HS2 delayed again?

[JamesT]

Where do they mention three years of testing? I couldn't see it in the statement or the letter

In Mark Wild's letter under Schedule:

2. The durations allowed for activities still to come has been underestimated. We have yet to
develop an integrated schedule for the deployment of railway systems and rolling stock. For
example, the time allocated to test the railway (14 months) is insufficient. A duration of up to 36
months has been assessed as more realistic based on equivalent completed projects.

 

[Nicholas Lewis]

Whilst all the management and political bickering is going on, HS2 have issued a series of summer newsletters covering middle section of HS2 with photos of recent progress and upcoming works in next few months.

North Chilterns area

https://assets.hs2.org.uk/wp-content/uploads/2025/06/NCA-Summer-Newsletter-2025-to-publish-2.pdf

Aylesbury area

https://assets.hs2.org.uk/wp-content/uploads/2025/06/NC2A-North-Newsletter-Summer-2025-v2.pdf

Calvert area

https://assets.hs2.org.uk/wp-content/uploads/2025/06/HS2-Calvert-Area-Summer-Newsletter-2025.pdf

Twyford-Greatworth (Brackley) area

https://assets.hs2.org.uk/wp-content/uploads/2025/06/T2G-HS2-Newsletter-Summer-2025.pdf

Greatworth-Southam

https://assets.hs2.org.uk/wp-content/uploads/2025/06/Greatworth-to-Southam-HS2-Newsletter-Summer-2025.pdf

all are pdf, but too lengthy to quote.

So some sections are virtually earthworks complete with landscaping going on. A few more bridges are expected to be completed soon. But does seem to be be rather a time gap before any track and signalling goes in which makes me wonder about timescale coordination..

Indeed civils progress looks good and you would have thought slab track installation could be begin mobilisation in certain areas from late 2026 with catenary installation to follow behind. I suspect there is an element of kitchen sinking going on here from both Wilde and DfT to give them enough of a buffer to avoid them having to come back to the despatch box and tell us its delayed again.

 

[absolutelymilk]

Oops, thanks!

 

[Shrop]

The vision should have been for a full Shinkansen style parallel network going to every city with more than 250,000 people. This should have been the dream sold with a plan to actually do all of this in the working lifetime of a voter.

It should have gone somewhere where NIMBYs were less organised maybe York - shin Middlesborough - shin Sunderland - Newcastle and it should have been built like Chinese/Japanese high speed rail mostly on a modularised concrete viaduct.

While I wouldn't agree exactly, it's nevertheless good to see someone making positive suggestions for a change, instead of the very regular comments on this forum which are all too often about finding reasons NOT to do things.

In terms of wanting to serve every large urban area, such proposals were around long before the HS2 route was finalised. The M1 corridor route proposal was to serve Leicester, East Midlands (Nottingham/Derby), Sheffield and Leeds (and then onwards to Teesside, Newcastle, Edinburgh and Glasgow), with Manchester and Liverpool being served via Sheffield, thus incorporating the Northern Powerhouse corridor. Birmingham was always less important since it is well served from London already, but a loop from south of Leicester, then roughly as HS2 should have gone towards East Midlands, would have completed the ideal initial HS network for the UK.

The problem with the UK is our weak thinking, which is what led to needing to find a far softer approach. HS2 perceived the need to appeal to politicians, in this case serving Heathrow (ostensibly to avoid the need for a third runway), with the consequent Chiltern story. Those who pointed out the weakness of a short route serving primarily Birmingham with other destinations being add-ons, were shouted down, and yet this is exactly what has now happened, with all of the attendant ridicule that the project continues to receive.

Are those with a genuine passion for railways not upset by the fact that the HS2 debacle will make future rail projects so much more difficult to propose, or are we really content with continuing to argue the minutiae? Where is the fire that our early rail pioneers had, but which most of us now seem to have lost? We, on this forum, should be hammering politicians and journalists at every opportunity to get the story right, ie. that railways are vital for the UK, not continually simpering to the “can’t do” attitude.

 

[Snow1964]

Three years of testing seems quite an outlier, for what will be a very straightforward railway with no interfaces with anything else

To put that into perspective, the Koralmbahn (126km new high speed railway between Graz and Klagenfurt, Austria), track laying finished December 2024, testing has just been announced as completed, driver and staff training to follow, with services expected to start December 2025.

