GEODETIC ASPECTS OF RAILWAY OVERHEAD CONTACT SYSTEM CONSTRUCTION AND ELECTRIFICATION

Abstract

The study analyzes and evaluates the specific features of geodetic works carried out during the construction of a railway overhead contact system and examines the technological process of electrification within the Vilnius–Klaipėda project. Railway electrification comprises construction and geodetic surveys, setting-out and control works, as-built documentation of installed overhead contact system foundations, cadastral files, plans, and quantity schedules prepared after performing construction geodesy calculations, as well as a set of various technological procedures required for the installation of the overhead contact system and other electrification components along the entire railway line. During the study, 1,461 overhead contact system elements—installed foundations, mast heads, single masts, and portal structures—were measured in the districts of Vilnius, Kaišiadorys, and Jonava. Following geodetic measurements of overhead contact system supports using a GNSS receiver, a robotic total station, and a glass prism at the Vaidotai and Livintai railway stations and along the Livintai–Gaižiūnai section, measurement values were obtained with an accuracy of up to 1–2 cm. The combined geodetic measurement method is the most economically efficient and fastest approach while meeting the required accuracy. When applying the combined method, a 2.4–3.2 km section can be measured per day, and the resulting measurement errors do not exceed the permissible limits. Geodetic works carried out during overhead contact system construction ensure the precise spatial positioning of installed foundations, overhead contact system supports, as well as portal and cantilever structures. The study developed a technological sequence for geodetic works in the railway electrification process. The main stages of geodetic works are distinguished as follows: preparatory works; geodetic measurements, verification, and control; as-built documentation and completion of works.