The Institution of Mechanical Engineers Railway Division has an enviable reputation for the organisation of technical conferences and seminars related to the rail industry. The most recent one held at the Birdcage Walk headquarters in London was ‘Rail Electrification 2017: Addressing the Challenges and Designing for the Future’.
This seminar was, in effect, the latest in a series of biennial occasions which started at the time of the resurgence of United Kingdom railway electrification; working on a theme of mobilisation and also tracking progress as proposals and designs were developed and implemented.
While being watched by impressive paintings of George and Robert Stephenson, an audience of rail professionals heard a broad review of the state of play and also technical presentations on the progress and the ups and downs of the current national electrification plan. Presenters came from a wide spectrum of UK and mainland European companies and organisations.
After the pause…
To set the scene the keynote address was given by Peter Dearman, electrification advisor to Bechtel. Peter is a long-term electrification engineer, being intimately involved with the subject from British Railways days to the current privatised structure.
Peter presented a “Status Update on Electrification in the UK after the Pause.” To refresh memories, the “Pause “ occurred some two years ago when the government decided to call a stop to electrification design and construction works in view of the emerging costs and timescales which were not in line with the original forecasts. Three questions were posed: has the industry taken on board the messages on costs, is the purpose of cost reduction really served at all by scope deferral, and what is the real safety or business case for electrification? To qualify and amplify the questions, Peter also asked whether exceeding direct requirements was simply over engineering.
To tackle these questions, it was necessary to examine a bit of history relating to railway electrification in the United Kingdom. The huge 1955 railway modernisation programme was rather a mix, but there was wide-scale electrification approval with Euston-Manchester-Liverpool being authorised. However, costs were out of control and the programme was delayed; the Minister of Transport at the time (who was also chairman of Marples Ridgeway, a road builder) halted the job.
British railways reacted to the challenge and, in the few years between 1967 and 1971, the whole process was addressed; engineering was simplified, design was mechanised and the implementation model was completely changed. The cost per kilometre was halved and delivery times reduced by a third. This led to many schemes being implemented with the East Coast being finished a year earlier than plan and under budget!
Fast forward to the twenty-first century – a major UK electrification programme was agreed; industry was slow to mobilise and ran late and way over budget: the Minister called a halt. (Sound familiar?)
The seminar proceeded to look at various angles – running from an operator’s point of view through design and innovation issues, touching on safety and risk assessment and also including a view from the rest of Europe in terms of a French company comfortably fitting into the UK arena.
An operator’s view
Before looking at the technical issues, there was a fascinating insight to the view of the operator – in this case Govia Thameslink Railway. Gerry McFadden, engineering director for the train operator explained that, with five hundred and twenty five trains and a huge change focussed round Thameslink, energy consumption was a major concern.
Gerry reviewed the progress of electric traction engineering, from the early days of the operating company to the present new generation of class 700 Desiro City trains. Overall trains have become heavier, with axle weights creeping up and greater ‘hotel’ loads. There had therefore been an effort to get weight back down, but perhaps not enough had been done early enough about regeneration. This had not been recognised as the energy (and money) saving option that it really was. The technical details are complex and enthralling but, in summary, by the time regeneration was properly acknowledged, consumption was reduced by around 20 per cent – and it could have been done earlier.
Standards and systems
The subject then moved on to design issues and associated developments in constructability and compliance. Firstly, Network Rail’s professional head of contact systems, Phil Doughty, described the move in overhead contact system (OCS) design from the type of equipment installed as part of the West Coast main line route modernisation, to the development of what has become known as the UK Master Series (UKMS). This single design range has emerged from Series Two, developed for use at up to 100mph on the northern schemes, and Series One, 140mph with twin pantographs and introduced as part of the Great Western project, providing clear and consistent rules and guidance on the application of standard designs.
In addition, UKMS has introduced a third standard, to provide the best option for multi pantograph operation at 125mph. The system comprises a single set of components, assemblies, technical sheets, general arrangements and foundations that can be allocated as appropriate and are arranged to be compatible with both legacy and TSI-compliant pantograph configurations.
It was relevant to note that, although the scope of UKMS is currently limited to new electrification schemes, there is scope to include retro-fitting to earlier mark one and mark three equipment if required.
