page_title: Slippery rail
section_title: Railhead treatment
hierarchical_section_title: Slippery rail / Mitigation measures / Railhead treatment
caption_attribution_description: To fight autumn train delays, the Long Island Rail Road operates work train that sprays water jets to clear tracks of slimy leaf debris during the fall season. The specialized train then applies a traction gel onto the freshly cleared rails that allows train wheels to maintain traction, even in the presence of crushed leaf slime. This photo shows the application of the traction gel. Photo: Metropolitan Transportation Authority / Patrick Cashin
context_page_description: Slippery rail, or low railhead adhesion, is a condition of railways where contamination of the railhead causes trains to experience less adhesion. This can lead to wheelslip when the train is taking power, and wheelslide when the train is braking. The most common cause of contamination is fallen moist leaves that lie on and cling to the top surface of the rails of railway tracks. The condition results in significant reduction in friction between train wheels and rails, and in extreme cases can render the track temporarily unusable. In Britain, the situation is colloquially referred to as "leaves on the line".
context_section_description: Treatment measures generally involve some system to jet or blast the accumulated deposit away, or to coat it with a high-friction material. Blasting is usually carried out with water jets, often in combination with mechanical scrubbing apparatus. The coating method usually involves depositing sand in a paste on to the rail; as the sand may exacerbate the risk of unwanted insulation, the sand mix sometimes contains metal particles. The coating is applied from special trains (colloquially referred to as "Sandite trains" after the original proprietary mixture applied) and in some cases locally by hand applicators.
  Lineside-fitted Traction gel applicators which apply liquid to the railhead as a train passes are fitted at sites where significant low adhesion regularly occurs, such as on the approach to stations.
  Both of these processes are effective for a limited duration; the jetting method is ineffective as soon as the next leaf falls; the sand deposition method is more durable, although rainfall usually removes the deposited sand quickly. Another method is using a high voltage electrical spark or plasma to volatilize the deposited material, but this method has only been used experimentally, as it is hindered by high power consumption, noise and rail degradation.
caption: A Long Island Rail Road work train pressure-washes the rail before applying a traction gel.
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