Was HS2 always a fraud?

I've been reading an opinion piece in the journal Rail Engineer, titled HS2 offered so much*, lamenting the government decision on HS2.

The main point it makes is that people have been focussing on excessive costs but forgetting the benefits. That is not the case at all. The costs have been escalating and the various decisions to trim back the route have hugely reduced the benefits, a classic double whammy. Changes in business travelling patterns have probably also caused forecast passenger numbers to shrivel, deferring benefits even if growth is assumed.

Amongst the hand wringing it notes that the original 2013 cost estimate was £16.3 bn (in 2011 prices). They describe this as a "basic estimate prepared for business case" and it was for phase 1 to Birmingham. While one never has a detailed design on which to base a business case, I didn't realise that it was acceptable to punt that much public money on a "basic estimate" that wasn't considered at all reliable, but there you go. I suppose in fairness there were Parliamentary votes to approve the full scheme once designed with supposedly reliable cost estimates, but by then the project had political momentum and was uncancellable. And we were preoccupied with Brexit.

The current budget for phase one (which no-one believes) is £40.3bn plus £4.4bn contingency. In 2015 the cost for the full route was £27bn, based on route drawings but no ground investigation. By 2017 it was £37bn based on a finalised route and limited ground and site investigations (eh - even by 2017?). They note the estimate comprised 15,000 lines of data. I don't really care how much detail there was if a lot of it was clearly bunkum. By 2019 it was £44.4bn with the design 80% complete and based on 260,000 lines of rubbish, sorry, data but the DfT was estimating that the total cost would be between £65bn and £88bn (at 2015 prices).

We now know that, before the northern leg was cancelled, the total cost was realistically expected to top £100 bn and that it is being seriously suggested that HS2 Ltd should be investigated for fraud** for keeping quiet about estimates they knew were totally unrealistic. (Remember that the original scheme was for the Y route including the leg up to Leeds, not just one northern leg to Manchester).

The Rail Engineer also notes that there's been a good degree of inflation in the economy since. But that doesn't explain costs going up by a factor of three.

It's rather hard to feel sympathy for those crying into their beer about the cancellation: they've been let down from the start by the HS2 protagonists.

The Rail Engineer article also notes that, after various studies had shown that UK projects are typically 10-30% more expensive than those in Europe, the government commissioned a high-speed rail benchmarking study. It looked at 32 comparator European high-speed rail schemes and was overseen by an expert panel chaired by Sir John Armitt. (Armitt was chief executive of Railtrack and then Network Rail from 2001 to 2007 after which he was chairman of the Olympic Delivery Authority). 

So he ought to know what he's talking about. But I wonder... After finding that HS2 phase 2 was 49% more expensive than a European high-speed rail line with similar characteristics, the panel decided that the factors accounting for this additional cost were:

• strategic objectives requiring greater capacity and more intermediate stations (7%). This could be partly true but the "more intermediate stations" bit can't be. According to Wikipedia there are 20 stations in France that are served by TGV trains - and that's just those beginning with the letter 'A', I couldn't be arsed counting the rest!
• limited capacity of UK rail infrastructure requires dedicated high speed lines into city centres (15%). This is plain wrong. The mainline stations in Paris from which you can catch a TGV train are Paris Gare du Nord,  Gare de l'Est, Gare Montparnasse and Gare de Lyon. That's four of the seven large mainline Paris railway termini. I haven't checked other French cities but there's a TGV station at Part-Dieu in the main business area of Lyon, so go figure.
• fragmented UK construction industry and continuity of work (12%). I can believe this, it applies to nuclear power stations in spades
• Onerous design requirements (5%). That's the speed then is it? I simply refuse to believe it's only 5% and economist Bridget Rosewell, who was a commissioner at the National Infrastructure Commission, is with me on that***
• scope development compounded by limited experience of delivering high-speed rail in UK (10%). In other words, we don't know what we're doing while we're gold plating it.

