HS2 Construction Updates -Brackley to Great Missenden / Chilterns North Portal

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This is about a 30 mile stretch from the northern portal of the Chilterns tunnel past Aylesbury to Brackely, found a couple of videos on youtube of some of the area.
This flyover covers about 2 miles going north of the portal towards Wendover Dean and the viaduct.

This flyover covers about 5 miles going south from Brackley to Newton Purcell

 

[swt_passenger]

No agenda on the second video, using the Funeral March as soundtrack…

 

[bib]

Drone footage shot just north of Aylesbury, bases of the Thame Valley viaduct under construction at the end of the video
- https://www.hs2.org.uk/building-hs2/viaducts-and-bridges/thame-valley-viaduct/

Slightly further south of the video above , seems pretty flat and level so maybe not much work need done in this area

 

[Snow1964]

HS2 has released series of photos of the Thame Valley viaduct prefabricated parts, the first pier of which is now installed

HS2 in UK first, as engineers begin assembling off-site manufactured viaduct

Download new images showing the first piers installed for the Thame Valley Viaduct, near Aylesbury

mediacentre.hs2.org.uk

 

[Fazaar1889]

Video of the first pier being installed as mentioned in #4

https://twitter.com/HS2ltd/status/1673597935089750018?t=iJh1qeQKoZ5qpEVveNI5yw&s=19

The first piers for our Thame Valley Viaduct have now been installed. Every major element of the viaduct is being manufactured in a factory before being slotted together on site like a giant Lego set. Find out more: gloo.to/6KbS

The link is broken. Idk ehat they were trying to link to.

 

[Geogregor]

https://www.constructionenquirer.co...-on-uks-first-double-composite-viaduct-video/

 

[bib]

Footage of the Chilterns north portal

Wendover Dean Viaduct and the Wendover Green Tunnel:

Lots of photos and info in this video, some photos from inside the Chiltern tunnel vent shafts which I haven't seen anywhere else.

 

[bib]

Long flyover from the Calvert EWR crossing to Aylesbury. Over 30 dump trucks at the Calvert site. A few shallow cuttings but doesn't appear to be much major civils required on this stretch.

 

[Snow1964]

New you tube video, which I don't think has been linked

 

[bib]

Short flyover just south of Aylesbury

 

[swt_passenger]

I think it’s noticeable that Stoke Mandeville gets a western bypass on completion of the various road diversions and stopping up, ie the old Risborough Rd will no longer be a through route. That’s going to be rerouted over the new bridge whose abutments are going up just next to the steel overbridge for the Chiltern line. Visible at 1m 14s - I believe that’s all delivered by HS2.

I believe there’s also a new bridge passing under the Chiltern line, visible at about 18 seconds, for a future Aylesbury southwestern bypass or distributor road dual carriageway width, which seems to be future proofing, not sure if HS2 are responsible for that one, does anyone know?

But then the Chiltern overbridge seems to be only suitable for a single line, might it not have been the time to future proof that too, with a 2 track span, surely it’s far less expensive to do when the whole worksite is set up?

 

[The Planner]

I think it’s noticeable that Stoke Mandeville gets a western bypass on completion of the various road diversions and stopping up, ie the old Risborough Rd will no longer be a through route. That’s going to be rerouted over the new bridge whose abutments are going up just next to the steel overbridge for the Chiltern line. Visible at 1m 14s - I believe that’s all delivered by HS2.

I believe there’s also a new bridge passing under the Chiltern line, visible at about 18 seconds, for a future Aylesbury southwestern bypass or distributor road dual carriageway width, which seems to be future proofing, not sure if HS2 are responsible for that one, does anyone know?

But then the Chiltern overbridge seems to be only suitable for a single line, might it not have been the time to future proof that too, with a 2 track span, surely it’s far less expensive to do when the whole worksite is set up?

Seems odd if it is single. NR responded to most of the protective provision elements of HS2 to enable growth, such as the Leamington to Coventry bridge. I am pretty sure the new Marsh Lane bridge is two tracks wide too. Could well be that NR said there is no need for it when the asset protection side were consulted from the council, but that doesn't appear very joined up if so.

 

[JamesT]

Seems odd if it is single. NR responded to most of the protective provision elements of HS2 to enable growth, such as the Leamington to Coventry bridge. I am pretty sure the new Marsh Lane bridge is two tracks wide too. Could well be that NR said there is no need for it when the asset protection side were consulted from the council, but that doesn't appear very joined up if so.

