Rationalization of diagnostic examination periods for metalwork elements of subway escalators

Introduction. The main element of the subway escalator is a supporting metal structure, on which all elements, components and assemblies are installed, ensuring its functioning as a continuous lifting machine. The supporting metal structure must withstand not only its own weight and the total weight of the components and mechanisms attached to it, but also provide resistance to dynamic loads arising during their operation. The implementation of comprehensive diagnostic measures aimed at analyzing the level of wear and determining the residual life of escalator metal structures encounters a number of difficulties associated with high demands on time, material and financial costs, as well as disruption of the public transport system. The main goal of this study is to optimize the timing for recording the initial data obtained during the diagnostic examination of escalator metal structures with an obvious reduction in the duration of their forced downtime. Materials and methods. During the research process, data from a comprehensive survey of escalators based on the State Unitary Enterprise “St. Petersburg Metro” in the amount of 218 pieces in the period from 2005 to 2019 were used, design documentation, statistical methods and mathematical modeling methods were used. Results. The use of a mathematical model and the principle of rationalization can significantly reduce the time and, consequently, other costs in determining the corrosion effect. Conclusion. The use of the proposed approach to the rational allocation of time periods for conducting diagnostic examinations of operated escalator metal structures facilitates the preventive final forecast estimate of the magnitude of the corrosion effect while reducing the total period of control measures by 38%. The principle of rationalization can also be used in the implementation of accelerated tests for corrosion resistance of materials.