Mersey Gateway Project (Spring 2017 update)

The Mersey Gateway project has now been under construction for almost 3 years and is due to be completed on time later this year.  The bridge itself is taking shape and on the 10th of March (2017) construction of the bridge deck had reached the half way mark.

The cable stayed bridge spans have been inching out across the Mersey since Autumn 2016, with 6 bridge sections being built simultaneously. Each of the 3 bridge pylons supports 2 'form travellers' which act as giant moulds into which concrete is poured.

The image below shows a close up of one of the form travellers making its way out across the River Mersey. The traveller rests on the previously constructed bridge section, the main form then extends out over the river.  Before the concrete for each new section can be poured the form is fitted out with steel rebar, an internal form to create a hollow cavity within the bridge and an anchor point on to which the stay cable will attached.

Once the stay cable is attached from the pylon to the anchor point the concrete to form the new bridge section can be poured. The total length of the main bridge span will eventually be 1000 metres in length.

The bridge will be supported by 146 stay cables connected to the 3 pylons with each cable containing 91 individual steel stands encased in a protective outer casing. In total 810 miles of steel strands will be required to support the 53,000 tonne structure. 

The images below shows progress on the bridge as of March 2017.

Southern pylon (Runcorn)

Central pylon

Northern pylon (Widnes)

View of all 3 pylons and deck spanning the River Mersey (click to enlarge)

The approach viaducts to the main bridge are also progressing well, MSS (Movable Scaffold System) Trinity which was being used to construct the approach viaduct on the Widnes side of the river is now in the process of being dismantled. The 'wing traveller' which is being used to widen the viaduct to final width was approaching the final span in March 2017.

Meanwhile on the Runcorn side of the Mersey MSS Webster which crossed the Manchester Ship Canal in December 2016 has almost completed construction of the southern approach viaduct. 

Wing traveller working its way across the northern approach viaduct

MSS Webster continues work on the southern viaduct

Another key milestone was reached on the 29th of March this year (2017) when the final beam was installed on the Astmoor Bridgewater Viaduct, which in itself is a massive feat of engineering. The image below taken in August 2016 shows the scale of the viaduct under construction at Astmoor. 

Work on the existing road connections is progressing well with key elements already complete such as the new roundabout for the M56. I will update on the progress of the road connections in the coming months prior to completion which is still set for Autumn this year (2017)

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Building a new North South railway - Part 2

In part of one of this series of blogs I wrote about the the likely methods that will be used to undertake the ground works in rural areas for HS2. In this second part I will investigate the bridge structures required and how disruption to the existing road network can be minimised.

One of the most common structures that will be built will be road overbridges. For HS2 phase one a large number of road overbridges will have to be constructed although I was unable to ascertain the exact number.

Luckily for motorists and local residents most bridges can be constructed with limited disruption to the road network. Many bridges are now constructed away from the existing road, this allows the road to remain open throughout the majority of the construction process.

A new bridge being constructed away from the existing road that it will replace for the A556 project 

If the bridge must be constructed on the original alignment of the road, a new temporary road alignment can be constructed, again reducing the need for road closures. Usually the only times when roads are required to be closed is during the "tie-in" process, this is when the existing road is connected to the new road alignment.

Building road overbridges is relatively straight forward and are usually constructed in 1 of 2 ways. if the railway is to pass under the road in a cutting then the ground to one side of the existing road is excavated down to required the final depth.

After the earth is excavated foundations can sunk and the construction of the bridge can begin. Concrete reataining walls and piers will be constructed onto which the new road deck will be placed. Piers and walls can either be poured into moulds in situ or can take the form of pre-cast sections made off site and then lifted into position.

In the images above you can see the new bridge that has been constructed inside the cutting, beyond that the earth mound at the time supported the existing road. Once the road was diverted over the bridge the earth mound was removed to continue the cutting. 

The image below shows a nearly completed bridge taken from the existing road which remained open throughout the majority of construction.

