On 24 March, GBRf locomotive 66733 hauled the 11:33 from Felixstowe North Terminal to Doncaster Railport, becoming the very first revenue earning freight train along the newly commissioned Ipswich Chord. Writes David Bickell

Following the running of this ‘test train’, the Chord opened to commercial traffic on time and on budget from 31 March. In railway operating terms, the Chord is now known officially as the ‘Bacon Factory Curve’, named after the Harris Bacon Factory which previously occupied part of the triangle created by the new line.

Changes over time

A brief step back in time reveals that the development of Felixstowe as a port came about in the nineteenth century thanks to the vision of one man – the wealthy Victorian George Tomline. He believed that Felixstowe could be developed to rival the port of Harwich on the opposite bank of the Orwell and Stour estuary, and drafted infrastructure plans for the railway and docks. Parliamentary approval was given in 1875 for the building of the Felixstowe to Ipswich line, which transformed Felixstowe from a small seaside village into what would become the UK’s largest container port and the sixth largest in Europe.

However, over the years, the rail infrastructure has struggled to keep pace with the rapid expansion of the container port. This is being addressed and the new Ipswich Chord forms part of the Felixstowe to Nuneaton (F-N) capacity upgrade project.

Felixstowe’s train services are now dominated by freight traffic to and from the port. Although Felixstowe remains a popular seaside town, the days of hundreds of trippers alighting at the station are long gone. The passenger service between Ipswich and Felixstowe is a shadow of its former self. The once extensive Town station, with four long terminal platforms, has been cut back to just one shorter platform that is sufficient to serve the hourly Class 153 shuttle. Nevertheless, these trains have to share the single line with the container trains serving the three Felixstowe freight terminals.

Main line snarl-up at Ipswich

Container trains from Felixstowe generally proceed via East Suffolk Junction into the Yard at Ipswich for a crew and/or traction change before continuing via the Great Eastern main line (GEML) to Stratford and thence via the North London line to join the West Coast main line. Some trains reverse in Ipswich Yard and initially head north before veering west at Haughley Junction on their way cross country towards Nuneaton.

The GEML route is already very busy with a mixture of InterCity, semi-fast and stopping outer suburban trains. The container trains have to be accommodated with these passenger services on what is basically a twin-track railway from Liverpool Street to Ipswich, with limited opportunities for fast trains to overtake at Chelmsford, Witham and Colchester.ap02-Ipswich-Chord-Visit2 [online]

Stratford is a challenging pinch-point for signallers. Whilst there is a second pair of tracks (‘Electric Lines’) between Liverpool Street and Shenfield, these are due to be handed over to Crossrail services in 2015. It seems unlikely that operator TfL will be see the offering of paths for freight trains as being compatible with the running of a reliable metro-style service.

Furthermore, there is a local ‘Norwich in Ninety’ campaign underway to reduce InterCity journey times between Norwich/Ipswich/London. The best time today of 100 minutes is achievable with only one train in each direction with specially crafted paths. Given the mixed-traffic nature of the twin-track main line and the knife-edge performance of the intensive morning and evening peaks, achieving such a reduction in journey time is likely to be challenging. However, this is where the Ipswich Chord can help increase paths for faster and/or more passenger trains by reducing container traffic routed via Stratford.

October 2012 – March 2014

Devised as part of the F-N capacity upgrade, the Ipswich Chord is a brand new double track section of railway 1.2 km long with double junctions at each end. It cost £59 million, co- financed with a contribution of £10.7 million from the European Trans-European Network (TEN-T).

Prior to the opening of the Chord there were 28 freight trains per day in each direction, 18 via London, 10 via Peterborough. When the Chord is at full stretch in 2030, after other infrastructure improvements are complete, it is anticipated that there will be 56 paths each way, though some may still be routed via Stratford.

The new chord line is the first Network Rail line to be authorised under ‘The Railways (Interoperability) Regulations 2011’. Certification will be achieved by the Network Certification Body, an independent subsidiary of Network Rail. NCB is accredited to act as a Notified and Designated Body (NOBO) to certify project compliance. Technical Specifications for Interoperability (TSIs) are drafted by the European Railway Agency and mapped to Railway Group Standards in respect of UK railway standards.

At the time of application, Network Rail envisaged that interoperability as a freight line was appropriate. Subsequently it has been realised that passenger services may use the chord. Indeed, several charter rail tour operators are already advertising tours that traverse the new chord line for the benefit of ‘track bashers’. Accordingly, now the line is open, application will be made to reclassify the line as ‘mixed traffic’.