If I'm looking at the right bit of aerial photos, shortly after crossing the bridge the line goes into Aylesbury where it's fairly tightly constrained. Would there be much point doubling the bridge if it almost immediately goes down to single track anyway?
I also note the new bridge is being built to the side of the current line and then the line will be realigned over it. Perhaps realigning for two tracks would go too far off, given it has to return back to the current alignment to get into Aylesbury?

 

[swt_passenger]

If I'm looking at the right bit of aerial photos, shortly after crossing the bridge the line goes into Aylesbury where it's fairly tightly constrained. Would there be much point doubling the bridge if it almost immediately goes down to single track anyway?
I also note the new bridge is being built to the side of the current line and then the line will be realigned over it. Perhaps realigning for two tracks would go too far off, given it has to return back to the current alignment to get into Aylesbury?

The track slew is gradual over about 1.5 km, so I think that would be easily manageable. But that’s a good point about the stretch through the Aylesbury built up area being tight. It’s possible I’ve misread previous proposals about ‘redoubling’ the route to Princes Risborough as being more extensive than is practical?

 

[stuving]

I was baffled by this talk of the Chiltern overbridge being single track. I thought it was easily OK for two, and perhaps more. I was judging its scale from the digger at the near end, and I wonder if others are thinking it is of similar design to those older steel bridges with a parapet/supporting girder only waist high.

To see how big it really is, here are some pictures (I can't link to) from EKFB.

 

[swt_passenger]

I was baffled by this talk of the Chiltern overbridge being single track. I though it was easily OK for two, and perhaps more. I was judging its scale from the digger at the near end, and I wonder if others are thinking it is of similar design to those older steel bridges with a parapet/supporting girder only waist high.

To see how big it really is, here are some pictures (I can't link to) from EKFB.

Ok - I think I was misled by what looks like only a single width pile of ballast on either approach. The picture of the overall channel structure with the workers lined up certainly looks much wider than I thought it was.

 

[The Planner]

I was baffled by this talk of the Chiltern overbridge being single track. I though it was easily OK for two, and perhaps more. I was judging its scale from the digger at the near end, and I wonder if others are thinking it is of similar design to those older steel bridges with a parapet/supporting girder only waist high.

To see how big it really is, here are some pictures (I can't link to) from EKFB.

That's the Marsh Lane overbridge, I thought the discussion was about a different one?

 

[stuving]

That's the Marsh Lane overbridge, I thought the discussion was about a different one?

Since when is Marsh Lane getting an overbridge? It's shown in the map in the video (above) as being blocked off in replaced, if anything, by the by-pass. The text in the linked EKFB page describes it as "the Princes Risborough to Aylesbury (PRA) Realignment Overbridge", which seems clear enough.

By the way, I wondered what that bridge in the PRA line just to the south was for, and guessed it's been built just in case a road should turn up that wants one. It seems that's right - HS2's works update says:

Our work in this area includes constructing a new railway embankment, the bridge itself, and other related structures including a road underpass which will support future development in the area.

 

[swt_passenger]

Since when is Marsh Lane getting an overbridge? It's shown in the map in the video (above) as being blocked off in replaced, if anything, by the by-pass. The text in the linked EKFB page describes it as "the Princes Risborough to Aylesbury (PRA) Realignment Overbridge", which seems clear enough.

By the way, I wondered what that bridge in the PRA line just to the south was for, and guessed it's been built just in case a road should turn up that wants one. It seems that's right - HS2's works update says:

Is that the one I was wondering about in post #11, the one in the video at 18 seconds? I thought it was towards the north end of the site though, but you’ve helpfully confirmed that it is an HS2 item. Hopefully not paid for by them though?

 

[The Planner]

Since when is Marsh Lane getting an overbridge? It's shown in the map in the video (above) as being blocked off in replaced, if anything, by the by-pass. The text in the linked EKFB page describes it as "the Princes Risborough to Aylesbury (PRA) Realignment Overbridge", which seems clear enough.

By the way, I wondered what that bridge in the PRA line just to the south was for, and guessed it's been built just in case a road should turn up that wants one. It seems that's right - HS2's works update says:

The realignment requires Marsh Lane to be blocked off as its at the start of the realignment, hence calling it the bridge there.

 

[12LDA28C]

If I'm looking at the right bit of aerial photos, shortly after crossing the bridge the line goes into Aylesbury where it's fairly tightly constrained. Would there be much point doubling the bridge if it almost immediately goes down to single track anyway?
I also note the new bridge is being built to the side of the current line and then the line will be realigned over it. Perhaps realigning for two tracks would go too far off, given it has to return back to the current alignment to get into Aylesbury?