The second method is used where the railway will run at level to the existing road, in this case the road is raised to cross the line. With this method the building of the bridge structure is the same, however earth is built up onto retaining walls either side of the bridge onto which the new road alignment is constructed.

In the image above the new road is level at the point where it crosses with and existing road, in this case the bridge was built at the same level as the existing road. Earth was built up either side of the bridge to create gentle slopes up to the bridge. The existing road was then diverted up and over what would later become a new grade separated dual carriageway. 

Minimising disruption to  motorists and local residents will be paramount for HS2 as it is for any large engineering project. Fortunately civil engineering companies are well versed in building this sort structure and a great many have been constructed for road and rail projects up and down the country.

In the third part of this series I will look specifically at how HS2 will cross and intersect with existing railway lines. The method used for crossing railways is similar to that of roads, however different standards must be observed and some different techniques employed.

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A556 opens

On the 6th of February 2017 the A556 opened to traffic,  the new road linking the M56 near to Altrincham to the M6 close to Knutsford will ease congestion along this busy corridor which provides access for motorists from South Manchester who wish to access the M6.

For more information about the project click here

Rather than describing the route and displaying images I thought it would be best if I simply drove along the new route, starting at the M6 junction 19 and finishing at the M56 junction 8 heading eastbound.

Enjoy!

Turn ON subtitles (CC) for route description 

It appears that there have been some issues with the traffic lights at Junction 19 of the M6, with motorists reporting increased congestion. A statement was posted on the A556 Facebook Page stating that engineers are currently monitoring the phasing of the lights.

"........ It became obvious during the peak periods of traffic on Monday afternoon and Tuesday morning that there is still an issue with the traffic signals.

Highways England apologises for the disruption that this has caused and currently have engineers on site investigating the issue. They have identified a fault which they hope to resolve shortly and which will return the traffic signals to full working order."

I will update on the de-trunking works in a few months, this final phase will provide improved cycle, pedestrian and equestrian access along the B5569 (Old A556).

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Manchester Second City Crossing 2CC

Manchester's latest Metro line is due to open on Sunday (26th Feb), the line known as Second City Crossing or 2CC will ease congestion through the city centre and allow more services to be routed though Manchester Victoria.

Work began on the new line in 2014 and coincided with the rebuilding of Victoria Station, the re-modeling of Metrolink platforms and the tracks leading into the station. A new junction was constructed at the southern entrance to Victoria with the new line leading down Corporation St.

The new line begins at Lower Mosley Street, runs through St Peter’s Square, before turning left down Princess Street and then heading along Cross Street and Corporation Street before re-joining the existing line just outside Victoria.

Tram stands at the new St Peter's Square platform

To accommodate the new line St Peter's Square has been completely remodeled, a third line has been added on Lower Mosley Street and a 3rd platform built at St Peter's Square. The square itself has been repaved and during my visit was still in the process of being refreshed.

New platforms at St Peter's Square

New junction and track heading toward Lower Mosley Street 

Services actually began operating along part of the route back in Dec 2015 when the link between Victoria and the new Exchange Square stop opened to the public. Since then trams have been turning back under the  the Arndale footbridge. 

From Sunday 26th of Feb trams will continue under the footbridge and head straight towards St Peter's Square, bypassing the congested city centre and providing new service opportunities. 

End of the line until Sunday 26th of Feb

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Ordsall Chord - key milestone

It has been almost a year since I first wrote about the Ordsall Chord project which once complete will connect Manchester Victoria and Piccadilly stations for the first time.

Tuesday (21st Feb) was a particularly important day as the steel arch which will carry part of the chord over the River Irwell was lifted into place. There were plenty of press and media in the area to report on this key milestone.

The lift of the 600 tonne arch began at around 5am (21st Feb), it was expected that the lift would commence later however the weather reports coming in showed high winds for later on in the day.

The lift viewed from Irwell Street

The lift required 2 Liebherr crawler cranes, the smaller of which is rated at 750 tonnes, the other which is also the biggest movable crane in the country is rated at 1350 tonnes.

