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The 4-year Channel Tunnel Rail Link Design Project
Value:
£45million
Timescale:
4 years.
Background:
Section 2 of the Channel Tunnel Rail Link (CTRL) now renamed High Speed 1 runs 39km from Southfleet Junction in Kent to the magnificent refurbished station at St Pancras, London and is the first new railway in Britain for 100 years.
The route has 17km of duel tunnels, in three sections, under the Thames, from Dagenham to Stratford and then from Stratford to just short of St Pancras. Additional to the main route, from Stratford there is a 1 km tunnel connection to the new Eurostar maintenance depot at Temple Mills.
Our Brief:
Balfour Beatty Management won the £45m contract to supply twenty seven 11kV/400V substations located at various positions along the Section 2 route after competing the installation of 4 smaller substations on Section 1.
Services Provided:
The project consisted of five 11kV Networks at Ebbsfleet, Rainham, London Tunnel (the tunnels from St Pancras to Dagenham), Temple Mills and St Pancras Station. The combined capacity of the order of 33MVA, with individual networks having capacity ranging from 750kVA at Rainham up to 8MVA on the London Tunnel. We installed over 180 circuit breakers, 60 11kV/11kV and 11kV/400V transformers and over 270 LV circuit breakers.
Our Achievements:
The specification held many challenges, not least the design and supervision of the installation of 60km of 11kV cabling which had to have a design life of 40 years. The system had to be earthed in a manor that had to be safe to the public and
future proofed against increases in fault levels due to infrastructure upgrades.
We also had to interface with numerous other contractors on the project in which we did not have contractual links. Once into the project additional challenges were
encountered at the St Pancras Station, where there were space constraints and the demanding requirements of working in an English Heritage building.
While these issues where of close concern to the team, we were foremost aware of
the importance of the safety aspects required on a railway such as CTRL.
As the 11kV cabling had to run in parallel with the track, the design of the cable had to be substantial enough to allow traction currents to pass down the screens without reducing the rating.
To achieve this with the HV cabling we paid special care with the terminations, using outdoor terminations on the internal cable boxes and additional cable box heaters to ensure that moisture could not cause breakdown. Experienced cable jointers were provided with additional training prior to making the cable joints. Each joint was checked during and after installation by a team of independent inspectors. Each cable was tested using the latest techniques. Firstly over-sheath tests to prove the outer integrity of the cable and thus ensure moisture could not enter, the cables where then partial discharge mapped to ensure reliability over the design life.
To make sure that traction currents could not enter the electricity supplier’s networks, 11kV/11kV isolation transformers have been employed. This isolation transformer mitigated the potential of direct currents causing corrosion in remote locations however it created problems with the earthing of the substations. The isolation transformer creates a break in the cable screen therefore all earth fault current would have to pass through the mass of earth, thus giving a potential hazard of high touch and step voltages. As very low earth resistance values from large earth mats were not possible, a device that bridges the two earth systems was developed to solidly bond the systems under the unlikely event of a fault, but to isolate the two systems under normal operations.
The greatest challenge for our team over the last four years was the effort required in the design, installation and energisation of our three 11kV Substations at St Pancras.
Working within the confines of an English Heritage grade1 listed building; Balfour Beatty Management had to ensure its design was constructible, safe and maintainable without disturbing or damaging the fabric of the building.
Energisation of the five 11kV networks has required the setting up of a control room staffed by control and deputy engineers and a team of ten senior authorised personnel. By using a system of procedures, safety rules, network control mimics and a web based substation-monitoring system, the team of SAP’s have ensured the safe 11kV and 400V energisation in an environment containing dozens of different contractors over a wide geographical area.
The range of activities Balfour Beatty Management has carried out on this project has been vast, ranging from concept design of HV protection systems, substation, earthing, HV and LV cabling design. The procurement of switchgear, transformers and control systems, the management, planning and supervision of contractors through to the commissioning and energisation of the networks. The project has been an outstanding success thanks to the co-operation of the design, construction, subcontractor and client teams working together on a project that probably will not be repeated for many years to come.
Transportation
In this complex and extremely broad-ranging sector, we focus on rail, major highways and multi-modal hub & spoke transportation systems. Within these areas our highly experienced team work through the entire development cycle; from feasibility and design right through to construction and delivery into service. This often requires a multidisciplinary approach, where we combine building, civil, M&E and rail engineering expertise with our project and commercial management skills to deliver in constrained and demanding environments.
