Permanent Defensive Structures of Khingan Tunnel: Design and Construction

This study explores the history of the fortification defense system of the Khingan Tunnel on the Chinese Eastern Railway during the years 1914–1918. The relevance of this research is underscored by the lack of specialized works addressing the history of permanent defensive structures that protect both the eastern and western portals of the Khingan Tunnel, as well as the viaduct at the Petlya junction. The research is grounded in primary source materials, including documents from the current administration of the Main Military-Technical Directorate of the War Ministry and the Main Directorate of the General Staff. The article examines the construction projects for concrete blockhouses intended to safeguard the tunnel portals and junction. It introduces data regarding the sequence, scale, and cost of the planned works into scholarly discourse. A comprehensive overview of the progress made in constructing these structures is presented. For the first time, information is published concerning the fabrication of two sets of armored gates for the Khingan Tunnel. An assessment is provided regarding the outcomes of implementing such a large-scale defensive project during wartime. The article emphasizes the significance of blockhouses as unique monuments of the early 20th-century Russian military engineering school located in Manchuria. The necessity for their preservation and musealization is highlighted.