on traditional roof mount. “The problem with placing the


me that energy performance would play a bigger and bigger role in train design,” he says. “But we faced the dilemma of developing an energy performance calculation tool which could consider isolated components developed by internal third parties and how adjusting any one of them would impact the overall train and its performance.” Orellano says that for example it is well known that increasing the size of transformers will reduce their energy consumption. However, replacing a two-tonne transformer with one that weighs four tonnes will impact overall energy consumption due to an increase in weight. Bombardier has subsequently


introduced a tool known as Train Energy Performance (TEP) which calculates overall energy consumption and performance and is now accessible to employees working on developing trains for all over the world. Orellano says that engineers used the tool for the Zefiro 380 and inevitably many of the technologies used in this train have been adapted for use in the Frecciarossa 1000. However, there have


IRJ July 2013


been some slight improvements to traction systems and brakes due to higher reliability requirements in Italy. Orellano says that a major challenge when developing a high-speed train is to use a design that prevents the natural inclination of an object travelling at such high-speed under cross-wind conditions to take off. The nose of the train is rounded and at high-speeds the airflow passing over the carbody can provide sufficient lift to cause elevation. However, by adjusting the design and appearance of the edges of the nose it is possible to reduce this lift and in fact produce downforce which will actually increase the stability of the train. The strong edges which provide its Cobra- like appearance are therefore crucial to overall aerodynamic performance.


Acoustic dynamics


Of course operating a train efficiently at up to 360km/h is not just dependent on aerodynamics; high-speed trains can also make a significant amount of noise. Orellano identifies the pantograph as one of the major sources of acoustic emission vibration as well as drag which resulted in a shift away from its


pantograph on the roof is that it vibrates a lot when the train is operating at high-speed,” Orellano says. “The carbody’s flat plate roof effectively vibrates like a drum. In older high- speed trains power cars were situated at either end so no-one was sitting below the pantograph. But in today’s trains passengers are seated throughout so this has become more of a problem and is something we wanted to address.” The solution adopted for the


Frecciarossa 1000 is to mount the pantograph directly to the sidewall of the carbody with the stiffness of the carbody and the curvature of the sidewall working to reduce the vibrations and as a result noise. In addition when the pantograph is not being used it is stored flat, again minimising vibrations and any impact on aerodynamics. Another major source of aero acoustics is the deflection of air on to the front bogie. Bombardier supplied the bogies for the train which Orellano says are a conventional and proven design for high-speed trains. However, engineers adapted the nose to deflect air in front of rather than directly onto the bogie which is proving quite successful at reducing this noise. The train is also using Bombardier’s


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