HS2 Bridges and Viaducts Engineering Challenges

A version of this article was published in RAIL Magazine issue 1040

Construction of the 220km (140 mile) long HS2 route between London and the West Midlands has unsurprisingly involved constructing a large number of bridges and viaducts. In fact, 50 “significant” viaducts and 175 other bridge structures are being constructed to cross roads, existing railways, waterways and other natural features.

Some of the viaducts will be engineering marvels in their own right, such as the 3.4km (2-mile) long Colne Valley Viaduct, while others, which have been designed to blend into the landscape, will be modest in comparison.

Given that so many bridges and viaducts are being constructed, it's unsurprising that some will share the same or similar construction techniques. Whilst others required a more bespoke solution to overcome certain challenges and meet a particular set of criteria.

It would have been ideal if it were possible to use a standardised method of construction across the whole route. However, the construction methods for each structure had to be decided upon based on several factors. They included length and height, the space available for construction, ground conditions, and nearby infrastructure.

In addition, the DfT specified that each structure must be designed to last 120 years without requiring significant maintenance. Many of the viaducts have also been designed to withstand immense lateral forces. The viaducts on the mainline, for instance, have been designed to resist the force that would be imparted if full braking were applied as a 400m long train travelling at up to 360km/h (225mph) was on or approaching the viaduct.

So, whilst using standardised methods would be preferable, it is not always possible to create just one or two viaduct designs that would meet all of the criteria.

That’s not to say that the contractors delivering HS2 haven’t tried to use as much standardisation as possible, and many of the viaducts share the same engineering principles. One technique which has almost universally been adopted is the use of as much off-site construction as possible to manufacture structural elements in a controlled environment.

Colne Valley Viaduct

In the case of the Colne Valley Viaduct, engineers had to determine how to build “the UK’s longest bridge” over a series of lakes, waterways and roads whilst keeping local disruption to a minimum.

The viaduct is being constructed by the Align Joint Venture, made up of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick, which is delivering a 22km long C1 HS2 section between the northern Northolt Tunnel portal and northern Chiltern Tunnel portal

Colne Valley Viaduct just prior to completion in 2024

Due to the uniqueness of the viaduct and the surroundings, it was decided to utilise a bridge-building leviathan imported from Hong Kong. The so-called launching girder christened Dominique was used to build the East Tsing Yi Viaduct, constructed by Bouygues Travaux Publics in 2008.

The 160m long, 700-tonne launch girder was used to lift 1000 precast concrete segments into place, which weighed between 60 and 140 tonnes. As each bridge span was completed, Dominique was able to move forward to construct the next.

The segments were manufactured close to the northern abutment at a purpose-built factory in West Hyde. Assembly of the viaduct began in 2022, and the final segment was lowered into place in September 2024, which is an incredible achievement.

The Colne Valley Viaduct is a landmark structure and is noticeably larger in scale than most of the viaducts along the route. But despite its sheer size, the viaduct looks graceful. This is thanks to the design, which was intended to mimic a stone skipping across water.

The Final segment being lowered into place in September 2024

Thame Valley Viaduct

Many of the viaducts on the route are more modest in scale, but construction has been no less challenging. A floodplain to the west of Aylesbury, for example, posed a unique challenge which drove engineers to use as much pre-fabrication as possible. So much prefabrication, in fact, it is thought that the construction of the viaduct is a UK first.

The viaduct crosses a flood plain, which meant there is little space to construct the deck, and a lot of preparation had to be carried out before assembly of the viaduct could begin.

First, a haul road had to be constructed, as well as pads used to support cranes. The temporary road, which had to be constructed above the floodplain, also had to be built in such a way that it did not contaminate or block the flow of water.

Completion of the haul road allowed workers to assemble the bridge piers and deck relatively quickly. Assembly of the deck structure began in October 2023 and were installed by the following year. Work then focused on pouring the final layer of concrete to permanently stitch the precast deck elements together.

One of the bridge beams being lowered into place in October 2023

Each span was constructed using 25m long, 100-tonne bridge beams manufactured by PACADAR on the Isle of Grain. The beams were transported to the site by road and lifted into place using two crawler cranes. The beams were then topped with bridge deck sections, which were also manufactured off-site. It is the use of prefabrication for the bridge piers, beams and deck, which makes this a UK first.

Wendover and Small Dean Viaducts

The Thame Valley Viaduct, which is only 3m high, is a relatively low structure, which meant that it was possible to assemble the viaduct in situ using cranes. The deck for the Wendover Dean Viaduct in Buckinghamshire, however, is much further off the ground. It would therefore have been difficult to utilise cranes to move large bridge sections into position.

