Spårväxlar i vinterförhållanden

Sammanfattning: During the period 2009-2011 Sweden had two really hard winters with lots of snow. The result was train delays because of snow in the railway switches. The purpose of this work is to highlight the problems that arise around switches during winter and to propose methods to reduce these problems. The switch has a core function of the railway system and must therefore work properly. Switches are also very vulnerable. It requires no more than 10 mm of packed snow in the moveable part of the switch before the risk of derailment is immediate. It is therefore important that the snow removal in switches works in order to ensure operation. The Swedish Transport Agency has today a snow removal strategy based on various methods before and during wintertime. Examples of indirect snow removal operations are snow fences, snow covers, brushes and switch heater systems. When these methods are insufficient, the snow removal has to be performed manually or by machine. In other snowy parts of the world with lots of railway systems such as Japan or USA (New York), they use different types of equipment. The City of New York, for example, has a snow removal fleet of nine vehicles equipped with jet turbines, three snow blowing machines and two vehicles equipped with rotating brushes/blowers. Japan, on the other hand, uses both sprinkler systems and slush removal systems. We have also presented and discussed two further technical solutions: track with curved rail and rubber lip and switch heating system with induction heating technology. The curved rail with rubber lip prevents snow from getting into the vulnerable parts of the switch. The induction solution effectively melts the snow that gets into the switch. To solve the problems that the winter and the snow cause, we conclude that it is not enough only to introduce more effective technical solutions. Better communication within the Swedish Transport Agency and between different actors who are on the railway market is needed.