Analysis of technological and competitive trends of weight reduction in high speed rolling stock industry
The incorporation to the transport of passengers sector of the high speed industry is preceded by a global society, which requires the possibility to travel quickly, comfortably and efficiently, imposing the current attitude of the concern with the environment. The development of the rail sector over recent decades, and especially in recent years, along with the technological development has allowed the formation of a network of high speed lines around the greatest part of the planet. Due to the great acceptance by users, the average occupancy of the most high speed trains worldwide equals or exceed 80% Leading manufacturers like Siemens, Bombardier and Alstom have had to bring their production lines to Asia, specifically China, due to the large difference in production costs. The major consequence of this fact has been the entrance to the high speed market of Chinese manufacturers JSR and CNR, occupying the positions of former leading manufacturers worldwide. Both the need to differentiate, by European and American leading manufacturers, the possibility to compete with airline industry on longer journeys and the need to be more efficient, give a great opportunity for the incorporation of the composite materials industry, which offer better properties and lower weights, for high speed trains. In this situation, it is proposed the analysis of the application of lightweight materials in the railway rolling stock, called rolling stock any part that is moved. It begins decomposing all high speed train systems, explaining their functions, features and structural requirements of each system, in addition to the process construction. To justify the project, the impacts of weight reduction on high speed trains are proposed. From a historical point of view, weight reduction has contributed to the possibility of increasing the speed of them, reaching in 1964 the high speed velocity of 240 km/h with the trains known as "bullet trains" Currently weight reduction causes greater competition with the airline industry in journeys which take less than 3 hours by train. This is largely due to the waiting time spent at airports by the passengers, and due to the great distances between airports and city centers. Such competition has brought a decrease of total number of air travelers in 2013 of 4.7 million passengers, increasing the number of passengers on high speed trains in 3 million in the same year, according to data from the National Statistics Institute. In addition, there will be a great environmental benefit due to the weight reduction, and consequently the reduction of emissions and energy expenditure by high speed trains. The occupation is relevant in the factor of emissions per passenger, but with the use of lightweight materials and its consequent weight reduction, there would be no doubt that high speed rail transport is the least polluting of all passengers transports. In terms of energy expenditure, weight reduction has a major influence on the operating costs of high speed trains. Therefore, the use of lightweight materials significantly reduce energy expenditure, and although weight reduction would have more influence in trains that operate with slower speeds, due to the higher influence of the total weight in the energy expenditure at these speeds. Major manufacturers and operators of high speed trains include the possibility of increasing the number of seats of the high speed trains due to their great occupation. The main impediment to do this is the requirement to have 17 tons per axle that all high speed trains have. The information provided by the president of the Spanish Railway Foundation, Alberto Garcia Alvarez, shows that each ton of weight reduction would represent an increase of 12 seats. With the proposed reduction of 15.9% on the total weight it is concluded that it is possible almost double the current capacity of high speed trains. Thus the project gives a greater interest in good industrial application due to the current needs of the sector. Composite materials besides being lighter, they have better properties that are manifested in lower maintenance cost of the trains. Once justified the possible improvements obtained with the use of lightweight materials, both weight distribution and cost distribution are analysed to know the systems that are more sensitive to the weight reduction, by building a database of the world fleet of high speed trains. With this database and using linear regression models, the most influential parameters in the weight function of high speed trains are studied. In addition, the requirements of these systems that form the high speed trains are explained, concluding that the car body, the interior and miscellaneous systems such as air conditioning system, plumbing systems, doors and windows account for 53% of the total weight of the train are the most attractive systems for applying lightweight materials. It is highly possible to achieve a weight reduction with the use of lightweight materials, which will mean a 15.9% reduction in overall weight. Then the different types of composite materials are introduced and characterized, as well as their production processes and their associated cost. When performing a market analysis of composites, we can appreciate that the current application of composites is very distributed around different industries such as aviation, marine, construction, aeronautics and rail among others. The high cost of composite materials, is the main cause of a later expansion around other industries, but greater integration between the different actors in the value chain is taken to gain greater knowledge of their properties and become more competitive. It also highlights cases in which companies from other sectors such as BMW have been introduced in the value chain to obtain in this case the batteries of the electric cars i3 and i8. With the economic contribution of other sectors is expected further growth in the composite sector, which will mean greater integration in industries such as automotive or railway industry. Examples of application of composite materials in different industries are proposed to justify the choice of the appropriate composite and to extrapolate the results to the rail industry. With this information it is possible to conclude that the situation is excellent to say that the right material is the fibre reinforced polymer composite. The application of such material at high speed trains will produce the desired weight reduction, making them more efficient. Finally, an analysis of return on investment is proposed where it is compared two different situations in a travel from Madrid to Barcelona. The first situation involves the acquisition of a high speed train, the AVE S103, without the application of lightweight materials, and the second involves the acquisition of the same high speed train with the application of lightweight materials in the systems above cited, obtaining a 15.9% reduction of the total weight. In both cases, both maintenance costs and operative costs during the life cycle of the train, 30 years, are taken in account. Benefits are calculated with an average ticket price of 85 euros, with an occupancy rate of 79% and an operation of 5 trips per day, 365 days a year, during 30 years.