For this reason, the viaduct was constructed using a method known as a deck slide, otherwise known as a “push launch”. This method quite literally involves pushing (or more accurately pulling) the bridge deck out onto pre-built piers.

Using this method meant the deck could be assembled in a single location rather than having to reposition cranes as construction progressed.

Wendover Dean Viaduct structural steel following the third and final slide

The nearby Small Dean Viaduct, which is 345m long, was also constructed using the same method. In this instance, however, the deck slide was used in part to keep disruption to the busy A413 and Chiltern Mainline to a minimum. This is because both had to close for a period of time during the slide, which took place in February 2025.

The Wendover Dean Viaduct deck was pushed into position over three separate slides, with sections of the deck assembled before each launch. The 4320-tonne deck for the Small Dean Viaduct, on the other hand, was pushed into position in one go to reduce disruption to the main road and railway.

The Wendover and Small Dean Viaducts are just two of five viaducts which are being delivered using the same structural design and construction technique. They are being delivered by the EKFB Joint Venture, formed of Eiffage, Kier, Ferrovial Construction and BAM Nuttall, which is constructing the central C2 and C3 section of HS2.

Small Dean Viaduct "deck slide" January 2025

The large steel beams for the viaducts were manufactured by Eiffage Metal in France. They were then transported to the UK by ferry, afterwhich they were delivered to the site by road.

The decks have been constructed using a double composite construction method, which involves placing precast concrete panels at the top and bottom of the steel beams. The top and bottom panels are then covered with a layer of in-situ poured concrete. This produces a hollow deck which is relatively lightweight but is also incredibly strong.

Delta Junction

Delta Junction, which is being built to the east of Birmingham, will comprise a series of viaducts, forming a three-way grade-separated junction. Such is the scale of the junction and its location that several techniques are being employed to construct several viaducts across the sprawling site.

Some methods are more straightforward than others, such as that used to construct the River Cole Viaducts built on the southern section of the Junction. The two 160m long spans were constructed using steel beams, which were lifted into place onto pre-built concrete piers. Installation of the beams was completed in December 2024, after which the process of lifting precast concrete deck segments and parapets began.

Although several construction methods are being employed across Delta Junction, the scale of the junction has allowed the Balfour Beatty VINCI joint venture (BBV JV) constructing N1 and N2 section in the West Midlands to use a standard method for the vast majority of the viaduct spans.

Delta Junction, River Tame Viaduct. The Blue tower forms the mast for the "temporary deck erection system"

Nine of the viaducts will be constructed using precast concrete deck segments, much like the Colne Valley viaduct; however, the assembly method used differs somewhat.

Although the Delta junction site as a whole is enormous, the individual site locations for the viaducts are, in some cases, incredibly constrained. The Water Orton Viaduct, for example, must cross the busy M6 Toll / M42 interchange, which is 11 lanes wide. Whilst the River Tame Viaduct, which is sandwiched between the M6 Toll / M42 Interchange and sprawling Hamms Hall Distribution Park, must cross the River Tame.

The challenging conditions mean that the viaducts, whilst sharing the same segmental design, will be assembled using three distinct construction methods.

The segments for 153 individual spans are being assembled off-site at a purpose-built facility established on the outskirts of Marston in Sutton Coldfield. The Kingsbury site, as it is known, is being used to manufacture 2,742 concrete segments, each weighing between 50 and 80 tonnes.

136 out of 153 individual spans will be constructed using a cantilever method, which utilises a so-called temporary deck erecting system. During construction the system resembles a cable-stayed bridge with stay cables attached to a temporary steel tower, which is installed above one of the pre-built piers. The stay cables are attached to the previously constructed deck span, whilst further stay cables are attached to concrete segments for the next span as they are installed.

The system also consists of a swivel crane, which lifts the segment, swivels it into position and holds it in place whilst temporary steel bars are installed within the segment. Once the steel bars are installed, the stay cables are attached, after which the segment can be released from the swivel crane. The crane is then moved into position on top of the segment, which has just been installed.

River Tame Viaduct, inside the concrete box girder

The segments are transported to the crane from a holding area and across the previously assembled using an SPMT (self-propelled modular transporter).

Due to the number of spans being assembled using this method, BBV JV ordered four temporary deck erection systems designed and manufactured by BERD. Although this is not the first time that a bridge has been constructed using a cantilever method in the UK, it is the first time that this particular system has been used to construct a viaduct in this country.

