INTRO: Work is now in progress at over 200 sites across southeast England to upgrade the 750V DC power supply for EMUs being introduced by three operators, but many vehicles are likely to remain in store beyond the deadline for withdrawal of older stock. Roger Ford explains how this mismatch between infrastructure enhancement and train deliveries is a direct result of the fragmentation of Britain’s rail network brought about by privatisation
THE STRENGHTHENING OF the traction power supply on Network Rail’s Southern Region is claimed to be Europe’s largest ongoing electrical engineering project. Work is in progress to meet the higher demands of electric multiple-units now being delivered by Bombardier and Siemens, but it is unlikely to be completed in time for all the new trains to enter service at the start of next year. A deadline of December 31 2004 has been set by law for the withdrawal of the slam-door MkI EMUs they are to replace, but up to 400 new vehicles are now expected to remain in storage well into 2005.
In contrast, the simultaneous introduction of Networker EMUs equipped with three-phase drives on Kent suburban services and the arrival of Eurostar trainsets and Class 92 freight locomotives on routes to the Channel Tunnel saw British Rail undertake in the early 1990s significant upgrading of existing 750V DC traction power supply systems. The Channel Tunnel routes alone required the conversion of 32 existing track paralleling huts to substations. Eight new 33 kV feeders from the national electricity supply network were installed and over 200 DC circuit-breakers were uprated and fitted with improved protection. Such integration between new trains and power supplies was normal practice until Railtrack took over responsibility for Britain’s railway infrastructure on April 1 1994.
Lack of oversight
BR’s Networker programme had been intended to meet one of the principal recommendations made by Sir Anthony Hidden’s inquiry into the train collision at Clapham Junction on December 12 1988 that killed 35 people and left 69 seriously injured. The inquiry report assumed that all MkI rolling stock similar to that involved in the accident would be withdrawn by January 2000, but this was overlooked when the process of awarding franchises to operate passenger services began in 1995.
Only after Train Operating Companies had started to pass into the private sector did the Health & Safety Executive intervene, proposing a new deadline for withdrawal of 2007. This was brought forward to December 31 2004 by the Labour government and made a legal requirement under the Railway Safety Regulations 1999. Around 1950 MkI vehicles were affected by the regulations.
Responsibility for ordering replacement stock and notifying Railtrack of any changes needed to the 750V DC power supply lay with the three operators of MkI EMU fleets, South West Trains, South Central and South Eastern. All TOCs have regulated track access agreements with the infrastructure owner, Part F of which covers changes to the types and characteristics of rolling stock operated. Should a change affect the maintenance or operation of the network, or the operation of trains, a TOC must notify the infrastructure owner and could be liable for meeting any resulting costs.
From BR’s experience with the Networker programme, it was clear that the new trains being ordered by the three TOCs to replace MkI stock would require changes to the power supply. However, the TOCs assumed that this was Railtrack’s responsibility.
To determine the implications for its traction power supply systems by means of computer modelling, Railtrack needed details of the performance characteristics of the new trains. South Eastern could not provide this information until 2001, followed by SWT early in 2002. Later that year South Central was the last to decide which train would replace its MkI fleet. Firm information on future service frequencies was also lacking, as the Thameslink 2000 project to upgrade the cross-London route and associated infrastructure slipped.
With these unresolved issues threatening to leave hundreds of new vehicles in store for lack of power, it was clear that the politically-sensitive replacement of MkI stock had to be co-ordinated. In January 2002 the Strategic Rail Authority formed a cross-industry team charged with overseeing the programme for replacing the slam-door trains on the Southern Region, and ensuring that electric power and infrastructure improvements were capable of meeting the deadline of December 31 2004.
With Railtrack now in administration, SRA also funded a dedicated project team within the company to be responsible for the Southern Region Power Supply Upgrade (SRPSU). This accelerated infrastructure work, beginning the tendering process for the supply of power equipment in April 2002.
In June that year former London Transport Commercial Director David Bailey was appointed by SRA to co-ordinate the overall project, now known as the Southern Region New Trains Programme (SRNTP). In addition to the new trains and power supply upgrade, his remit also covered associated station modifications to accept longer train formations and improvements to rolling stock maintenance depots.
Time is (less) money
On-going modelling work by SRPSU, plus tenders for electrical work received in October 2002, produced the first cost estimates for the project. In February 2003 the government gave the figure as £915m, subject to further work on scope, scale and cost. By this time, the growing cost of railway projects had become a major political issue in the UK.