Taking the chord

Container trains from Felixstowe docks approach the Ipswich suburbs from a north easterly direction along the East Suffolk line from Lowestoft which is joined at Westerfield. An existing bridge over the River Gipping has had to be replaced with a new wider structure known as Boss Hall Bridge. The track bed on this structure incorporates the switches of the new Boss Hall Junction.

Freight trains taking the chord then veer right onto new embankments – which even include reptile basking areas. A new underbridge provides maintenance access to the land that is now enclosed by the new triangle of lines.

Continuing around the chord, after a new bridge across the River Gipping the line runs alongside the Norwich main line in a north-westerly direction for some 650 metres. This is to ensure that the length of chord is sufficient to stand a 775 metre long freight train clear of the main lines in both directions. A long retaining wall with soak away segregates the railway from various properties including a supermarket and bowling alley.

Another new bridge takes the chord across the Sproughton Road. The line then converges with the main line at the new Europa Junction where freight trains, after awaiting a suitable path, continue on their journey westwards via the cross-country route. Europa Junction is designed for 50 mph and provides for the shortest possible time for a train entering the Up curve to clear the junction and avoid delaying a following passenger train. The curve itself is limited to 30 mph.

The Works

The principal contractor for the scheme was the Spencer Group working jointly with Network Rail. Spencer Rail constructed the four new bridges on the Chord. Jacobs Engineering UK Ltd delivered consultancy services including preparation of documentation and environmental considerations. CSL provided project management and delivery consultancy for the SMEs involved and structures work.

The existing Underbridge 404 across the River Gipping on the East Suffolk line was in poor condition and, as the new crossover would occupy much of the bridge, a wider structure was required. Network Rail’s standard half-through Type E design with steel deck was chosen for the new span, which is 23.9 metres wide. The new abutments and wing-walls are clad with bricks chosen to replicate the blue engineering bricks of the original, now demolished, abutments piers.

Other works included a further three new bridges, a long retaining wall, and tunnel construction to re-route a sewer. Design of the new River Gipping bridge had to make provision to allow the Environment Agency to gain access to the sluice gate and the embankment and for the future provision of a cycle path. Sustrans had requested that the new River Gipping bridge should provide the necessary engineering to allow the cycle track to be extended and to offer a continuous path and DDA compliant ramp for the benefit of pedestrians. National Cycle Network 51 is constrained by the existing bridge/sluice structure and this should not be made worse by the scheme.

Electrification ready

Although there is an aspiration to electrify the cross-country route from Felixstowe to Nuneaton, at present OLE work is limited to the modification of existing wiring where the chord intersects the GEML at Europa Junction. The building of the new embankment parallel to the main line would have destabilised the OLE stanchions. Accordingly, new catenary has been installed along the embankment and across Europa Junction. The junction tracks have also been wired plus a 150 metre section of the Up Curve. This is part of future proofing and will obviate the need for complex alterations to the catenary here if electrification of the chord proceeds at some point in the future.

50221184dc298c6a5c7b2eb9a377d2ee-xlarge[1] [online]The short wiring on the chord covers the scenario of an Up electric train being mis-routed onto the curve, providing a margin for a driver to react to a signal displaying the route indication for the Up curve and being able to bring the train to a stand before the pantograph runs out of catenary causing damage and the train becoming powerless. The chord is ‘electrification ready’ in that the proposed positions and clearances of OLE masts has been taken into consideration with the design of the various retaining walls and structures. Pod-Trak Ltd has provided the AWAC MkIIIb catenary. This utilises an aluminium conductor with two aluminium-coated steel cores for strength. AWAC uses a different suspension arrangement compared with earlier steel types. At the pulley wheels, stainless steel bridles are deployed as the aluminium would wear rapidly if it ran over a pulley.

Modular track

Ian Clark, Alma Rail’s project track engineer, explained that the track sections were built at Doncaster, to the design radius of 203m and pre-drilled at Doncaster by VAE, consisting of twenty-seven 60-foot panels on the Up and Down lines with breather switches at each end. A McCulloch Rail HD panel-moving machine was deployed for this work. The chord has been designed at the maximum radius possible and a lubricating system will be used to mitigate any possible noise.

CEN56 ‘FV’ IBCL switches have been installed at each junction. The junctions include the first use on Network Rail of modular switch diamonds. The original plan was to install the S&C at Europa Junction during Easter 2013 but, due to snow, this work was postponed. Prudent contingency in the planning of the project allowed for this work to be rescheduled. During the Christmas 2013 blockade, due to the phasing of the signalling commissioning, three dummy plain line panels were installed at Boss Hall Junction with the real switches following a week later.