Although the majority of spans will be constructed using this method, 11 spans must first be constructed using a so-called “side span” method. This utilises a temporary steel truss, which is placed between two piers and is used to support the segments during assembly. This method is used to construct each initial viaduct span, as the cantilever method requires a completed span to which stay cables are attached.

"Side span" system being lifted into position. Image credit HS2 Ltd

A further six spans will be pre-assembled and then moved into position using SPMTs. This method involves fully assembling and post-tensioning the spans close to the viaduct site. The spans will be moved into position above the M6 Toll / M42 Interchange during a series of weekend-long closures, which are due to take place in mid 2026.

The reason for using pre-assembly is to reduce disruption to a key motorway interchange. Whilst it may have been technically feasible to use the side-span or cantilever method, this would involve working above the motorway for extended periods, which is best avoided.

Despite using three different methods to assemble the 153 spans, they will all share the same structural design. Which means the deck sections will all take the form of hollow post-tensioned concrete box girders.

Curzon No.3 Viaduct

Heading towards Birmingham, a series of bridges and viaducts will bring trains into the city from Bromford Tunnel. The techniques used for some of the bridges will be somewhat similar to those described so far.

However, Curzon No. 3 Viaduct is unusual in that it is being constructed entirely in situ, rather than being assembled from pre-manufactured elements.

In situ construction first involves assembling formwork on top of a scaffold structure. Rebar (reinforcing bar) is then placed inside the formwork before concrete is poured to form the structure for the deck.

The dense scaffold structure used to support the formwork into which the concrete is poured.

This method was chosen due to the size and shape of the viaduct, which fans out from three tracks leading from Curzon No. 2 Viaduct to seven tracks which form the throat of Curzon St station.

The dense scaffold structure used to support the formwork into which the concrete is poured.

Work to build the first span appeared to progress relatively slowly, with construction of the span continuing throughout 2023 and was only completed in April 2024. However, the first span closest to the station consisted of three individual spans, which together will support the seven tracks.

The mostly complete section of Curzon No.3 Viaduct in August 2025

Given the scale of HS2, it is unsurprising that so many different construction methods are being used for the various structures. However, even though the route is being delivered by three joint ventures that have been tasked with delivering 50 significant viaducts, it is perhaps more surprising to learn that so many of the viaducts share the same design principles and broadly similar construction methods.

Despite many of the viaducts appearing to be different, they are or have been built using only a small number of different techniques. A large number of the viaducts also share the same segmental concrete design, which has been widely adopted by the three joint ventures.

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www.EngineeringFocus.co.uk

Midlands Rail Hub

A version of this article was published in Rail Magazine issue 1016

Since November 2022 Volkerfitzpatrick has been working on behalf of the West Midlands Rail Executive and the West Midlands Combined Authority to deliver three new stations on the Camp Hill Line in Birmingham to replace ones which had closed in 1941. Thankfully the line remained open, however for the last 80 years it has only been used for freight traffic, empty stock moves and some Cross Country services in order to bypass the Cross City Line.

The £61m scheme to reopen the Camp Hill Line will see three stations rebuilt with accessible, two platform stations capable of handling six-car trains. The initial two trains per hour service will operate between Birmingham New Street and Kings Norton, with trains joining the Camp Hill Line at St Andrews Junction. As the line will remain unelectrified the service will be operated by West Midlands Railway using Class 196 DMUs.

Heading south from New Street the first of the rebuilt stations on the route will be Moseley Village, which is located on St Mary’s Row in Moseley, just to the north of the short tunnel which takes the line underneath what will eventually be the entrance to the station and St Mary’s Row.

Moseley Village station progress April 2024

The next station will be approximately 1km to the south, located close to the A435 High Street in Kings Heath, next to a small retail park. The new Kings Heath station will be situated alongside the car park for the retail park and will have access from a new pedestrian overbridge onto High Street.

CG render of Kings Heath station (West Midlands Combined Authority) 

The final station to be rebuilt will be Pineapple Road, located approximately 1.5km to the south of Kings Heath, just north of the bridge which takes Cartland Road over the line in Stirchley. From there, trains will head south to Kings Norton, where the trains will terminate, before reversing to head back to New Street station.

Rebuilding stations which existed previously would normally be relatively straightforward, however, the re-opening of the three stations has not been without its challenges as after eight decades almost nothing remained of the former stations. The sites for the three stations are also especially constrained and substantial remediation works had to be carried out in order to stabilise cuttings and provide space for the longer platforms. Piling work is clearly visible at Kings Heath and Pineapple Road stations, whilst ground anchors and concrete has been used to stabilise embankments on either side of Moseley Village station.