This analysis seems to me to be missing the point. We know our projects tend to cost more than those of similar countries, though theirs are also subject to large overruns on time and cost (see Berlin airport for example). In April the High Speed Rail Alliance noted that American sources were lamenting the fact that the New York Second Avenue subway was costing 8 to 12 times more than the "composite baseline case"  compiled from data from several European countries. Factors identified included a lot of bespoke design. But on the other hand the Americans use a lot less tunnels than the Europeans (the Brits are using even more on HS2).

The real question is why, even though we know our projects cost more, do our projects cost a lot more than we think they are going to? Especially when we completed HS1 less than 10 years ago.

It seems it's because they did know (or at least strongly suspected) that was going to be the case but thought they'd never get the project approved if they fessed up.

Which is not new of course. It's exactly what the builder of some of New York's earliest transit infrastructure did. Get the project approved, start building it, then they won't dare to cancel it. Well Sunak just called your bluff chums.

And while I thought it was ridiculous to use the term 'fraud' when I first read it, now I'm beginning to wonder. The Sunday Times investigation** spoke to a number of whistleblower/malcontents who had worked at HS2, one of whom has been contacted by HS2's fraud and ethics team. The article went in some detail through the cost evolution, with numbers which are difficult to relate in detail to those given in the Rail Engineer article, though the general picture is even more stark. The main thrust of the article is that there were people working in the HS2 team who had felt for a long time - and sometimes popped their head up and said - that the costs were totally unrealistic.

Of course that's what happens in big projects that go off track. Management will always initially say that the cost estimate remains valid and press their team to find ways of finding savings. If you don't do that the steadily increasing numbers just become self-fulfilling prophesies and all discipline about containing the cost is lost. It's a game I played many times myself, with more success on some occasions than others, though my project totals were typically several millions rather than tens of billions.

What I found interesting in the article was that Chris Grayling, on appointment as SoS for Transport in 2016, had grave misgivings about the project. He called it a "crackpot scheme" according to a DfT source, while backing it publicly. Later that year a confidential report by Paul Mansell, a Treasury adviser, estimated that it was "highly likely" the scheme would cost more than £80 bn against the then budget of £55.7bn. But when the final vote to approve construction of phase one was taken in February 2017 there was no mention of that report and Grayling said it was "on track for delivery". The bill was passed with big majorities in the Commons and Lords. The DfT source said Grayling was unaware of the Treasury report at that time. I wonder if the chancellor, Philip Hammond, was aware of it?

By summer 2017 Michael Byng, a consultant who devised the method used by Network Rail to cost its projects, calculated that the overall cost of HS2 would be £104 bn. That may have been the first realistic estimate. It was nearly double the then official figure and 15 times the cost of the most recent high-speed TGV line in France (They have the benefits of much replication and an infrastructure of experienced personnel and suppliers as a result. But you wouldn't expect that to explain a factor of more than 2 or 3 at the most).

By late 2018 Grayling had appointed a new HS2 chairman, Alan Cook and had asked him to review the costs. The next month Grayling told Cook that, if the scheme couldn't be delivered for £55.7 bn "I think we will have a serious discussion about scrapping the project". One might have expected that would lead to HS2 closing ranks and standing behind the budget. But no, In June 2019 Cook sent a first draft of his report to Grayling. It suggested the project was billions over budget and years behind schedule.

This was not reflected in submissions to Parliament. In July 2019 the minister for transport, Nusrat Ghani, answered questions in a Westminster Hall debate on HS2 before the Commons vote on the bill to approve the Birmingham to Crewe phase two leg. She said "I stand here to state confidently that the budget is £55.7 bn and the timetable is 2026 and 2033". She repeated her assurances five days later during the third reading debate. But a freedom of information request later revealed Ghani had been told three months earlier that the project would breach its budget. In which case Ghani, now minister of state for industry, would appear to have misled Parliament.

By August 2018 Cook's final report revealed that the cost was now expected to be £88 bn, very close to Treasury expert Mansell's estimate. Even that number proved optimistic.