We’re currently involved in some truly high-profile projects, including the King’s Cross Redevelopment – a hugely complex station redevelopment valued at around £800m – and BAA’s Terminal 5 Rail Link. We’re also playing a lead role in the upgrading of London’s Underground network, providing services to London Underground Ltd and its PPP partners through our dedicated Metro delivery team.
Above ground, we’re part of the Regional and City Airports (RCA) consortium - the Balfour Beatty Group’s specialist airport investment and development group. In 2007, our technical expertise developed the business model and capital expenditure plans that enabled RCA to successfully acquire Exeter and Devon International Airport Ltd.
Exeter is already one of the fastest-growing regional airports in the UK, but now it will be substantially redeveloped with new terminal facilities, an aircraft stand and (in the longer term) further terminal capacity, stand and taxiway development. It’s the kind of project that will require strong development, management and asset management skills. All of which we have in abundance. Our project history to date has clearly demonstrated expertise in airport master planning and development solutions, long-term capital investment planning, as well as operational skills in the aviation market, so we firmly believe we have much to offer.
Building
Heery’s strengths and track record have provided an excellent foundation in this area. Offering services across a range of sectors including commercial development, public amenities, education and healthcare, we work closely with customers to understand their needs, provide solutions for complex projects, and, in doing so, create maximum value on each project.
Some of the truly inspirational projects we’ve helped to deliver include turning Kempton Racecourse into an all-weather, all-year round facility, and completing the Playfair Project in Edinburgh, where we’ve refurbished the Royal Scottish Academy building and linked it, underground, to the National Gallery of Scotland. Heery have also been selected as Construction Manager for the two-year Cutty Sark Conservation Project, involving both repair and conversation for the ship herself, together with creating an improved visitor environment. A key national heritage project, our selection for this reflects our strong track record within this field.
And it doesn’t stop there. Current projects include the relocation of Queen Margaret University College (Scotland’s first entirely new higher education campus development for 30 years); seven new buildings across the UK for the NHS Blood and Transplant Service; and the 1,000,000sq ft, £170m Silverburn retail development centre in Glasgow.
Utilities
Drawing on our extensive experience in water, gas, electricity and telecoms networks, we’re able to manage a wide range of multi-utilities projects. Our projects include the rehabilitation and renewal of networks, where we handle every aspect of the planning and design to the management of utility diversions for major building and infrastructure projects, dealing directly with the utility companies and other stakeholders. We also have an established track record working with companies such as Three Valleys Water to reduce leakage from water networks.
A good example of BBM’s utilities activity is our alliance with National Grid on the North West Gas Alliance. We’re working together on the abandonment of iron gas mains across the distribution network in the North West of England – replacing the iron pipes, where necessary, with non-metallic materials. It’s a strong partnership that focuses on working together, sharing knowledge and getting the job done. BBM play a key role on the alliance management team and our staff on the project include commercial managers, programme planners, designers and network planners. All of the project’s targets have been met and we’ve also made considerable safety improvements. As a result of this success, we are now an alliance partner with National Grid working on the analogue to digital switch over programme and upgrading National Grid’s transmission infrastructure.
Other key customers include Merseytravel, for whom we managed utilities diversions to prepare for the Merseytram lines running from Liverpool to Kirby.
The work we do in this sector is supported by the latest technology, including GIS vector mapping and bespoke applications that we’ve developed using a variety of software, including Java.
Industry
Industry is a new and growing market for BBM, in which we’ve recently won substantial and challenging contracts.
Take, for example, our £24m construction management project with Kodak at Harrow – the first step in a programme of similar work right around the world. Kodak is streamlining its business to take advantage of new technology and reorganising its facilities and assets on the 40-acre site in North-West London. The modernisation process poses a number of technical challenges for BBM. For instance, the work must be carried out while the facilities are still operational and some of the buildings involved contain various quantities of asbestos.
We are also working on a number of PetroChem contracts. Lucite International have charged us with managing maintenance, turnaround and engineering projects on their site at Cassel Works, Teesside, and we also look after Q8 Petroleum’s site in Europoort, Holland.