Image from 2024 shows the extent of the piling work required at Kings Norton to stabilise an embankment 

Lack of space is not the only challenge faced by the contractor. In June last year, it was reported that the discovery of badgers in Moseley was to blame for a significant delay in the reopening of the station. Badgers are classified as an endangered species, which means their sets cannot simply be removed. This meant that Volkerfitzpatrick had to work with ecologists to rehome the badgers to a suitable location before work on the station could continue.

Operating services to Birmingham New Street is currently the only practical way to get trains into the city centre, although capacity at the station has been constrained for a number of years. However, the new service will be able to make use of paths into New Street which have become available following the Pandemic. In particular, Cross City Line services have not returned to pre-pandemic levels and currently, four trains per hour operate in each direction, as opposed to six trains per hour before the pandemic. This also means that there will be capacity to turnback the new Camp Line trains at Kings Norton on the Cross City Line without any expensive infrastructure modifications.

Ultimately, following the completion of the Midlands Rail Hub project, it is proposed to restore six trains per hour on the Cross City line into New St and to re-route the Camp Hill Line services into Birmingham Moor Street station.

The Midlands Rail Hub scheme is being developed jointly by the Department for Transport, sub-national transport body Midlands Connect, West Midlands Rail Executive and Network Rail. The project involves the construction of a two new chords in the Bordesley area from the Chiltern Mainline onto to connect the Camp Hill Line and line from Water Orton with the existing Chiltern Main Line into Birmingham Moor St. The project also involves building additional platforms at Moor Street and a new platform at both Snow Hill and Kings Norton, as well as increasing the number of tracks between Moor Street and Bordesley.

Two new chords will be constructed in Bordesley linking the Camp Hill to the Chiltern Main Line

The western Bordesely chord would not only allow Camp Hill Line services to terminate at Moor Street, but together with other proposed infrastructure interventions south of Kings Norton would allow additional services from Moor Street to serve Bristol, Cardiff, Worcester and Hereford. Similarly, in conjunction with other infrastructure works east of Birmingham, the second chord at Bordesley will allow additional trains to head from Moor Street towards the East Midlands. In total more than 50 stations will benefit from the Midlands Rail Hub plans.

Constructing the two new chords is likely to be one of the most challenging aspects of the scheme and will likely involve the rebuilding of the bridge over Bordesley Middleway, and the construction of a bridge over the roundabout at the western end of Small Heath Highway. In addition, both the eastern and western chords would also have to cross the Grand Union Canal. Ideally, both chords would be constructed at the same time, which should provide overall cost savings, by delivering the works within a single package.

The budget for the combined Midlands Rail Hub interventions is estimated to be £1.75bn and it is hoped to complete the project around the early 2030s, should funding be agreed. At the beginning of March, the Government announced funding of £123m to progress the Full Business Case stage and begin design work.

Due to the scale of the project, the Government as well as agreeing to fund the scheme must also grant a Transport and Works Act Order (TWAO), which would provide Network Rail with permission to begin construction. The TWAO will only be granted once the full business case has been appraised and funding granted which is likely to still be a few years away.

The reopening of the Camp Hill Line will provide benefits for residents who live in the south of the city who currently don’t have access to rail services. The Camp Hill Line could also improve local and regional connectivity with HS2 services from Curzon Street should the western chord be constructed. The western concourse of Curzon Street will be adjacent to the entrance to Moor Street station, however, the current plans for the new HS2 station do not include full integration with Moor Street, it is therefore hoped that plans will eventually be progressed to fully integrate the two stations.

The main entrance of the new HS2 station in Birmingham will be adjacent to Moor St station

If the full Midlands Rail Hub scheme can be realised then connectivity with HS2 services will be further enhanced and could bring passengers from Bromsgrove and Worcester within easy reach of HS2 services.

From the very beginning, the location of the new HS2 station has come under criticism, due to the distance from New Street station. But if the Midlands Rail Hub is realised then Birmingham Moor St could become a much more convenient station for onward travel from Curzon Street to destinations across Birmingham and further afield to the West and East Midlands, should both of the chords at Bordesley be constructed.

The Government has claimed that the Midlands Rail Hub has been made possible by “reallocated HS2 funding” freed up by the cancellation of the northern sections of HS2. However, in addition to the improved regional and cross-regional connections it delivers, Midlands Rail Hub has always been seen as key to unlocking the full benefits of HS2 and in fact, the cancellation of the northern section appears to have reduced the overall benefits and limits the scope for further connectivity improvements.