One wonders if the ministers of the day actually knew the estimates were unrealistic before the Commons vote and sent HS2 away to confirm the number, get the vote through and then come back with their request for more money. In that case they could hardly place all the blame on HS2 Ltd and were complicit in the "fraud". More likely they'd be able to hide behind the fact that costs on big projects are always under review and the "official" cost estimate hadn't been changed. Nevertheless this seems a matter ripe for an enquiry to me.

It's all so stupid. we could have built HS2 like HS1 and had a prefectly acceptable railway, bringing the overwhelming majority of the benefits. The Sunday Times article points the finger, as I have***, at Lord Adonis, who wanted the railway to be "super fast", meaning it had to be as level and straight as possible, constraining choices on the route and adding cost in land purchase, construction methods and materials. 

I accept that if we had gone for an HS1 spec the project would still have cost more than the original estimate, everything has gone that way. But it would be much more likely to have been completed in full, at an affordable cost and on a reasonable timescale. Basically it could have worked.

*published 18 October 2023, www.railengineer.co.uk

** We were instructed to lie about the true cost of HS2. Sunday Times Insight investigation, 22 October 2023. 

*** see Who to blame for HS2 20 October 2023

The cost of the New York subway project and the general lament about costs of projects in the USA can be found at https://www.hsrail.org/blog/why-transit-projects-cost-more-in-the-u-s-than-almost-anywhere-else-and-what-we-can-do-about-it/#:~:text=In%20the%20case%20of%20New,high%20even%20by%20U.S.%20standards.

Who to blame for HS2

Rishi Sunak's decision to cancel the northern, Birmingham to Manchester, leg of HS2 was one of the least surprising political announcements of recent times. We all knew it was coming because his plan to announce it at the party conference in Manchester along with a bunch of new and recycled alternative projects in the north was blown by, yet again, a Downing Street aide carrying unconcealed documents (d'oh!). But also because it's quite clear that none of the cost estimates can, even now, be considered remotely reliable. 

I haven't commented about HS2 since my post "Take the H out of HS2 now" (16 September 2019). That suggestion was prompted by the rather cursory review commissioned by Boris Johnson before the decision to proceed. In it I posited that the reason the costs were out of control was that we were building a project with technology we didn't have when we started. The one time Chief Engineer and later Technical Director of HS2, Andrew McNaughton, told MPs in 2012: 

"We learnt very strongly from people we respect, like Guillame Pepy in France [Pepy was boss of the French state owned rail company SNCF] that they had wished they had not designed to the limit of the day because the technology continues to advance"

In other words we were trying not to copy other countries but leapfrog them by being at what I often heard referred to in discussions of technology development projects as the "bleeding edge", a word play on the phrase "leading edge" much used by people advocating caution about unproven technology.

So they designed HS2 for sppeds of up to 400km/h (260mph). In comparison the French trains run at 320km/h, just shy of 200mph, 

I've now come to the view that McNaughton and his colleagues, while absolutely culpable for the fiasco, are not actually at most fault. Who is? It's a long list:

Gordon Brown, David Cameron,Theresa May and Boris Johnson

Alistair Darling, George Osborne and Philip Hammond.

Geoff Hoon, Andrew Adonis, Philip Hammond (again), Justine Greening, Patrick McLoughlin and Chris Grayling.

You will have guessed that these are the prime ministers, chancellors and secretaries of state for transport from when HS2 was first given the go ahead in 2009 up to the quick and dirty review sanctioned by Boris Johnson in 2019. The people who have followed in those posts aren't exactly innocent, but the project had gone too far by then to be sensibly descoped.

Why are they all to blame? Simply because, having conceived a vanity project which could have made sense, they blessed the vision for HS2 and left the railway nerds to get on with it. I would place most blame at the feet of the chancellors as they are supposed to ensure value for money and keep the flights of fancy of PMs and departmental colleagues within sensible bounds.

I've read that Gordon Brown first kick-started the HS2 project because he was spooked by the Tories stealing a march as David Cameron and George Osborne were advocating it. The project then got the go ahead after a cursory 10 minute discussion at Brown's cabinet.

