Editing Railroad switch (section)

=== Operation in cold conditions <span class="anchor" id="Cold conditions"></span>===
[[File:Weichenheizung.JPG|thumb|Gas heating keeps a switch free from snow and ice.]]
[[File:Rail Switch Heater.jpg|thumb|Similarly, an electric forced-air heater can keep a switch free from snow and ice.]]

Under cold weather conditions, snow and ice can prevent the proper movement of switch or [[#Frog|frog]] point rails, essentially inhibiting the proper operation of railroad switches. Historically, railway companies have employees keep their railroad switches clear of snow and ice by sweeping the snow away using switch brooms (Basically wire brooms with a chisel attached onto the opposite end of the broom – quite similar to ice scrapers used today), or gas torches for melting ice and snow. Such operation are still used in some countries, especially for branch routes with only limited traffic (e.g. seasonal lines). Modern switches for heavily trafficked lines are typically equipped with switch heaters installed in the vicinity of their point rails so that the point rails will not be frozen onto the stock rail and can no longer move. These heaters may take the form of electric heating elements or gas burners mounted on the rail, a lineside burner blowing hot air through ducts, or other innovative methods (e.g. geothermal heat sink, etc.) to keep the point & stock rails above freezing temperatures. Where gas or electric heaters cannot be used due to logistic or economic constraints, anti-icing chemicals can sometimes be applied to create a barrier between the metal surfaces to prevent ice from forming between them (i.e. having frozen together by ice). Such approaches however, may not always be effective for extreme climates since these chemicals will be washed away over time, especially for heavily thrown switches that experience hundreds of throws daily.{{Citation needed|date=March 2025}}

Heating alone may not always be enough to keep switches functioning under snowy conditions. Wet snow conditions, which generate particularly sticky snow and whiteout conditions, may occur at temperatures just below freezing, causing chunks of ice to accumulate on trains. When trains traverse over some switches, the shock, vibration, possibly in combination with slight heating caused by braking or a city microclimate, may cause the chunks of ice to fall off, jamming the switches. The heaters need time to melt the ice, so if service frequency is extremely high, there may not be enough time for the ice to melt before the next train arrives, which will then result in service disruptions. Possible solutions include installing higher capacity heaters, reducing the frequency of trains, or applying anti-icing chemicals such as [[ethylene glycol]] to the trains.<ref>{{cite web |url=http://www.prorail.nl/reizigers/weersinvloeden/winter |title=Information on Winter Operation by Dutch Infrastructure Manager Prorail |language=dutch |website=Prorail.nl |access-date=30 June 2024 }}</ref>