Without significant upgrades to the WCML, or the construction of a new line between Handsacre and Crewe/Manchester it will be unlikely that services will be able to operate from Curzon Street to Manchester, the North West and Scotland. And whilst this shouldn't affect the business case for the Midlands Rail Hub, it will limit the usefulness of Curzon Street Station and ultimately curtail the transformational connectivity HS2 Phase 2b would have provided between Britain's two largest regional cities.

That’s not to say the Midlands Rail Hub will not be transformational on its own, if delivered in full, but the benefits could be spread much further if HS2 was to be constructed in full.

HS2, Handsacre

A version of this article was Published in Rail Magazine, issue 999

The small village of Handsacre has recently become the focus of attention after the Prime Minister announced at the Conservative Party Conference on the 4th of October that he was cancelling phase 2 of HS2 to Crewe and Manchester. Now the parish of Handsacre and Armitage, which is more often associated with the manufacture of bathroom fixtures has another claim to fame, being the likely permanent end point for HS2.

It was always intended that HS2 would join the WCML at Handsacre, however, it was assumed that this would be the first of three connections that would allow trains to leave the new line and head north on the existing railway. The other two were to be located to the south of Crewe and Golborne to the North of Warrington.

Before Phase 2 was split into phases 2a and 2b it was proposed that HS2 services would leave the high-speed line at Handsacre and continue on the existing network to Manchester, Liverpool and Glasgow before the completion of Phase 2 to Manchester and Golborne.

The plan was changed in 2014, when it was decided to build HS2 to Crewe first (Phase 2a), then continue the line to Manchester and Golborne (Phase 2b). After the re-phasing, it was proposed that Manchester, Liverpool and Glasgow could each be served by one HS2 service per hour to London Euston (later, further revised to terminate temporarily at Old Oak Common) until the completion of phase 2a to Crewe.

Site of Handsacre Junction, 2023

Once phase 2a opened, Manchester would have been served by three trains per hour, Liverpool two and Glasgow one train per hour, joining HS2 just south of Crewe. After which two additional services were proposed. One originating in Macclesfield calling at Stoke and Stafford, before joining HS2 at Handsacre utilising the capacity released by Phase 2a. The other would start at Lancaster and call at Preston, Wigan and Warrington Bank Quay before joining a service from Liverpool at Crewe to form a single 400m set (2x 200m). This service would then join the WCML at the connection south of Crewe.

Now though, after Rishi Sunak’s announcement, trains will join the WCML at Handsacre indefinitely, as he has cancelled arguably the most transformative section of HS2. HS2 Phase 1 will still provide some capacity gains between Rugby and London Euston, with benefits for commuters south of Birmingham, however, there will be no additional capacity freed up between Rugby and Manchester.

The PM's decision may also potentially create a severe bottleneck between Handsacre and Colwich, which could have implications for the WCML north of Lichfield, affecting both passenger and freight services.

HS2 - WCML Spur

To further complicate matters Handsacre Junction requires two separate junctions to work, with a flyover taking a down line over the core section (that would later have become Phase 2a), to the spur which would join the WCML. Now though, this first junction is no longer technically required, but work on the junction has already begun before being paused in March this year.

If the grade-separated junction from HS2 to the WCML spur is no longer required then it may be the case that changes to the Hybrid Bill for Phase 1 will be required, which could mean the bill would have to go back to Parliament. The best outcome would be that a stub be left so that HS2 could potentially continue north at some point in the future.

For the moment however, no one seems to know what will happen and those working within the DfT and HS2 Ltd are only now starting to understand what the implications of the PM's decision will be. When asked for comment, a spokesperson for HS2 Ltd said “We understand the Government’s ambition is to run HS2 trains via the Handscare Link to serve destinations in the North. We await formal notification as to whether the Government intends to repeal the Phase 2a Act, and therefore whether any amendment would be required to the Phase One Act powers for this train service specification to be delivered”.

For now, the sites between Lichfield and Handsacre have been mothballed after all construction north of Streethay (Lichfield) was paused. Since then, the most northerly work that has taken place was the construction of a bridge taking the WCML over HS2 at Fulfen Wood, which was moved into place in July. The Balfour Beatty VINCI joint venture delivering this part of the route is continuing work on the bridge that will take the A38 over HS2, but workers have been stood down between Streethay and Handsacre.

The situation at Handsacre was further complicated when the Phase 2a bill was deposited, as the WCML connection was redesigned so that the HS2 tracks would connect to the Up-Down slows on the WCML. The original proposal for Phase 1 would have seen the HS2 tracks join the UP-Down fasts, which would have been more costly and complicated but would have maximised capacity.

