AVENTRA – Bombardier’s flagship EMU for the UK

The UK’s rail network is looking for a step change in performance from commuter trains. Its high density routes – particularly around London and the south-east – require a radical advancement in rolling stock to meet changing operational and passenger demands. Higher capacity, increased accessibility, more sophisticated on-board technology and the consistent demand for frequent and reliable services are just some of the criteria that mean tomorrow’s trains will have to work harder than ever. Requirements for reduced energy consumption and less track damage are also creating a drive for lighter units.

Bombardier has delivered and maintains more of the UK’s trains than any other manufacturer. Its Electrical Multiple Unit (EMU) platform, the ELECTROSTAR, has received numerous awards for ‘best performing modern-era EMU’; it was also exported for the Gautrain project in South Africa which opened ahead of the 2010 World Cup, shattering all forecasts by transporting more than 400,000 passengers in its first month of operation. But even the best products merit revision to reflect changing market needs. Bombardier has therefore developed AVENTRA, its new flagship EMU for the UK.

The company has drawn upon the experience of its 22 product platforms and an in-service base of over 100,000 vehicles worldwide to optimise AVENTRA’s design against the requirements of the global EMU market. Whilst reliability of the existing vehicles is already high, Bombardier is confidently predicting that AVENTRA will achieve an impressive reliability improvement of 68% over existing vehicles and reduce net energy consumption by 46%. It also provides increased capacity, reliable journey times, enhanced safety, environmental sustainability and a flexible configuration. Quite a list!

Advanced bogie design
Whilst ELECTROSTAR is the lightest EMU in the market, weighing in at an average of just 42 tonnes per car, AVENTRA promises to be 20% lighter. This is achieved in no small part thanks to the introduction of Bombardier’s FLEXX Eco inside-frame bogie. It was designed for the UK market as part of the pioneering ‘Advanced Suburban Bogie’ project in the early 1990s. Initially tested in prototype form for two years under Class 320 vehicles (in 1991-92 using trailer bogies) and subsequently under Class 466s using motor bogies, it remains the only lightweight high-performance bogie in the world on main line passenger services.

The FLEXX Eco has an extremely credible track record, having travelled 1.5 billion kilometres in the UK under Voyager, Meridian and, more recently, TURBOSTAR units. It has also been exported to Norway, with 122 bogies supplied to state operator NSB. In reducing overall vehicle weight, the bogie makes a significant contribution to the energy saving advantages of the AVENTRA. It is particularly stable at high speed – it has been tested to 275kph under a Japanese Shinkansen and 392kph beneath an ICE2 – and delivers excellent performance through curves.

Optimising costs
Bombardier is committed to making its vehicles as environmentally friendly as possible and additional energy saving is achieved through the introduction of EBI Drive 50. This is a software tool that provides drivers with real-time recommendations to help optimise their driving style, powering greater efficiency and improved energy consumption whilst meeting the requirements of the timetable. In trials with First Capital Connect, as well as tests in Germany and Sweden, the EBI Drive 50 has brought consistent benefits in the region of 10-15%.

Bombardier’s service resources enable its customers to gain not only from the supplier’s extensive expertise in rolling stock engineering but also from a global materials supply network and component overhaul capability. This means that the company is also a market leader in the vehicle aftercare market. In the UK alone, it services more than 5,000 vehicles – around one-third of the total UK fleet.

Whole-life maintainability was at the heart of AVENTRA’s intrinsic concept design. To ensure downtime is kept to a minimum, the platform is equipped with Bombardier’s ORBITA – a market-leading tool that provides asset information to rail operators and maintenance teams, identifying operational anomalies in vehicles before they manifest themselves as a failure in service. A defining feature is its alert-generating capability which highlights to the operator in a simple and highly visible way the priority for maintenance action.

ORBITA already monitors more than 2,600 vehicles in the UK and this figure will soon increase to 5,000. Alongside the added ability to cross-reference performance data with other global fleets, ORBITA helps in the move towards full condition-based maintenance, enabling fleets to stay in service for longer. ScotRail, the first customer in the UK to use it, achieved a 14% reliability improvement in 18 months.

Focus on the passenger
AVENTRA has been developed with a keen focus on the commuting passenger. It features an open gangway design allowing maximum use of the interior space and ease of movement throughout the train. It also contributes to engendering a safe environment, providing good sight lines for passengers and reciprocally for surveillance equipment.

Bombardier has worked extensively with both train operators and focus groups to help develop its Passenger Information and Entertainment System (PIES) for AVENTRA. This is differentiated from others on the market by its incorporation within an IP-based Train Control Management System (TCMS) architecture. This facility has featured on recent projects including London Underground’s sub-surface lines, the Ile-de-France Francilien and the Sprinter Light train for the Netherlands.

An advantage of connecting with the TCMS IP backbone is that it enables the passenger information system to share common TCMS functionality including the route databases, unit position, error reporting and train-to-wayside communication. Its core functions are to provide passengers with infotainment and relevant audio-visual information about the route, as well as communications between the driver, crew, passengers and the service control centre.

Whilst Bombardier awaits its first order for AVENTRA, the company is confident that it can realise all its aims – to be even lighter and more energy efficient than its existing UK ‘best in class’ EMU. The key to this lies in the fact that all its core components have already been tried and tested, combining the unrivalled track record of the FLEXX Eco bogie and other proven technological advances in one extremely lightweight, high performance EMU.

Article courtesy of the rail engineer magazine.


  1. Most modern passenger stock has been spoilt by rigid adherence to daft Health and Safety “requirements” – meaning that seat backs are ludicrously high in case just one passenger over six feet tall might injure his neck in an accident, and has resulted in the dreadful “refurbishment” of HSTs out of Paddington. I guess air bags will be the next measure to be introduced!


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