As far as I know the new bridge over HS2 is only being built for a single line - rumours of the AYS-PRR line being doubled or at least a passing loop installed at Little Kimble have been doing the rounds for years and nothing has ever come of it, despite the 7-mile stretch of line causing a huge constraint on capacity. I am surprised however that the opportunity hasn't been taken to extend the flyover over Marsh Lane in order to remove the LC but instead it appears that a new level crossing will be installed at the foot of the incline which is surely less than ideal. New signals are also to be installed each side of the new LC.

 

[The Planner]

As far as I know the new bridge over HS2 is only being built for a single line - rumours of the AYS-PRR line being doubled or at least a passing loop installed at Little Kimble have been doing the rounds for years and nothing has ever come of it, despite the 7-mile stretch of line causing a huge constraint on capacity. I am surprised however that the opportunity hasn't been taken to extend the flyover over Marsh Lane in order to remove the LC but instead it appears that a new level crossing will be installed at the foot of the incline which is surely less than ideal. New signals are also to be installed each side of the new LC.

No, its got space for twin track.

 

[12LDA28C]

No, its got space for twin track.

Interesting. I'll be surprised if that capacity is ever needed.

 

[stuving]

Interesting. I'll be surprised if that capacity is ever needed.

In papers for the 2016 change to the HS2 plans in the hybrid bill (I have no idea whether that has changed again since) I found this listed as a "mitigation" (p15):
•Future twin tracking of the Princes Risborough railway line allowed for in the earthworks and bridge over the HS2 alignment

Those papers for the 2016 change to the HS2 plans in the hybrid bill also listed this as a "scheme development":
•An underpass included under the realigned Princes Risborough line to make provision for future access for a potential development area/south west link to the A418.

That's the concrete bridge in the embankment, and was correctly identified by swt_passenger as north of HS2. It's called the South West Aylesbury Link Road, or maybe the A413/A448 Link, and is part of Bucks Council's piecemeal ring road for Aylesbury. Work has already started on the next bit eastward, the South East Aylesbury Link Road.

I'd visualised the images from the wrong side, possible because the map shows another road of some kind through the embankment to the south. With no legend, and colours hard to make out, it's not clear what that is.

I've found a full sheet of pretty much the same map, with a legend and covering a larger area. As you zoom in to it, the red/brown/orange colours resolve (except for very narrow lines). Those roads to the south are now seen as HS2 access roads (white with red edges), and a realigned right of way that's also a road or track (orange with black edges). That replaces a path along the west side of the railway, with a foot crossing 650 m north of the Marsh (Lane) level crossing.

So there should be a little tunnel through the embankment, and looking in the video I can't see a road bridge but a foot tunnel might not be visble in the distance. I did think it might be a replacement for the Marsh (Lane) level crossing, so if it's not going to be a road that might be why the crossing has to survive.

 

[bib]

Flyover from Chiltern north portal to wendover dean viaduct, the viaduct now has some pillars

 

[bib]

Another flyover of the north portal to the first vent shaft

Flyover showing the crossover between HS2 and the Princes Risborough-Aylesbury line

 

[12LDA28C]

That video is rather out of date. Track has now been laid on the single line over the new alignment and bridge and is awaiting ballasting.

 

[snowball]

Media invitation on Network Rail's press releases page, with photo showing clearly that the bridge over HS2 is designed to allow future doubling of the Aylesbury-PR line.

MEDIA INVITE: Aylesbury rail upgrades in preparation for HS2 reach half-way mark

Information for journalists, press, bloggers and the media about Network Rail. Contact the press office to receive news, updates, press releases, videos, pictures, and factsheets, and to arrange interviews, filming and photography

www.networkrailmediacentre.co.uk

WHAT: A tour around the construction site of a new railway bridge which will allow HS2 to be built beneath the line between Aylesbury and Princes Risborough. Railway engineers are half way through a ten-week rail closure where a 1.8km section of the existing railway is being realigned on a new embankment. Work is underway to install brand new track on the new embankment and the new bridge structure. HS2 engineers have begun work to excavate the earth beneath the bridge to prepare for the new high speed railway to be built. Once complete, HS2 – which passes to the west of Aylesbury - will improve rail journeys between London, Birmingham and the north while freeing up space on the existing network for more freight and local services.

WHEN: Monday 25 September, 2pm – 5pm.

WHERE: EKFB - A418 Oxford Road, Oxford Road, Buckinghamshire, HP17 8NP.