A grandiose vision having been embraced by the PM and authorised by the cabinet, the transport secretaries would be unlikely to pipe up "shouldn't we build something we know will work at a lower cost?"  So Geoff Hoon (known as "Buff" to his colleagues - Buff Hoon, geddit?) didn't need to bother himself about the practicalities as the concept was already blessed on high. And he was only around while they prepared the scheme for formal sanction. By then Andrew Adonis had taken over as SoS.  Adonis championed the project then and has continued to do so ever since. Indeed as recently as June Adonis placed the blame for the time and cost overruns on all of his successors:

"Since I launched HS2 13 years ago, there have been six prime ministers, seven chancellors and eight transport secretaries. Almost every one of these has caused some delay in HS2 by reviewing, amending or otherwise interfering with the scheme."

So he's saying if you'd stuck with what I started it would all have worked out fine. Sorry, Andrew, you can't get off that easily. They had to keep looking at it because you got a risky project approved at an unrealistic cost. Do you really think if none of them had made any changes it would be on time and cost? I blame Adonis as much as anybody because he gave the railway nuts free rein. And they took it - it's no surprise a railway nut would want to be known for building the most futuristic railway in the world, is it?

There were early opportunities to stop the madness. The Commons Public Accounts Committee was given evidence in March 2012 that HS1 had been expensive costing £5.8bn, £84m per mile. At that time the cost of HS2 per mile was estimated to be another 38% higher, £116m per mile. Even then HS2 was expected to be four times as expensive per mile than high speed projects in France. But then HS1 had cost quite a bit more than a French railway too. (Note: you will see different numbers for the costs of HS1 and HS2 quoted in the money value of different years, unhelpfully not telling you which year). 

The summary of the PAC's report in July 2012 focussed on the fact that the forecast for passenger numbers had been "inaccurate and wildly optimistic" leading to the project not being self funding as was intended. Now forecasting passenger numbers is notoriously finger in the air stuff so I might extend my blame to the committee for not emphasising the cost issues, though they did comment that "This isn’t the first time that over-optimistic planning and insufficiently robust testing of planning assumptions has got the Department into trouble."  and " The Department must revisit its assumptions on HS2 and develop a full understanding of the benefits and costs of high speed travel compared to the alternatives." It also referred to "costly mistakes".

When that report was published Justine Greening was the SoS for Transport, so she could have called for a review. But within 2 months the changes were rung again and Patrick McLaughlin took over. There were a lot of changes at Transport, a fact which has some bearing on the fiasco I suspect, but McLaughlin was there for nearly four years and his successor Grayling for three so they must carry a lot of the can.

I saw McLaughlin address a railway industry event while he was SoS. He struck me as an amiable  duffer, who had been a miner before becoming MP for Derbyshire constituencies. He obviously liked railways. And he also seemed way out of his depth on anything technical or complex.

So chances were missed to set the project on a sounder footing before it was too late.  Given that McLaughlin wouldn't have said boo to any kind of goose I'm going to have to point the finger primarily at Adonis for putting the nerds in charge and Osborne for not getting a grip.

But why is it costing so much? I'm sure it's because building a railway for extreme speed is highly onerous. High speeds require a more precise track alignment with gentler curves and hammer the track once in operation. More costly materials have to be used for the trains and the track.

You may have read that the main reason that the HS2 line to Birmingham is costing so much is because of the tunnels they had to add to placate the Tory MPs with seats along the route in the leafy Chilterns. While it has undoubtedly added cost, I don't really buy that.  The surviving leg of HS2, assuming the section to Euston gets built, will have 65 miles of tunnels on its 140 mile route. That's nearly half. With a lot of cuttings as well, passengers will only see the countryide for 9 minutes of the 49 minute journey.

 But wait: HS1 was built pretty much to time (11 years) and cost (about £6bn at the time). HS1 runs at 185 mph - nearly as fast as the French high speed trains. It has 37 miles of tunnels on its 68 mile route. That's more than half. And yet HS2 was already by 2012 expected to cost nearly 40% more per mile than HS1 (and nearly four times as much as an equivalent French railway running through open country). So can it be the tunnels? 