If the Austrians can test and commission a high speed line in 12 months, why do Brits need 36 months ?

 

[JamesT]

To put that into perspective, the Koralmbahn (126km new high speed railway between Graz and Klagenfurt, Austria), track laying finished December 2024, testing has just been announced as completed, driver and staff training to follow, with services expected to start December 2025.

If the Austrians can test and commission a high speed line in 12 months, why do Brits need 36 months ?

The Austrians have been building that line for 25 years and have opened sections already. It’s a much less significant thing that they’re testing.

 

[LNW-GW Joint]

The Austrians have been building that line for 25 years and have opened sections already. It’s a much less significant thing that they’re testing.

The Koralmbahn, and the related Semmering base tunnel further north, are built for a maximum of 250km/h.
The Swiss base tunnels and the new Brenner route are similar.
They are also all built for heavy freight traffic, unlike HS2, and link major TEN-T routes across the Alps.
They replace/supplement slow and winding mountain routes rather than a 125mph main line.

 

[SynthD]

This should have been the dream sold with a plan to actually do all of this in the working lifetime of a voter.

HS2 had that plan, then met politicians. It was never meant to have a way to overrule Osbourne, Javid, Reeves etc in their power as Chancellor to make the choices they have.

Clearly something is badly wrong with infrastructure construction in the UK - British projects are more expensive and take longer than most other countries in the western world.

But that’s the funding plan, not the rail plan. We don’t know what the full rail plan in the real world (construction inflation, unexpected problems) would have cost or taken, because of the cost of spending less in the next twelve months.

 

[Sonik]

I suspect there is an element of kitchen sinking going on here from both Wilde and DfT to give them enough of a buffer to avoid them having to come back to the despatch box and tell us its delayed again.

100% agree. I'd go further to say it's expectation management - best to start from a very low baseline and improve from there.

And ironically, this is an easy sell politically, because the naysayers have nothing to argue with, when you say it's all terrible.

 

[Technologist]

Why? That means more cost and more visual impact.

Building High Speed Rail on viaducts is the preference from the people who actually build the most of it China, Japan and other Shinkansen style lines (Taiwan has a 110km long viaduct).

The advantages are when you use a standardised design you just have a small range of standardised components that you can mass produce in a factory and install using very high productivity single purpose capital equipment on site. The pillars then just vary in height which is pretty easy to adapt mass production for. So instead of having to survey and move every road and utility for hundreds of miles you just adjust the route and span lengths to just bridge over everything and drop the pillars where there is very little to move out of the way.

1 giant standardised bridge can be cheaper than 50 bespoke individual large bridges to get the line over various obstacles plus about 500 bridges to allow existing rights of way over or under the line. In addition to all those crossing points there are numerous points where rights of way have been closed due to HS2, not least route closed to animals. Building a viaduct on land means that you need an easement whereas building cuttings and embankments means that you need to purchase land outright.

You also don't affect local hydrogeology so no new flood mitigations and drainage ponds, the construction site is also much smaller and because you are producing a standardised product you can go much faster which means that you save on things that scale with time rather than construction output e.g. security, HSE, management, procurement, goods in and welfare/catering.

Regarding visual impact, it is perfectly possible to design a rail bridge to look striking and people tend to get quite used to them. It's actually the construction which is the disruptive activity and again potentially we can go much faster building a bridge and the footprint is much smaller.

Concrete is relatively cheap, looking at the Beijing–Shanghai high-speed railway they used about 40,000m3/km, which comes out at around £12m/km in cost at an average of £300/m3 for poured concrete or about £2.8bn for the length of HS2. Ergo the cost of a long bridge is pretty piddling compared to all the ways we've made HS2 cost an incredible amount.

 

[HSTEd]

Why? That means more cost and more visual impact.

The chinese build high speed rail lines on viaducts because it appears to be faster and cheaper than building them on the ground.
Traditionally the chinese have used only two viaduct span lengths, and mixed them in such a way that they don't have to expend time and money moving utilities and the like.

If you chose your span lengths carefully you can place bridge supports such that you don't interfere with anything already on or in the ground.

No arguments with farmers about access to fields, no need to relocate roads or utilities etc etc etc.
It also has the advantage that you only have a few percent chance of hitting some buried utility or other that was missed by the survey for whatever reason - because if you don't put a pillar footing through it you don't really care about it.

Supposedly, the Chinese also claim it reduces the amount of land that has to be temporarily taken over for construction.