-------------------- automerge ------------------

and a press release with a video of tracklaying on the diversion

Bird's eye footage shows work to prepare Aylesbury’s railway for HS2

Network Rail has released spectacular aerial video footage of work to realign almost 2km of track between Aylesbury and Princes Risborough stations which will allow HS2 to build new high-speed lines beneath the existing railway network.

www.networkrailmediacentre.co.uk

Network Rail has released spectacular aerial video footage of work to realign almost 2km of track between Aylesbury and Princes Risborough stations which will allow HS2 to build new high-speed lines beneath the existing railway network.

The dramatic video shows engineers using a ‘New Track Construction’ train to install brand new sleepers and rail across an impressive new 100m bridge built by HS2’s contractor EKFB which will allow passenger and freight trains to run over the top of Britain’s new high-speed railway in the future.

The specialist engineering train, which is one of only two of its kind in the country, successfully installed 2,953 concrete sleepers and 2000 metres of new rail on Sunday 17 September.

Network Rail and HS2 have worked closely to minimise disruption to passengers by preparing a new embankment for the railway to be moved onto before closing the railway in August. As the major project moves past the half-way mark, passengers are being reminded that until Sunday 29 October buses continue to replace Chiltern Railways trains between:

Princes Risborough – Monks Risborough – Little Kimble – Aylesbury

 

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Flyover of the Thame valley viaduct site

 

[snowball]

NR press release with video

Aylesbury rail route reopens for passengers and freight after HS2 work

Rail passengers and local people in Buckinghamshire are being thanked for their patience during a ten-week project to move a section of railway between Aylesbury and Princes Risborough to make way for Britain’s new high-speed line, HS2.

www.networkrailmediacentre.co.uk

Rail passengers and local people in Buckinghamshire are being thanked for their patience during a ten-week project to move a section of railway between Aylesbury and Princes Risborough to make way for Britain’s new high-speed line, HS2.

The work involved replacing almost 2km of track across a brand-new embankment built by HS2’s contractor, EKFB (a team made up of Eiffage, Kier, Ferrovial Construction and Bam Nuttall).

Time-lapse video footage released by Network Rail shows the scale of work completed with the installation of:

2,953 concrete sleepers
2,000 metres of rail
11,000 tonnes of railway ballast (stone).

The railway between Aylesbury and Princes Risborough reopened to passengers and freight trains this morning (Monday 30 October).

The new section of track will provide smoother and more reliable journeys for Chiltern Railways' passengers as well as allowing HS2 to construct new high speed lines which will pass beneath a new 100m steel bridge carrying the existing railway.

To the north of the new high speed route HS2 has installed a further bridge structure which will allow the proposed South West Aylesbury Link Road to also pass beneath the route between Aylesbury and Princes Risborough.

To reduce the impact of the major construction work on the local environment, most of the materials needed were delivered to site by rail, including the new railway ballast (stone) which has helped to remove over 800 lorry movements from the local and national road network.

Patrick Cawley, director for ‘On Network Works’ for Network Rail and HS2, said: “I’d like to say a huge thanks to passengers and local people for their patience while we carried out our major improvements in Aylesbury which will pave the way for HS2, Britain’s new high-speed railway.

“As part of the project we’ve upgraded almost 2km of track in the area which will mean locally that our passengers and freight customers will also benefit from smoother and more reliable journeys.”

To help keep passengers moving during the railway closure, Chiltern Railways operated a bus replacement service between Aylesbury, Little Kimble, Monks Risborough and Princes Risborough stations.

Tony Baxter, operations director at Chiltern Railways, said: "We'd like to offer our sincere thanks to our customers, whose patience and understanding during this ten-week line closure has enabled these vital HS2 works to take place.

"We're looking forward to welcoming customers back to our route between Princes Risborough and Aylesbury, and staff will be on site delivering cakes and vouchers for respective station cafes on Tuesday 31 October as a small gesture of our gratitude.

"We know that this has been a long period of disruption, and are pleased to be sending the rail replacement buses back to the garage and resuming our train services along the line.”

Staff from Network Rail and Chiltern Railways will be at Aylesbury and Princes Risborough stations between 3pm and 6pm on Tuesday 31 October giving out locally supplied cakes to thank passengers for their patience during the improvement work.

Marsh Lane level crossing - which was closed to enable the track realignment work - will remain shut to road users until 2024 while a project to upgrade the level crossing and bring it up to modern safety standards takes place. Network Rail will keep local people informed about this work.