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Thameslink – A very busy Easter!

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Over the last few years I have been very fortunate to have written quite a number of articles about this most fascinating and complex railway project known as the Thameslink project. The latest article I wrote about this £6 billion project appeared in the May issue of The Rail Engineer (issue 115) and was based on the Canal Tunnels.

So, when I was preparing for my latest meeting with Chris Binns, Network Rail’s head of engineering for the Thameslink project in late spring, I considered the progress that Network Rail has made with regard to the overall scheme, asking myself, although the completion date is 2018, would it be reasonable for me to suggest that the project was now moving into the final stages, albeit that they will be substantial, of this long running project? After all, it started back in 1991 and it was dubbed ‘Thameslink 2000’. Do you remember?

I’m not sure whether the original Thameslink 2000 project included the two six-metre diameter Canal Tunnels I have referred to, which were constructed about 10 years ago. The tunnels offer a new 900 metre long, two track link between the East Coast main line at Belle Isle Junction just outside Kings Cross station and the Midland main line just north of St Pancras station.

In August 2012, Network Rail announced that Carillion was to be the contractor responsible for connections into the main lines, fitting out the tunnels installing slab track, associated emergency walkways, signalling and telecoms equipment and fire services and pumps and other associated safety equipment throughout the tunnels, as well as overall site management as the principal contractor. In addition, Balfour Beatty was appointed the contractor responsible for the 25kV overhead line electrification (OLE) installation work.

A new route available

In the lead up to Easter this year, the new Canal Tunnels junction at the St Pancras end was completed and is now ready for use. Also completed was complex preparatory work to the existing junction at Belle Isle ready for the installation of a new double junction. This work, coupled with the fitting out of the tunnels, is well advanced and will be completed this year. However, the tunnels will not be brought into service until commissioning of the overall project in 2018 but the intention is to use the tunnels from 2015, to enable the new Class 700 Siemens trains that are currently being built in Germany to travel up to the new Hornsey Depot, ready for final commissioning.

IMG_0015 [online]At London Bridge station, now without its old train shed roof, a significant milestone was achieved when the new terminating platforms 14 and 15 were brought in to service at the end of March, replacing the old platforms 14, 15 and 16. It is the first part of a plan to take possession of two platforms at a time, working from the south of the station. The old platforms have been removed along with the tracks and ballast. Supporting brick archways have been demolished and piles driven to support bridge deck piers that in turn will support the new platforms.

The space below the platforms will eventually provide the station with a new expansive concourse area that will extend across the width of the station with lifts and escalators serving all 15 platforms. Costain is the principal contractor for this work and Chris explained that the completion of platforms 14 and 15 was significant because it assured the team that the approach adopted was achievable and appropriate and that, by Christmas 2014, all six terminating platforms should be completed and the new concourse below extended accordingly.

This work also gives the travelling public a first glimpse of what the station will look like on the surface. The new concourse however, will have to remain behind hoardings for some time as it is used for access to the worksites during construction.

Teams working together

Costain has had to work in tandem with Balfour Beatty, the principal contractor for the trackwork, and Siemens which had to renew and relocate many miles of signaling cable and associated equipment. This, coupled with the operating issues associated with a station that receives more than 52 million passengers each year, demands total cooperation and team spirit from all involved.

As you would expect, the project team has painstakingly produced detailed staging diagrams that cover all the work up to 2018. These diagrams show each integrated station and track remodelling stage underpinned by further detailed charts showing sequences and diagrams. Each event is detailed down to the hour. Chris explained that a minimum 14-day buffer has been built into each critical stage of the programme. This is one of the many lessons learnt through experience and there can’t be many teams around with the experience that Thameslink offers.

As with many successful projects today, there is no longer any ‘man-marking’ within the London Bridge station project. Instead, the most suitable person for the job is appointed, irrespective of their employer. So, where appropriate, Network Rail personnel will take instruction from Costain personnel and vice versa. It is this approach that has ensured that platforms 14 and 15 were delivered on time.