I believe they cast the pillars with reusable slip forming equipment too.

 

[Krokodil]

Does that use more concrete than ground level methods? I recall that the sheer quantity of concrete required for HS2 caused a considerable spike in prices.

Is the lifespan of the viaducts a concern?

 

[HSTEd]

Does that use more concrete than ground level methods? I recall that the sheer quantity of concrete required for HS2 caused a considerable spike in prices.

That depends heavily on the design of the relevant routes.

But the cost of concrete could double and it still wouldn't be a dominant driver on costs of a viaduct project.
It's also worth noting that the cost of a new cement plant is only a few hundred million pounds, so ultimately HS2 could just have built one themselves (and an aggregates quarry!) and avoided distorting the UK cement/concrete market so much etc.

Is the lifespan of the viaducts a concern?

Probably not, they will last decades, at which point the life has become long enough not to strongly effect scheme economics.

 

[The Ham]

You also don't affect local hydrogeology so no new flood mitigations and drainage ponds,

The reason for drainage ponds is to do with catching the excess water which runs of hard surfaces vs a green field.

Due to the rules (water discharging at a 1 in 2.5 year storm event whilst storing enough water to fall in a 1 in 100 year storm plus an allowance for climate change) it significantly reduces the risk of flooding down stream, especially during winter storms when the ground may well be saturated and will act like concrete anyway.

 

[Xavi]

HS2 had that plan, then met politicians. It was never meant to have a way to overrule Osbourne, Javid, Reeves etc in their power as Chancellor to make the choices they have.

HS2 did not overrule the Treasury, quite the opposite in fact. Target Cost contracts were tendered for the civils works but the Treasury would not approve the contractor’s proper cost estimates (they didn’t suit the capital budgets that were already locked in Treasury forecasts). The Tories didn’t want to ditch the project (remember levelling up), so DfT instructed HS2 to proceed with cost reimbursable contracts (the contractors would obviously not reduce the prices in the target cost contracts when they’d have been on the hook for pain) and to suppress the cost forecasts until sometime in the future, which ultimately led to Rishi’s hotel moment.

 

[Brubulus]

HS2 did not overrule the Treasury, quite the opposite in fact. Target Cost contracts were tendered for the civils works but the Treasury would not approve the contractor’s proper cost estimates (they didn’t suit the capital budgets that were already locked in Treasury forecasts). The Tories didn’t want to ditch the project (remember levelling up), so DfT instructed HS2 to proceed with cost reimbursable contracts (the contractors would obviously not reduce the prices in the target cost contracts when they’d have been on the hook for pain) and to suppress the cost forecasts until sometime in the future, which ultimately led to Rishi’s hotel moment.

Interesting, where did the desire to use "new techniques" at every available opportunity come from instead of simply copying what had worked on LGVs and similar regarding tunnel design and construction methods. Decisions such as 360kmh and slab track are defendable. However stuff like the design of the Chiltern tunnel, seems to have been an extreme case of trying to do "innovation" for no reason.

Regarding 36 months of testing being the benchmark for "comparable projects" are there any other European HSRs which had a 36 month testing period?

 

[HSTEd]

Interesting, where did the desire to use "new techniques" at every available opportunity come from instead of simply copying what had worked on LGVs and similar regarding tunnel design and construction methods. Decisions such as 360kmh and slab track are defendable. However stuff like the design of the Chiltern tunnel, seems to have been an extreme case of trying to do "innovation" for no reason.

Regarding 36 months of testing being the benchmark for "comparable projects" are there any other European HSRs which had a 36 month testing period?

I am not entirely sure where it came from, but it seems to have been in the project from the very beginning.

I suspect it dates back to Lord Adonis and a desire to create a "world beating" railway.

The practice in the rest of the world has been to move to larger tunnels over time as they make most of your issues go away.
HS2 has gone the other direction, which has provoked a whole range of choices that I think have caused serious issues.

 

[Xavi]

Interesting, where did the desire to use "new techniques" at every available opportunity come from instead of simply copying what had worked on LGVs and similar regarding tunnel design and construction methods. Decisions such as 360kmh and slab track are defendable. However stuff like the design of the Chiltern tunnel, seems to have been an extreme case of trying to do "innovation" for no reason.

Regarding 36 months of testing being the benchmark for "comparable projects" are there any other European HSRs which had a 36 month testing period?