Handsacre original junction design

This change wasn’t as important with the plans for Phase 2a taking HS2 to Crewe and therefore reducing the burden on Handsacre. But without phase 2a, will provide a constraint which will impact capacity on the WCML.

Updated junction design

Professor McNaughton highlighted the issue during a Transport Select Committee HS2 update on the 16th of November, during which he suggested that the WCML connection will have to be redesigned if HS2 is to terminate at Handsacre permanently. When Jack Brereton, MP for Stoke-on-Trent asked “You are advocating a redesign of Handsacre?" Professor McNaughton replied, “I think it is inevitable and an unfortunate consequence, and then bang goes some of the money that you might have saved from not doing 2a.”

Prior to that exchange Professor McNaughton alarmingly said “Unless something has fundamentally changed in the laws of physics since I last looked at it, you cannot deliver the whole of the HS2 phase 1 service on to the slow lines without actually cancelling your freight trains.”

So it seems clear that significant design change will be required, to one or both of the junctions, from what would have been Phase 2a and the spur to the WCML at Handsacre. But even if the WCML connection is reverted to the original more efficient design, it would still be the case that HS2 trains will join the WCML at a section which is already constrained. Just a few miles north of Handsacre is Colwich Junction, which is a flat junction where the Stone and Colwich line meets the WCML from Stafford. This junction funnels Avanti services from the North and LNR services from Crewe down the Trent Valley line. Being at-grade means that capacity is inherently constrained and that’s before the introduction of additional HS2 services.

It is important to note that current Avanti services will largely be replaced by HS2 services, however, it was always proposed that some “classic services” would be retained. The classic services would not only retain or improve local and regional connectivity but would also free up seating capacity for passengers on the WCML. An indicative service pattern within the Phase 1 business case (which was updated in 2020), shows an hourly service from Manchester calling at Rugby and Milton Keynes, in addition to the three proposed HS2 services per hour.

Stopping at Milton Keynes not only benefits Milton Keynes commuters but also maintains connectivity between North and the largest settlement in Buckinghamshire which has a population of 260,000. Milton Keynes is also home to head offices for several large international and national companies, and from 2025 will provide improved links to Bicester and Oxford via East West Rail

Not only would the PM's decision limit capacity on the WCML, it will fail to provide any meaningful capacity for passengers from the North. In fact seating capacity could be reduced unless the current order for 54, 200m long trains is modified. The expected capacity of the HS2 units that will be delivered by a Hitachi/Alstom Joint Venture would only be 550 seats. This wasn’t a problem with phase 2 providing Manchester Piccadilly with the ability to accommodate 400m long (2x 200m), 1,100 seat sets. However, without phase 2 the existing platforms could only accommodate 200m long units. If so this would lead to a reduction in seating capacity when compared to the 265m long, 11 car Class 390 Pendolinos, which have a capacity of 589.

Capacity comparison, 200m long HS2 trains vs existing Avanti Class 390

Even if the order is modified to deliver say 250m long HS2 units, that would only provide a marginal gain, versus the capacity provided currently. A potential for a 294 seat per hour gain from Manchester to London is hardly transformation, not when compared with phase 2, which would have provided up to 1550 additional seats per hour. This reduction also applies to Glasgow, which would only be served by one HS2 service per hour, instead of the 2tph that would have been provided with the completion of the Golborne Link. Liverpool could potentially still see two HS2 services per hour, but it is unclear if the additional service would be a straight swap for the proposed Avanti service calling at Liverpool South Parkway using Class 807s.

It's too early to tell what the implication of the PM's decision will be, but it seems patently clear that if nothing else, reliability will suffer by trying to squeeze more capacity out of the existing railway North of Handsacre and that the proposed capacity gains provide by HS2 will be marginal at best.

155mph Class 390s on HS2?

You may have to forgive the grammar, this article was based on a script for a Youtube video

Should we operate 155mph (250km/h) capable Class 390 Pendolinos on HS2? The short answer, in my opinion, is no. However, it is a complicated issue that deserves further investigation.

The renowned and well-respected railway veteran Chris Gibb has proposed that Class 390s should be fitted with new traction systems and bogies so they can operate in regular service at 155mph in non-tilt mode on HS2. 

The primary benefit is capacity from Glasgow and Manchester to London.  But it is also claimed that the Glasgow to London journey time will be 17 minutes slower via HS2 than the existing service.

Firstly I have to agree with the point about capacity, In fact, I was one of the first people to demonstrate that HS2 in its current form could lead to a reduction in seating capacity from Manchester and Glasgow into London. However, it is important to stipulate seating capacity.