You won't be surprised to hear that the faster a train goes the more careful you have to be with the tunnel design and clearances. "You don't want all the passengers getting off with burst and bleeding eardrums" it was patiently explained to me when I worked for a railway technology company and naively asked why you couldn't run much faster trains through existing tunnels. So I suspect the finger is pointed at the tunnels by the people who want to hide the fact that, to paraphrase another saying, "it's the speed, stupid".

Of course it is possible to build a railway to run at 260 mph. While we've been pratting about with HS2 the Chinese have conceived, designed and built the Fuxing (I'm not making that up - it means rejuvenation) railway between Beijing and Shanghai and also between Beijing, Guangzhou, Shenzen and Hong Kong. We started work on the case for HS2 in 2009.  China started development of its high speed trains in 2012 and they've been in service since 2017, with a design speed of 400km/h and a normal service speed of 350km/h. But on test it has achieved 420km/h (260 mph). But then they don't need to worry about planning, newts, or Tory voters in the shires. And it's over 2000km from Beijing to Shenzen so the speed makes more sense, there's a genuinely beneficial time saving on the journey.

In contrast I've seen it suggested that no sooner have HS2 trains reached their its top speed after pulling out of Old Oak Common heading for Birmingham they will have to start slowing down. In a small country with cities quite close together there's just no need for ultra high speed. 

In any case I've always thought the project should have been designed primarily to provide the extra capacity needed since the large expansion of demand following rail privatisation in 1996. Simply having a direct route from London to Birmingham with only one stop at Old Oak Common and then on to Manchester without sharing the track with slower moving trains would provide quicker journeys anyway so ultra high speed wasn't essential, though I've always doubted the supposed economic benefit of shaving off a few minutes travel time anyway. 

However I do accept one part of Sunak's speech - travelling patterns have probably changed enough to affect the rationale for the project. Post covid business travel to and from London is much lower and so as well as the costs perpetually increasing the benefits have shrunk. The capacity argument is therefore weaker but looking ahead to a decarbonised infrastructure I think it's still valid, the benefits will just be delayed.

I'm far from the only one to point out that the design basis was flawed. Economist Bridget Rosewell has been Commissioner of the National Infrastructure Commission, the independent agency established in 2015, since 2020. The Commission is charged with undertaking a national infrastructure assessment each parliament, making recommendations and monitoring the government's progress on infrastructure.  Rosewell told the House of Lords economic affairs committee in 2019 that she had never understood why HS2 was looking to run trains at 360km/h. 

"The route alignment chosen for HS2 was designed to allow for 400km/hr trains, with 360 or 320 km/hr in tunnels. Speed isn’t irrelevant, I don’t want to say it’s just about capacity and it’s not about speed, but I’ve never understood the need for very high speed,” Rosewell said then, adding “I’ve said this right at the very beginning back in 2008/09. I don’t see why we are privileging at 400km/h for the cost that that would imply.”

Rosewell added that designing the line for 400km/h constrained engineers' ability to "sensibly" plan the route alignment. "That was the top priority [to design for 400km/h] and then everything filled in after that" she said. "It was a mistake".

High speed trains in France and Japan operate at 320km/h. Rosewell added that the 360 km/h speed limit would produce a time saving of only two or three minutes compared with services running at 320km/h. "...it seems implausible that we could ever justify that" she said, " I see no reason to go faster than the French TGVs, I think it's silly".

There are some important cost implications of running at over 320km/h. Above that speed conventional ballasted track cannot be used. The HS2 rails are being built on concrete slabs and the rolling stock was specified as recently as 2021 for speeds up to 360 km/h (225mph). At 320 km/h (200mph) cheaper ballasted track can be used. Proponents of slabtrack argue that ballasted track systems are noisy in use, expensive to maintain and pose safety risks with individual ballast particles liable to be dislodged by the turbulent air caused by passing high speed trains. But both systems are in use on modern high speed railways around the world. The Germans, Dutch and Japanese tend to use slabtrack while the French and Spanish tend to use ballast. (Significantly the German Inter City Express goes 20mph faster than the French TGV). 