Against a deadline set by law and with the new trains already in production, the only way to cut the cost of the project was to reduce the scope of the power supply strengthening. In a complex power supply network, this could be done only through an interactive process. Under Project Director Andrew Mitchell, the SRPSU System Design Department produced a revised scope document every six to seven weeks during 2003. Each document detailed the work required at every site and its priority. This was made possible by bringing modelling in-house, using the former BR Vision and OSLO systems.
Successive iterations took out what Bailey described as ’a huge amount of scope’ from the original proposition, saving around £200m. This was a multi-dimensional optimisation. ’I am utterly time-driven’, he explained, ’and this has been reflected in my perception of value for money’. On the one hand, repeated iterations of the project scope were still driving down costs, but Bailey had to identify at which stage the savings produced by a further iteration would be less than the financial and political benefits of starting work and getting trains out of storage and into service.
This point was reached in December 2003, when the final scope document detailed work needed at 98 substations, 89 high-voltage feeder locations plus 35 areas where DC cabling would be reinforced. Bids for the upgrade work had been received in October 2002 and by March 2003 framework contracts had been signed with suppliers (left).
These contracts covered the financial year to March 2004, and provided the basis for joint design and planning of the power upgrade in parallel with the modelling work. Within the contract areas, there are core sections termed Phase 1. These have priority and are due to be commissioned by June this year. They cover the main lines from London to Brighton and Portsmouth plus strengthening of high-voltage supplies for the inner-London suburban network.
Phase 2 completes the work needed for the remaining routes to accept all the new trains. Cost pressures mean that the proposed Phase 3, which would have provided additional capacity for future expansion, has been abandoned. As a result, the nominal current rating will remain at the present 1500A per four-car train. This is considered a missed opportunity by Network Rail and the TOCs, although SRA insiders hope that service experience following completion of the upgrade may allow the rating to be increased to around 1 800A.
However, some further strengthening may yet prove necessary. Modelling to define project scope showed that around 50% of the upgrades originally identified were no longer necessary because of either marginal overloads or unlikely combinations of operating conditions.
In order to get the new trains into service with minimum delay and at minimum cost, these marginal upgrades are not being implemented. Network Rail and SRA have agreed that when all the MkI replacement EMUs are in service, these locations deemed to be marginal will be monitored for 12 months. Should significant overloading be detected, SRA will fund the necessary strengthening.
With Phase 1 work now underway, Mitchell says SRPSU has had to change from a centrally-managed major project to a dispersed ’production line’. He believes ’a lot of people are comfortable with big projects, but that’s not where we need to be now’. Throughout 2004, contractors will be working on between 40 and 50 individual sites at any one time, with activity peaking in the second and third quarters of the year.
While the scope was being finalised, procurement had already reached £200m. Four new substations were ordered last year for pilot installations, and this was followed by production orders for all Phase 1 substations, now being delivered. In the inner-London area around 40% of the Phase 1 HV cables have been laid.
Up to now the programme has had little impact on passengers, but with around 1600 possessions required to complete Phase 1 alone, minimising service disruption caused by the intensive work programme will be essential. This will be made harder by the fact that the new trains will, initially, be significantly less reliable than the existing stock.
Network Rail is confident that the power supply work will be completed this year. Driver training is now emerging as the key constraint, since this takes several months and cannot start until the new trains can run over a route. Current best estimates are that between 300 and 400 MkI vehicles will remain in service beyond the legal deadline, requiring an exemption from the regulations for up to six months.
CAPTION: Siemens has installed this new substation to power the Desiro EMU maintenance depot at Northam, with provision to feed the adjacent main line at a later stage
TABLE: Associated works
Traction power control systems (SCADA) Transmitton, Westinghouse Rail Systems
Impedance bonds Westinghouse Signals (manufacture and installation), Bombardier Transportation (supply)
Cabling Pirelli (HV and pilot cable), APEX Cable (HV, pilot and DC cable)
Cable troughing Anderton Concrete
Platform extensions Rail Construction Partnership
Depot modernisation AMEC, Fitzpatrick Construction Partnership, Edmund Nuttall
TABLE: Framework contracts
Contract area Contractor
Inner London SEEBOARD Contracting Services Ltd/ Balfour Beatty Rail Projects Ltd joint venture
Kent ABB Ltd/Mowlem Railways consortium
Sussex Integrated Utility Services Ltd/ Peterhouse plc (First Projects) JV
Wessex Siemens Transportation Systems/ AMEC Spie Rail Systems JV
CAPTION: Electrostar EMUs are starting to enter service on South Central routes in increasing numbers as power supply upgrades such as the new substation at Hove are completed