 minutes later than 51M show us. What’s more, the following “Virgin” train also has to be slugged by a couple of minutes in turn, arriving not just 6 minutes later than 51M tell us, but 2 minutes later than now. There is no choice – as the conflicted London Midland train already leaves Coventry right behind the hourly Cross Country service it cannot be brought forward like the first one.
New Street station
So, the pattern as shown can be forced to fit, but only if we accept several significant downsides for both freight and passenger customers. The extent of the compromises show just how close to capacity this section is – you can’t make one thing better without making another thing worse. But even that is only considering one direction along the corridor in isolation. What this analysis has not considered is the feasibility of running extra trains into Birmingham New Street, where paths across the station throat and slots in the platforms are already at a premium. This isn’t just a matter of a couple more paths, which might well be found if we weren’t fussed as to when they fall, but a couple more paths that line up with available platform slots in New Street station, and also fit that intricate and highly structured pattern not just through the Coventry corridor but also onto the South end of the WCML, where 51M will be trying to run 16 trains per hour.
Another thing is the effect of the equivalent Southbound pattern, as, at junctions such as Coventry, Southbound trains must fit between Northbound trains on conflicting routes. Frankly, whether it works or not is chance, and in this area that is already notorious for congestion and poor punctuality, I wouldn’t bet the farm on it.
What 51M need to reveal
In summary, 51M need to tell us:
- Whether their plan does or does not include the Beechwood – Stechford 4-tracking?
And if it doesn’t:
– Which they intend to do – cut local services or decelerate InterCity and regional services, not just compared with their diagram but in some case compared with now?
- And if they don’t intend to cut local services:
– How do they know whether New Street station can accept two more trains per hour, at precisely the times that fit the paths through the Coventry corridor?
– How do they know whether the equivalent Up service can be dealt with on junctions where the Up and Down services interact?
– How they envisage freight (such as from Southampton to the North-West) will be catered for;
– What the impact is on demand of the decelerations and lost local connectivity in their business case.
Because just one thing’s for sure in all this – if HS2 doesn’t go ahead, and we have to fall back on something else, what 51M are telling us now is not what it will be.