"If they did do ballast to start with it would not be a disaster, you would still get the benefits, But it comes down to what can be afforded" said Prof William Powrie of Southampton University.

But the design choices are, of course, inter-linked. A high proportion of the first phase of HS2 is in tunnels. Slabtrack systems require a shallower base which means the tunnels can be smaller in internal diameter. According to Rail Engineer slabtrack is twice the cost of ballasted track to install, though it does have advantages in use, maintaining better track geometry. After all, you don't want the trains falling between the tracks going at 200mph, as a much more slowly moving train did on a section of rail in the tunnel near to Liverpool Lime Street that had been overlooked in the monitoring programme about 25 years ago.

But by the time grown ups like Rosewell became involved it was too late to make major changes without wasting even more time and money.

So what should we have done and what should Rishi Sunak have decided to do? Not start from here, of course but given how we have long since started how much has been spent and how much is committed? It's not easy to find definitive figures so I do sympathise with those who say the HS2 costs, despite lots of published information, remain opaque, though a figure of £15bn was published on gov.uk in March 2022 and spend was running then at over £5bn a year so it's clearly going to be more than £20bn. That figure may not include contractual committments (e.g for trains, tunnelling machines and other equipment ordered), so we could guess £25bn to £30bn. The HS2 website claims £23 bn has been "contracted into the supply chain"* without saying how much has been spent and how much there is to go. I don't know what cancellation costs there are, including making sites safe and potentially reusable. 

What were the options?

Cancel it, get nothing for the £25bn, look very stupid and damage Britain's cedibility (such as it is).
Continue with the full Euston to Manchester route and accept that the cost could easily be £100bn but at least get something useful, even if not till the mid 2030s or even later.

Scrap the Birmingham to Manchester leg to save several tens of billions of pounds but leaving a project which wouldn't remotely produce the benefits originally projected, which were down to £1.30 for every £ spent by the 2019 review (and that still included the eastern leg to Leeds). Some argued that this would mean that the whole project rationale would fall anyway, leading to cancellation of the whole project anyway after parliamentary scrutiny. (Though people saying that don't understand the concept of sunk costs).

Scrap also the Old Oak Common to Euston section as well eaving a futuristic railway running between Birmingham and a suburb of north London few had previously heard of, 7 miles from the city centre. 

Of these options I would, at this stage and despite all my criticism of the project, have continued it to Manchester, though I accept that many business leaders were always against HS2, saying that the money would be better spent on other infrastructure projects. Sunak's decision, provided a decent number of those projects get implemented, makes a degree of sense. Provided those projects are for real, which doesn't seem to be the case for some of them at least.

Interestingly I've read that chancellor Jeremy Hunt would also have continued with the route to Manchester.

What I certainly wouldn't do is sell the land for the painstakingly put together route between Birmingham and Manchester, closing off the option of a new railway at a future date, whether it be high speed, ultra high speed or whatever. That seems to me to be an act of political vandalism, especially if it crystallises a loss for the taxpayer of £100m, as reported. Though one which Labour might actually be grateful for, as they wouldn't have to consider whether to reinstate that part of HS2 if it wins the election.

What is most frustrating is that it didn't need to be like this. If we'd just built it like HS1 we'd be in a better place. Had we started construction of HS2 in the north as Alistair Osborne said in the Times (using 20:20 hindsight admittedly) we'd probably have or be close to having an operational railway over part of the route by now. We might have had a fast railway linking Birmingham and Manchester and Birmingham and Leeds. As I've always thought the problem with building high speed links to London is that it doesn't really help the north, it just encourages more people to commute to London, this could have been very beneficial for the north. However, I don't think that was ever realistically going to happen. 

But it's a lesson for the future perhaps. Build things that you know are going to work. And start at the place you are supposed to be benefiting.

One final thought. I have in recent years longed for the time when a government would appoint some kind of royal commission in an attempt to depoliticise an issue and gain cross party concensus. What to do about social care is the obvious current example. And yet... on the issue of HS 2 there has been, until Sunak's speech, almost total concensus between the Conservatives, Labour and the LibDems. Just because they all back it doesn't mean that they're right or that they've understood what it actually is that they are backing.

