Electrification to prompt surge in demand for cables

Cables have applications all across the railway industry. Increasing interest in electrification implies extra demand for cables.

Electrified railways are the way forward for the future, as they are cleaner and cheaper to operate than diesel. Another key point is that they are able to draw their power from any primary source – nuclear, renewable or fossil fuel – rather than being dependent on oil.

These advantages have long been recognised in many countries in continental Europe, which have high proportions of their railway networks electrified. Switzerland, with the resource of Alpine hydro-electricity to hand, has 100% of its network electrified, but many of the major European countries also have extensive wired stretches.

Italy, for example, has over 70% electrified, Spain and Germany nearly 60% and France over 50%. In absolute terms, Germany is top of the table, with 19,000 route-km electrified, and France second with nearly 15,000 route-km under wires.

Trailing down the bottom of the league of the major European countries is the UK, where just a third of the network is electrified. With the aim of reducing exposure to rising oil prices and reducing the environmental impact of the railways, in 2009 the Labour government in the UK made a major commitment to further electrification of the country’s railways, with wires due to extend along the Great Western main line from London to South Wales. Electrification was also pencilled in for lines in the north west of England.

“Electric trains are over 35% cheaper to operate than diesels,” said the UK Department for Transport, justifying the decision. “They require less maintenance and have considerably lower energy costs since electricity is a significantly cheaper fuel than diesel. They are lighter and so do less damage to the track. Although there are additional costs involved in maintaining electrification infrastructure, these are significantly outweighed by the train operating cost savings.”

Purchase costs for electric trains are lower than those for diesel. “Electric trains are generally cheaper to buy than diesel trains, reflected in lease costs which are typically around 20% lower,” said the Department. “This relative advantage is set to increase: engines for diesel trains are likely to become more expensive following the introduction of stricter EU emissions standards from 2012. The engines required by these standards are likely to be heavier, larger and more complicated as a result of the emissions control technology required.”

There are also significant environmental benefits. The Department said that rail electrification is an important part of its carbon strategy: “Electric trains generally perform better than equivalent diesel vehicles even on the basis of the current electricity generation mix. Typically an electric train emits 20-35% less carbon per passenger mile than a diesel train. This advantage will increase over time as our power generation mix becomes less carbon intensive. The roll-out of regenerative braking enables many electric trains to re-use the energy that would otherwise have been lost when braking, by converting the energy of motion back into electricity. Electric trains have zero emissions at the point of use, which is of particular benefit for air quality in pollution ‘hot-spots’ such as city centres and mainline stations. Electrification reduces rail’s reliance on imported diesel fuel. Electric trains are quieter than diesel trains, and virtually silent when waiting at stations.”

On top of these advantages, the Department said there would be benefits in terms of increased capacity, improved reliability and an enhanced passenger experience, partly because electric trains can offer a higher power to weight ratio than diesels, resulting in better acceleration and reduced journey times.

In an election in the UK in May 2010, the Labour government that propounded the electrification strategy was replaced by a coalition government comprising the Conservative and Liberal Democrat parties. The coalition administration pledged to reduce the country’s fiscal deficit and as part of that promise the railway electrification programme was looked at again.

The coalition government has since committed itself to electrifying the suburban routes out of London Paddington to Newbury and Oxford, and lines in the north west of England also remain in the programme. Electrification of the main inter-city route to South Wales is still being studied, and the Department for Transport has also asked the infrastructure owner, Network Rail, to investigate the cost of electrifying the line from London to Sheffield.

‘Factory’ trains

Reflecting the fact that a major programme of electrification will take place in the UK, even if it turns out to be not quite as large a programme as was planned under Labour, Network Rail is studying ways of cutting the costs of electrification. Some methods were tried out in electrification of a reopened line in Scotland, linking the country’s two largest cities of Edinburgh and Glasgow via Airdrie and Bathgate, which was completed at the end of 2010.

