Rolling stock technology for the future

The paper presents a vision for future rolling stock with a timescale of 30-50 years to identify the key changes that are likely to be influential, in particular to meet the challenges associated with the UK’s ambitious technical strategy. Overall it suggests the authors’ vision for future rolling stock, not necessarily as a perfect prediction, but certainly to highlight the main possibilities. Introduction Railways in Europe and elsewhere in the world have undergone substantial change in the last two decades, and now they are not only an essential part of national infrastructure but also contribute significantly to a sustainable future. However in the UK in particular there is a general acceptance that both the cost to government in terms of subsidy and the price to passengers have risen disproportionately [ 1]. The railway’s "green credentials" are well founded but are under challenge from competing transport modes, especially the improvement in automobiles, and the customer's expectations in terms of quality and reliability of service inevitably rise as time goes on, and so in both the UK and across Europe there are ambitious technical strategies aimed towards meeting these various challenges [ 2, 3]. In order to consider possible technological changes that might address these issues, the following questions will be addressed: • Which are the key engineering sub-systems of today’s railway vehicles that are most likely to undergo significant change? • What technologies are either already happening or on the horizon that will determine how future railway vehicles might look? • How might these vehicles operate within railways of the future? • Are there any “competitive” ground transportation technologies (e.g. Maglev) that might have a significant impact upon railways? A particular focus of the paper will be to consider the concept of “Design for Control”, i.e. a fundamental re-thinking of the design possibilities. This needs to be considered more thoroughly in future railway vehicle design due to the system level benefits it can bring, the true benefits of which can only be properly assessed by taking a systems wide view. If one looks back (say) 40 years to the 1970s there have been a number of substantial changes that were not envisaged (or more generally dismissed with little evidence), for example:  Tilting train technology had been demonstrated at the time but was not used operationally as there was uncertainty at the time about its value. However it is now an established, mature technology [ 4]  A.C. electric traction with power electronic drives had been considered but discounted on the basis that it was not economic. Of course is now the traction system of choice for modern trains [ 5]  The now ubiquitous use of computer bus architectures to transmit information throughout the train was not even anticipated at the time [ 6]. The message from this retrospective is that it’s difficult to make predictions of the future, particularly when looking 40-50 years ahead, but also that too much caution is not appropriate. Railway vehicle technology – overview of future possibilities In order to provide a framework for answering the first question above, one way of breaking things down is by function, and there is a European Standard [ 7] that lists a number of top level functions to be provided:• Carry and protect passenger, train crew and load • Provide appropriate conditions to passenger, train crew and load • Provide access and loading