I full agreed that less innovation and more “tried and tested” would have reduced some costs, and 36 months is a lengthy period for testing. Wild is setting a low bar and I think he’ll beat it. Win Win Wild.

 

[eldomtom2]

Building High Speed Rail on viaducts is the preference from the people who actually build the most of it China, Japan and other Shinkansen style lines (Taiwan has a 110km long viaduct).

That is due to political will, not low construction costs. Chinese high-speed rail constructions costs are fairly high and those in Japan are pretty much the highest in the world outside of the UK.

You also don't affect local hydrogeology so no new flood mitigations and drainage ponds, the construction site is also much smaller and because you are producing a standardised product you can go much faster which means that you save on things that scale with time rather than construction output e.g. security, HSE, management, procurement, goods in and welfare/catering.

These are hypothetical cost advantages. But the data says that the more of your line you build on viaduct, the more expensive it becomes.

 

[Sonik]

The practice in the rest of the world has been to move to larger tunnels over time as they make most of your issues go away.
HS2 has gone the other direction, which has provoked a whole range of choices that I think have caused serious issues.

Pretty sure this design choice was for to carbon reduction, not prestige. Larger tunnels increase excavation and materials in a non-linear fashion.

As we know most of the tunnels exist purely for political reasons. HS2 have stated that non-essential tunneling (i.e. that added to scope) is 1/3 of the total carbon of the project, the largest single contribution.

So the real problem (yet again) is NIMBYs.

 

[HSTEd]

Pretty sure this design choice was for to carbon reduction, not prestige. Larger tunnels increase excavation and materials in a non-linear fashion.

As we know most of the tunnels exist purely for political reasons. HS2 have stated that non-essential tunneling (i.e. that added to scope) is 1/3 of the total carbon of the project, the largest single contribution.

It's not quite that simple.
Because the smaller tunnels resulted in the need to construct enormous 100m concrete tunnel hoods (hoods that size have never been proposed anywhere else, much less built!), the need for extra tunnel damper equipment in the ventilation shafts, the restrictions on train operations related to evacuation etc etc etc etc.

The list goes on and and on and on.

All for a marginal reduction in carbon emissions from spoil excavation and disposal, and a marginal reduction for somewhat less concrete used.

Nevermind that construction emissions for HS2 will amortise to nothing quite rapidly.
They don't really matter.

Indeed, the aforementioned explanation posted by HS2 doesn't even attempt to quantify carbon savings.

The stated 1.5 million cubic metres of reduced excavation is a rather small amount in the scheme of things. HS2 Phase 1 has involved over 50 million cubic metres of excavation.

As someone who's job is life cycle assessment, the argument that this meaningfully reduces carbon emissions is not persuasive.

So the real problem (yet again) is NIMBYs.

No, the real problem are the fools that thought they were ever going to get to cut straight through an AONB on the surface.

 

[Sonik]

The stated 1.5 million cubic metres of reduced excavation is a rather small amount in the scheme of things. HS2 Phase 1 has involved over 50 million cubic metres of excavation.

As someone who's job is life cycle assessment, this argument is appears to me to be simply a fig leaf.

Regardless, tunneling is evidently particularly carbon intensive, and as the largest single contribution, it's going to be a prime target for reduction.

It's also the case that most all other excess earthworks (e.g. cuttings and bunds) are also due to political reasons.

So I think it's still fair to say that adjustments to appease NIMBYs blew the carbon budget, forcing expensive esoteric design choices in mitigation.

I don't dispute that using a bunch more concrete in a conventional design is likely cheaper.

 

[stuu]

It's not quite that simple.
Because the smaller tunnels resulted in the need to construct enormous 100m concrete tunnel hoods (hoods that size have never been proposed anywhere else, much less built!), the need for extra tunnel damper equipment in the ventilation shafts, the restrictions on train operations related to evacuation etc etc etc etc.

I'm really puzzled by lots of the decisions. The tunnels are 0.5m wider than the Guadarrama tunnels in Spain, which don't have any bizarre portals or restrictions, so why do we do we need them here? The trains aren't going to be any bigger or faster

 

[Snow1964]

I'm really puzzled by lots of the decisions. The tunnels are 0.5m wider than the Guadarrama tunnels in Spain, which don't have any bizarre portals or restrictions, so why do we do we need them here? The trains aren't going to be any bigger or faster

When trains run at very high speeds, potential to get air pressure waves which in confined spaces causes the air to go so fast it goes supersonic, this results in sonic boom.