The idea is “applying high volumes and achieving low costs, like a factory,” says Steve Yianni, Network Rail’s Director Engineering. There are several separate processes involved, including putting in the piles for the masts, erecting the masts and stringing the wires between the masts. Different types of train, such as piling/manipulator trains and wiring trains, are needed for these separate tasks. Analysis has shown that productivity rates on the individual tasks are such that, for example, three piling/manipulator trains are needed for each wiring train. Network Rail intends to order machines that will undertake these tasks in a cost-efficient way, with one type of machine following on after another.

Project Synergy

A wider project concerning Network Rail’s physical supply chain has been conducted over the past five years. Known as ‘Project Synergy’, the project began when a team from the Accenture consultancy conducted a 12-week assessment of the physical supply chain, including site visits, surveys and workshops. This team identified future opportunities and developed key recommendations supported by business cases.

By late 2009, a new inventory management system was in place. “Our overall aim is have a stable, responsive and profitable supply base,” said Network Rail, adding that Project Synergy was intended both to improve cash flow and the service delivered to the front line.

An example of Project Synergy at work can be seen in cable supply for Network Rail, where a collaboration of cable supplier Eland Cables and logistics provider Unipart Rail has been selected to supply NR’s cable requirements. These two companies worked together on the West Coast Route Modernisation, a 10-year improvement programme on the busiest main line in the UK that was completed in 2008.

Network Rail awarded framework supplier status to the Eland Cables/Unipart Rail team based on its ability to deliver a wide range of NR-approved rail cables and accessories at competitive prices. All quotes and orders for railway cables from Eland Cables will be channelled through Unipart Rail.

In a joint statement, the Eland Cables and Unipart Rail Managing Directors Philip Brown and Graham Jackson said: “By collaborating on Project Synergy, we can give rail customers greater choice and stock availability and even more competitive prices, while continuing to deliver fast turnaround times and a consistently high level of service.”

Project Synergy is continuing to evolve. “Moving forward, a key part of our strategy is to develop more strategic relationships with suppliers where appropriate and widen the supply base in certain categories,” said Network Rail.

Safety requirements

Modern high-speed trains demand cables with different characteristics in terms of bandwidth, safety, electromagnetic immunity and resistance. “A definite trend is interoperability, which allows trains to move easily across borders and even continents,” says cable supplier Nexans. “Cables must comply with the new consolidated ERTMS/ETCS (European signalling) standards which are progressively integrating GSM-R radio technologies for train control, while continuing to rely on older route control systems (relay interlocking) for safety and redundancy. Indeed, safety has become a prime concern for the world’s rail operators, and there is a demand not only for more reliable operating systems, but also for materials with improved fire-performance characteristics, especially in tunnels, stations and public areas.”

As an example of this, Nexans points to the Lötschberg Base Tunnel, which opened in 2007. Here, the company was responsible for all cables: power, signalling and telecoms. The turnkey contract covered both supply and installation, including:

• 63km of 132kV high voltage cable lines
• 512km of medium voltage cable networks
• 692km of cables for five fibre optic networks
• All telecom and power components.

Nexans worked with the general contracting team of companies on the project, including Implenia, Rhomberg, Alstom, Siemens and Alcatel.

Rolling stock too

While railway infrastructure has big cable requirements, rolling stock manufactures also uses large quantities of cable. A modern train incorporates several kilometres of cable, and although the introduction of wireless control technologies is expected to reduce the requirement for cable, a substantial demand will remain.

There are often high demands placed on cabling within rolling stock. One example is 35 new double-deck trains for the Zürich S-Bahn system, ordered by SBB (Swiss Federal Railways) from Siemens in a €280 million contract.

Siemens had already used cables in the carriage connections in the ICE3 inter-city trains in Germany from Swiss manufacturer Huber + Suhner, and turned to the same supplier for the Zürich trains. “The carriage connection cable resists high mechanical influence,” says Huber + Suhner. “The system features a special pressure reducing nozzle that is sprayed onto the cable to reduce voltage peaks and to give the vehicle a protected fastening option. Therefore you don’t have to use thick protective tubes as you would otherwise have to,” says the company. “Even in carriage connections a compact, space-saving connection is a great advantage.”