Why is this the case? Because the new HS2 trains on order will be 200m long and were intended to work in multiple to Birmingham Curzon St and the new HS2 platforms at Manchester Piccadilly, so would be 400m long during peak hours, providing up to 1100 seats.  But with no new HS2 platforms at Manchester there will be no room at Piccadilly for 400m long trains

Artist impress of the rolling stock intended for HS2. Source HS2 Ltd

Even if HS2 were built in full to Golborne, Glasgow would still have been served by 200m HS2 sets but would have benefited from an increased frequency, leading to an overall capacity gain. But unfortunately curtailing HS2 means no more trains can operate between Glasgow and Euston that already do currently.

The main issue is that a 265m long, 11 car Pendolinos have 589 seats, whereas the proposed HS2 units will have up to 550 seats per 200m long sets. So there could be an overall reduction in seating capacity on some routes

HS2 units vs Class 390 comparison

However, once HS2 opens to Handsacre there may still be potential to operate a so-called “classic” between Manchester and London, calling at Milton Keynes. So Manchester could see up to 4 trains per hour to London, comprised of 3 HS2 and 1 classic. This means there could still be an overall capacity gain and more choice for passengers.

Glasgow is a bit more challenging, as capacity is limited between Crewe, Warrington and Wigan and on the northern section of WCML. So without HS2 to Golborne, no more trains can operate than currently do, so technically there could be a reduction in seating capacity from Glasgow. At least for the direct Glasgow to London via HS2 service, which would replace the existing direct service.

Liverpool to London will still see an overall increase with the service increased to 2tph with HS2 to Handsacre. Even taking into account the proposed additional Avanti service from Liverpool to London. However, Gibb suggests that one service per hour should continue to use the WCML via Milton Keynes, but use the new HS2 trains. This idea possibly may have some merit, at least until HS2 is completed to Euston.

The report also recommends the existing two Cross Country services per hour from Manchester should replaced by 200m long HS2 service from Manchester to Birmingham. This would provide a capacity uplift between Manchester and Birmingham and the Chris claims would reduce the journey from 90 to 50 minutes

Although the current services stop at Stockport, Macclesfield, Stoke, Stafford and Wolverhampton and takes 57 minutes just to get to Stafford. So is there a suggestion that some stops would be missed out between Manchester and Birmingham? 

This proposal also removes the direct connectivity from Manchester with the South and South West, with XC services continuing to Bristol and Bournemouth. Although it should be pointed out that some journeys such as those to Reading could switch to HS2 and GWR, with passengers changing trains at Old Oak Common.

Manchester to Birmingham connectivity is an issue I have continually tried to raise, and I feel it has been repeatedly ignored within the HS2 debate, despite time savings between the UK's two largest regional cities that would have been transformational. But HS2 would have retained the existing service and supplemented it with new services between the UK's two largest regional cities. So, as it stands I do not think we should be replacing the existing services with HS2 services. Not least because the time-saving claiming would not be achievable without removing stops between Manchester and Birmingham.

Manchester to Birmingham

Current: 90 minutes 

HS2 to Manchester: 49 minutes

The other significant proposal is to de-scope Euston to just 2, 400m HS2 platforms, to be used for the Birmingham services. Beyond that I'm not sure what Gibb is suggesting, he makes reference to Caledonian Sleeper platforms, but with no connection from HS2 to the existing station possible, they seem irrelative.

I'm working on the basis that he means to continue to build some new platforms at Euston, but only build 2, 400m long platforms. With new shorter platforms which would be served by Class 390s and 200m long HS2 units. But I can't imagine that building shorter platforms would save a significant amount of money, so I'm not sure what the benefit would be.

It is worth pointing out that the current design for Euston Tunnel and the approach would not allow for a connection from HS2 to the existing platforms simply because of the lack of space available. In fact, the HS2 platforms will be lower than the existing ones due to the lack of space, to get from the tunnel portal to the station throat.

Layout of Euston approach, source HS2 Ltd

Why do I oppose this plan? I think Richard Bowker put it best, during the interview that Chris Gibb did with Green Signals. Richard said “The critics will say you're letting the politicians off the hook” [Green Signals episode 35].  This was said when Sunak was in power and Richard appeared to be playing devil's advocate. But I do still agree with the sentiment.

In essence, it begs the question, why should any Government continue to develop HS2 if we can just operate some Pendolinos along the route and call it a day? I know Gibb does make further suggestions about Northern Powerhouse Rail and Handsacre to Crewe. But it could be all too tempting just to use slower trains on HS2 and perhaps carry out some upgrades on the WCML.

