DIN SPEC 91369:2018-04

This DIN SPEC has been drawn up by a temporary body ('Workshop') in accordance with the PAS procedure. This DIN SPEC has been developed and adopted by the authors named in the Foreword. This DIN SPEC is intended for use by railway infrastructure companies (EIU) and specifies criteria defining what are clean tracks. Cleaning of the superstructure of special tracks such as those with transverse profiles or with vegetation is one of the procedures forming part of preventive track maintenance. To ensure the optimum functioning and durability of the ballast, it is important to ensure that it is free of foreign matter so as to enable surface water to readily drain off. Cleaning the ballast is an aspect of regular maintenance that is essential for ensuring the durability of the ballast and extending its lifetime. There are many causes of ballast contamination. It can occur as a result of the operation of the rail infrastructure, in the form of braking sand, fuel or lubricants. Contamination can also be brought in by the environment (e.g. leaves, twigs) or by the public (e.g. cigarettes, cans, newspapers, bottles). Contamination that is concealed due to having penetrated deep into the ballast is an important aspect when considering the lifetime and functioning of the ballast. This DIN SPEC defines the degree to which tracks are clean, not the degree of pollution.