Based on the analyses of the works of Soviet, Ukrainian and foreign researchers, archival and published documents, service regulations and directives, memoir literature and other sources, it has been shown the status of scientific elaboration of the topic, investigated the process of origin and development of rail-based combat vehicles in the Russian Empire and the USSR in 20th century. As a result of the analysis of labors on the research topic, it had been established that single conceptual framework for rail-based combat vehicles has not yet been formed. Refined and author's definitions of terms on the research topic are proposed. It was refined the definitions of the terms "rail-based combat vehicles", "armored train" and "armored draisine"; given the interpretation of the concepts "self-propelled armored rail wagon" and "railway gun", as well as established the fundamental difference between terms "armored truck" and "armored platform car". In addition, it was developed the author's classification of rail-based combat vehicles, based on the criterion of tactical purpose. The factors that influenced the origin, formation and succession development of rail-based combat vehicles were identified and analyzed. They are conditionally divided into: tactical and technical requirements for equipment; technical and economic conditions; experience in the design, creation and use of weapons and military equipment. After analysis of the above factors interaction it was offered a general algorithm for the development of rail-based combat vehicles - from the stage of the need for it to its tactical employment. Common algorithm for the development of weapons and military equipment was developed after analysis of the factors interaction. It has been shown the development of certain types of rail-based combat vehicles, revealed their tasks, and analyzed the features of their tactical employment. The author's periodization of the process of rail-based combat vehicles development in the Russian Empire and the USSR in 1914-1945 is proposed and justified. It includes four intercon-nected stages and each of them has its own characteristics. During the first (1914-1917) and third (1924-1941) stages the development of the rail-based combat vehicles was carried out centralized, and during the second (1917-1924) and the fourth (1941-1945) stages this process had an improvised character. Another feature was that during the first two stages (1914-1924) the vast majority of them were created according to individual projects, and during the last two (1924-1945) stages typical projects were prevailing. It is revealed the tendencies of the development of rail-based combat vehicles in determined chronological frameworks. They are as follows: an air defense capabilities increase; an firepower increase; increased flexibility of fire by expanding the sectors of fire; fire-control improvement; implementation of standardization at in the construction of rail-based combat vehicles. The paper formulates recommendations for the implementation of research results in the interests of the Armed Forces of Ukraine. Keywords: rail-based combat vehicles, armored train, anti-aircraft armored train, armored platform car, armored draisine, railway guns, self-propelled armored railroad car, USSR.