Gibb's proposal also means that Birmingham's services will have to run slower and could operate a maximum of 186mph, instead of between 200mph (320km/h) and 225mph (360km/h). It wouldn't be practical or possible to operate trains with a speed differential ranging from 45mph to 70mph and maintain the headway. Although I appreciate HS2 is primarily about capacity, but it doesn't seem right to cut the benefits for Birmingham, just so we can operate Class 390 on HS2.  

Gibb also said during the Green Signals interview that he is “challenging” the industry to see if it's possible to re-engineer Class 390s. This seems to be a change from the tone of the report, which makes it seem as if it is already possible.

Perhaps instead we should be challenging the industry to find a cost-effective and practical way to modify the HS2 rolling stock order and instead order 250m or 260m long HS2 sets, which would have more capacity than Class 390s despite being a similar length. I'm not saying all units, but perhaps 8, 10 to 12, to operate peak Manchester and Glasgow services would be sufficient?

I understand there may also be an issue with the Washwood Heath Depot and the maintenance hall may not be long enough to accommodate longer sets. But perhaps the units could be maintained in existing WCML depots with the installation of new equipment?

Washwood Heath plan. Source HS2 Ltd

Surely modifying the HS2 rolling stock order and creating provision for maintenance would be no more expensive or technically challenging than fitting new traction equipment to 20-year-old trains? Which will be close to 30 years old by the time HS2 opens to Handsacre.

I also have to question the “up to 17 minutes longer” claim between Glasgow and London, to which I wasn't able to get a satisfactory answer to what this means. As far as I can tell, it most certainly will not mean services from Glasgow to London via HS2 would be 17 minutes slower than today. As even the most pessimistic time penalty for non-tilting trains between Glasgow and Handsacre would be more than made up for with the time saving between Handsacre and London.

And plans to lift the non-tilt speed on the WCML are already well in advance and a special speed limit can be applied on straight sections of the WCML to allow no-tilting multiple units to travel at 125mph, rather than 110mph, further reducing the time penalty.

Raising the MU speed to 125mph on straight sections of the northern WCML would benefit Transpennine Express services served by Class 397s. In addition, raising the non-tilt MU speed is already planned for Avanti services operated by Class 805s (which do not tilt) between Crewe and London.

Avanti's new Class 805 units do not tilt. But the journey time between Chester and Euston will not be significantly longer once the MU speed is raised. 

Also, as far as I can tell, there may still be scope for a Lancaster to Euston service within the current HS2 plan, This service would have stopped at Preston, Wigan and Warrington, then joined with a Liverpool HS2 service at Crewe. This means it will only occupy a single path between Crewe and Handsacre.  

This could mean that the Glasgow service could make fewer stops on the WCML, further reducing the overall journey time. This service would have been introduced only after HS2 was completed to Crewe but before the completion of HS2 to Golborne. So would have operated over the constrained section between Crewe and Wigan.

HS2 and Classic services, potential

I imagine capacity for this service would be released by running the Glasgow service non-stop south of Preston. But I'm not sure if there would be scope to run the Lancaster service to and from Glasgow instead.

What I'm trying to say is, that there are other options and this proposal could be seen as defeatest. But I think ultimately there may be little point in running the proposed full HS2 timetable until HS2 is open to Euston. So this gives the Government time to reconsider its decision and come up with a better plan than operating 25 to 35-year-old trains at 155mph on HS2.

Until HS2 opens to Euston, it may be better to operate limited service from Manchester to Old Oak Common, perhaps, 2 HS2 trains per hour to Old Oak, with 2 classic services to Euston. Similarly, Liverpool to London could be 1 HS2 and 1 Classic service per hour

Admittedly this leaves a question about Glasgow, to which I don't have a satisfactory answer. Perhaps an alternating HS2 and Classic service, with 260m long HS2 trains. This would provide Glasgow with a connection to Old Oak Common, whilst maintaining capacity into Euston.

HS2 + Classic service, potential prior to opening of HS2 to Euston

Terminating at Old Oak Common is far from ideal and HS2 must be built to Euston. But there will be benefits of changing trains at Old Oak, with connections via the Elizabeth Line to central London and Heathrow and the Reading and the South West via GWR services. So there would be a benefit of providing services from the North to Old Oak Common

I know I'm just a solitary railway commentator and Chris has decades of experience has the support of many within the rail industry and should be said has my full respect. But myself and others, including industry experts I have spoken to privately disagree with this proposal, as pragmatic as it may seem on the surface.

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