* HS2 also say that 97% of the supply chain is made up of UK businesses. Whether they measure that by value or number of companies they don't say. The trains are indeed being built in Britain - by a Hitachi - Alstom joint venture. This is typical of the dissembling we see these days. Just as with our "world lead in wind turbines" what we are doing is installing technology from other countries, which doesn't really give us any kind of commercial or technological lead.

Sources include: 

Bridget Rosewell's comments to the House of Lords and William Powrie's comments are covered in the New Civil Engineer article "Pressure mounts for HS2 to reduce speed" 22 Feb 2019 

Articles in The Times over just two days in the run up to Sunak's announcement included:

Rishi Sunak Aide called HS2 "greatest mistake in 50 years" Oliver Wright, Stephen Swinford, 27 Sept 2023. The aide was Andrew Gilligan and he said HS2 was Britain's greatest infrastructure mistake in half a century in 2019. Gilligan has a chequered history: Telegraph newspapers twice had to pay out damages in 2016 and 2018 for defamation cases arising from Gilligan's articles and in 2019 the Sunday Times had to issue a correction about a Gilligan article rued to be "misleading". Still he was right on HS2.

Too late to stop HS2's runaway costs, Alistair Osborne The Times 26 Sept 2023. Among other things this article noted that construction of HS2 should have started in the north. The "Northern Powerhouse" cross pennine rail link requires a chunk of HS2 to be built anyway. But of course, the trains don't need to go at 260mph, so it doesn't really need to be quite like HS2. But the point is well made: if construction of HS2 had started in the north 

How HS2's fate will be decided in 2025, Robert Lea, The Times 27 September 2023. This article discusses the options available at Easter 2025 when the two boring machines which would create the 7 miles of tunnel from Old Oak Common to Euston. If it's decided to terminate at Old Oak Common the six platforms designed for the interchange wouldn't really work as a terminus (11 were planned for Euston but recent announcements imply fewer). Unless of course HS2 only runs from Birmingham in which case there might be fewer trains and passengers (though they'll be as long, I presume). Either way more work would be needed at Old Oak Common so saving the Euston leg would still bring costs and maybe delays.

Disgraceful HS2 should have been axed years ago. The Times 26 Sept 2023. Noting that there are fears that the project finances are "far worse than anyone knows" the Times reported Lord Hague saying “It should have been cancelled a few years ago when it was clear that the whole thing was out of control, that the costs are out of control, they wouldn’t be able to ever go to Leeds. I would have cancelled it then. Now you’ve got this classic problem. If you’re halfway though something and it’s been terribly badly managed — really a national disgrace as a project — do you say okay, I’m stopping this, or do you say actually now we’re halfway through we have to at least complete and make sense of the parts that we can still do.” And that Sunak was “alarmed” at the increasing costs amid claims that project executives have acted like “kids with the golden credit card”

Other sources:

How did HS2 become a £100bn money pit? The Times 29 January 2023

HS2 6-monthly report to Parliament, March 2022. gov.uk 16 March 2022

High Speed 1 and St Pancras Station. Institution of Civil Engineers website. Gives HS1 length 68 miles including 37 miles of tunnels. Cost £11bn (£14bn "today" - without saying when "today" is). Journey time to Paris cut from 2hr 56min to 2hrs 15min, a saving of 41 minutes. HS1 took 11 years to build (Wikipedia)

Committee of Public Accounts - The completion and sale of HS1. Evidence by Andrew Bodman, https://publications.parliament.uk/pa/cm201213/cmselect/cmpubacc/464/464we05.htm

(Public Accounts) Committee publishes report on the completion and sale of HS1, https://committees.parliament.uk/committee/127/public-accounts-committee/news/179224/committee-publishes-report-on-the-completion-and-sale-of-high-speed-1/

Why HS2 will be built in full - eventually. Andrew Adonis, Prospect Magazine 7 June 2023

Rail Engineer. Slab Track for HS2, 2 September 2020. https://www.railengineer.co.uk/slab-track-for-hs2/

Photo from HS2 website