Midland Main Line Electrification

About the project

At Enable Infrastructure (formerly BCM Construction), we have played a significant part in the Midland Main Line Upgrade – the biggest programme of improvements to the line since it was completed in the 1870s.

We were contracted by SPL Powerlines UK to work over a distance of more than 100 miles at multiple sites along the Midland Main Line (MML), with our hugely experienced Enable Power Systems team providing their specialist expertise and our civils team carrying out construction.

The first stage of the upgrade was the now-completed Network Rail London to Corby (L2C) Electrification Project. SPL Powerlines UK’s £300m contract for this project involved the electrification of 192 single track km. This involved 350 design submissions, more than 2,300 foundations, 3,240 overhead line equipment (OLE) structures, the installation of eight substations, a total of approximately 900 km of wire (OLE, Return Screening Conductor [RSC], fibre, LV/HV) and a total length of steelwork for OLE structures of 38 km.

One of the most significant parts of Enable Infrastructure’s work was cable routeing and cable installation. In total, we laid more than 220,000 metres of HV (25kV) and red bond cable, both by hand and using road rail vehicles (RRVs). We installed a mix of: Trough-Tec Systems solutions; elevated Schneider Electric GRP; raised Arco GRP; concrete troughing; buried route containment for the new 25kV HV cables and bonding cabling. The work included Under Road Crossings (URX), Under Track Crossings (UTX) and Over Track Crossings (OTX).

Overall, our MML work involved the following (some at locations north of the L2C section of line):

• Cable routeing and cable installation, as detailed above
• HV cable jointing, testing and commissioning
• Construction of Braybrooke substation and cabling routes from the National Grid to the newly built substation
• Installation of the Braybrooke Auto Transformer Feeder Station (ATFS)
• Construction of Napsbury ATFS site
• Construction of East Hyde ATFS site
• Installation of bypass and trackside OLE switch locations, including hardstands, retention, handrail, access steps and paths
• Installation of full Road Rail Access Points (RRAP) and aprons
• Compound construction, RRAP, including gates and highway modifications
• Drainage
• Signalling & telecommunications (S&T) routes and chambers
• Snagging and repair of existing route for re-use
• Platform works, including buried routes
• Full bonding installation of trackside assets and OLE-associated assets, civil and electrical.

Following the successful completion of all elements of the L2C project (including our own separate project for Amey to deliver four platform extensions at Kettering Station to serve new 240m trains, thus increasing the capacity of the line), the Office of Rail and Road (ORR) authorised the entry into service of the new ‘Energy Subsystem using the United Kingdom Master series overhead contact system’ for L2C in April 2021.

In the months after the completion of L2C, Enable Infrastructure continued work on the delivery of a National Grid 400kV-to-25kV supply point substation parallel to the track at Braybrooke, just outside Market Harborough in rural Leicestershire. Work began on farmland in October 2021, with the winter period seeing the removal of all trackside scrub, a ‘reduce dig’ to level the cleared land and the formation of a 400mm-thick concrete pad measuring 29.9 x 4.1 metres to host the 400kV substation. Among the most notable aspects of the work was the sheer amount of spoil – almost 5,000 tonnes! – that had to be excavated and relocated during the dig.

Conditions on the ground were sometimes challenging – our teams faced snow, rain and frost – but we persevered to keep the project moving and on schedule.

The challenge

• Need to interface with other contractors on site and other third parties, such as National Grid
• Geographical challenge of having to work over a distance of more than 100 miles, with several sites running at any one time
• Multidiscipline challenge, with Enable Infrastructure working as a tier 2 contractor to SPL Power Lines UK over disciplines including S&T, P&D, civils, T&C, and design
• Working to a client design programme, where there were, on occasion, issues that made elements of the programme not feasible for installation.

The solution

We held weekly interface meetings and dilapidation surveys to prevent congestion on-site and during any stand-down time whilst carrying out construction or electrical tasks. Enable Infrastructure implemented a logistical plan to minimise fleet mileage, project costs and, most importantly, environmental impact. This included reducing carbon emissions by the use of a pool project van and the projecting of material movements to combine multiple deliveries by utilising only one vehicle.

We solved the multidiscipline challenge by using the correct, experienced staff in a collaborative way, holding regular meetings to make sure no skill gaps were left. This approach was vital in our on-budget, on-time, accident-free delivery of the project.

Enable Infrastructure leveraged our long years of knowledge and experience to deliver design solutions to the client that resulted in better build times, cost savi

The deliverables

Deliverables in this phase of our project included:

• Installation of a distribution network operator (DNO) unit, of a glass-reinforced plastic (GRP) yellow handrail and a GRP post route as crucial adjuncts to the substation
• Construction of traction power building reinforced concrete (RC) foundation
• Construction of external stairs & ramp, inclusive of handrail
• Supply and installation of hardstanding
• Supply and installation of type 1 walkway around hardstanding
• Construction of crane turning area hard standing
• Installation of six 4-way XL multiduct buried routes from SGT1 & SGT2
• Installation of Cubis Ultima chambers
• Installation of four 150mm-diameter multicore cable ducts
• Installation of Cubis Stakka Boxes
• Installation of four URXs (approx. 12mtrs each)
• Installation of 3.0-high hot-dip galvanised palisade fencing
• Installation of 1.8m-wide 3.0m high palisade access gate
• Installation of Cubis Stakka chambers
• Installation of twenty 160mm-diameter rigid coil power ducts buried route from HV chambers to the traction power building
• Installation of C1/9 traction bonding route
• Installation of traction bonding
• Installation of four 19/4 22mm RSC
• Installation of a full 150m earthing farm, including eleven augured earth rods at 6,000mm deep.

The substation work was followed on April 23rd-24th 2022 by the overnight installation of the Braybrooke ATFS, which had been built adjacent to the site to connect to the substation. The Siemens module building was delivered in split sections that were lifted into place by a 500-tonne crane during an eight-hour night-time possession of the MML. The lift was preceded by the completion of a substantial number of earthworks and other civils work necessary to enable the successful delivery of this building to the site.

“The safe and professional manner of all work prior to the night, followed by the safe and smooth organisation for the lift, highlights the wonderful collaboration between SPL Powerlines UK and Enable Infrastructure.”

Tom Walker, P+D Project Manager for SPL Powerlines UK

The Braybrooke ATFS is a major feeder station for the line, powering OLE from Kettering to Market Harborough. It is key to the future development and electrification of the MML railway infrastructure and supports the running of Long Distance High-Speed Intercity (LDHSI) bi-mode trains using electric traction.

Throughout Enable Infrastructure’s work on the Midland Main Line Upgrade programme, the close and effective collaboration maintained with our client, SPL Powerlines UK, has been a fundamental factor in the project’s success. We delivered on time, on budget and with a 100 per cent safety record.

Enable Infrastructure is proud to be part of the Midland Main Line Upgrade programme, which is electrifying a key part of the nation’s rail infrastructure and thus supplying greater efficiencies and capabilities to the transport network. By enabling the railway to innovate beyond diesel power towards cleaner electric power, it will ultimately assist in the reduction of polluting greenhouse gas emissions.

All of this corresponds closely to the aim of Enable Infrastructure – and of the whole Enable Group –to deliver infrastructure that will give lasting social value.