Rob Daffern from Furrer+Frey continued the design theme, looking at an overhead contact system for high-output construction. Series One was designed as just such an OCS, to be installed mid-week on two tracks out of four with adjacent line open (ALO) working – easy to install and therefore easy to renew. Rob commented that Series One was intended to maximise installation efficiency and build quality, reduce the supply chain complexity and achieve economy by standardisation. High output is not necessarily about getting the cheapest or the lightest, instead it is “the simplest overall solution to cut through the complexity of real life”.
Reviewing the lessons learnt from the Great Western project, Rob suggested that the contract scopes and goals should be more closely aligned, there should be more time for feedback from early trials, focussing on the whole ‘factory’ process, and stronger management of change.
It takes innovation
Railway engineering cannot stand still – innovation is always needed to go forward. Steve Cox, engineering and technical director of Alstom Transport, looked at how the industry is suffering under the influences of rising costs, milestones missed and aims to reduce HSE risk. Capital costs are rising and a focus on reducing life cycle costs needs to look at cost of development, the costs of BIM (although the benefits are acknowledged), the impact of any single source of supply and an increase in equipment costs. Steve headlined a simple equation from his company:
Innovative Equipment + Innovative Plant + Integrated Process = Efficient Delivery at Reduced Cost.
As an example of controlling capital costs, Steve highlighted Alstom’s patented modular ‘CLever Cantilever’ which delivers a reduced number of components, high adjustability and lower weight. The equipment has gained Network Rail Product Acceptance and can even be integrated into the Network Rail MK ranges, allowing upgrade through maintenance.
Design and safety were subjects for Gary Keenor, group engineer for Atkins and contact system specialist for Great Western Electrification. Having introduced himself in terms of ‘How to be an Engaged Designer’, Gary explained that there is a heavy responsibility for safety in a design. He then presented an absorbing study on the facets of electrical safety and working in and around live electrical equipment on the railway infrastructure, with parallel emphasis being placed on the modern addition of an extra conductor in the form of the Auto Transformer conductor.
To round off, Sebastien Lustro, rail electrification director of TSO Catenaires, explained how systems are dealt with in France. The company has three design offices, its own training centre and a large fleet of rail related plant and machinery.
Sebastien explained that a continuous programme of high-speed line construction had resulted in TSO having regular electrification work. The example given was TSO’s work on the new 350km/h, 600km Tours – Bordeaux high speed line. Basic design was delivered by SNCF and then applied to the route to meet specifications and project requirements for this new part of the French high-speed rail system. Of particular interest was the initial structures installation which, with the formation down but no track in place, was road based from lorries and road based plant using poured foundations. Structures were planted with small part steelwork installed, final adjustment and wiring being undertaken when the rails had been laid. The scale of the project and the construction work was striking and the insight to this level of railway building with accompanying electrification was valuable in view of the future high-speed route developments in the UK.
As a contrast, the more elderly French electrified systems are now in serious need of update and restoration to modern standards. The route from Paris Austerlitz to Bretigny has equipment dating from before the 1930s and has reached unacceptable levels of poor reliability and high running costs. This 1,500-volt system requires complete replacement and an innovative scheme was essential, incorporating OCS renewal with minimal disruption on this high density line that carries 500,000 passengers a day.
The existing inventory of multiple types of poles, masts and gantries, tensioning devices and corroded structures on a system with no compensation on the catenary (messenger wire in mainland European parlance) added to the challenge of bringing this high density route up to modern reliability standards of performance. TSO is approaching the OCS renewal task with a new high-performance type for 1,500 volt DC, a simplified design with a reduced number of components and reduction of sections from 1800 to 1400 metres.
A requirement is also the ability to migrate to 25kV AC at a later stage. The contract will run for eight years, be BIM compliant and all works under possessions at night must hand back to operation every single morning.
TSO is thus involved with two completely contrasting projects, which together gave an enthralling view of the challenges faced by our close neighbours.
Don’t forget Crossrail!
The discussion then returned to the Great Western programme. Rishi Ravindran, depot engineering manager at Great Western Railway (GWR), spoke of the work necessary in preparing for electrification coupled with the delivery of a new fleet of Class 800 trains.
A coded map of the route to be electrified showed incremental parts, not necessarily adjacent, leading to mixed traction and even an inability to take electric trains to the maintenance depot under energised wires, a point underscored by a photograph of a Class 57 hauling an EMU.