Attention to detail essential

For Chris, it is this partnering approach that will ensure that the project will be delivered on time and to budget. Also, absolutely everything that is planned has a knock-on effect that has to be understood, communicated, recorded and managed. As Chris kept reminding me, there is no other project quite like it and attention to every detail is absolutely essential. It is the complexity of the project and the need to provide the level of detail necessary throughout the project that he and the team find so fascinating.

At the west end of the station, an approach viaduct cast in-situ with a precast beam decking is slowly emerging, designed to link the existing network with the new and so far unused, 350 metre pathway which includes Borough Market viaduct, designed to carry an additional two dedicated Charing Cross tracks. At the moment, the approach roads to the new bus station are in the way, so plans are being developed with the local community to take possession of the site and complete the work.

Whilst these details are being finalised, Skanska carried out strengthening work on three bridges between Waterloo East and London Bridge over Easter, closing Charing Cross station. The work included the removal of a bridge girder to accommodate new S&C and realigned track yet to be installed. On an adjacent bridge, longitudinal timber beams were removed and the deck reconstructed and waterproofed. This essential work is required to help comply with Route Availability level 8 standards and to create a proposed track alignment that is required to meet a target of 24 trains per hour through the core of the route – between Blackfriars and St Pancras station.

Dive Under taking shape

Moving to the east of London Bridge station, work over Easter extended to the New Cross Gate area, incorporating a new structure known as the Bermondsey Dive Under. Working together, a 500 tonne and a 250 tonne crane lifted three large steel span sections onto four previously-constructed reinforced concrete piers. Then, 28 precast concrete L-shaped units were fixed onto the steel structures secured by 1000 shear studs that were welded on site. This work took place alongside the brick arched viaducts carrying six main lines.

The new structure forms the start of a transitional structure that will eventually span from the existing brick viaduct to the Bermondsey Dive Under. The plan requires Skanska to complete this work in 2016.

IMG_0012 [online]Whilst this work was underway, and in order to maximise the benefits of the possession time between London Bridge Station and the Bermondsey Dive Under, Balfour Beatty was carrying out major track works including the recovery of an existing crossover and the installation of two new crossovers in the same area.

It is a very congested area, site access is difficult and the track is supported on ageing brick arches that can only support limited loading. Therefore, to minimise point loading, two ‘baby’ Kirow 250 cranes were used to lift the track panels that were transported to site by twenty of the now-familiar tilting wagons to install the new layout.

There were eight engineering trains used for this work alone. A total of 71 welds were installed and the track stressed. One new crossover was brought into service straight away and the associated signalling panel alterations at London Bridge incorporated into the plan.

More major blockades

That’s not a bad parcel of work for an Easter break! Now, back to the question which I asked Chris – do you think that you are moving into the final straight for this project? Chris thought about this for a while then said that there isn’t any more major work that hasn’t been started. However, passengers have only just seen a glimpse of what the London Bridge station will look like when it is finished.

He then explained that Network Rail will be closing the whole of the route at London Bridge Station for a nine day blockade in August and then 16 days at Christmas. This is to address the need to totally renew and remodel the throat to the station. He added that, at Christmas, they will be using 43 engineering trains to carry out the work that will see all the final six new terminating platforms brought into use.

Chris then confirmed that new sidings and carriage cleaning facilities at Peterborough, Brighton, Cricklewood and Hornsey are either complete or well underway. Also, eight-car and twelve-car sets of the new Class 700 trains are undergoing preliminary tests on third-rail test track in Germany. He added that, to enable work on the new through platforms to happen, Thameslink trains will be diverted away from London Bridge station from December 2014 until January 2018, and that they will have to educate the travelling public accordingly.

It is this last comment that reminds me that, although we are certainly past the end of the beginning, and we might be seeing the beginning of the end, there is still a fair way to go and much to be done by teams working effectively together. There will also be more articles to write about this intriguing project!


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