HS2 Colne Valley Viaduct construction updates

[stuving]

In the PWI video above they explain that there are temporary extra steel props each side of the piers, while the segments are being put into place, to deal with this problem.

And there's more than that: two kinds of temporary PT to hold segments in place before the final PT is put in, and "nails" to pull down onto those temporary supports.

 

[Geogregor]

Dominique is over the Grand Union Canal:

 

[Nicholas Lewis]

Dominique is over the Grand Union Canal:

Caught a glimpse of the works from a Chiltern train yesterday most impressive and can see how well it will blend into the surrounding environment once the temporary works are removed.

 

[LNW-GW Joint]

Looks like the viaduct is now about 2/3 complete, with something like 600m over water to reach the south pier.
You can see the next 5 piers in the lake beyond Dominique.
Dismantling the haul road when they finish will be quite a job, too.

 

[swt_passenger]

A couple of days later and the gap over the Grand Union canal is being filled.

 

[Flying Phil]

Thanks for these updates, it really is an impressive, elegant, structure.

 

[swt_passenger]

I saw an HS2 video report last night that said the last of 56 Colne Valley viaduct piers were now completed:

 

[Nicholas Lewis]

I saw an HS2 video report last night that said the last of 56 Colne Valley viaduct piers were now completed:

Excellent progress but wont see a commercial service for at least another 5 years!

 

[Snow1964]

New drone over Colne Valley viaduct, appears parapets are now in for part of it

 

[Nicholas Lewis]

New drone over Colne Valley viaduct, appears parapets are now in for part of it

Another nice drone video.

The temporary road puts most UK roads to shame must have cost a fair bit and and its going to cost a fair bit to remove it and remediate the site.

 

[Snow1964]

Bidstats has a new tender, seems HS2 are planning seating by Colne Valley regional park. Perhaps will be able to sit and watch trains whizz past

1 buyer​

• HS2 Birmingham

1 supplier​

• White Wall Erith

Description​

HS2 would like to take forward a commission to create designs for a suit of seating and rest areas that respond to and enhance enjoyment of the setting of the Colne Valley Regional Park. HS2 are committed to good design across all aspects of the project. In terms of how this might relate to seating we follow the principles of Intuition, Delight and Comfort. The project consists of three phases as shown below: - Phase One: developing design stage - Phase Two: delivery of detailed designs - Phase Three: Oversee the fabrication and installation of the furniture in the key areas

Award Detail​

1	White Wall (Erith) Value: £119,950

CPV Codes​

• 39151000 - Miscellaneous furniture

HS2 LTD - Colne Valley Seating Area [Award]

HS2 would like to take forward a commission to create designs for a suit of seating and rest areas t... A Contract Award Notice by HS2. Value £120K.

bidstats.uk

 

[bib]

Looks like the over water viaduct spans are pretty much finished now. Not sure if the actual viaduct will continue up to the Copthall tunnel or if it will transition to embankment.

Dominique has touched land, the workers are doing a happy dance

 

[swt_passenger]

Looks like the over water viaduct spans are pretty much finished now. Not sure if the actual viaduct will continue up to the Copthall tunnel or if it will transition to embankment.

I think there’s still about 500 metres of viaduct (if I’ve read the scale right), until the transition to a short embankment then almost immediately another change into a retained cutting, (under the new Harvil Road).

A map extract from the HS2 site:



This video is probably better, shows numerous land piers, the transition to the short embankment is clear at 1m 45s or so, and also a good view looking northward at 3m 35s.

 

[LNW-GW Joint]

It's good to see the over-water section complete.
There appear to be about 12 land-based piers for Dominique to bridge before the whole viaduct is complete up to the embankment section.
Some of those piers, nearest the lake, look decidedly unfinished.
So that looks to be several months work for Dominique, maybe a year-end completion.

 

[swt_passenger]

It's good to see the over-water section complete.
There appear to be about 12 land-based piers for Dominique to bridge before the whole viaduct is complete up to the embankment section.
Some of those piers, nearest the lake, look decidedly unfinished.
So that looks to be several months work for Dominique, maybe a year-end completion.

I’d say the opposite, that the visible piers are at their finished height. If you go on Google Streetview and compare with the finished “land piers” at the other end, ie alongside the A412 road north of the lakes, or at the Moorhall Road crossing, (there are two slightly different designs of pier), the level they’re at is about right for the gap where the viaduct bearings will be fitted. HS2 did actually report ‘completion” of the 56 piers back in March. Or put another way, the section immediately above what you can see here will be part of the viaduct and separate to the piers. The main ‘V-piers” across the lakes are constructed differently, and are significantly higher, because their two cast in situ sections extend higher to viaduct level.

 

[Nicholas Lewis]

Looks like the over water viaduct spans are pretty much finished now. Not sure if the actual viaduct will continue up to the Copthall tunnel or if it will transition to embankment.

Dominique has touched land, the workers are doing a happy dance

Excellent videos nice close views of construction and Florence. Also shows the scale of the temporary works that have been created across the lake looks far superior to many roads in this country but its all going to have to be recovered at some point.

