Euston: why 11 platforms are essential
Without the ‘spare’ 11th platform at Euston, HS2’s operational response to late-presenting (more than ten minutes) trains would have to be to terminate them short (at Old Oak Common) as a first line of defence.
The view that ten platforms can handle 16 trains per hour (tph) maximum is presumably (and rightly, in operating terms) based on retaining one of the ten platforms as a contingency platform.
So, from the business case of 18tph, which is to be cut? Clearly, the path unallocated for future growth is the obvious first candidate.
By comparing service levels and capital cost, you can make a crude estimate that an HS2 passenger service justifies spending around
£ 4 billion up front. That makes it very difficult to see that cutting Euston to ten platforms will have anything other than a negative impact on its business case, as the cost pressure is an order of magnitude less.
Obviously, not all trains have the same value - a 400-metre Manchester or Birmingham train must be worth more than a 200-metre train to somewhere else. Sheffield services probably have a fairly weak case, but as both trains per hour run combined with a Leeds or York portion, the paths serve two purposes and thereby trigger two sets of benefits.
The trains with the weakest potential benefits are probably the Stoke/Macclesfield services and the Newcastle trains, as their time advantage over existing services is relatively modest. But politics will play a part here, too, because the Stoke service was only recently added in response to political pressure. Also, because it serves Stafford, a much more rational pattern for the two Liverpool trains per hour becomes possible, so its benefits likewise go wider than just Stoke.
If one of the two Newcastle trains per hour were to be cut, you have to wonder about the value of running the other, as the benefits come more from having a regular half-hourly service than from speed in itself.
My guess: if Euston were to be reduced to ten platforms, both Newcastle trains might drop out of the timetable. The 16th path might then be used simply for a service from Euston to York - roughly on the opposite half-hour to the combined Sheffield/ York and calling at Birmingham Interchange and East Midlands Hub, because by providing a plug-in to the East Coast Main Line some of the benefit is still captured (with Interchange to York a link not provided in the current specification).
This might be tricky to communicate in the North East.
But reducing Euston to ten platforms might simply shift the spending saved into spending elsewhere! For example, what ECML improvements would be demanded to enable the service enhancements comparable to what HS2 would have offered in those Newcastle trains, and in terms of released capacity from diverting them to HS2?
Would the consequence of ‘baking in’ a constraint at Euston for the sake of a shortterm construction programme saving mean that major cost items such as a Newark flyover or Welwyn track quadrupling have to be resurrected?
If all we do is shift the capital spend elsewhere, what have you really achieved? Government needs to weight these factors carefully in making its decision about Euston.
A further consideration is that single-stage construction presumably takes longer than the first of the two stages previously planned for Phase 1/2A alone, in which six platforms are built outside the existing footprint of the station.
A service terminating at Old Oak (as opposed to dropping off the briefcase brigade for the Docklands at Old Oak and continuing to Euston for the luggage-laden and those going on the North-South axis for their final destination) has no significantly greater value than the existing service to Euston.
The DfT thinking to run six trains as an initial service is, in my view, both commercially irrational and operationally impractical.
Reaping benefit from HS2 requires Euston. I believe the business case for the railway is damaged if that benefit is postponed or seriously constrained.