The introduction of the new system requires the coordination of driver, maintenance and station staff training, station improvements, testing and compatibility assessments as well as a complex juggling act of coordinating infrastructure availability and rolling stock storage and stabling.
At the time of the presentation, Rishi was pleased to be able to point to the introduction of electric services, mobilisation of sites away from the home depot, Class 387 compatibility with Series one OCS at 110mph, operation through to Maidenhead and driver and technician training undertaken. Further work remains, of course, but there is a confidence that the programme can be achieved.
Of course, GWR isn’t the only railway with a new fleet and new electrification. Phil Hinde, principal engineer, rolling stock and depots at Crossrail, spoke on ‘Power for the trains, a rolling stock engineer’s perspective’.
Phil gave a very useful overview of the Crossrail scheme: reminding those present that the scheme was, in fact, much more than building a new railway in the core. It also involves massive alteration to the existing railway out to Maidenhead and Shenfield, routes which have to stay open while provision is being made for the new services.
The new Class 345 train was described, including the features necessary to comply with the disparate existing and new infrastructure configurations, designed and constructed to the principles and project requirements for the programme.
One of the recurring topics at the conference was the question of wire heights and their relationship with the infrastructure, looking at clearances between live elements and standing surfaces (issue 149, March 2017). There was intense debate as to how the industry should react to the appearance of requirements to achieve standards which were not easily or financially achievable, and where the historical alignment showed there had been no incidents relevant to the enhanced requirements in the UK over the years.
The problem doesn’t only come about due to the current standards regime. There is a legacy element where previous electrification schemes have taken approaches to configuration which do not fit well with today’s rolling stock.
Examples quoted were extremely high wire heights in Ilford depot and steep wire gradients at overbridges; severely challenging modern pantograph overheight protection. On the other hand, there are also bridges and other locations where the wire height is too low, carrying a risk of pantograph well flashover. A potential challenge could also be from the increased fault currents at 12kA and harmonic resonance.
All these are conditions that have to be managed, but they are indicative of the need to bring parts of the industry together in consultation, to ensure that project requirements are clear and can be met in a suitable timescale. Rolling stock and infrastructure engineers need to work together to:
- Strengthen the professional focus on OCS power;
- Ensure infrastructure knowledge is up to date;
- Improve local feedback to HQ engineers;
- Fill any gaps in standards;
- Prioritise fuel consumption data supplied by rolling stock manufacturers;
- Realise energy is as much a system capacity constraint as track or signalling;
- Recognise that more trains place more stress on equipment;
- Integrate the system.
As a valuable finale to the presentations, Roger White, director of the Rail Electrification Consultancy, presented a most absorbing paper dealing with issues on earthing, bonding, traction return and, in effect, system integration – but in this case the integration between the electrical engineering and the fixed mechanical and civil engineering structure. Roger clarified what is earth in an electrical sense and visited the hazards experienced through earthing and bonding hazards, with touch potentials and step potentials all receiving attention.
A very useful run down on segregated and integrated earthing and bonding followed, with illustration of functional and historical preferences. Earthing and bonding issues had led to some serious and spectacular incidents involving equipment that was either degraded or not of suitable design; sometimes impacting on neighbours and stakeholders. A series of cross-section diagrams, illustrating potentials in and around the ground on electrification systems, gave pause for thought.
The debate continues
The seminar was rounded off by a panel of experts drawn from the day’s participants, and a lively debate ensued. The future of electrification, seen as a good thing by those present, may not look that way to others. However, if the cost is trebled, there won’t be a future. Also, the imposition of apparently unnecessary standards is a downward influence the industry could well do without – perhaps a challenge should be mounted by the experienced and knowledgeable professionals forming the panel.
The last word goes to Peter Dearman, who opened the conference. “In all this remain some painful realities. Fossil fuel will not dominate the energy market forever; its time is now short. Price and availability will begin to become a problem from 2050.
Major cities are banning diesels, how long before that ban is complete: 30 years? That is less than the life of a single train fleet. Sniff the air in an HST front coach or on a platform as a class 66 hauls past and wonder when the public backlash will surface.
If we kill off electrification, what will our response be?
Written by Peter Stanton
Thanks to the IMechE and all the team members who put the day together and enabled such a wide ranging educational and discussion event.