 

[TheHSRailFan]

Looks like the over water viaduct spans are pretty much finished now. Not sure if the actual viaduct will continue up to the Copthall tunnel or if it will transition to embankment.

Dominique has touched land, the workers are doing a happy dance

Good to see HS2 Ltd giving their workers a much-needed workout on a video with an intresting title... XD

Exciting but also jaw-dropping stuff that it's close to finishing. where have those years gone?

 

[LNW-GW Joint]

Exciting but also jaw-dropping stuff that it's close to finishing. where have those years gone?

I'd say the viaduct construction is running about 6 months late.
When Dominique was launched in May 2022, the aim was to complete it in 2 years, with a 3rd year for fitting out (and removing the access roads).
Being late usually also means being over budget.

 

[swt_passenger]

The first complete span over the land is now in position, seems to have used a different construction method with jacks supporting it between the two piers. For some reason the distance to the next pier seems shorter than the rest, is it variable depending on where finished roads etc are going to end up?

 

[Backroom_boy]

The first complete span over the land is now in position, seems to have used a different construction method with jacks supporting it between the two piers.

Are all those girders going to fit under the power cables when it gets there?

 

[swt_passenger]

Are all those girders going to fit under the power cables when it gets there?

I expect so. If you look at around 4 mins into the video I linked in post #193 the power lines look much higher than the assembly gantry.

 

[Nicholas Lewis]

I expect so. If you look at around 4 mins into the video I linked in post #193 the power lines look much higher than the assembly gantry.

Yes but you need 4-5m clearance to a 275kV circuit ( I believe this is the Iver to Watford circuit) and then you would nominally have to allow for line sag as they do droop a fair bit when under full load on a hot day. So I would reckon they will need to be deenergised to pass under but them but this is the right time of the year to do it when demand is at lowest.

 

[swt_passenger]

Yes but you need 4-5m clearance to a 275kV circuit ( I believe this is the Iver to Watford circuit) and then you would nominally have to allow for line sag as they do droop a fair bit when under full load on a hot day. So I would reckon they will need to be deenergised to pass under but them but this is the right time of the year to do it when demand is at lowest.

That makes sense, I must admit I only thought of physical clearance initially. Still, it would be odd if they hadn’t already taken it into account wouldn’t it…

 

[Snow1964]

Are all those girders going to fit under the power cables when it gets there?

The latest span under the gantry appears to have lots of temporary support falsework.

It is obviously lot easier to erect the viaduct on dry land where sections can be lifted by crane or built in situ on temporary supports.

Not sure what plan is, but possibly the big Dominique gantry won't need to pass under the high voltage cables, and end spans will be built from ground up instead of being lifted forward.

 

[stuving]

The latest span under the gantry appears to have lots of temporary support falsework.

It is obviously lot easier to erect the viaduct on dry land where sections can be lifted by crane or built in situ on temporary supports.

Not sure what plan is, but possibly the big Dominique gantry won't need to pass under the high voltage cables, and end spans will be built from ground up instead of being lifted forward.

I suspected that too, since it's what was done for the Toulouse Metro project recently. One of those spans being assembled on falsework collapsed, with the death of two site workers (which you may remember).

But no, in the PWI presentation on this viaduct (see post #157), on slide 40 (40:20), it says:

• Lower headroom allowing to pass under the HV power lines

I think the lower headroom comes from the fact that the sections, in lifted position, don't need legs as long as in the Hong Kong project to pass through the legs.

There is also a diagram of the power lines clearance geometry, which is far too small to read. But it does have "6.3m > 4.6m = OK" is big letters, which presumably is about the clearance itself. Of course that might apply to other power lines and not this one, but I don't think so.

 

[dosxuk]

These are the powerlines that were re-routed for the project (they used to go over the lake) - it would be a bit silly of them to have moved them for this project, but then not left enough space to carry out the works.

 

[swt_passenger]

Another video with some good close up views of Dominique. Now that it‘s completed that first land viaduct section, (that was supported by all that falsework, posts #199 and #204 refer), they seem to have reverted to adding segments working in a balanced fashion, i.e. adding them outwards from either side of the next pier.

I think the close ups also confirm what I thought in post #195, that the remaining piers are already at their finished height.

 

[bib]

Looks like that first pier on land is actually 2 back-to-back, maybe some sort of expansion joint? That might be why the next span needed to be supported with falsework as it was pieced together, if it is not cantilevered/attached to the preceding span.

 

[LNW-GW Joint]

Those sequences of new viaduct sections being transported along the already-built section for Dominique to install are just amazing.

 

[swt_passenger]

Looks like that first pier on land is actually 2 back-to-back, maybe some sort of expansion joint? That might be why the next span needed to be supported with falsework as it was pieced together, if it is not cantilevered/attached to the preceding span.
View attachment 160906

Good point. Perhaps there’s a similar one visible in the overland section at the northwest end, or where it crosses Moorhall Rd?