The Japanese first discovered the problem (the early French lines didn't have any tunnels on fast bits). There are two solutions, build a long nose on the trains (and Japanese opted for duckbill noses) to disipate pressure wave, or add some transition vents for air to escape when entering a tunnel.

The HS2 solution is effectively overkill, as it covers possibility of going at 400km/h and with minimal nose faring to maximise space within the 200m unit length. But of course trains are not likely to operate that fast, and initially at least won't be to bigger UIC cross section. So rather gold plating a theoretical future need. If the top speed had been specified at nearer 320-350km/h wouldn't be required.

 

[LNW-GW Joint]

Regarding 36 months of testing being the benchmark for "comparable projects" are there any other European HSRs which had a 36 month testing period?

The details are impossible to know, but several Spanish LAV sections have been "completed" and then lain idle for years with no apparent plan to go live.
There were suggestions that they were built to the wrong specification, and needed extensive rework.
Two sections I am aware of were Valladolid-Burgos and Xativa-Valencia.

 

[stuu]

When trains run at very high speeds, potential to get air pressure waves which in confined spaces causes the air to go so fast it goes supersonic, this results in sonic boom.

The Japanese first discovered the problem (the early French lines didn't have any tunnels on fast bits). There are two solutions, build a long nose on the trains (and Japanese opted for duckbill noses) to disipate pressure wave, or add some transition vents for air to escape when entering a tunnel.

The HS2 solution is effectively overkill, as it covers possibility of going at 400km/h and with minimal nose faring to maximise space within the 200m unit length. But of course trains are not likely to operate that fast, and initially at least won't be to bigger UIC cross section. So rather gold plating a theoretical future need. If the top speed had been specified at nearer 320-350km/h wouldn't be required.

Is the Chiltern tunnel designed for 400 km/h? I thought that was only north of Wendover but I might be wrong.

Japan needed to do that because the earlier tunnels were built as narrow as possible. Newer tunnels are wider - the most recent extension to Kanazawa has lots of tunnels but uses conventional looking high speed trains.

 

[ThirteenArches]

water discharging at a 1 in 2.5 year storm event whilst storing enough water to fall in a 1 in 100 year storm

But 1 in 100 year events happen pretty frequently now.

Building High Speed Rail on viaducts is the preference from the people who actually build the most of it China

But perhaps not of the people who have to live near them? No one cares about them in China, one word out of place and you never existed.

Are those with a genuine passion for railways not upset by the fact that the HS2 debacle will make future rail projects so much more difficult to propose

Of course we are. Defending the total f-up of HS2 from conception to non- implementation doesn't make the reality different. It's going to be impossible to do anything with railways for the rest of my lifetime. and probably that of my kids. But another road tunnel under the Thames?

 

[may032]

In terms of wanting to serve every large urban area, such proposals were around long before the HS2 route was finalised. The M1 corridor route proposal was to serve Leicester, East Midlands (Nottingham/Derby), Sheffield and Leeds (and then onwards to Teesside, Newcastle, Edinburgh and Glasgow), with Manchester and Liverpool being served via Sheffield, thus incorporating the Northern Powerhouse corridor. Birmingham was always less important since it is well served from London already, but a loop from south of Leicester, then roughly as HS2 should have gone towards East Midlands, would have completed the ideal initial HS network for the UK.

The only way HS2 could have gone worse is if we’d have been left with a stub from London to Leicester. A different route would not have changed the fundamental structural problems identified and discussed in great depth on here and in the recent Stewart review.

 

[stuu]

Of course we are. Defending the total f-up of HS2 from conception to non- implementation doesn't make the reality different. It's going to be impossible to do anything with railways for the rest of my lifetime. and probably that of my kids. But another road tunnel under the Thames?

Quite a bit of hyperbole there. Seeing as the government have said they are going to fund the next phase of East-West Rail, and they are talking about Liverpool-Manchester etc

The last tunnel under the Thames opened 55 years ago, it's not something that happens every day

 

[NCT]

The Chiltern Natural Landscape extends all the way into Hertfordshire, and an M1 alignment would have to cross it just as much.

I find the 'if we upset a marginally fewer number of marginally less rich and powerful people we'd get an easier pass' argument rather troubling - in that it suggests at the core we accept and want to perpetuate the remaining feudal characteristics of how we are governed as a society.