We’re increasing capacity for passenger trains on the East Coast Main Line (ECML) by building a new two-track railway line that dives under the ECML.
The fly through video below visualises how the new dive under will look when in operation.
What are we doing?
The project is a part of the wider East Coast Upgrade Programme in which we are trying to increase the number of passenger seats on the East Coast Mainline (ECML).
The new line, located just North of Peterborough, will remove constraints to the timetable caused by slower freight trains on the Great North Great Eastern (GNGE) route crossing over the high-speed East Coast lines at Werrington Junction.
A new dive under provides an alternative route by enabling the new two track railway to run underneath the ECML, separating it from any high speed passenger traffic.
The project has several phases and associated key milestones, the first of these milestones is the Stamford Slews.
The Stamford Slews relocated the two Stamford Lines approx. 30m to the west, generating space between the Stamford Lines and the ECML to allow construction of the Southern ramp.
The Stamford Slews phase of works was completed in early January 2020, with critical disruptive works achieved over the Christmas 2019 period.
Works included 3,580m of new track, associated overhead lines, signalling and telecoms. As well as a significant number of enabling stages:
Cock Lane Footbridge
Replacement of the existing Cock Lane Footbridge with a wider span to accommodate the new alignment of the Stamford Lines. The new footbridge also included ramps, making the structure compliant with the Equality Act 2010.
The footbridge opened in November 2019.
Brook Drain River
840m re-alignment of Brook Drain river, north of Cock Lane Footbridge, to accommodate the build of the new Stamford Lines.
The newly aligned river has been designed to help with local flooding issues.
The design also features riffles – shallow sections of water – and side pools, where aquatic wildlife can take refuge during storm surges. Soft bank ledges have also been installed to help vegetation grows, with existing vegetation transferred to help maintain a habitat for the rare Four Spotted moth on the riverbank.
The diversion of a further 500m section of Brook Drain river, south of the new footbridge was also required.
This location was constrained by running parallel to 132kV overhead power lines and a large commercial estate. The designed solution enabled the new Stamford Lines to sit on top of a cast in situ concrete box culvert which carries the relocated river.
The position of the old Hurn Road clashed with the proposed route of the new Dive-under Lines. In order to progress works, the project worked closely with Peterborough City Council to agree a new route for Hurn Road, which would makes way for the new Dive-under Lines, whilst continuing to provide access and egress to the properties along the old Hurn Road.
Works to Hurn Road were completed in late 2019, allowing works to construct the north ramp to continue.
A temporary 61m footbridge has been installed alongside the existing Lincoln Road Bridge.
This temporary structure, installed in late Autumn of 2019, will allow users of the existing bridge, including a number of utilities, to be temporarily diverted across the new structure.
Whilst the temporary Lincoln Road Bridge is used, works will be able to commence with installing an additional span to the existing Lincoln Road Bridge, which will allow the new Dive-under Lines to run underneath it.
Once works are complete, all users will be able to use the extended existing bridge again.
Milestones in progress
The project are now well underway with works to complete our next major phase of works, completing civils works to support the dive-under’s north and south ramps and installing the dive-under structure itself.
Several key milestones in delivering this next phase have already been completed with many more under progress.
The north ramp has been constructed by installing 183 x 18 metre-long, 900mm diameter, rotary bored contiguous piles and over 900 x eight to 10 metre-long soil nails, finished with sprayed concrete facing. In total 120,000m3 of soil and clay has been excavated to create one of two 940 metre ramps.
Two three and a half metre diameter, 168 metre-long guide tunnels need to be installed underneath the ECML. These two tunnels will be used to help install the dive-under structure below the ECML, once built in-situ next to the ECML.
When fully assembled the 65m long TBM will bore the two 168m long tunnels under the live operational East Coast Mainline (ECML) which will be running at 125mph.
The project has installed state of the art remote track monitoring equipment which constantly measures the position of the tracks. The system triggers alarms to pre-determined values, to help ensure the operational railway is not disrupted.
South Ramp and TBM Reception Pit
Mirroring the north ramp, a second 940 metre ramp will be constructed to the south of the div-under, in the enlarged area made by Slewing the Stamford Lines.
Works to construct the Reception Pit, which included the installation of 66 x 18-meter-long bored contiguous piles and excavating over 2,000m3 of soil and clay, completed in early April 2020.
The Reception Pit will be used to receive and remove the TBM from the ground once it has completed each of the 168-metre-long tunnels.
Piling has commenced for the South Ramp.
Where the ramp is at its deepest point there will be 693 bored contiguous piles, 900mm diameter and up to 18m in length. This section of piling following on from the Reception Pit. As the ramp gets shallower there will be 10m long steel sheet piles, 340m on either side of the ramp. The sheet piles installed to date can be seen on either side of the photograph, with the piling rig busy at work behind.
By relocating the Stamford Lines in the earlier phase, construction of the South Ramp can be progressed with no impact to the operational railway and passengers.
From March 2020 work began to build the dive-under structure.
The ‘curved box’ will be built up, next to the ECML in nine, interconnected sections. The structure will be 155m long, 9.5m wide and 5.1m high, with 1m thick walls and soffit. It will weight just over 11,000 tonnes, with is 1,000 tonnes heavier than the Eiffel Tower!
Once built, the ‘curved box’ will be pushed under the ECML using large jacks to propel and steer.
To build the ‘box’ we are using a specialist sliding formwork system, when the concrete is cured for one section, we slide the formwork to the next pour and repeat the process.
There are two further phases planned for this project.
New track crossings will be installed on the GNGE and Stamford Lines, ready for full installation of the new Dive-under Lines and Up Stamford Line.
As these works require disruption of services on the GNGE and Stamford Lines, the project will prioritise only works that require the railway to be closed.
This approach will minimise disruption to rail users and passengers.
Following completion of all previous phases, the final phase of works will be the installation of the final track formation, track drainage and track which will form the new Dive-under Lines and the new Stamford Line.
At the same time, the temporary Up Stamford Line will be removed.
The new Werrington Dive-under lines will be ready for use.
Keeping you informed
This project is one of the most significant on the ECML and involves major construction activity that has the potential to be disruptive to residents and businesses at specific points in time. We will write to everyone affected in advance of this type of work.
Unfortunately the series of community events have been cancelled due to Covid-19. We endeavour to re-start these as soon as possible. We are sorry for any inconvenience caused.