By 10am the arch had been lifted into position over the bridge deck however had not been fully lowered into its final position. At one end of the arch (pictured below) engineers were ready to connect the arch to pre-positioned end sections. If you enlarge the picture you can see the gap still remaining through the scaffolding.

The other end of the arch was ready to be lowered and secured onto spherical bearings which will allow for expansion and contraction.

I had hoped to see the final connections being made, however I was informed that lowering the final few inches could take a number of hours as measurements were checked (and re-checked) and engineers prepared to secure the arch.

As the forecast inclement weather rolled in I left with still about 6 inches left to go before the arch would be in its final position. If the engineer I spoke to was correct it may not be fully in place until 10pm. As was the arch finally touched down at around 6pm (21st Feb)

The arch will be secured with temporary bolts to hold it into position, the horizontal tension cables supporting the arch shape will then be released.  

The horizontal tension cables connected to stand jacks were used to hold the arch in shape until it is finally in place and connected. If the cables had not been attached the arch would have flattened out and would not have fit into the gap.

Temporary bolts will support the arch in place for around a month whilst each end of the arch is welded to make the final physical connection. It will also take around a month to attach the hangers which will connect the arch to the bridge deck. Currently the bridge is supported underneath by temporary supports until the arch and bridge are joined.

Network Rail say that the chord will be open in time for services to begin operating in Dec 2017, so hopefully my next report will from one of the first services to cross the chord in late 17.

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Building a new North South railway - part 1 (update)

It is widely anticipated that the Bill giving the go ahead to construct the first phase of HS2 between London, Birmingham with a connection to the WCML at Rugeley will receive Royal Assent early this year (2017). So I thought now would be a good time to take a look at the methods that will likely be used to construct the new railway.

Update
The bill giving the go ahead to construct phase 1 of HS2 was given Royal Assent on Thursday 23rd of February.

This blog will focus solely on the construction and engineering involved, so I will leave a description of project and the political aspects of the planning to one side.

To begin with I want to explore how you go about altering the landscape in order to build a new high-speed railway that is as flat and straight as possible. With a maximum design speed of 400km/h (250mph) over the straightest sections of track it is important that the curve radius is long as possible, in the case of HS2 the minimum horizontal radius for 400km/h operation is 7200m.

Using knowledge gained from following other road and rail projects it's possible to examine how the new line will likely be built and the construction methods involved.

The closest recent parallel that I can draw upon is the construction of a new grade separated rail junction at Norton Bridge (Staffordshire), this project required the construction of 11 bridges and 9.6km of new railway.

Other parallels can be drawn from the construction of 7.5km of new dual carriageway connecting the M6 and M56 in Cheshire.

With both projects a large part of the work "simply" involved moving earth via moxy (articulated dump truck) from one part of the site to the other, although there was of course a systematic and very purposeful way in which this is done.

As with any large construction project the first stage will involve establishing compound sites along the route in which offices and staff facilities will be located and plant machinery stored.

Before any site clearance can commence the area within the site boundary must be free of protected species such as great crested newts for a number of weeks, during which time regular inspections must take place. 

Once the site boundary is established (and free of newts) and compounds complete the next task is to begin preparing the land through which the line will be built. In rural areas this will involve stripping and storing the initial layer of fertile earth. The earth is stored close to where it was originally excavated from, this is so it can be returned back to the land once final landscaping commences.

In built up areas the initial phase of construction will involve demolition and site clearance. For HS2 this demolition will mostly take place around the Euston terminus and Birmingham station. In this part though I'd like to focus on the groundworks required in rural areas.

In rural areas the fertile earth is stored close to where it was excavated from, by doing this much of the ecology can be retained, this will help with the process of reestablishing wildlife habitats and returning agricultural land back to use. 

A556 initial groundworks March 2015

The next phase of construction will involve deep excavation of cuttings and the building of embankments and structures. To do this excavators working in tandem with moxys will excavate and then move material from cuttings to areas where embankments will be built.

