It is an almost impossible task to define “winter conditions”. Just within the field of “snow” there are many variations depending on the temperature, wind conditions and amount of snow. The different types of snow may require different measures, and a measure taken to counter one type of snow may have a negative effect when a different type of snow manifests itself.
As for the track, snow mostly constitutes a problem in switches. Once the snow has been cleared of the track itself, the problem is solved. However, very cold weather and temperatures below 0°C may cause rail breakage, as rails are most of the time vulnerable when faced with extreme temperatures due to weak welding. In addition, cold temperatures may cause the catenary to freeze up, inflicting damage to the pantograph coal, and causing improper power supply to the trains.
In the coming years, climate changes may cause the weather to become more instable, and winter conditions may vary even more than what has been experienced in earlier years, 2009, 2010 and 2011.
Lots of problems can occur while operating high speed trains in extreme winter conditions, especially in Scandinavia and Siberia. Some of these issues are considered to be of significant importance from a high-speed perspective. These are winter problems that are expected to get worse with the increase of speed, specialists say.
Also, the winter climate conditions require thorough considerations on the various rolling stock design aspects. For instance, all equipment must be very robust in order to cope with the large ice build-ups that can weigh up to several hundred kilograms. This concerns for instance cables, pipes and other more sensitive equipment that is exposed to snow or melting water.
The combinations of snow, temperature, wind make the conditions differ from one region to another. During a run a train may be subject to varying climate conditions, from coldness and dry snow to temperatures above zero centigrade. Furthermore, the various rolling stock designs react different to the various kinds of weather and are in some situations more sensitive than others.
Snow and ice in bogies and under frames must be reduced as far as possible. There have been some solutions proposed in order to reduce snow and ice. For instance, surfaces that need to be free of snow and ice due to movements can be covered with Plexiglas on a thin foam rubber layer. Any ice formation on these flexible plastic covers will crack and fall off for an applied force on the ice. Anti icing methods can be used in order to prevent snow and ice build-up. Also a cellular rubber fill can be used in holes in the bogies and around components in order to prevent snow gathering. Finally spoilers in different positions and of different design can be used to change the wind and snow flow around the bogie and car body as well as around bogie and car body components.
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