Previously, Ipswich station area was provided with four-aspect signalling, with three-aspect signalling on the approaches to East Suffolk Junction from both the Norwich and Lowestoft lines. To allow for adequate junction signalling onto the new chord from both Norwich and Lowestoft lines, four-aspect junction signals have been provided for both new junctions with the provision of flashing aspects on the approach to the junction signal at each divergence. Signals on the curve are three-aspect.

Visible on the chord are the new lightweight LED signals, clamp lock points, and apparatus or ‘location’ cases. However, out of the pubic gaze, in relay rooms and the signal box, the project has required significant and complex signal engineering works.

Ipswich is on panel 5 at Colchester Signal Box. It is a combined near vertical control and indication NX Type and was manufactured by Henry Williams Ltd and commissioned in 1983. The panel consists of small individual battleship- grey ‘Domino’ type tiles which slot into a metal lattice in the rear of the panel. The company has returned 30 years later to incorporate the curve into the track layout diagram.

The section of the panel that the new chord line affects is at the bottom right hand side. It is already quite congested as the lines towards Norwich and Lowestoft are skewed to allow alignment with Panel 6. As the new layout incorporates new signal sections on both Up Main and Up Lowestoft lines as well as the Chord lines, there are new Train Describer (TD) windows, track occupied/route indications and buttons to be provided.

The main commissioning was in March 2014 but enabling works took place late last year during which the existing panel tiles were relocated to free up sufficient space for the Ipswich Chord lines.

Henry Williams Ltd also provided signalling Class I power supply location cases.

Signal interlockings

The Ipswich interlocking is situated in a room on the station. Unfortunately, the distance to the new junctions is just outside the maximum 1.25 miles distance for lineside multicore 50V DC signalling safety circuits. Beyond this distance, repeater relays would be required to ensure that induced currents from the 25KV OLE do not create a potentially dangerous false feed. There was insufficient space to locate the interlocking at Ipswich station for the new junctions, and this would anyway require long runs of multicore cables.

The novel solution adopted has been to build a new relay interlocking in a relocatable building near Hadleigh Road bridge. Incidentally, for a small scheme such as this, a new relay interlocking is a more cost effective solution than a computer based version. This interlocking is linked by a new Time Division Multiplex (TDM) data transmission system to Ipswich relay room. The controls and indications data is then transferred via the existing TDM connecting the existing Ipswich relay room with Colchester. GE Transportation Systems (GETS) was the contractor for the TDM and TD systems.

The existing interlocking at Ipswich is a GEC geographical relay system. Some minor modifications have been necessary for the chord, but this interlocking will be extended during this summer in conjunction with the East Suffolk Junction remodelling, of which more anon.

Amaro Signalling Ltd was responsible for lineside signalling equipment, new interlocking and alterations to existing interlocking.

Aerial views of the Ipswich Chord Project

Ipswich Yard and East Suffolk Junction remodelling

This project, also funded under CP4 and part of the Spencer Rail portfolio of works, will create a new longer reception siding. Currently the yard cannot take 775 metre long trains. When resignalled in 1984, the layout of East Suffolk was rationalised from a double junction to a single lead. This prevented a freight train arriving in the yard from the docks simultaneously with a passenger train heading for Lowestoft or Felixstowe. A new line will be installed using a disused arch of the Hadleigh Road bridge, thereby restoring the facility of parallel moves at the junction. This work is due for completion in August this year.

CP5 and beyond

Further improvements on the F-N route are funded under the CP5 package including Haughley Junction doubling from single lead, Ely to Soham doubling and provision of Ely Dock Junction long freight loops. As well as increasing capacity for freight trains, Greater Anglia has aspirations to increase the current two-hourly Ipswich to Peterborough passenger service to hourly.

As described above, the all important Felixstowe branch suffers from the severe capacity constraint of the single line. At GRIP Stage 2, options currently under consideration include a new dynamic loop, passing loops and the relocation of Westerfield station. Complete redoubling is unlikely, not least due to the Spring Road viaduct which would be very costly to replace. The Network Rail project team is hopeful of match funding from the Port of Felixstowe and that capacity improvements should be completed by 2030.

Investment in this route is critical to improve the distribution of goods from Britain’s largest container port with the potential to take up to 750,000 lorries a year off the roads by 2030.