In this way it is possible to sculpt the landscape without having to move any earth off site by road or rail. Spoil from the excavation of tunnels can also be translocated to different parts of the site in this way.

Stafford Area Improvement Programme ground works.

The construction of a new grade separated junction at Norton Bridge is a good example how vast quantities of earth can be moved without the need to take any off site. In all 1 million tonnes of earth was moved in order to construct the 7.5km track and 11 bridges required for the project, yet non had to be taken off site.

This was achieved by creating a temporary road which extended along the length of the site, this haul road was then used to transport the material from where it was being excavated to where it was required. With 11 bridges constructed a lot of material was required in order to build approaches to overbridges. Earth was also used for landscaping either side of the line in order reduce the impact of the line on the landscape.

Of course for HS2 there will not a be a single 100km haul road, a project of this scale will be split up into sections, however withing each section it is likely that the same method of moving material will be employed.

A556 overbridge

The image above of a new overbridge constructed for the A556 project demonstrates where material is required in order to build new approaches. Earth was eventually built up on either side in order to build approaches for a new road overbridge.

It was suggested by a rural campaign group that millions of lorry loads will be required to take material off site by road, however the A556 and SAIP projects show that this needn't and will more than likely not be the case.


In part two I will discus the construction of bridge structures and look at how the impact on the existing road network can be minimised.


You can read part two here

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A556 project February 2017 update - Part 2

In part one of the February update I detailed progress from the M6 junction 19 to the new A50 overbridge and roundabout, in part two I will detail progress from the M56 junction 7 heading south to the new Chapel Lane overbridge. 

The new grade separated junction at the M56 junction 7 was one of the largest single elements of the project, requiring the construction of a new overbridge, roundabout, slip roads and refurbishment of the existing bridge over the M56.

The new grade separated junction of the M56/A556 interchange was one of the first beneficial elements of the project to open. Now traffic travelling to and from Manchester can avoid the existing flat roundabout which connected the A556 to the A56 westbound to Warrington and northbound to Altrincham

New A556 alignment carrying traffic to/from the M56 toward Manchester

Looking west towards Manchester from the new bridge over the A556 which connects the existing roundabout for Altrincham to the new roundabout which connects to the A556 southern entry slip, westbound exit slip and westbound entry slip from/to the M56.

Overbridge connecting the existing roundabout for Altrincham to the new roundabout which connects to the A556 southern entry slip and the exit slip from the westbound M56

New A556 alignment carrying traffic to/from the M56

The initial map I produced (shown below) shows the new alignment and should help with the explanation of the new junction 7 arrangement.

click to enlarge

One of the last major tasks to completed before the new road can open is the tying in of the M56 with the new carriageway. This will require a number of overnight and weekend closures. The image below shows the the northern-most section of the new A556 alignment, which like the M6 end has been surfaced to within a few meters of where the new and existing carriageways will tie in.

View from Millington Lane looking north toward Altrincham

The new overbridge at Millington Lane is now open, with some work still being undertaken to provide access for local residents and business. 

View from Millington Lane looking north toward Altrincham

The image below shows that work on the new carriageway is at an advanced stage, the central concrete barrier is now complete and work is now focusing on installing steel barriers, signs and landscaping.

View from Millington Lane looking south toward the M6

Millington Lane overbridge as viewed from Chapel Lane 

Chapel Lane overbridge is also complete and open to traffic, this bridge provides cycle lanes either side of the road.

View from Chapel Lane looking north toward the M56

View from Chapel Lane looking south toward the M6

This will probably be the last blog update on the A556 until the new road opens at the end of March. I hope to be there on the opening day if possible. I'll be sure to provide full details of the new road and later in the year return to see how work is progressing on de-truncking what will become the B5569.

I will leave you with one of the very first images I captured of the project back in March 2015 showing initial ground works at junction 7 of the M56.