Three Stubs for the Future
HS2 has been cut back, but Britain has a trend of rising rail use, and there is good reason to think we might want to extend HS2 later. At minimal cost, we can keep our options open.
This week has seen one of the largest policy shifts in British infrastructure in the last decade. The PM announced that the new HS2 line will be cut back to the Handsacre Junction immediately north of Birmingham, with the East Midlands spur, and the route on to Crewe and Manchester, all to be abandoned.
The funding released from this substantial change has been reallocated to smaller infrastructure projects across the North (and the rest of the country), including new tram networks, rail electrification, railway line reopenings, and several road projects. I’m going to try and avoid commenting on the costs and benefits of this decision for the moment, until I’ve fully digested everything, because I’m more concerned about making sure we maximise the value of the section of HS2 that we are building.
Phase 1 of HS2 is by far the most expensive and most complex section of the entire project. Not only does it travel through areas with some of the highest land values in the country, but as a share of the route, it has far more tunnelling and bridging than the northern components, which all add considerable cost1. Euston has become a huge unwieldy mammoth in itself, and the Government has sought to transfer it to a new delivery mechanism to regain some control over cost and delivery.
Collectively these changes mean that despite being designed and built for a service pattern of 18 trains per hour2, Phase 1’s gleaming new viaducts and stations are only likely to see a service of 83, in part due to having to squeeze all services on to the congested West Coast Main Line. This leaves a huge amount of spare capacity on HS2 itself.
One or more very cheap elements of passive provision4 could preserve the option to use the enormous spare capacity of the line if the business case becomes sufficiently compelling in future. After all, any future extensions will be able to uplift the frequency of trains between London and Birmingham at no/minimal capital cost, and it was the northern sections of HS2 that had the lowest costs, the highest benefits, and the best value-for-money within the original full network5.
Thankfully, as HS2 Phase 1 was designed with future extensions in mind, and is under construction, two stubs are already planned. These are tiny branching lines that connect in to the mainline but run to nowhere, like a roundabout on a new bypass with a junction to a wasteland that will one day provide homes for new families.
The first stub is near Birmingham, to provide for a connection to a potential eastern branch towards Derby and Nottingham, and the other is near Handsacre, to allow the lengthening of HS2 northwards, bypassing the congested WCML. Continuing to build both of these would be eminently sensible; they are included within the existing plans and they are partially under construction. They’re also an extremely cheap way of avoiding expensive retrofitting and network closures if a (in my opinion, likely) decision to extend HS2 is ever made, not to mention saving on redesign costs and contract variations in the immediate future.
However, any new services that we power on to the network will still need somewhere to go…
Euston, we have a problem
And that’s why this little line in the ‘Network North’ paper worries me:
Instead we will deliver a 6-platform station which can accommodate the trains we will run to Birmingham and onwards and which best supports regeneration of the local area.
The ‘6-platform station’ being referred to here is Euston. Originally designed at 11 platforms, the station was pulled back to 10 in order to save costs and simplify the construction timeline. The further reduction to 6 platforms will save additional costs, but it will also make the full 18 trains per hour service that Phase 1 is being built for, undeliverable.
The descoping at Euston means that we are baking in a permanent capacity cap into the Phase 1 network, perhaps at half of what it was built to handle, to save only a fraction of the cost. And of course, the cost of retrofitting additional platforms later would be astronomical.
There is however, a cheap and easy way to mitigate this. A tunnelled junction and stub immediately east of Old Oak Common would provide the option of building an alternative terminal or through-routing under London at some point in the future. The cost of building such a connection at a later date (and having to close the whole line for a substantial period of time - several months at an absolute minimum)6, would be astonishingly large7, but right now, for a cost in the millions, we could ensure that billions weren’t spent in vain.
A stub here would provide several options for potential extension: a through line to connect with HS1 for services to Kent and Europe, a line through the West End and the City to connect in with services to Ipswich and Norwich, or a link to the Brighton Mainline with a stop at Clapham Junction. The decision on which to take would be made as and when the additional terminal capacity is needed, to accommodate the network demands at the time, maximise any regeneration opportunities, and deliver service improvements to additional regional cities.
So there you have it, three little stubs at very little cost (at Old Oak, Handsacre, and Birmingham), to provide future-proofing to ensure that the line can ultimately deliver its full potential for levelling up, ensure we didn’t spend billions for something that we can’t fully use, and to maximise the value-for-money that we could one day achieve. It’s good engineering, and it’s very good economics.
Much of the tunnelling on Phase 1 is needed given the geography of the Chiltern Hills and the urban expanse of London, however in some cases these are longer than necessary, to accomodate local concerns. Additionally, there are six separate ‘green tunnels’ where the line will be dug into the ground then covered over (cut and cover) to mitigate noise, visual, and environmental impact. https://www.hs2.org.uk/building-hs2/tunnels/
18 trains per hour, as noted in: Full Business Case, High Speed 2 Phase One, para.1.43. https://assets.publishing.service.gov.uk/media/5fc51d7b8fa8f54755392863/full-business-case-hs2-phase-one.pdf
8 trains per hour, as noted in: Continuing investment in HS2 Phase 1: accounting officer assessment (October 2023). https://www.gov.uk/government/publications/government-major-projects-portfolio-accounting-officer-assessments/continuing-investment-in-hs2-phase-1-accounting-officer-assessment-october-2023
Passive Provision: a change to a design or construction that is unneccessary by itself, but that makes the infrastructure ready for a future addition or upgrade. E.g. building a two-storey school with foundations strong enough to accomodate a third storey at a later date, avoiding the need to build a separate new building.
Benefit Cost Ratios (BCRs), as noted in: The case for an integrated new rail network serving the Eastern Leg, table 2. https://hs2east.co.uk/wp-content/uploads/2021/08/Volterra-HS2-Eastern-Leg-NICInput-REISSUE-1.pdf
The Northern line in London was closed for 17 weeks in 2022 to connect up new running tunnels at Bank. Not only were these tunnels far smaller in diameter than HS2’s, but it was also a redirection of services rather than requiring a flying junction.
This would be a magnitude cheaper than having to reconfigure and expand a brand new Euston station with over site development, but will likely still be in the hundreds of millions as it would require land acquisition, excavation around the HS2 line (whilst attempting to minimise its closure), and the construction of a new underground junction box.