Easing the flow

It’s not often that we have the pleasure of reporting on the new construction of a main line railway in England. But, in the heart of the country, a 4km stretch of brand new double track electrified railway is taking shape. Not heard of it? Well, to many of us it does almost seem like a well-kept secret, but look left as you travel the West Coast main line (WCML) between Stafford and Crewe and the activities can be glimpsed.

The brief view of earthworks seen from a speeding train belies the true extent of what’s involved. Technically this is an upgrade, but with eleven new bridges, 10km of 100mph track, major river and road diversions and three new junctions – this is, by any standards, a substantial project. So what’s it all about?

The work forms part of a £250 million scheme known as the Stafford Area Improvements Programme (SAIP). It is designed to remove the last major bottleneck on the WCML, at Norton Bridge. The full programme comprises three key stages:

• Upgrading of the slow lines between Crewe and Norton Bridge;
• Resignalling of Stafford station and the installation of a down goods loop;
• Separation of the slow lines at Norton Bridge onto an entirely new alignment and the creation of a grade separated junction.

Alliance

All of these works are being delivered by an alliance that involves four partners participating in one collaborative contract. It follows the Australian ‘Pure Alliance’ model in that the member companies are working together as one organisation. Known as the Staffordshire Alliance, it is a partnership of Atkins, Laing O’Rourke, Network Rail and VolkerRail.

This is the first example of such an alliance operating within the UK rail industry and it has been driven by the need to embrace the findings and recommendations of the McNulty report. In other words, to reduce costs and improve the quality of what’s being delivered. Network Rail says it wants to ‘develop mature collaborative relationships with key industry participants, creating a fundamentally different operating landscape.’

Different it is. The alliance draws upon the specialist skills and experience offered by the participating organisations, but with complete integration and equal sharing of the benefits and risks. Decisions are made on a ‘best for project’ basis. Whilst the collaboration must not remove accountability to deliver, it addresses concerns that quality and scope may be sacrificed in order to achieve cost savings when delivering multi-disciplinary programmes.

The result is a joint project team with widespread trust and the elimination of man marking. It looks beyond purely financial interests and creates incentives for the partners to work together in areas such as quality, safety and environmental impact. On SAIP, the alliance has also been important in developing a robust strategy for possessions on the WCML and to facilitate working with adjacent line open.

Slow lines fast

The works to upgrade the slow lines over an 18-mile distance between Crewe and Norton Bridge were completed in March 2014. Extensive OLE modifications were carried out by Network Rail’s overhead condition renewals team while track alignment works were undertaken by Network Rail/Amey Colas. In addition, four new banner repeater signals were installed.

The line speed has been raised from 75mph to 100mph, allowing the slow lines to be optimised for London Midland and CrossCountry services. This also gives improved access to the fast lines for maintenance work.

New signalling

SAIP Phase 2 involves the soon-to-be-completed re-signalling of Stafford station, with scheme boundaries at Shugborough on the London line and Penkridge on the route to Wolverhampton. Running concurrently with it is the upgrade of the slow lines between Stafford and Great Bridgeford to allow 100mph running.

Signalling in the Stafford area had seen little investment since the 1960s and was deemed life expired. There have also been capacity constraints through Stafford station itself. The signalling system is therefore being replaced entirely. All platforms at Stafford will become bi-directionally signalled and the line speed on the Up fast is to be increased. Additionally, a new 775-metre Down goods loop was installed to the south of the station during the May 2015 bank holiday weekend.

The new signalling includes 78 new signal heads, 176 axle counters and five WESTLOCK interlockings and is to be controlled from a desk at the Rugby Route Operating Centre (ROC). In fact, this will be the first desk at the ROC to become operational. The scheme is to be commissioned over the August bank holiday weekend. Following this the two remaining electro-mechanical signal boxes, Stafford No.4 and Stafford No. 5, both dating from the 1950s, will be demolished.

Congested

Norton Bridge Junction is the point at which the twin-track line to Stoke and Manchester Piccadilly diverges from the four-track route that serves Crewe, Liverpool and Scotland. A mixture of InterCity, commuter and freight trains all have to share a complex flat junction. Services for Manchester that need to traverse the junction, especially those using the slow lines, can create congestion and pathing difficulties.

It is estimated that there are currently 40% more passenger journeys and 60% more freight than 20 years ago and passenger numbers are forecast to double within the next 20 years. With capacity on the route at an all time high, intervention was needed to ease the bottleneck at Norton Bridge and to future proof it for decades to come.

The ambitious solution has been to separate the slow lines at a new junction near Little Bridgeford. They will now follow an entirely new alignment, which includes a flyover that passes over the WCML almost at right angles. Seen as a project of national significance, the Norton Bridge project has been the subject of a Development Consent Order application which was approved by the Secretary of State for Transport in March of this year. This follows a consultation process dating back to 2010. Work on site was commenced during the spring of 2014.

Phase 3 – Grand Junction

The WCML route through Norton Bridge was an early railway, being constructed in the 1830s by the Grand Junction Railway. It passes immediately to the east of the Norton Bridge hamlet, following a series of sweeping curves. There are several roads and rivers in the area and the constructors chose a course for their railway that took advantage of the land contours and minimised bridge construction.

Creation of a flyover has meant that the slow lines need to take a path through open countryside. Several routes were considered and the Staffordshire Alliance worked closely with the local community during the design process. It was clear from the outset that roadways and watercourses would have to be diverted. Environmental issues included protected woodland and, of course, the ubiquitous Great Crested Newts.

The chosen alignment had to be something of a compromise, but a key factor in its favour is that the cut and fill is in balance, obviating the need to haul material over the local highways. A route further west would have created excess spoil, whereas a route further east would have required large quantities of imported material. The chosen route therefore has the best carbon footprint.

Split

The concept is that the Up and Down slow lines will leave the existing WCML route at Little Bridgeford Junction following an almost straight route, climbing to the north at a constant gradient of 1 in 125. Making use of the height gain, the twin-track route swings to the north east after Searchlight Lane to pass above the WCML well to the north of the existing Norton Bridge Junction. The new lines then fall to tie in with the Stoke line at a new junction near Yarnfield.

The existing four-track route through Norton Bridge will be reduced to three tracks by the removal of the Down slow. The new Down slow will split at Searchlight Lane with a new single track heading north to join end-on with the existing Down slow near Heamies Farm.

The existing junction at Norton Bridge will be reduced to a bi-directional single line chord. This line is retained only for flexibility and will not normally be used by timetabled services.